GENERATING AND CONTROLLING MAGNETIC FIELDS FOR ELECTROLYZER STACKS

Abstract

An electrochemical reactor, including: a first magnetic field source; a second magnetic field source; and an electrochemical cell between the first magnetic field source and the second magnetic field source, the electrochemical cell comprising an anode and a cathode, wherein the anode and the cathode are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, and wherein the anode and the cathode are configured to contact the electrolyte stream, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

Description

BACKGROUND

The steel industry is responsible for approximately 10% of global CO₂ emissions and is the largest industrial consumer of coal. In order to meet global energy and climate goals, the steel industry must incorporate emerging near-zero emission steelmaking technologies into its development plan. A promising direction for reducing CO₂ emissions in steelmaking is the electrolytic reduction of iron oxide in alkaline solutions at moderate temperatures.

There remains a continuing need for improved methods to produce iron metal from iron-containing feedstocks, such as iron ores.

BRIEF DESCRIPTION

Disclosed is an electrochemical reactor, including: a first magnetic field source; a second magnetic field source; and an electrochemical cell between the first magnetic field source and the second magnetic field source, the electrochemical cell comprising an anode and a cathode, wherein the anode and the cathode are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, and wherein the anode and the cathode are configured to contact the electrolyte stream, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

Also disclosed is an electrochemical reactor, including: an electrochemical cell comprising an anode and a cathode; and at least one electromagnetic coil disposed adjacent to the electrochemical cell, wherein the anode and the cathode are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, wherein the anode and the cathode are configured to contact the electrolyte stream, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the at least one electromagnetic coil.

Also disclosed is a method of processing an iron-containing feedstock to produce iron metal, the method including: flowing the electrolyte stream comprising the iron-containing feedstock through an electrochemical cell of the electrochemical reactor; applying a magnetic field at the cathode of the electrochemical cell; electrochemically reducing at least a portion of the iron-containing feedstock to produce the iron metal at the cathode while the magnetic field is applied at the cathode; and collecting the iron metal to produce the iron metal, wherein the iron metal is optionally a powder.

Also disclosed is an iron metal produced by the method.

Also disclosed is an iron metal produced by the reactor.

Also disclosed is an electrochemical reactor system.

Also disclosed is a method of operating the electrochemical reactor system.

The above and other aspects and features are described and exemplified by the following figures and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are exemplary embodiments, where like elements are numbered alike.

FIG. 1 is a schematic diagram of an embodiment of an electrochemical reactor system comprising electrochemical cells having a bipolar configuration.

FIG. 2 is a schematic diagram of an embodiment of an electrochemical reactor system comprising electrochemical cells having a bipolar configuration.

FIG. 3 is a schematic diagram of an embodiment of an electrochemical reactor system comprising electrochemical cells having a bipolar configuration.

FIG. 4 is a schematic diagram of an embodiment of an electrochemical reactor system comprising electrochemical cells having a monopolar configuration.

FIG. 5 is a schematic diagram of an embodiment of an electrochemical reactor system comprising electrochemical cells without a separator between an anode and a cathode.

FIG. 6 are graphs of voltage (arbitrary units), magnetic field (arbitrary units), ore concentration (arbitrary units), and iron concentration (arbitrary units), each versus time (arbitrary units) with corresponding schematic diagrams of the electrochemical reactor to illustrate an embodiment of the disclosed electrochemical reactor system and process.

FIG. 7 is a schematic diagram of an embodiment of an electrochemical reactor system comprising an electrochemical reactor having a separator between an anode and a cathode.

FIG. 8 is a schematic diagram of an embodiment of an electrochemical reactor system comprising electrochemical cells in a monopolar configuration.

FIG. 9 is a schematic diagram of an embodiment of an electrochemical reactor system comprising electrochemical cells in a monopolar configuration.

FIG. 10 is a schematic diagram of an embodiment of an electrochemical reactor system comprising electrochemical cells in a bipolar configuration.

FIG. 11A is a schematic diagram of an embodiment of a chlor-alkali reactor system.

FIG. 11B is a schematic diagram of an embodiment of a chlor-iron reactor system.

FIG. 12 is a perspective view of a first electromagnetic coil and a second electromagnetic coil arranged in a Helmholtz coil configuration.

FIG. 13 is a perspective view of the first electromagnetic coil and the second electromagnetic coil of FIG. 12 generating a magnetic field.

FIG. 14 is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor.

FIG. 15 is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor.

FIG. 16 is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor.

FIG. 17 is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor.

FIG. 18 is a schematic diagram of an embodiment of a first cell assembly and a second cell assembly which may be utilized in an electrochemical reactor.

FIG. 19A is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor, where current is applied to a first subset of electromagnetic coils of the cell assembly.

FIG. 19B is a schematic diagram of the cell assembly of FIG. 19A, with current applied to a second subset of electromagnetic coils of the cell assembly.

FIG. 20 is a perspective view of a first electromagnetic coil and a second electromagnetic coil arranged in an anti-Helmholtz coil configuration and generating an electromagnetic field.

FIG. 21 is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor.

FIG. 22 is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor.

FIG. 23 is a schematic diagram of an embodiment of a first cell assembly and a second cell assembly which may be utilized in an electrochemical reactor.

FIG. 24 is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor.

FIG. 25 is a perspective view of a first electromagnetic coil, a second electromagnetic coil, and a third electromagnetic coil arranged in a three-coil Maxwell coil configuration.

FIG. 26 is a schematic side view of the first electromagnetic coil, the second electromagnetic coil, and the third electromagnetic coil of FIG. 25 generating a magnetic field.

FIG. 27 is a schematic diagram of an embodiment of a cell assembly which may be utilized in an electrochemical reactor.

FIG. 28 is a perspective view of a first electromagnetic coil and a second electromagnetic coil arranged in a two-coil Maxwell coil configuration.

DETAILED DESCRIPTION

The disclosed subject matter provides for the production of iron metal through the reduction of an iron-containing feedstock by an electrolysis reaction. In particular, the present subject matter relates to an electrochemical reactor and a corresponding method for producing iron metal powder from an iron-containing feedstock using a positioned magnetic field. The reactor and the method are beneficial for use in various iron electrolysis processes, such as alkaline iron electrolysis and chlor-iron electrolysis.

For alkaline iron electrolysis, while not wanting to be bound by theory, the relevant chemical reactions may be described by Equations (1), (2), and/or (3), wherein the iron species in the iron-containing feedstock is/are reduced at a cathode, and an oxygen evolution reaction (OER) occurs at an anode:

Fe₂O₃→2Fe(0)+3/2O₂  (1)

Fe₃O₄→3Fe(0)+2O₂  (2)

FeO→Fe(0)+O₂  (3)

For chloro-iron electrolysis, the iron species in the iron-containing feedstock is also reduced at a cathode producing iron metal, and chlorine is generated at the anode from NaCl brine.

Since both the starting iron-containing feedstock and the produced iron metal can include particles, it may be desirable to restrict particles to a selected region of the electrochemical reactor during electrolysis, for example to reduce electrolyte resistance or to create a different chemical environment at the anode. A physical separator, such as a frit or a membrane, may be used to restrict particles to a selected region. However, a frit or separator may be susceptible to clogging or fouling by small ore particles. A magnetic field may be used to concentrate ore particles near the cathode and in a cathode reaction zone to extend the life of the physical separator. In iron ore electrolysis, physical proximity between the solid ore particles and the cathode (i.e., the working electrode) is desirable. There remains a continuing need for a configuration which provides improved physical proximity between the solid iron-containing feedstock particles and the working electrode to facilitate electrochemical reduction, preferably a configuration suitable for a continuous method to produce iron metal from iron-containing feedstocks. In addition, since the magnetic field strength, gradient, homogeneity, and/or orientation with respect to the area of interest can influence the properties of the iron product or production efficiency, it would be a further advantage if the configuration or the method can allow the generation of precision magnetic fields to facilitate conversion of iron ore powder to iron metal powder, in particular production of iron metal with tuned product properties and improved production efficiency.

An aspect provides an electrochemical reactor including a first magnetic field source; a second magnetic field source; and an electrochemical cell between the first magnetic field source and the second magnetic field source. The electrochemical cell includes an anode and a cathode in a channel configured to contain an electrolyte stream that includes the iron-containing feedstock, wherein the anode and the cathode are configured to contact the electrolyte stream. The electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof. In some aspects, the iron-containing feedstock may not be subjected to electrochemical reduction before the electrochemical reduction in the magnetic field of the electrochemical reactor that is provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

As used herein, the term “iron metal” refers to Fe(0), which is iron with an oxidation state of zero.

The term “cathode reaction zone” or “working electrode reaction zone” refers to a region where a reduction reaction occurs during electrolysis. In the case of iron ore electrolysis, the cathode reaction zone is the region where reduction of iron oxide to iron metal occurs and where magnetic field properties are beneficial.

As used herein, “anode reaction zone” or “counter electrode reaction zone” refers to a region where oxidation occurs during electrolysis. For the chlor-iron process, the anode reaction zone is the region of chlorine generation from NaCl brine.

The electrochemical reactor includes a first magnetic field source, and a second magnetic field source, wherein at least one of the first magnetic field source and the second magnetic field source is positioned in proximity to the cathode. For example, the first magnetic field source may be positioned in proximity to the cathode, and the second magnetic field source may be positioned in proximity to the anode. As used herein, “in proximity” means a distance such that the magnetic field source is configured to provide a suitable magnetic field in the corresponding reaction zone, e.g., a field of 0.5 to 10,000 gauss, 250 to 10,000 gauss, 250 to 5000 gauss, or 1000 to 5000 gauss, or a distance such that the magnetic field source is configured to provide a field gradient ranging from 0.1 to 1×10⁶ gauss per meter in the corresponding reaction zone. The reaction zone may be at a surface of a working electrode, e.g., the cathode or the anode, and the field gradient may increase in a direction towards the surface of the working electrode.

In some embodiments, the first magnetic field source is a field generating device, and the second magnetic field source is also a field generating device. In other embodiments, the first magnetic field source is a field generating device, and the second magnetic field source is a field propagating device. The electrochemical reactor may further include one or more additional magnetic field sources, each of which may be a field generating device or a field propagating device. The magnetic field sources are described in further detail herein below.

As used herein, a “field generating device” refers to a magnetic field source that produces a magnetic field. In various embodiments, the field generating device may be a permanent magnet, an electromagnet, or an electropermanent magnet. As used herein, a “field propagating device” refers to a magnetic field source with a high magnetic susceptibility and a low magnetic coercivity (e.g., iron).

Aspects provided herein relate to generating precision magnetic fields for electrochemical cells. The magnetic field may be provided by the magnetic field source, e.g., the first magnetic field source, the second magnetic field source, or any additional magnetic field source(s). Some aspects provide magnetic fields to keep the magnetic products under cathodic protection until being intentionally released.

According to various aspects, the magnetic fields (i.e., as provided by the first magnetic field source, the second magnetic field source, and any additional magnetic field source(s)) may be used to keep magnetic products (e.g., iron metal) at or near the cathode current collector surface and thereby keep the magnetic products under cathodic protection until intentionally released. The magnetic field strength, gradient, homogeneity, and/or orientation with respect to the area of interest are properties that can influence the properties of the iron product or production efficiency. Additional aspects provide magnetic field-generating devices in combination with scaled electrolyzer cell stackups, each with flexibility in terms of material selection, surface area, volume, power, spacing, orientation, target area, coupling phenomena, design, and/or dimensions to vary the generation and control of magnetic fields.

The magnetic field source and the corresponding magnetic field may be positioned to modify the kinetics of iron-containing feedstock transport to or assembly at the cathode (e.g., the cathode current collector), such as to enhance deposition kinetics. This may be done over an entire surface of the cathode or may be done in a selected region of the cathode. In some embodiments, the magnetic field source may enhance deposition over substantially an entire surface of the cathode, such as by providing magnetic field source(s) to provide a magnetic field that is effective over the entire surface of the cathode. In some embodiments, one or more magnetic field sources may be positioned relative to the cathode as to preferentially direct materials susceptible to magnetization to particular locations about the cathode.

In an aspect, the first magnetic field source and the second magnetic field source are positioned external to the channel that includes the electrolyte stream. In some embodiments, at least a portion of the first magnetic field source and/or the second magnetic field source may be positioned within the channel comprising the electrolyte stream, such that at least a portion of the first magnetic field source and/or the second magnetic field source may be in physical contact with the electrolyte stream. For example, at least a portion of the magnetic field source that is in contact with the electrolyte stream may be enclosed within a protective sheath to prevent corrosion from the electrolyte. In some embodiments, a portion of the magnetic field source may be positioned within the channel including the electrolyte stream, and the magnetic field source may be enclosed within the protective sheath. Exemplary materials that may be used to provide the protective sheath to the magnetic field source include, for example, a polymeric material such as a polycarbonate or a polyethylene film, a metal-containing material (e.g., such as those having a similar composition to the cathode current collector), or a combination thereof.

The first magnetic field source and/or the second magnetic field source can be distinct from a current collector of the cathode, such that the reduction of the iron-containing feedstock does not occur on a surface of the first magnetic field source or the second magnetic field source. The strength of the magnetic field provided by the first magnetic field source, the second magnetic field source, and the one or more optional additional magnetic field sources may be selected based on the amount of iron-containing feedstock in the electrolyte stream, for example to limit the thickness of any layers formed from unreduced iron ore on the cathode current collector. Accordingly, in an embodiment in which the first magnetic field source, the second magnetic field source, and/or the one or more optional additional magnetic field sources includes a permanent magnet or an electropermanent magnet, the strength of the magnetic field provided thereby can be adjusted to a desired state by selecting a permanent magnet and/or an electropermanent magnets of a particular size and/or material composition. In an embodiment in which the first magnetic field source, the second magnetic field source, and/or the one or more optional additional magnetic field sources includes an electromagnet, the strength of the magnetic field provided thereby can be adjusted to a desired state by increasing or decreasing the flow of current through the electromagnet, increasing or decreasing the number of turns in a coil of the electromagnet, selecting a particular core material for the electromagnet, and/or adjusting the size, type, and/or diameter of wiring utilized in the electromagnet.

In some embodiments, the orientation of a magnetic field, which may be provided by the first magnetic field source, the second magnetic field source, one or additional magnetic field sources, or a combination thereof, with respect to the electrical field, may be chosen to minimize the adhesion of the reduced iron metal to the cathode current collector. In some embodiments, the orientation or application of the magnetic field provided by the first magnetic field source, the second magnetic field source, and/or one or more additional magnetic field sources may be varied over time. For example, in some embodiments, the first magnetic field source, the second magnetic field source, and/or the one or more additional magnetic field sources may be defined by an electromagnet or electropermanent magnet, such that the magnetic field produced thereby can be selectively applied by supplying and removing the electromagnet or electropermanent magnet with current. In this regard, in some embodiments, the first magnetic field source, the second magnetic field source, and/or one or more additional magnetic field sources may be utilized to provide a pulsating magnetic field. In another example, in some embodiments, the orientation of the magnetic field provided by the first magnetic field source, the second magnetic field source, and/or one or more additional magnetic field sources may be selectively reversed by periodically reversing the direction of current flow to the electromagnet. As yet another example, in some embodiments, the first magnetic field source, the second magnetic field source, and/or one or more additional magnetic field sources may be defined by an electromagnet which is continuously or selectively supplied with an alternating current to provide an alternating magnetic field. Without wishing to be bound by any particular theory, it is believed the application of a pulsing magnetic field, reversal of a magnetic field, or application of an alternating magnetic field by the first magnetic field source, the second magnetic field source, and/or one or more additional magnetic field sources may prove particularly useful in disassociating particles from the cathode. In some embodiments, the first magnetic field source, the second magnetic field source, and and/or one or more additional magnetic field sources may be oriented and supplied with three-phase current to provide a rotating magnetic field.

In some embodiments, the first magnetic field source, the second magnetic field source, and/or the one or more additional magnetic field sources may be configured to be coupled magnetic field devices. As used herein, “coupled magnetic field devices” refers to the enhancement or extension of a magnetic field through the use of two field generating devices or a single field generating device with one or more field propagating devices.

In some embodiments, the first magnetic field source, the second magnetic field source, and/or the one or more additional magnetic field sources may be non-coupled magnetic devices. As used herein, “non-coupled magnetic field device” refers to an isolated magnetic field generating device with no other field generating devices or field propagating devices nearby, e.g., in proximity, resulting in an unamplified magnetic field.

Magnetic fields can be generated from permanent magnets, electromagnets, electropermanent magnets, or a combination thereof. In some embodiments, the first magnetic field source, the second magnetic field source, and optionally one or more additional magnetic field source(s) are each independently a permanent magnet, an electromagnet, or an electropermanent magnet. Any suitable magnet may be used.

Permanent magnets are composed of paramagnetic materials that remain magnetized (have a persistent net magnetic dipole moment) at steady-state to generate a magnetic field. As used herein, a “permanent magnet” refers to an object made from a material that is magnetized and creates its own persistent magnetic field. A permanent magnet as used herein may also refer to a plurality of smaller permanent magnets that are arranged in a configuration that generates specific magnetic field gradients. Suitable permanent magnets may include, for example, neodymium iron boron (NdFeB or NIB) magnets, samarium cobalt (SmCo) magnets, alnico magnets, ceramic magnets, ferrite magnets, or a combination thereof. Some aspects provide a permanent magnetic array. Permanent magnet arrays, such as quadrupoles, include multiple permanent magnets arranged in a specific configuration to generate magnetic gradients. Quadrupoles, in particular, can provide a highly stable and adjustable magnetic field, enabling precise control over particle trajectories within the electrochemical cell(s). Some aspects provide interpole magnets using a combination of materials with varying magnetic properties to generate high gradient magnetic fields and additionally limit the interaction of magnetic fields to only be orthogonal to the surfaces of interest.

Electromagnets generate a magnetic field by the motion of electrons within a conducting circuit, as can be described by Faraday's law of induction. As used herein, an “electromagnet” refers to a magnet which produces a magnetic field while an electric current is applied to the magnet. Multiple electromagnets can be utilized in different configurations to provide a desired magnetic field. In this regard, multiple electromagnets can be utilized as magnetic field sources in the electrochemical reactor and in combination as to provide a Helmholtz coil, an anti-Helmholtz coil, a two-coil Maxwell coil, a three-coil Maxwell coil, or a combination thereof.

In some embodiments, two electromagnets are utilized in combination to provide a Helmholtz coil. In this regard, each of the two electromagnets includes a coil that is of a selected diameter and has a selected number of turns. The coil corresponding to one of the two electromagnets (or “first electromagnetic coil”) and the coil corresponding to the other of the two electromagnets (or a “second electromagnetic coil”) are provided on the same axis as each other, have the same diameter as each other, and are spaced apart from each other a distance that is equal to half the diameter (i.e., a radius of one of the two coils). Embodiments in which the first electromagnetic coil and the second electromagnetic coil both have a core as well as embodiments in which the first electromagnetic coil and the second electromagnetic coil are hollow are contemplated herein. A Helmholtz coil generates a homogeneous (uniform) magnetic field in response to the application of current to the first electromagnetic coil and the second electromagnetic coil in the same direction. In some embodiments, the first electromagnetic coil and the second electromagnetic coil are wired in series. In some embodiments, the first electromagnetic coil and the second electromagnetic coil are wired in parallel. In some embodiments, the first electromagnetic coil and the second electromagnetic coil are operably connected to separate current sources. The strength of the magnetic field provided by the Helmholtz coil is significant as the magnetic vector fields of the first electromagnetic coil and the second electromagnetic coil are summative and in combination create a high degree of uniformity in transverse directions relative to the planes in which the first electromagnetic coil and the second electromagnetic coil reside. Accordingly, the first electromagnetic coil and the second electromagnetic coil of a Helmholtz coil may be positioned relative to a working electrode of the electrochemical reactor and supplied with a current in a direction that causes the Helmholtz coil to provide a magnetic field that is, at least in part, orthogonal to the working electrode, which causes particles susceptible to the magnetic field, e.g., the iron ore feedstock or the iron metal product, to be directed to and maintained in the working electrode reaction zone, thereby enabling colloidal dipole-dipole interactions which are conducive to powder production and also change the rheology of iron-containing slurries. In this regard, the working electrode can be positioned so that an axis common to the first electromagnetic coil and the second electromagnetic coil are transverse to a surface of a working electrode at which at least a portion of feedstock is reduced when the electrochemical reactor is in operation. In some embodiments, the two electromagnetic coils may be configured to provide a magnetic field strength of 500, 600, 700, 800, 900, 1000, 2000, or 3000 gauss to 3500, 3700, 4000, 4100, 4200, 4500, 4800, or 5000 gauss. Mentioned is use of 500 gauss to 5000 gauss. Accordingly, the amount of current supplied to the two electromagnetic coils, the number of turns for the two electromagnetic coils, the core material utilized for the two electromagnetic coils, and the diameter (and thus radius) of the two electromagnetic coils can be selected to provide such magnetic field strength. For instance, and while not wanting to be bound by theory, the number of turns, amount of current supplied, and diameter may be determined in some cases utilizing a Helmholtz configuration with the Equation 4:

$\begin{array}{cc}{H}_{\mathrm{center}}\left(t\right)=\left(N_{\mathrm{each}}\times I\left(t\right)\times 8\right)/\left(r\times \surd 125\right)\approx 0.71554\times \left(\left(N_{\mathrm{each}}\times I\right)/r\right)& \left(4\right)\end{array}$

where H_center(t) is the magnetic field strength of the Helmholtz coil at a given time, N_each is the number of turns in each electromagnetic coil, r is radius, and I(t) is current at a given time. Determination of the field for other configurations disclosed herein, e.g., a two-coil Maxwell coil or three-coil Maxwell coil configuration, can be similarly determined without undue experimentation.

In some embodiments, the first electromagnetic coil and the second electromagnetic coil of a Helmholtz coil are positioned so that a working electrode (cathode) of the electrochemical reactor is positioned between the first electromagnetic coil and the second electromagnetic coil. In some embodiments, the first electromagnetic coil and the second electromagnetic coil of a Helmholtz coil are positioned so that both a working electrode and a counter electrode (anode) of the electrochemical reactor is positioned between the first electromagnetic coil and the second electromagnetic coil. In some embodiments, the first electromagnetic coil and the second electromagnetic coil of a Helmholtz coil may correspond to the first magnetic field source and the second magnetic field source of the electrochemical reactor. In some embodiments, the first electromagnetic coil of a Helmholtz coil may correspond to one of the first magnetic field source and the second magnetic field source, while the second electromagnetic coil of the Helmholtz coil corresponds to a magnetic field source of the one or more additional magnetic field sources. In some embodiments, the one or more additional magnetic field sources includes multiple additional magnetic field sources. In some such embodiments, the first and second electromagnetic coil of a Helmholtz coil may correspond to two magnetic field sources from the multiple additional magnetic field sources. In some embodiments, the electrochemical reactor may include multiple Helmholtz coils, where each respective Helmholtz coil is configured to, when supplied with current, provide a magnetic field which causes ore particles to be directed to and maintained in one of multiple working electrode reaction zones present in the electrochemical reactor. For instance, in embodiments where multiple working electrodes are utilized in the electrochemical reactor, a first Helmholtz coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a first working electrode, and a second Helmholtz coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a second working electrode. For instance, in some embodiments, the first Helmholtz coil may be formed by the first magnetic field source and a first additional magnetic field source positioned between the first magnetic field source and the second magnetic field source, and the second Helmholtz coil may be formed by the second magnetic field source and a second additional magnetic field source positioned between the first additional magnetic field source and the second magnetic field source.

Electrochemical reactor embodiments in which multiple Helmholtz coils are supplied current (i.e., activated) at different times are also contemplated herein. In some embodiments, current may be selectively supplied to electromagnetic-based magnetic field sources present in the electrochemical reactor as to cause a magnetic field source acting as one of the two coils of a first Helmholtz coil at a first time to act as one of the two coils of a second Helmholtz coil at a second time. In this regard, embodiments in which three magnetic field sources are utilized to provide two Helmholtz coils are contemplated herein. The number of Helmholtz coils utilized in the electrochemical reactor may vary based on the number of electrochemical cells present in the electrochemical reactor and/or the configuration of the electrochemical cells (bipolar or monopolar). In some embodiments, multiple electrochemical cells, each including a working electrode, may be positioned between the first electromagnetic coil and the second electromagnetic coil of a Helmholtz coil utilized in the electrochemical reactor.

In some aspects, one or more anti-Helmholtz coils may be used. Anti-Helmholtz coils apply similar principles as Helmholtz coils. In this regard, anti-Helmholtz coils also utilize a first electromagnetic coil and a second electromagnetic coil in the same manner and in the same configuration as Helmholtz coils, except that current is supplied to the first electromagnetic coil and the second electromagnetic coil in opposing directions. Accordingly, the magnetic field produced by the first electromagnetic coil and the magnetic field produced by the second electromagnetic coil oppose each other. When the fields oppose each other, energy may be lost, and the arrangement can create a fairly linear gradient in a homogenous manner. The opposing magnetic fields created by anti-Helmholtz coils can be leveraged and incorporated into the electrochemical reactor to create magnetic traps which may help to regulate ore particle position relative to working electrode reaction zones in a desired manner. In this regard, the first electromagnetic coil and the second electromagnetic coil of an anti-Helmholtz coil may be positioned relative to a working electrode of the electrochemical reactor and supplied with opposing currents to provide opposing magnetic fields orthogonal the working electrode which causes ore particles to be trapped in a neutral point between magnetic fields proximate to the working electrode reaction zone, thereby enabling colloidal dipole-dipole interactions which are conductive to powder production and change the rheology of iron-containing slurries. In this regard, the working electrode can be positioned so that an axis common to the first electromagnetic coil and the second electromagnetic coil of an anti-Helmholtz coil are transverse to a surface of a working electrode at which at least a portion of feedstock is reduced when the electrochemical reactor is in operation.

In some embodiments, a first electromagnetic coil and a second electromagnetic coil of an anti-Helmholtz coil may be positioned so that a working electrode (cathode) of the electrochemical reactor is positioned between the first electromagnetic coil and the second electromagnetic coil. In some embodiments, a first electromagnetic coil and a second electromagnetic coil of an anti-Helmholtz coil may be positioned so that both a working electrode and a counter electrode (anode) are positioned between the first electromagnetic coil and the second electromagnetic coil. In some embodiments, the first electromagnetic coil and the second electromagnetic coil of an anti-Helmholtz coil may correspond to the first magnetic field source and the second magnetic field source. In some embodiments, the first electromagnetic coil of an anti-Helmholtz coil may correspond to one of the first magnetic field source and the second magnetic field source, while the second electromagnetic coil of the anti-Helmholtz coil corresponds to a magnetic field source of the one or more additional magnetic field sources. In some embodiments, the one or more additional magnetic field sources includes multiple additional magnetic field sources. In some embodiments, the first and second electromagnetic coil of an anti-Helmholtz coil may correspond to two magnetic field sources from the multiple additional magnetic field sources.

In some embodiments, the electrochemical reactor may include multiple anti-Helmholtz coils, where each respective anti-Helmholtz coil is configured to, when supplied with opposing currents to the first electromagnetic coil and second electromagnetic coil thereof, provide a magnetic field which causes ore particles to be maintained in one of multiple working electrode reaction zones present in the electrochemical reactor. For instance, in embodiments where multiple working electrodes are utilized in the electrochemical reactor, a first anti-Helmholtz coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a first working electrode, and a second anti-Helmholtz coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a second working electrode. In some embodiments, the first anti-Helmholtz coil may be formed by the first magnetic field source and a first additional magnetic field source positioned between the first magnetic field source and the second magnetic field source, and the second anti-Helmholtz coil may be formed by the second magnetic field source and a second additional field source positioned between the first additional magnetic field source and the second magnetic field source.

Electrochemical reactor embodiments in which multiple anti-Helmholtz coils are supplied current (i.e., activated) at different times are also contemplated herein. In some embodiments, current may be selectively supplied to the electromagnetic-based magnetic field sources of the electrochemical reactor as to cause a magnetic field source acting as one of the two coils of a first anti-Helmholtz coil at a first time to act as one of the two coils of a second anti-Helmholtz coil at a second time. In this regard, embodiments in which three magnetic field sources are utilized to provide two anti-Helmholtz coils are contemplated herein. For instance, in some embodiments, the electrochemical reactor may include the first magnetic field source, the second magnetic field source, and an additional magnetic field source positioned between the first magnetic field source and the second magnetic field source, where each respective magnetic field source is an electromagnet in the form of a coil and adjacently positioned coils are spaced apart from each other a distance equal to the radius of the coils. The first magnetic field source and the second magnetic field source can be adapted to receive current in a first direction and the additional magnetic field source can be adapted to receive current in a second opposite direction. Accordingly, current can be selectively applied to the first magnetic field source and the additional magnetic field source (in opposing directions) at a first time to activate a first anti-Helmholtz coil, and current can selectively be applied to the second magnetic field source and the additional magnetic field source (in opposing directions) at a second time when no current is applied to the first magnetic field source to activate a second anti-Helmholtz coil. The number of anti-Helmholtz coils utilized in the electrochemical reactor may vary based on the number of electrochemical cells present in the electrochemical reactor and/or the configuration of the electrochemical cells (bipolar or monopolar). In some embodiments, multiple electrochemical cells, each including a working electrode, may be positioned between the first electromagnetic coil and the second electromagnetic coil of an anti-Helmholtz coil utilized in the electrochemical reactor.

In some embodiments, Helmholtz and anti-Helmholtz coils may be used together to create a strong gradient to direct and maintain ore particles in a working electrode reaction zone. Summing the fields creates a strong gradient in a homogenous manner. The strong gradient can be incorporated into the electrochemical reactor. For example, the first magnetic field source and the second magnetic field source may be arranged as to provide both a Helmholtz coil configuration and a Maxwell coil configuration in the electrochemical reactor. For example, in some embodiments, the first magnetic field source may include two subdevices, and the second magnetic field source may include two subdevices, wherein a first subdevice of the first magnetic field source and a first subdevice of the second magnetic field source are arranged in a Helmholtz coil configuration, and a second subdevice of the first magnetic field source and a second subdevice of the second magnetic field source are arranged in an anti-Helmholtz coil configuration. In some embodiments, the electrochemical reactor may include a combination of one or more Helmholtz coils and one or more anti-Helmholtz coils, where each respective Helmholtz coil and each respective anti-Helmholtz coil is configured to, when supplied with current, provide a magnetic field which causes ore particles to be directed to and maintained in one of multiple working electrode reaction zones present in the electrochemical reactor. For instance, in embodiments where multiple working electrodes are utilized in the electrochemical reactor, a Helmholtz coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a first working electrode, and an anti-Helmholtz coil may be utilized to direct ore particles to a working electrode reaction zone of a second working electrode. In some embodiments, the first magnetic field source and a first additional magnetic field source positioned between the first magnetic field source and the second magnetic field source may form one of the Helmholtz coil and the anti-Helmholtz coil, and the second magnetic field source and a second additional magnetic field source positioned between the first additional magnetic field source and the second magnetic field source may form the other of the Helmholtz coil and the anti-Helmholtz coil.

In some embodiments in which both a Helmholtz coil and an anti-Helmholtz coil are utilized, the Helmholtz coil and the anti-Helmholtz coil may be supplied with current (i.e., activated) at different times. In some embodiments, current can be selectively supplied to electromagnetic-based magnetic field sources present in the electrochemical reactor as to cause a magnetic field source acting as one of the two coils of a Helmholtz coil at a first time to act as one of the two coils of an anti-Helmholtz coil at a second time. In this regard, embodiments in which three magnetic field sources are utilized to provide a Helmholtz coil and an anti-Helmholtz coil are contemplated herein. For instance, in some embodiments, the electrochemical reactor may include the first magnetic field source, the second magnetic field source, and an additional magnetic field source positioned between the first magnetic field source and the second magnetic field source, where each respective magnetic field source is an electromagnet in the form of a coil and adjacently positioned coils are spaced apart from each other a distance equal to the radius of the coils. The first magnetic field source and the additional magnetic field source can be adapted to receive current in a first direction and the second magnetic field source can be adapted to receive current in a second opposite direction. Accordingly, current can be selectively applied to the first magnetic field source and the additional magnetic field source (in the same direction) at a first time to activate a Helmholtz coil, and current can selectively be applied to the second magnetic field source and the additional magnetic field source (in opposing directions) at a second time when no current is applied to the first magnetic field source to activate an anti-Helmholtz coil. The number of Helmholtz and anti-Helmholtz coils utilized in the electrochemical reactor may vary based on the number of electrochemical cells present in the electrochemical reactor and/or configuration of the electrochemical cells (bipolar or monopolar).

In some aspects, multiple electromagnets are utilized in combination as to provide a Maxwell coil. In some embodiments, a Maxwell coil includes three electromagnets. Each of the three electromagnets includes a coil that is of a predetermined diameter and has a predetermined number of turns. The coil corresponding to one of the three electromagnets (or “first electromagnetic coil”), the coil corresponding to a second of the three electromagnets (or “second electromagnetic coil”), and the coil corresponding to the third of the three electromagnets (or “third electromagnetic coil”) are provided along the same axis as each other and arranged so that the second electromagnetic coil is positioned between the first electromagnetic coil and the third electromagnetic coil. In this regard, the first electromagnetic coil and the third electromagnetic coil may each be characterized as an “outer electromagnetic coil” of a three-coil Maxwell coil and the second electromagnetic coil may be characterized as a “central electromagnetic coil” of a three-coil Maxwell coil. The diameter of the central electromagnetic coil is of a predetermined diameter which is greater than that of the outer electromagnetic coils. In some embodiments, each outer electromagnetic coil has a radius which is equal to or approximately equal to the radius of the central electromagnetic coil multiplied by the square root of 4/7, that is:

$\begin{array}{cc}{r}_{\mathrm{outer}\mathrm{electromagnetic}\mathrm{coil}}=r_{\mathrm{central}\mathrm{electromagnetic}\mathrm{coil}}\times \surd 4/7.& \left(5\right)\end{array}$

In some embodiments, the distance between each outer electromagnetic coil and the central electromagnetic coil is equal to or approximately equal to the radius of the central electromagnetic coil multiplied by the square root of 3/7, that is:

$\begin{array}{cc}{d}_{\mathrm{outer}\mathrm{coil}\mathrm{to}\mathrm{central}\mathrm{coil}}=r_{\mathrm{central}\mathrm{coil}}\times \surd 3/7.& \left(6\right)\end{array}$

In some embodiments, the ratio of the number of the turns of each outer electromagnetic coil is equal to or approximately equal to 49/64 to the central electromagnetic coil. Embodiments in which the outer electromagnetic coils and the central electromagnetic coil each have a core as well as embodiments in which the outer electromagnetic coils and the central electromagnetic coil are each hollow are contemplated herein. In some embodiments, the three electromagnetic coils may be configured to provide a magnetic field strength of 500, 600, 700, 800, 900, 1000, 2000, or 3000 gauss to 3500, 3700, 4000, 4100, 4200, 4500, 4800, or 5000 gauss. Mentioned is use of 500 gauss to 5000 gauss. Accordingly, the amount of current supplied to the three electromagnetic coils, the number of turns for the three electromagnetic coils, the core material utilized for the three electromagnetic coils, and the diameter (and thus radius) of the three electromagnetic coils can be selected to provide such magnetic field strength without undue experimentation.

A three-coil Maxwell coil generates a homogeneous (uniform) magnetic field in response to the application of current to the outer electromagnetic coils and the central electromagnetic coil in the same direction. In some embodiments, the outer electromagnetic coils and the central electromagnetic coil may be wired in series. The strength of the magnetic field provided by the three-coil Maxwell coil is significant as the magnetic vector fields of the outer electromagnetic coils and the central electromagnetic coil are summative and in combination create a high degree of uniformity in a transverse direction relative to the planes in which the outer electromagnetic coils and the central electromagnetic coil reside. Accordingly, the outer electromagnetic coils and the central electromagnetic coil of a three-coil Maxwell coil may be positioned relative to a working electrode of the electrochemical reactor and supplied with a current in a direction that causes the three-coil Maxwell coil to provide a magnetic field that is orthogonal to the working electrode, which causes ore particles to be directed to and maintained in the working electrode reaction zone, thereby enabling colloidal dipole-dipole interactions which are conducive to powder production but also change the rheology of iron-containing slurries. In this regard, the working electrode can be positioned so that an axis common to the first electromagnetic coil, the second electromagnetic coil, and the third electromagnetic coil are transverse to a surface of a working electrode at which at least a portion of feedstock is reduced when the electrochemical reactor is in operation.

In some embodiments, the outer electromagnetic coils and the central electromagnetic coil of a three-coil Maxwell coil are positioned so that a working electrode (cathode) of the electrochemical reactor is positioned between one of the outer electromagnetic coils and the central electromagnetic coil of the three-coil Maxwell coil. In some embodiments, the outer electromagnetic coils and the central electromagnetic coil of a three-coil Maxwell coil are positioned so that both a working electrode and a counter electrode (anode) of the electrochemical reactor is positioned between one of the outer electromagnetic coils and the central electromagnetic coil of the three-coil Maxwell coil. In some embodiments, the outer electromagnetic coils of a three-coil Maxwell coil may correspond to the first magnetic field source and the second magnetic field source, while the central electromagnetic coil of the three-coil Maxwell coil corresponds to an additional magnetic field source positioned between the first magnetic field source and the second magnetic field source. In some embodiments, one of the two outer electromagnetic coils of a three-coil Maxwell coil may correspond to the first magnetic field source or the second magnetic field source while the other of the two outer electromagnetic coils and the central electromagnetic coil of the three-coil Maxwell correspond to a first additional magnetic field source and a second magnetic field source that are positioned between the first magnetic field source and the second magnetic field source. In some embodiments, the outer two coils and the central electromagnetic coil of a three-coil Maxwell coil may correspond to a first additional magnetic field source, a second additional magnetic field source, and a third additional magnetic field source that are positioned between the first magnetic field source and the second magnetic field source. In some embodiments, multiple electrochemical cells, each including a working electrode, may be positioned between one of the two outer electromagnetic coils and the central electromagnetic coil of a three-coil Maxwell coil. In some embodiments, one or more electrochemical cells including a working electrode may be positioned between one of the two outer electromagnetic coils and the central electromagnetic coil of a three-coil Maxwell coil and one or more electrochemical cells including a working electrode may be positioned between the other of the two outer electromagnetic coils and the central electromagnetic coil of the three-coil Maxwell coil.

Electrochemical reactor embodiments in which multiple three-coil Maxwell coils are utilized are contemplated herein, where each respective three-coil Maxwell coil is configured to, when supplied with current, provide a magnetic field which causes ore particles to be directed to and maintained in one of multiple working electrode reaction zones present in the electrochemical reactor. For instance, in embodiments where multiple working electrodes are utilized in the electrochemical reactor, a first three-coil Maxwell coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a first working electrode, and a second three-coil Maxwell coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a second working electrode. In some embodiments, current may be selectively supplied to electromagnetic-based magnetic field sources present in the electrochemical reactor as to cause a magnetic field source acting as one of the two outer electromagnetic coils of a first three-coil Maxwell coil at a first time to act as one of the two outer electromagnetic coils of a second three-coil Maxwell coil at a second time. In this regard, embodiments in which five magnetic field sources are utilized to provide two three-coil Maxwell coils are contemplated herein.

In some embodiments, the electrochemical reactor may include one or more three-coil Maxwell coils and one or more Helmholtz coils and/or one or more anti-Helmholtz coils. In some embodiments, current may be selectively supplied to electromagnetic-based magnetic field sources present in the electrochemical reactor as to cause a magnetic field source acting as one of the two outer electromagnetic coils of a three-coil Maxwell coil at a first time to act as one of the coils of a Helmholtz coil or an anti-Helmholtz coil at a second time. The number of three-ring Maxwell coils utilized in the electrochemical reactor may vary based on the number of electrochemical cells present in the electrochemical reactor and/or the configuration of the electrochemical cells (bipolar or monopolar).

In some embodiments, a Maxwell coil includes two electromagnets. Each of the two electromagnets includes a coil that is of a predetermined diameter and has a predetermined number of turns. The coil corresponding to one of the two electromagnets (or “first electromagnetic coil”) of a two-coil Maxwell coil and the coil corresponding to the other of the two electromagnets (or “second electromagnetic coil”) of a two-coil Maxwell coil are provided on the same axis as each other, have the same diameter and the same number of turns as each other, and are spaced apart from each other a distance that is greater than half the diameter (i.e., greater than the radius of one of the two coils). In some embodiments, the distance between the two coils of a two-coil Maxwell coil is equal to approximately the radius multiplied by the square root of three, that is: (i.e., d=r×√3). As in an anti-Helmholtz coil, the first electromagnetic coil and the second electromagnetic coil of a two-coil Maxwell coil are supplied current in opposing directions. Accordingly, the magnetic field produced by the first electromagnetic coil and the magnetic field produced by the second electromagnetic coil oppose each other. When the fields oppose each other, energy may be lost, and the arrangement can create a fairly linear gradient in a homogenous manner. The opposing magnetic fields created by two-coil Maxwell coils can be leveraged and incorporated into the electrochemical reactor to create magnetic traps which may help to regulate ore particle position relative to working electrode reaction zones in a desired manner. In this regard, the first electromagnetic coil and the second electromagnetic coil of a two-coil Maxwell coil may be positioned relative to a working electrode of the electrochemical reactor and supplied with opposing currents to provide opposing magnetic fields orthogonal the working electrode which causes ore particles to be trapped in a neutral point between magnetic fields proximate to the working electrode reaction zone, thereby enabling colloidal dipole-dipole interactions which are conductive to powder production and change the rheology of iron-containing slurries. In this regard, the working electrode can be positioned so that an axis common to the first electromagnetic coil and the second electromagnetic coil of the two-coil Maxwell coil are transverse to a surface of the working electrode at which at least a portion of feedstock is reduced when the electrochemical reactor is in operation. In some embodiments, the two electromagnetic coils may be configured to provide a magnetic field strength of 500, 600, 700, 800, 900, 1000, 2000, or 3000 gauss to 3500, 3700, 4000, 4100, 4200, 4500, 4800, or 5000 gauss. Mentioned is use of 500 gauss to 5000 gauss. Accordingly, the amount of current supplied to the two electromagnetic coils, the number of turns for the two electromagnetic coils, the core material utilized for the two electromagnetic coils, and the diameter (and thus radius) of the two electromagnetic coils can be selected to provide such magnetic field strength without undue experimentation.

In some embodiments, a first electromagnetic coil and a second electromagnetic coil of a two-coil Maxwell coil may be positioned so that a working electrode (cathode) of the electrochemical reactor is positioned between the first electromagnetic coil and the second electromagnetic coil. In some embodiments, a first electromagnetic coil and a second electromagnetic coil of a two-coil Maxwell coil may be positioned so that both a working electrode and a counter electrode (anode) are positioned between the first electromagnetic coil and the second electromagnetic coil. In some embodiments, the first electromagnetic coil and the second electromagnetic coil of a two-coil Maxwell coil may correspond to the first magnetic field source and the second magnetic field source. In some embodiments, the first electromagnetic coil of a two-coil Maxwell coil may correspond to one of the first magnetic field source and the second magnetic field source, while the second electromagnetic coil of the two-coil Maxwell coil corresponds to a magnetic field source of the one or more additional magnetic field sources. In some embodiments, the one or more additional magnetic field sources includes multiple additional magnetic field sources. In some embodiments, the first and second electromagnetic coil of a two-coil Maxwell coil may correspond to two magnetic field sources from the multiple additional magnetic field sources.

In some embodiments, the electrochemical reactor may include multiple two-coil Maxwell coils, where each respective two-coil Maxwell coil is configured to, when supplied with opposing currents to the first electromagnetic coil and second electromagnetic coil thereof, provide a magnetic field which causes ore particles to be maintained in one of multiple working electrode reaction zones present in the electrochemical reactor. For instance, in embodiments where multiple working electrodes are utilized in the electrochemical reactor, a first two-coil Maxwell coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a first working electrode, and a second two-coil Maxwell coil may be utilized to direct ore particles to a working electrode reaction zone corresponding to a second working electrode. In some embodiments, the first two-coil Maxwell coil may be formed by the first magnetic field source and a first additional magnetic field source positioned between the first magnetic field source and the second magnetic field source, and the second two-coil Maxwell coil may be formed by the second magnetic field source and a second additional field source positioned between the first additional magnetic field source and the second magnetic field source.

Electrochemical reactor embodiments in which multiple two-coil Maxwell coils are supplied current (i.e., activated) at different times are also contemplated herein. In some embodiments, current may be selectively supplied to the electromagnetic-based magnetic field sources of the electrochemical reactor as to cause a magnetic field source acting as one of the two coils of a first two-coil Maxwell coil at a first time to act as one of the two coils of a second two-coil Maxwell coil at a second time. In this regard, embodiments in which three magnetic field sources are utilized to provide two two-coil Maxwell coils are contemplated herein. For instance, in some embodiments, the electrochemical reactor may include the first magnetic field source, the second magnetic field source, and an additional magnetic field source positioned between the first magnetic field source and the second magnetic field source, where each respective magnetic field source is an electromagnet in the form of a coil and adjacently positioned coils are equally spaced apart from each other. The first magnetic field source and the second magnetic field source can be adapted to receive current in a first direction and the additional magnetic field source can be adapted to receive current in a second opposite direction. Accordingly, current can be selectively applied to the first magnetic field source and the additional magnetic field source (in opposing directions) at a first time to activate a first two-coil Maxwell coil, and current can selectively be applied to the second magnetic field source and the additional magnetic field source (in opposing directions) at a second time when no current is applied to the first magnetic field source to activate the second two-coil Maxwell coil.

In some embodiments, the electrochemical reactor may include one or more two-coil Maxwell coils and one or more Helmholtz coils, one or more anti-Helmholtz coils, and/or one or more three-coil Maxwell coils. In some embodiments, current may be selectively supplied to electromagnetic-based magnetic field sources present in the electrochemical reactor as to cause a magnetic field source acting as one of the coils of a two-coil Maxwell at a first time to act as one of the coils of a Helmholtz coil, an anti-Helmholtz coil, or a three-coil Maxwell coil at a second time. The number of two-coil Maxwell coils utilized in the electrochemical reactor may vary based on the number of electrochemical cells present in the electrochemical reactor and/or the configuration of the electrochemical cells (bipolar or monopolar). In some embodiments, multiple electrochemical cells, each including a working electrode, may be positioned between the first electromagnetic coil and the second electromagnetic coil of a two-coil Maxwell coil utilized in the electrochemical reactor.

It is appreciated that, in embodiments of the electrochemical reactors disclosed herein in which one or more electromagnetic coils are used, each respective electromagnetic coil is operably connected to a current source, such that current can be supplied from the current source to the electromagnetic coil to cause the electromagnetic coil to generate a magnetic field. In some embodiments, a current source may supply current to multiple electromagnetic coils present in the electrochemical reactor.

In some aspects, due to wire resistance, electromagnets dissipate electrical energy as heat. This heat can be repurposed for various applications, such as heating cells or heating electrolyte or extracting work. Electrolysis reactions are often temperature-sensitive, and precise temperature control may be used to provide improved performance.

Electropermanent magnets regulate their external magnetic field by an electrical pulse and retain their magnetic state with zero power. As used herein, an “electropermanent magnet” refers to a permanent magnet wherein the external magnetic field can be switched on or off by a pulse of electric current in a wire winding around part of the magnet. For example, an electropermanent magnet may include two magnetic materials, one magnetically hard (e.g., Nd—Fe—B) and one semi-hard, (e.g., Alnico, which may comprise Al, Ni, Co and may further comprise Fe, Cu, Ti, or a combination thereof), capped at both ends with a magnetically soft material (e.g., iron) and wrapped with a coil. A current pulse of one polarity magnetizes the materials together, increasing the external flow of magnetic flux. A current pulse of the opposite polarity reverses the magnetization of the semi-hard material, while leaving the hard material unchanged. This diverts some or all of the flux to circulate inside the device, reducing the external magnetic flux. The instantaneous power draw during the switching pulse for an electropermanent magnet is an order of magnitude greater than that of an equivalent electromagnet. However, the switching time can be short, often only 100 picoseconds (ps). Thus the total energy consumption of magnetic field sources can be reduced relative to electromagnets.

In an embodiment, the iron-containing feedstock is not subjected to electrochemical reduction before the electrochemical reduction in the magnetic field. For example, the iron in the iron-containing feedstock is in an oxidized state before the electrochemical reduction in the magnetic field to provide the iron metal.

The electrolyte stream includes an iron-containing feedstock. The term “iron ore” may be substituted or interchanged for the term “iron-containing feedstock.” The iron-containing feedstock may include any suitable iron compound, and may include an oxide of iron. The iron-containing feedstock refers to an iron-containing material that is capable of undergoing reduction during operation of the electrochemical reactor. As used herein, the terms “iron ore” and “iron-containing feedstock” may be used synonymously to refer to iron-containing materials that may be used as the feedstock into the various systems and methods described herein. “Iron ores” and “iron-containing feedstocks” may include iron in any form, and can be an iron oxide, hydroxide, oxyhydroxide, carbonate, or combination thereof. Also mentioned are other iron-containing compounds, ores, rocks, or minerals, including any mixtures thereof, in naturally occurring states or purified states. The iron-containing feedstock may include materials recognized, known, or referred to in the art as iron ore, rock, natural rock, sediment, natural sediment, mineral, and/or natural mineral, whether in naturally-occurring states or in otherwise purified or modified states. A combination comprising at least one of the foregoing iron-containing feedstocks may be used. Some embodiments of processes and systems described herein may be particularly useful for iron-containing feedstocks including hematite, maghemite, goethite, magnetite, limonite, pyrite, red mud, siderite, ankerite, turgite, bauxite, or a combination thereof.

Specifically, the iron-containing feedstock may include metallic iron (Fe) and/or one or more iron hydroxides (e.g., Fe(OH)₂, Fe(OH)₃, or the like, or a combination thereof), anhydrous and/or hydrated iron oxyhydroxides (e.g., FeOOH; e.g., FeO(OH)·nH₂O where n is a number of water molecules in the hydrated iron hydroxide molecule, or the like), iron oxides, sub-oxides, mixed oxides, including FeO (wustite), FeO₂ (iron dioxide), α-Fe₂O₃ (hematite), γ-Fe₂O₃ (maghemite), Fe₃O₄ (magnetite), Fe₄O₅, Fe₅O₆, Fe₅O₇, Fe₂₅O₃₂, Fe₁₃O₁₉, other iron-containing compounds, a polymorph(s) of these, or a combination of these. For example, in some embodiments, the iron-containing feedstock may include hematite (α-Fe₂O₃), maghemite (γ-Fe₂O₃), magnetite (Fe₃O₄), goethite (α-FeOOH), limonite (FeOOH-nH₂O), or a combination thereof. In particular embodiments, the iron-containing feedstock may include magnetite (Fe₃O₄). In particular embodiments, the iron-containing feedstock may include maghemite, magnetite, or a combination thereof. The iron-containing feedstock may be a product of one or more of several sources. In some embodiments, the iron-containing feedstock may include raw material in the form of hematite, maghemite, magnetite, limonite, siderite, bog-iron ore, clay minerals, ores with concentrations of less than about 30% iron by weight, scrap metals, magnets, slag, fly ash, red mud, a combination thereof, or other materials that have iron as is known by those of ordinary skill in the art.

The iron-containing feedstock may include one or more impurities or minor components. Examples of impurities or minor components may include oxides and/or complexes of aluminum, magnesium, calcium, carbon, cobalt, chromium, silicon, titanium, phosphorus, sulfur, or a combination thereof. The content of the impurity or minor component may be less than 10 weight percent (wt %), less than 5 wt %, less than 1 wt %, or less than 0.1 wt %, or less than 0.01 wt %, based on a total weight of the iron-containing feedstock. In an aspect, a content of the impurity is 0.001 to 10 wt %, or 0.01 to 4 wt %, or 0.01 to 1 wt %, based on a total weight of the iron-containing feedstock.

The iron-containing feedstock in the electrolyte stream may be a slurry or a suspension of iron-containing feedstock particles in the electrolyte material. In some embodiments, the electrolyte stream may include 0.1 to 80 wt %, or 0.1 to 30 wt %, preferably 0.1 to 15 wt % or 0.2 to 10 wt %, more preferably 0.1 to 5 wt % or 0.2 to 2 wt % of the iron-containing feedstock, based on a total weight of the electrolyte stream. The amount of the iron-containing feedstock in the electrolyte stream may vary based on the type of iron-containing feedstock being used. In some embodiments, the iron-containing feedstock may include hematite, wherein the electrolyte stream may include 1 to 30 wt %, preferably 2 to 30 wt %, more preferably 10 to 30 wt % of the iron-containing feedstock, based on a total weight of the electrolyte stream. In some embodiments, the iron-containing feedstock may include magnetite, wherein the electrolyte stream may include 0.1 to 30 wt %, 0.1 to 15 wt %, or 0.1 to 10 wt %, preferably 0.1 to 5 wt %, more preferably 0.2 to 2 wt % of the iron-containing feedstock, based on a total weight of the electrolyte stream. In some embodiments, the iron-containing feedstock may be present in the electrolyte stream in an amount of at least 5 wt %, and preferably greater than 10 wt %, for example, 10 to 80 wt %, based on a total weight of the electrolyte stream.

The electrolyte stream includes an electrolyte. In some embodiments, the electrolyte stream includes an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof. The electrolyte stream may comprise a solution including water as a solvent and one or more dissolved hydroxides. For example, the electrolyte stream may include an aqueous solution of NaOH, KOH, LiOH, CsOH, ammonium hydroxide (NH₄OH), or a combination thereof. Mentioned is an aspect wherein the electrolyte stream includes an aqueous solution of NaOH.

In the electrolyte stream including the aqueous solution, the alkali hydroxide, the organic hydroxide, or the combination thereof may be present in the aqueous solution in an amount from 20 to 50 weight percent (wt %), preferably 30 to 50 wt %, more preferably 30 to 40 wt %, based on a total weight of the aqueous solution (not including the iron-containing feedstock). In some embodiments, the electrolyte may include an aqueous solution of an alkali hydroxide, wherein the alkali hydroxide may be present in the aqueous solution in an amount from 20 to 50 wt %, preferably 30 to 50 wt %, based on a total weight of the aqueous solution.

The electrolyte stream may optionally contain additives to promote or inhibit certain desired or undesirable reactions. Any suitable amount of additive(s) may be included in the electrolyte stream. For example, the electrolyte stream may further include a hydrogen evolution reaction suppressor (HER suppressor), an iron activator (e.g., a sulfide salt, such as bismuth sulfide (Bi₂S₃) or sodium sulfide (Na₂S)), or the like, or a combination thereof. In some embodiments, electrolyte stream may further include an alkali metal sulfide or a polysulfide including one or more of lithium sulfide (Li₂S) or lithium polysulfide (Li₂S_x, x=2 to 6), sodium sulfide (Na₂S) or sodium polysulfide (Na₂S_x, x=2 to 6), potassium sulfide (K₂S) or potassium polysulfide (K₂S_x, x=2 to 6), cesium sulfide (Cs₂S) or cesium polysulfide (Cs₂S_x, x=2 to 6), or the like, or a combination thereof. Non-limiting examples of additives include sodium sulfide (Na₂S), potassium sulfide (K₂S), lithium sulfide (Li₂S), iron sulfides (FeS_x, where x=1-2), bismuth sulfide (Bi₂S₃), lead sulfide (PbS), zinc sulfide (ZnS), antimony sulfide (Sb₂S₃), selenium sulfide (SeS₂), tin sulfides (SnS, SnS₂, Sn₂S₃), nickel sulfide (NiS), molybdenum sulfide (MoS₂), mercury sulfide (HgS), bismuth oxide (Bi₂O₃), or the like, or a combination thereof. In addition, the electrolyte stream may include other additives, including those as described herein and those known in the art.

The HER suppressor may include one or more of sodium thiosulfate, sodium thiocyanate, polyethylene glycol (PEG) 1000, trimethylsulfoxonium iodide, zincate (by dissolving ZnO in NaOH), hexanethiol, decanethiol, sodium chloride, sodium permanganate, lead (IV) oxide, lead (II) oxide, magnesium oxide, sodium chlorate, sodium nitrate, sodium acetate, iron phosphate, phosphoric acid, sodium phosphate, ammonium sulfate, ammonium thiosulfate, lithopone, magnesium sulfate, iron(III) acetylacetonate, hydroquinone monomethyl ether, sodium metavanadate, sodium chromate, glutaric acid, dimethyl phthalate, methyl methacrylate, methylpentynol, adipic acid, allyl urea, citric acid, thiomalic acid, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, propylene glycol, trimethoxysilyl propyl diethylene, aminopropyl trimethoxysilane, dimethyl acetylenedicarboxylate (DMAD), 1,3-diethylthiourea, N,N′-diethylthiourea, aminomethyl propanol, methyl butynol, amino modified organosilane, succinic acid, isopropanolamine, phenoxyethanol, dipropylene glycol, benzoic acid, N-(2-aminoethyl)-3-aminopropyl, behenamide, 2-phosphonobutane tricarboxylic, mipa borate 3-methacryloxypropyltrimethoxysilane, 2-ethylhexoic acid, isobutyl alcohol, t-butylaminoethyl methacrylate, diisopropanolamine, propylene glycol n-propyl ether, sodium benzotriazolate, pentasodium aminotrimethylene phosphonate, sodium cocoyl sarcosinate, laurylpyridinium chloride, steartrimonium chloride, stearalkonium chloride, calcium montanate, quaternium-18 chloride, sodium hexametaphosphate, dicyclohexylamine nitrite, lead stearate, calcium dinonylnaphthalene sulfonate, iron(II) sulfide, sodium bisulfide, pyrite, sodium nitrite, complex alkyl phosphate ester (e.g. RHODAFAC® RA 600 Emulsifier), 4-mercaptobenzioc acid, ethylenediaminetetraacetic acid, ethylenediaminetetraacetate (EDTA), 1,3-propylenediaminetetraacetate (PDTA), nitrilotriacetate (NTA), ethylenediaminedisuccinate (EDDS), diethylenetriaminepentaacetate (DTPA), and other aminopolycarboxylates (APCs), diethylenetriaminepentaacetic acid, 2-methylbenzenethiol, 1-octanethiol, bismuth sulfide, bismuth oxide, antimony(III) sulfide, antimony(III) oxide, antimony(V) oxide, bismuth selenide, antimony selenide, selenium sulfide, selenium(IV) oxide, propargyl alcohol, 5-hexyn-1-ol, 1-hexyn-3-ol, N-allylthiourea, thiourea, 4-methylcatechol, trans-cinnamaldehyde, iron(III) sulfide, calcium nitrate, hydroxylamines, benzotriazole, furfurylamine, quinoline, tin(II) chloride, ascorbic acid, tetraethylammonium hydroxide, calcium carbonate, magnesium carbonate, antimony dialkylphosphorodithioate, potassium stannate, sodium stannate, tannic acid, gelatin, saponin, agar, 8-hydroxyquinoline, bismuth stannate, potassium gluconate, lithium molybdenum oxide, potassium molybdenum oxide, hydrotreated light petroleum oil, heavy naphthenic petroleum oil (e.g., sold as Rustlick® 631), antimony sulfate, antimony acetate, bismuth acetate, hydrogen-treated heavy naphtha (e.g., sold as WD-40), tetramethylammonium hydroxide, NaSb tartrate, urea, D-glucose, C₆Na₂O₆, antimony potassium tartrate, hydrazinesulphate, silica gel, triethylamine, potassium antimonate trihydrate, sodium hydroxide, 1,3-di-o-tolyl-2-thiourea, 1,2-diethyl-2-thiourea, 1,2-diisopropyl-2-thiourea, N-phenylthiourea, N,N′-diphenylthiourea, sodium antimony L-tartrate, rhodizonic acid disodium salt, sodium selenide, or the like, or a combination thereof.

The electrolyte stream may further include a solid conductive additive. For example, the electrolyte stream may further include carbon in an amount from 0.01 to 10 wt %, based on a total weight of the electrolyte stream.

The electrochemical reactor includes an anode, which can comprise carbon, titanium, lead, nickel, iron, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof. The anode includes a suitable anode current collector. The anode current collector may be a metal, metal alloy, or a combination thereof. In some embodiments, the anode current collector may include lead, nickel, platinum, iridium, ruthenium, tantalum, titanium, an alloy thereof, or a combination thereof. Optionally, the anode current collector may be coated with mixed metal oxides of iridium, ruthenium, tantalum, or the like, or a combination thereof.

The anode may include a catalyst. Exemplary catalysts include a metal oxide catalyst, such as manganese oxide (e.g., MnO₂, Mn₂O₃, Mn₃O₄, or Mn_xO_y (where x=1 to 3 and y=1 to 8), or a combination thereof), nickel-doped manganese oxide (Ni—Mn_xO_y), nickel oxide (NiO_x), nickel oxyhydroxide (NiO_x(OH)_y), iron oxide (FeO_x), iron oxyhydroxide (FeO_x(OH)_y (where x=0 to 2 and y=0 to 3)), cobalt oxide (Co₃O₄, Co_xO_y (where x=1 to 3 and y=1 to 8)), manganese cobalt oxide (MnCo₂O₄, Mn_1+xCo_2−xO₄ (where x=0 to 2)), cobalt manganese oxide (CoMn₂O₄), nickel manganese oxide (NiMnO_x (where x=2 to 4)), manganese iron oxide (MnFe₂O₄, Mn_1+xFe_2−xO₄ (where x=0 to 1)), nickel-doped manganese oxide (Ni—Mn_xO_y(where x=1 to 3 and y=1 to 8)), manganese cobalt iron oxide (Mn_xCo_yFe_zO₄ (where x=0 to 4 and y=0 to 4 and z=0 to 4)), zinc cobalt manganese oxide (ZnCoMnO₄, Zn_xCo_yMn_zO₄ (where x=0 to 4 and y=0 to 4 and z=0 to 4)), cobalt nickel oxide (CoNiO_x (where x=0 to 4)), calcium manganese oxide (CaMnO_x (where x=0 to 4)), lanthanum manganese oxide (LaMnO₃), lanthanum cobalt oxide (LaCo₂O₄, La_1+xCo_2−xO₄ (where x=0 to 2), lanthanum nickel oxide (LaNiO₃), lanthanum calcium aluminum manganese oxide (La_xCa_yAl_zMn_vO₃ (where x=0 to 3 and y=0 to 3 and z=0 to 2 and v=0 to 3)), nickel iron oxide (Ni_zFe_1−zO_x (where z=0 to 1 and x=0.5 to 2.5)), manganese ferrite (MnFe₂O₄), zinc ferrite (ZnFe₂O₄), nickel cobaltite (NiCo₂O₄), lanthanum strontium manganate (La_0.8Sr_0.2MnO₃), or the like, other transition metal oxides or nitrides (such as Fe₃N, FeCN, ZrN, Mn₄N, or a combination thereof), or a combination thereof. A combination comprising at least one of the foregoing oxides may be used. The particles of the catalyst may be coated by electrodeposition, electroless plating, or other chemical deposition process(es); for example, atomic layer deposition (ALD), thermal evaporation, sputtering, spray pyrolysis, solution-based deposition, hot dip coating, inkjet printing, or a combination thereof.

The anode current collector may have a thickness in the range from 0.05 to 0.5 centimeters (cm), such as from 0.1 to 0.3 cm. In some embodiments, the anode current collector may be at least partially porous.

The electrochemical reactor also includes a cathode. The cathode includes a suitable cathode current collector. Preferably, the current collector of the cathode is selected to minimize or prevent adhesion of the iron-containing feedstock and/or the iron metal thereto. Exemplary materials that are suitable for use in the cathode include, but are not limited to, aluminum, carbon, molybdenum, copper, nickel, titanium, iron, an alloy thereof, or a combination thereof. In some embodiments, the cathode current collector may include steel, graphite, copper, nickel, iron, a nickel-iron alloy, or a combination thereof. In some embodiments, the cathode may further include an inert conductive matrix including carbon black, graphite powder, charcoal powder, coal powder, nickel-coated carbon steel mesh, nickel-coated stainless-steel mesh, nickel-coated steel wool, or the like, or a combination thereof.

In some embodiments, the cathode may further include one or more additive(s) to enhance the electronic and/or physical properties of the cathode. In some embodiments, the additive in the cathode may include one or more of bismuth (III) oxide (Bi₂O₃), bismuth (III) sulfide (Bi₂S₃), barium oxide (BaO), barium sulfate (BaSO₄), barium hydroxide (Ba(OH)₂), calcium oxide (CaO), calcium sulfate (CaSO₄), calcium hydroxide (Ca(OH)₂), magnesium oxide (MgO), magnesium hydroxide (Mg(OH)₂), carbon nanotubes, carbon nanofibers, graphene, or a combination thereof.

In some embodiments, the cathode may further include one or more binder compound(s). In some embodiments, the binder compound may include polytetrafluoroethylene (PTFE), polyvinylidene difluoride (PVdF), polypropylene (PP), polyethylene (PE), polyacrylonitrile, styrene butadiene rubber, sodium carboxymethyl cellulose (Na-CMC), or the like, or a combination thereof.

The cathodic material may be positively charged or negatively charged. The cathodic material may be charged by a direct current (“DC”) source, by an alternating current (“AC”) source, and/or by a pulsed current.

The cathode current collector may have a thickness in the range from 0.05 to 0.5 cm, such as from 0.1 to 0.3 cm. The cathode current collector may be at least partially porous.

The distance between the anode and the cathode can be referred to as an interelectrode gap. The interelectrode gap may be selected, e.g., to provide suitable ohmic drop. The interelectrode gap may be 1 millimeter (mm) to 100 mm. For example, the interelectrode gap may be 2 mm to 50 mm, or 3 mm to 30 mm, or 4 mm to 20 mm.

The voltage of the electrochemical cell may be from 1.5 to 5.0 Volts (V), preferably from 1.6 to 2.9 V, and more preferably from 1.7 to 2.8 V. The voltage of the electrochemical cell may also be from 2.6 to 5.0 V, or from 2.8 to 4.0 V. The mechanism for selecting the cell voltage within the electrochemical cell will vary in accordance with various exemplary aspects and embodiments as described herein. Moreover, the overall cell voltage achievable is dependent upon a number of other interrelated factors, including reaction chemistry, electrode spacing, the configuration and materials of construction of the electrodes, the configuration and materials of construction of the separators, electrolyte concentrations and iron concentration in the electrolyte, current density, electrolyte temperature, and, to a smaller extent, the nature and amount of any additives to the electrochemical process (such as, for example, flocculants, surfactants, or the like).

The electrochemical reactor may be operated at a temperature of 50° C. to 140° C., preferably 70° C. to 120° C., more preferably 85° C. to 110° C. For example, the electrolyte stream may be at a temperature of 50° C. to 140° C., preferably 70° C. to 120° C., more preferably 85° C. to 110° C. before the electrolyte stream is introduced to the electrochemical reactor, such that the temperature of the electrolyte stream in the electrochemical reactor may be 50° C. to 140° C., preferably 70° C. to 120° C., more preferably 85° C. to 110° C. The operating temperature of the electrochemical reactor may refer to the temperature during which the magnetic field is applied to the electrochemical reactor.

The operating temperature of the electrolyte stream in the electrochemical reactor may be controlled through any one or more of a variety of means, including, for example, heat exchange, an immersion heating element, an in-line heating device (e.g., a heat exchanger), or the like, preferably coupled with one or more feedback temperature control means for efficient process control. The operating temperature of the electrolyte stream in the electrochemical reactor may be achieved through self-heating of the electrochemical reactor due to heat generation associated with operating at less than 100% energy efficiency. In the case of self-heating, a cooling system may be implemented to prevent the electrochemical cell from reaching temperatures greater than the optimal operating range.

A current density at the cathode for the reduction of the iron-containing feedstock may be 40 to 5,000 milliamperes per square centimeter (mA/cm²), preferably 150 to 1,000 mA/cm². In some embodiments, the current density at the cathode may be selected to promote the formation of iron dendrites at the surface of the cathode. The current density may be periodically pulsed, modulated, or a combination of pulsing and modulation used to control the iron metal dendrite growth or to limit the competing HER at the cathode.

The electrochemical reactor may operate with a suitable fluid flow, which may be varied based on operating conditions. The fluid flow may be a laminar flow, a turbulent flow, or a combination thereof. The fluid flow may be present as a flow rate. Any suitable flow rate may be used. The flow rate may include, but is not limited to, at least 0.01 liters per minute per square meter of cathode area (L/min/m²), for example, 0.05 to 5 L/min/m², or 0.1 to 2.5 L/min/m².

In some embodiments, the channel may be arranged substantially vertically. For example, the channel may be arranged to provide a vertical flow channel relative to the ground.

In some embodiments, the electrochemical reactor may further include a separation unit that is disposed downstream of the channel. The separation unit may be configured to separate at least a portion of the iron metal from the electrolyte stream, for example after the electrochemical reduction of the iron-containing feedstock. Exemplary separation units are further described below in conjunction with FIG. 5.

In some embodiments, the channel may be separated by a separator to provide a catholyte channel and an anolyte channel. The catholyte channel is configured to contain a catholyte stream including the iron-containing feedstock, and the anolyte channel is configured to contain an anolyte stream. When the separator is present, the anolyte and the catholyte may be different. For example, in an aspect including the separator, the catholyte may be alkaline (basic) and the anolyte may be acidic.

The catholyte stream includes an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof. The alkaline electrolyte and representative cathode materials are discussed above and not repeated for clarity. In some embodiments, the alkali hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount from 20 to 50 wt % or 30 to 40 wt %, based on a total weight of the catholyte stream excluding the iron-containing feedstock. In some embodiments, the catholyte stream comprises from 0.1 to 30 wt % of the iron-containing feedstock, based on a total weight of the catholyte stream.

The anolyte may include an aqueous solution including a supporting electrolyte compound; and optionally a mineral acid. Representative acidic electrolytes include aqueous solutions of mineral acids having a pKa of 2 or less. For example, the anolyte may include a mineral acid, such as HCl, HNO₃, H₂SO₄, HClO₄, H₃PO₄, or a combination thereof, and may comprise a supporting electrolyte compound to provide improved conductivity, preferably the supporting electrolyte compound is of the formula MClO₄, MNO₃, M₂SO₄, MF, MCl, MBr, or MI, wherein M is Li, Na, or K, or tetra-n-butylammonium X, wherein X is F, Cl, Br, I, or hexafluorophosphate; and water, and optionally further including a nonaqueous solvent, such as acetonitrile, dimethylsulfoxide, dimethylformamide, methanol, ethanol, 1-propanol, isopropanol, ether, diglyme, tetrahydrofuran, glycerol, or the like, or a combination thereof. In some embodiments, the anolyte may include one or more mineral acids, optionally one or more supporting electrolyte compounds, and water. For example, the anolyte may include an aqueous solution of a mineral acid, preferably HCl, H₂SO₄, or a combination thereof, and optionally a supporting electrolyte compound, preferably one or more of M₂SO₄, MCl, MBr, MI, or a combination thereof, where M is Li, Na, or K.

In an aspect where the anolyte is acidic, an acid compatible anode material may be used. Representative acid compatible anode materials include, but are not limited to, carbon, titanium, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, tin, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof. The anode may further include a binder, which may include polytetrafluoroethylene (PTFE), polyvinylidene difluoride (PVdF), polypropylene (PP), polyethylene (PE), polyacrylonitrile, styrene butadiene rubber, sodium carboxymethyl cellulose (Na-CMC), or the like, or a combination thereof.

The separator may be a passive separator, such as diaphragm separator, or may be an active separator, such as ion exchange membrane. In some embodiments, the separator may be chosen based on an ability to allow selective transfer of desired molecules or materials while substantially limiting or preventing transfer of undesired molecules or materials. For example, the separator may be an ion-selective membrane configured to allow the transfer of negative (or positive) ions while substantially preventing transfer of positive (or negative) ions. In other examples, the separator may be a material selected to allow or prevent the cross-over of gas bubbles from one side (e.g., associated with the working electrode) to the opposite side (e.g., associated with the counter-electrode).

In some embodiments, the separator may be formed of a dielectric material, or a porous material, which is permeable to positive ions, such as Li⁺, K⁺, Na⁺, Cs⁺, and/or NH₄⁺ ions, or the like, or a combination thereof, or negative ions, such as hydroxide ions, or the like. The separator may be impermeable or effectively impermeable to an active material of the catholyte or anolyte. In some embodiments, the separator may be a membrane, such as a membrane formed from a polymer with a tetrafluoroethylene backbone and side chains of perfluorovinyl ether groups terminated with sulfonate groups (e.g., a sulfonated tetrafluoroethylene membrane, a membrane made of polymers sold under the Nafion brand name, etc.), or the like.

In some embodiments, the separator may include an anion exchange membrane (AEM), a cation exchange membrane (CEM), a zwitterionic membrane, a porous membrane having an average pore diameter of less than 10 nanometers, a polybenzimidazole-containing membrane, a polysulfone-containing membrane, polycarboxylic-containing membrane, a polyetherketone-containing membrane, a membrane including polymer(s) of intrinsic microporosity (PIM), or the like, or a combination thereof. Preferably, the separator includes an anion exchange membrane (AEM) or a cation exchange membrane (CEM). In some embodiments, the separator may include a composite membrane including an inorganic material and an organic material. In some embodiments, the inorganic material may include a metal oxide or a ceramic material. In some embodiments, the organic material may include a polyether ether ketone (PEEK), a polysulfone, a polystyrene, a polypropylene, a polyethylene, or the like, or a combination thereof.

In some embodiments, a separator may be used that provides a physical barrier between the anolyte and the catholyte. For example, the separator may include a porous polyolefin film, a glass fiber mat, a glass frit, a cotton fabric, a rayon fabric, cellulose acetate, paper, or the like, or a combination thereof.

In some embodiments, when the separator is included in the electrochemical cell, the electrochemical cell may have a zero-gap configuration. As used herein, a “zero-gap cell” refers to an electrochemical cell in which at least one electrode is in contact with the separator (in contrast to a cell in which each electrode has a non-zero gap between the electrode surface and the separator). The second electrode may be in contact with the separator or situated at an offset from the separator. The electrodes in zero-gap electrochemical cells are preferably porous to enable ion transport between the electrolyte and the separator. In some embodiments, at least one of the anode or the cathode is directly on the separator, preferably wherein the at least one of the anode or the cathode contacts the separator.

In other embodiments, when the separator is included in the electrochemical cell, a first distance between a surface of the anode and the separator is 0.001 cm to 2 cm; a second distance between a surface of the cathode and the separator is 0.001 cm to 2 cm; or a combination thereof. For example, a first distance between a surface of the anode and the separator may be 0.001 cm to 2 cm, and a second distance between a surface of the cathode and the separator may be 0.001 cm to 2 cm.

In some embodiments, the electrochemical cell may be a plurality of electrochemical cells that are between the first magnetic field source and the second magnetic field source. For example, the plurality of electrochemical cells may include 2 to 500 electrochemical cells, preferably 5 to 200 electrochemical cells, or 50 to 170 electrochemical cells that are arranged between the first magnetic field source and the second magnetic field source. One or more additional magnetic field sources may be arranged between adjacent electrochemical cells, such that the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each electrochemical cell and in magnetic field(s) provided by the first magnetic field source, the second magnetic field source, the one or more additional magnetic field sources, or a combination thereof.

The plurality of electrochemical cells may be arranged in a bipolar configuration or a monopolar configuration.

As used herein, “bipolar” refers to a configuration wherein pairs of cathodes and anodes electrodes are electrically mated together, such that the cathode of one electrochemical cell is electrically connected to the anode of the next electrochemical cell. Current collection generally occurs over an area equivalent to the geometric area of the electrochemical cell, thereby reducing ohmic losses resulting from current collection relative to when current collection occurs in a direction perpendicular to the active area of the cell, e.g., where current is carried in a perpendicular direction and through a small cross sectional area of current collecting material. In some embodiments, the plurality of electrochemical cells may be connected in series.

As used herein, “monopolar” refers to distinct anodes and cathodes, where the cathode of one electrochemical cell is adjacent to the cathode of a next electrochemical cell, and the anode of one electrochemical cell is adjacent to the anode of a next electrochemical cell. When in a monopolar configuration, a group of electrodes may be connected in parallel. Multiple electrochemical cells may be connected in parallel.

In some embodiments, the electrochemical reactor includes a bipolar plate that is disposed between some or all of the adjacent electrochemical cells. For example, the electrochemical reactor may include a bipolar plate between a pair of adjacent electrochemical cells. In some embodiments, the electrochemical cell may include (n−1) bipolar plates, wherein n is the number of electrochemical cells in the plurality of electrochemical cells. For example, the electrochemical reactor may include a bipolar plate between a pair of adjacent electrochemical cells, or, for example, the electrochemical reactor may include a bipolar plate between each pair of adjacent electrochemical cells.

The bipolar plates may each include an anode side that is in electrical contact with the anode of a first electrochemical cell, and a cathode side that is in electrical contact with the cathode of a second (adjacent) electrochemical cell. In other embodiments, the bipolar plates may each include a cathode side that is in electrical contact with the cathode of a first electrochemical cell, and an anode side that is in electrical contact with the anode of a second (adjacent) electrochemical cell.

When the electrochemical reactor includes (n−1) bipolar plates, the plurality of electrochemical cells may be connected in series and configured to have a reactor potential applied between a cathode of an initial electrochemical cell and an anode of a final electrochemical cell, wherein the reactor potential is a cell potential multiplied by n, wherein n is the number of electrochemical cells in the plurality of electrochemical cells.

In some embodiments, one or more of the bipolar plates may further include an additional magnetic field source that is disposed between adjacent electrochemical cells, wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each of the electrochemical cells and in a magnetic field provided by the first magnetic field source, the second magnetic field source, the additional magnetic field source, or a combination thereof. For example, the electrochemical reactor may include (n/m−1) additional magnetic field sources, wherein m is a number of the electrochemical cells that are influenced by the magnetic field provided by a single pair of magnetic field sources, preferably wherein m is an integer from 1 to 10, and wherein n is a number of electrochemical cells in the plurality of electrochemical cells. The additional magnetic field source may be a separate component independent of the bipolar plate, or the additional magnetic field source can part of or integrated into the bipolar plate. When a bipolar plate further includes an additional magnetic field source disposed therein, it may further include an insulator to prevent the conduction of current through the embedded magnetic field source.

When the electrochemical cells are arranged in a bipolar configuration, each additional magnetic field source independently may be a field generating device or a field propagating device. For example, each additional magnetic field source independently may include a permanent magnet, an electromagnet, or an electropermanent magnet. In some embodiments, some or all of the additional magnetic field sources may be utilized in combination with one or more other additional magnetic field sources in the electrochemical reactor to provide a Helmholtz, an anti-Helmholtz coil, a two-coil Maxwell coil, or a three-coil Maxwell coil. For instance, in some embodiments, each additional magnetic field source may be utilized in combination with the first magnetic field source, the second magnetic field source, or another magnetic field source to provide a Helmholtz coil, an anti-Helmholtz coil, a two-coil Maxwell coil, or a three-coil Maxwell coil in the electrochemical reactor. In some embodiments where multiple additional magnetic field sources are utilized, only a subset of the multiple additional magnetic field sources may be utilized to provide a Helmholtz coil, an anti-Helmholtz coil, a two-coil Maxwell coil, or a three-coil Maxwell coil. In some embodiments, an additional magnetic field source may be utilized in combination with more than one other magnetic field source in the electrochemical reactor when the electrochemical reactor is in use.

In some embodiments, adjacent electrochemical cells may be arranged in a monopolar configuration. For example, adjacent electrochemical cells may be arranged in a monopolar configuration such that the anodes of adjacent cells are adjacent, and the cathodes of adjacent cells are adjacent. In such an arrangement, the plurality of electrochemical cells may be connected in parallel and configured to have a same cell potential applied between the cathode and the anode of each electrochemical cell.

When the electrochemical cells are arranged in a monopolar fashion, the electrochemical reactor may further include one or more additional magnetic field sources that are disposed between adjacent electrochemical cells, wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each of the electrochemical cells and in a magnetic field provided by the first magnetic field source, the second magnetic field source, the one or more additional magnetic field source, or a combination thereof. For example, the electrochemical reactor may include (n/m−1) additional magnetic field sources, wherein n is the number of electrochemical cells in the plurality of electrochemical cells, and m is a number of the electrochemical cells that are influenced by the magnetic field provided by a single pair of magnetic field sources, preferably wherein m is an integer from 1 to 10.

When the electrochemical cells are arranged in a monopolar configuration, each additional magnetic field source independently may be a field generating device or a field propagating device. For example, each additional magnetic field source independently may include a permanent magnet, an electromagnet, or an electropermanent magnet. In some embodiments, some or all of the additional magnetic field sources may be utilized in combination with one or more other magnetic field sources in the electrochemical reactor and arranged to provide a Helmholtz coil, an anti-Helmholtz coil, a two-coil Maxwell coil, or a three-coil Maxwell coil. For instance, in some embodiments, each additional magnetic field source may be utilized in combination with the first magnetic field source, the second magnetic field source, or another magnetic field source to provide a Helmholtz coil, an anti-Helmholtz coil, a two-coil Maxwell coil, or a three-coil Maxwell coil in the electrochemical reactor. In some embodiments where multiple additional magnetic field sources are utilized, only a subset of the multiple additional magnetic field sources may be utilized to provide a Helmholtz coil, an anti-Helmholtz coil, a two-coil Maxwell coil, or a three-coil Maxwell coil. In some embodiments, an additional magnetic field source may be utilized in combination with more than one other magnetic field source in the electrochemical reactor when the electrochemical reactor is in use.

FIG. 1 shows a schematic diagram of an embodiment of an electrochemical reactor 100. The electrochemical reactor 100 includes an anode 10, e.g., a counter electrode, and a cathode 20, e.g., a working electrode, which are spaced apart and disposed in a channel 50 of the electrochemical reactor 100, wherein the anode 10 and the cathode 20 are in contact with an electrolyte stream 55 including an iron-containing feedstock. The iron-containing feedstock includes a feedstock that is susceptible to magnetization. The anode 10 and the cathode 20 are disposed between a first magnetic field source 30 and a second magnetic field source 32. The first magnetic field source 30 and the second magnetic field source 32 may include an electromagnet or other magnet as provided herein. In operation, the feedstock (e.g., the iron-containing feedstock) is reduced to provide iron metal. The electrochemical reactor 100 may further include a separator 52.

The electrochemical reactor 100 in FIG. 1 includes a plurality of electrochemical cells that are disposed between the first magnetic field source 30 and the second magnetic field source 32. The electrochemical reactor 100 includes additional anodes, such as anodes 10a and 10b in FIG. 1, and additional cathodes, such as cathodes 20a and 20b in FIG. 1. When the plurality of electrochemical cells are present, a first electrochemical cell may be formed between the anode 10 and the cathode 20a, a second electrochemical cell may be formed between the anode 10a and the cathode 20b, and a third electrochemical cell may be formed between the anode 10b and the cathode 20. The electrochemical reactor 100 may further include a separator, such as separator 52, 54, and 56. In FIG. 1, for clarity of illustration, three electrochemical cells are shown, although as indicated above the electrochemical reactor 100 may comprise any suitable number of electrochemical cells, e.g., 2 to 500 cells.

The configuration shown in FIG. 1 is a bipolar configuration, wherein bipolar plates 40 and 42 are disposed between the first and second cells and between the second and third cells. The bipolar plate 40 has a cathode side that is in electrical contact with cathode 20a and an anode side that is in electrical contact with anode 10a. The bipolar plate 42 has a cathode side that is in electrical contact with cathode 20b and an anode side that is in electrical contact with anode 10b.

The configuration shown in FIG. 1 further includes an additional magnetic field source 34 that is disposed between cathode 20a and anode 10a, and an additional magnetic field source 36 that is disposed between cathode 20b and anode 10a. Although the magnetic field sources 34 and 36 can be embedded in the corresponding bipolar plate 40 or 42 as shown in FIG. 1, it is understood that the magnetic field sources 34 and 36 can be independent and separated from the bipolar plates 40 and 42. The additional magnetic field sources 34, 36 may include an electromagnet or other magnet as provided herein. In operation, for example, the electrochemical reactor 100 may reduce at least a portion of the iron-containing feedstock 55 to iron metal at the cathode 20 in a magnetic field provided by the first magnetic field source 30, the additional magnetic field source 34, or a combination thereof. The electrochemical reactor 100 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 20a in a magnetic field provided by the additional magnetic field source 34, the additional magnetic field source 36, or a combination thereof. The electrochemical reactor 100 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 20b in a magnetic field provided by the additional magnetic field source 36, the second magnetic field source 32, or a combination thereof.

FIG. 2 shows a schematic diagram of an embodiment of an electrochemical reactor 200. The electrochemical reactor 200 includes an anode 210, e.g., a counter electrode, and a cathode 220, e.g., a working electrode, which are spaced apart and disposed in a channel 250 of the electrochemical reactor 200, wherein the anode 210 and the cathode 220 are in contact with an electrolyte stream including an iron-containing feedstock. The iron-containing feedstock includes a feedstock that is susceptible to magnetization. The anode 210 and the cathode 220 are disposed between a first magnetic field source 230 and a second magnetic field source 232. The first magnetic field source 230 and the second magnetic field source 232 may include an electromagnet or other magnet as provided herein. In operation, the feedstock (e.g., the iron-containing feedstock) is reduced to provide iron metal. The electrochemical reactor 200 may further include a separator 252.

The electrochemical reactor 200 in FIG. 2 includes a plurality of electrochemical cells that are disposed between the first magnetic field source 230 and the second magnetic field source 232. The electrochemical reactor 200 includes additional anodes 210a, 210b, 210c, 210d, etc. and additional cathodes 220a, 220b, 220c, 220d, etc. When the plurality of electrochemical cells are present, a first electrochemical cell may be formed by anode 210 and cathode 220a, a second electrochemical cell may be formed by anode 210a and cathode 220b, a third electrochemical cell may be formed by anode 210b and cathode 220c, a fourth electrochemical cell may be formed by anode 210c and cathode 220d, and a fifth electrochemical cell may be formed by anode 210d and cathode 220. The electrochemical reactor 200 may further include separators 252, 254, 256, 258, and 260. In FIG. 2, for clarity of illustration, five electrochemical cells are shown, although as indicated above the electrochemical reactor may comprise any suitable number of electrochemical cells, e.g., 2 to 500 cells.

The configuration shown in FIG. 2 is a bipolar configuration, wherein bipolar plates 240, 242, 244, and 246 are disposed between the respective adjacent electrochemical cells. The bipolar plate 240 has a cathode side that is in electrical contact with cathode 220a and an anode side that is in electrical contact with anode 210a. The bipolar plate 242 has a cathode side that is in electrical contact with cathode 220b and an anode side that is in electrical contact with anode 210b. The bipolar plate 244 has a cathode side that is in electrical contact with cathode 220c and an anode side that is in electrical contact with anode 210c. The bipolar plate 246 has a cathode side that is in electrical contact with cathode 220d and an anode side that is in electrical contact with anode 210d.

The configuration shown in FIG. 2 further includes additional magnetic field sources 234 and 236, which are disposed in the bipolar plates 242 and 246, respectively. Although not shown, it is understood that the additional magnetic field sources 234 and 236 can be separate components from the bipolar plates 242 and 246. The additional magnetic field sources 242, 246 may include an electromagnet or other magnet as provided herein. In operation, for example, the electrochemical reactor 200 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 220 in a magnetic field provided by the first magnetic field source 230, the additional magnetic field source 234, or a combination thereof. The electrochemical reactor 200 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 220a in a magnetic field provided by the first magnetic field source 230, the additional magnetic field source 234, or a combination thereof. The electrochemical reactor 200 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 220b in a magnetic field provided by the additional magnetic field source 234, the additional magnetic field source 236, or a combination thereof. The electrochemical reactor 200 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 220c in a magnetic field provided by the additional magnetic field source 234, the additional magnetic field source 236, or a combination thereof. The electrochemical reactor 200 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 220d in a magnetic field provided by the additional magnetic field source 236, the second magnetic field source 232, or a combination thereof.

FIG. 3 shows a schematic diagram of an embodiment of an electrochemical reactor 300 having a zero gap configuration. The electrochemical reactor 300 includes an anode 310, e.g., a counter electrode, and a cathode 320, e.g., a working electrode, which are spaced apart and disposed in a channel 350 of the electrochemical reactor 300, wherein the anode 310 and the cathode 320 are in contact with an electrolyte stream 360 including an iron-containing feedstock. The iron-containing feedstock includes a feedstock that is susceptible to magnetization. The anode 310 and the cathode 320 are disposed between a first magnetic field source 330 and a second magnet magnetic field source 332. The first magnetic field source 330 and the second magnetic field source 332 may include an electromagnet or other magnet as provided herein. In operation, the feedstock (e.g., the iron-containing feedstock) is reduced to provide iron metal. The electrochemical reactor 300 further includes a separator 352.

The electrochemical reactor 300 in FIG. 3 includes a plurality of electrochemical cells that are disposed between the first magnetic field source 330 and the second magnetic field source 332. The electrochemical reactor 300 includes additional anodes 310a, 310b, etc., and additional cathodes 320a, 320b, etc. When the plurality of electrochemical cells is present, a first electrochemical cell may be formed by anode 310 and cathode 320a, a second electrochemical cell may be formed by anode 310a and cathode 320b, and a third electrochemical cell may be formed by anode 310b and cathode 320. The electrochemical reactor 300 may further include separators 352, 354, and 356. In FIG. 3, for clarity of illustration, three electrochemical cells are shown, although as indicated above the electrochemical reactor may comprise any suitable number of electrochemical cells, e.g., 2 to 500 cells.

The configuration shown in FIG. 3 is a bipolar configuration, wherein bipolar plates 340 and 342 are disposed between the first and second cells and between the second and third cells, respectively. The bipolar plate 340 has a cathode side that is in electrical contact with cathode 320a and an anode side that is in electrical contact with anode 310a. The bipolar plate 342 has a cathode side that is in electrical contact with cathode 320b and an anode side that is in electrical contact with anode 310b. In the zero gap configuration shown, any suitable material may be used to provide electrical contact between the bipolar plates 340, 342 and the respective electrodes contacting each bipolar plate.

The configuration shown in FIG. 3 further includes an additional magnetic field source 334 that is disposed between cathode 320a and anode 310a, and an additional magnetic field source 336 that is disposed between cathode 320b and anode 310b. The additional magnetic field sources 334, 336 may include an electromagnet or other magnet as provided herein. In operation, for example, the electrochemical reactor 300 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 320 in a magnetic field provided by the first magnetic field source 330, the additional magnetic field source 334, or a combination thereof. The electrochemical reactor 300 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 320a in a magnetic field provided by the additional magnetic field source 334, the additional magnetic field source 336, or a combination thereof. The electrochemical reactor 300 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 320b in a magnetic field provided by the additional magnetic field source 336, the second magnetic field source 332, or a combination thereof.

FIG. 4 shows a schematic diagram of an embodiment of an electrochemical reactor 400. The electrochemical reactor 400 includes an anode 410, e.g., a counter electrode, and a cathode 420, e.g., a working electrode, which are spaced apart and disposed in a channel 450 of the electrochemical reactor 400, wherein the anode 410 and the cathode 420 are in contact with an electrolyte stream including an iron-containing feedstock. The iron-containing feedstock includes a feedstock that is susceptible to magnetization. The anode 410 and the cathode 420 are disposed between a first magnetic field source 430 and a second magnetic field source 432. The first magnetic field source 430 and the second magnetic field source 432 may include an electromagnet or other magnet as provided herein. In operation, the feedstock (e.g., the iron-containing feedstock) is reduced to provide iron metal. The electrochemical reactor 400 may further include a separator 452.

The electrochemical reactor 400 in FIG. 4 includes a plurality of electrochemical cells that are disposed between the first magnetic field source 430 and the second magnetic field source 432. The electrochemical reactor 400 includes additional anodes 410a and 410b, etc., and additional cathodes 420a, 420b, etc. When the plurality of electrochemical cells is present, a first electrochemical cell may be formed by anode 410 and cathode 420a, a second electrochemical cell may be formed by anode 410a and cathode 420b, and a third electrochemical cell may be formed by anode 410b and cathode 420. The electrochemical reactor 400 may further include separators 452, 454, and 456. In FIG. 4, for clarity of illustration, three electrochemical cells are shown, although as indicated above the electrochemical reactor may comprise any suitable number of electrochemical cells, e.g., 2 to 500 cells.

The configuration shown in FIG. 4 is a monopolar configuration, wherein the first and second cells have adjacent cathodes 420a and 420b, and the second and third cells have adjacent anodes 410a and 410b. The configuration shown in FIG. 4 further includes an additional magnetic field source 434 that is disposed between cathode 420a and cathode 420b, and an additional magnetic field source 436 that is disposed between anode 410a and anode 410b. The additional magnetic field sources 434, 436 may include an electromagnet or other magnet as provided herein. In operation, for example, the electrochemical reactor 400 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 420 in a magnetic field provided by the first magnetic field source 430, the additional magnetic field source 434, or a combination thereof. The electrochemical reactor 400 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 420a in a magnetic field provided by the additional magnetic field source 434, the additional magnetic field source 436, or a combination thereof. The electrochemical reactor 400 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 420b in a magnetic field provided by the additional magnetic field source 436, the second magnetic field source 432, or a combination thereof. In some embodiments, one or more of the plurality of electrochemical cells may not contain an additional magnetic field source disposed therebetween.

Shown in FIG. 5 is a schematic diagram of an embodiment of an electrochemical reactor system 500. The electrochemical reactor system 500 includes an electrochemical reactor, a feedstock handling system, and a product handling system. The electrochemical reactor includes an anode, e.g., anodes 510 and 510a, and a cathode, e.g., cathodes 520 and 520a, which are spaced apart and disposed in a channel 560 of the electrochemical reactor 500, wherein the anodes 510, 510a and the cathodes 520, 520a are in contact with an electrolyte stream including an iron-containing feedstock. The iron-containing feedstock includes a feedstock that is susceptible to magnetization. The anode 510 and the cathode 520 are disposed between a first magnetic field source 530 and an additional magnetic field source 534, whereas the anode 510a and the cathode 520b are disposed between the additional magnetic field source 534 and the second magnetic field source 532. The first magnetic field source 530, the second magnetic field source 532, and the third magnetic field source 534 may include an electromagnet or other magnet as provided herein. In operation, the feedstock (e.g., the iron-containing feedstock) is reduced to provide iron metal. In FIG. 5, for clarity of illustration, two electrochemical cells are shown, although as indicated above the electrochemical reactor may comprise any suitable number of electrochemical cells, e.g., 2 to 500 cells.

The electrolyte stream is provided to the channel 550 of the electrochemical reactor 500 by the feedstock handling system. The feedstock handling system may include a mixing tank 540 for mixing a concentrated ore slurry from a concentrated ore unit 542 with an electrolyte from an electrolyte unit 544. Optionally provided is an electrolyte treatment unit 546 providing electrolyte treatment. The electrolyte treatment unit 546 may optionally include a filter, may optionally control a pH or a temperature of the electrolyte, and/or may optionally provide an additive to the electrolyte. Any suitable electrolyte additive may be used, including combinations of two or more additives.

From the electrochemical reactor an electrolyte product stream 550 including the electrolyte, and optionally the iron metal product or unreacted iron-containing feedstock particles, to the product handling system. The product handling system may include a separation unit 552. The separation unit 552 may be configured to separate the iron metal product from unreacted iron-containing feedstock material, and may include a magnetic separator or a physical separator. The product handling system may optionally include a post processing unit 554. The post processing unit 554 may wash and/or dry the iron metal product. The product handling system may also optionally include residuals separation unit 556 configured to separate residual iron-containing feedstock from the electrolyte stream. The residual iron-containing feedstock may be provided by the concentrated ore slurry to the concentrated ore unit 542 and the electrolyte provided to the electrolyte unit 544. In some embodiments, the electrolyte stream may be transported to the separation unit 552, where at least a portion of the iron metal may be separated from the electrolyte stream and other processing may occur as described herein, and the electrolyte stream is recirculated back to an upstream region of the channel, such as into the mixing tank 540.

A method of operating the electrochemical reactor system to produce iron metal may comprise flowing the electrolyte stream comprising the iron-containing feedstock from the feedstock handling system to the electrochemical reactor; applying a magnetic field at the cathode of the electrochemical cell; electrochemically reducing at least a portion of the iron-containing feedstock to produce the iron metal at the cathode while the magnetic field is applied at the cathode; collecting the iron metal from the cathode by flowing the electrolyte stream to a product handling system; separating the iron metal from unreacted iron-containing feedstock in the separation unit to produce iron metal.

The method may further comprise flowing the unreacted iron-containing feedstock to the feedstock handling system; and treating the unreacted iron-containing feedstock in the feedstock handling system to provide a replenished electrolyte stream. The treating of the unreacted iron-containing feedstock may comprise mixing the unreacted iron-containing feedstock with a concentrated ore, adjusting a pH of the electrolyte stream, adjusting a temperature of the electrolyte stream, adding an electrolyte additive, adjusting a water content of the electrolyte stream, or a combination thereof. For example, treating of the unreacted iron-containing feedstock may comprise adjusting a water content of the electrolyte stream may comprise adding or removing water to adjust the concentration of the iron-containing feedstock to 5 to 80 wt % of the electrolyte stream. The replenished electrolyte stream may be flowed from the feedstock handling system to the electrochemical reactor to repeat the iron metal production process.

Shown in FIG. 6 are graphs of voltage (arbitrary units), magnetic field (arbitrary units), ore concentration (arbitrary units), and iron concentration (arbitrary units), each versus time (arbitrary units) with corresponding schematic diagrams of the electrochemical reactor to illustrate an embodiment of the disclosed electrochemical reactor system and process. In a first step 6A, with the magnetic field off (that is, without the magnetic field derived from the first magnetic field source and the second magnetic field source), the electrolyte stream including the iron-containing feedstock may be added (or introduced) to the electrochemical reactor. As shown in FIG. 6, the iron-containing feedstock concentration increases upon addition. The magnetic field is then turned on (that is, providing the magnetic field with the first magnet magnetic field source and the second magnetic field source) to attract iron-containing feedstock particles to the cathode. Increasing the voltage results in reduction of the iron-containing feedstock to iron metal, indicated by the increasing content (e.g., concentration) of iron in the electrochemical reactor as shown in step 6B. Also, while illustrated to have the magnetic field on before the voltage is increased, also disclosed is an aspect wherein the voltage may be increased before the magnetic field is increased. In an aspect, the iron-containing feedstock may be continuously provided to the electrochemical reactor, thus the concentration of ore in the electrical reactor may be constant.

Harvesting the iron product may be facilitated by reducing the voltage and reducing the magnetic field, as shown in step 6C. When the magnetic field is reduced or the magnetic field is turned off, the iron metal product may release from the cathode, facilitating recovery of the product. Also, the voltage may be modulated, or turned off, to select the particle characteristics of the product or to facilitate harvesting of the product. In step 6C, while illustrated to have the magnetic field decreased after the voltage is decreased, also disclosed is an aspect wherein the voltage is decreased after the magnetic field is decreased or removed. Alternatively, in step 6C, the magnetic field may be stopped entirely during the harvesting step. It should be understood that in some embodiments, the first magnetic field source and/or the second magnetic field source may be movable to provide for the removal or decreasing of the magnetic field.

In an aspect, a separator may be provided between the cathode and the anode as shown, for example, in FIG. 7. In the embodiment shown in FIG. 7, the electrochemical reactor 700 includes a separator 752 that is disposed in a channel 750 between the anode 710 and the cathode 720. The anode 710 is disposed on a current collector 730 and the cathode 720 is disposed on a current collector 732. The separator 752 may be in the form of a membrane, such as a microporous polyolefin membrane, an ion-exchange membrane, or may be a porous compact separator such a glass frit, for example. The separator is further described herein.

When the separator 752 is present, the anolyte 712 and the catholyte 722 may be different. For example, in an aspect including the separator 752, the catholyte 722 may be alkaline (basic) and the anolyte 712 may be acidic. The alkaline electrolyte, the anolyte, and representative anode and cathode materials are as described herein.

The anolyte 712 may be provided from an anolyte reservoir 760 using a pump 762. The catholyte 722 may be provided by a feedstock handling system, such as feedstock handling system as previously described. The catholyte 722 may be provided from a catholyte reservoir 770 using pump 772. The catholyte 722 may be further connected to a product handling system, which is not shown in FIG. 7.

FIG. 8 shows a schematic diagram of an embodiment of an electrochemical reactor 800. The electrochemical reactor 800 includes an anode 810, e.g., a counter electrode, and a cathode 820, e.g., a working electrode, which are spaced apart and disposed in a channel 850 of the electrochemical reactor 800, wherein the anode 810 and the cathode 820 are in contact with an electrolyte stream including an iron-containing feedstock. The iron-containing feedstock includes a feedstock that is susceptible to magnetization. The anode 810 and the cathode 820 are disposed between a first magnetic field source 830 and a second magnetic field source 832. The first magnetic field source 830 and the second magnetic field source 832 may include an electromagnet or other magnet as provided herein. In operation, the feedstock (e.g., the iron-containing feedstock) is reduced to provide iron metal. The electrochemical reactor 800 may further include a separator 852.

The electrochemical reactor 800 in FIG. 8 includes a plurality of electrochemical cells that are disposed between the first magnetic field source 830 and the second magnetic field source 832. The electrochemical reactor 800 includes additional anodes 810a, 810b, 810c, etc., and additional cathodes 820a, 820b, 820c, etc. When the plurality of electrochemical cells are present, a first electrochemical cell may be formed by anode 810 and cathode 820, a second electrochemical cell may be formed by anode 810a and cathode 820a, a third electrochemical cell may be formed by anode 810b and cathode 820b, and a fourth electrochemical cell may be formed by anode 810c and cathode 820c. The electrochemical reactor 800 may further include separators 852, 854, 856, and 858. In FIG. 8, for clarity of illustration, four electrochemical cells are shown, although as indicated above the electrochemical reactor may comprise any suitable number of electrochemical cells, e.g., 2 to 500 cells.

The configuration shown in FIG. 8 is a monopolar configuration, wherein the first and second cells have adjacent anodes 810 and 810a, the second and third cells have adjacent cathodes 820a and 820b, and the third and fourth cells have adjacent anodes 810b and 810c. The configuration shown in FIG. 8 further includes an additional magnetic field source 834 that is disposed between cathode 820a and cathode 820b. The additional magnetic field source 834 may include an electromagnet or other magnet as provided herein. In other embodiments, additional magnetic field sources may be further provided between anode 810 and anode 810a, and/or between anode 810b and anode 810c. For example, in operation, the electrochemical reactor 800 may reduce at least a portion of the iron-containing feedstock to iron metal at the anode 810 in a magnetic field provided by the first magnetic field source 830, the additional magnetic field source 834, or a combination thereof. The electrochemical reactor 800 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 820a in a magnetic field provided by the first magnetic field source 830, by the additional magnetic field source 834, or a combination thereof. The electrochemical reactor 800 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 820b in a magnetic field provided by the additional magnetic field source 834, the second magnetic field source 832, or a combination thereof. The electrochemical reactor 800 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathode 820c in a magnetic field provided by the additional magnetic field source 834, the second magnetic field source 832, or a combination thereof.

Although the magnetic field sources shown in FIGS. 1-5 and 8 are generally illustrated as being oriented in-line with the electrochemical cells, such that the magnetic field sources and the electrochemical cells of the electrochemical reactors in such figures are arranged in a row, with the one or more additional magnetic field sources and/or the component in which the one or more additional magnetic field sources are provided (e.g., bipolar plate) providing a degree of spacing between adjacent electrochemical cells, it is appreciated that electrochemical reactors made in accordance with the present disclosure are not necessarily limited to such construction. Rather, in another aspect, the present disclosure also provides an electrochemical reactor that includes an electrochemical cell including an anode and a cathode; and a plurality of magnetic field sources disposed about an exterior of the electrochemical cell, wherein each electromagnetic field source is in the form of an electromagnetic coil and the electrochemical cell is positioned along an axis common to each of the electromagnetic coils. The anode and the cathode are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, wherein the anode and the cathode are configured to contact the electrolyte stream. For example, the anode and the cathode may be disposed around the electrolyte stream, such that the anode and the cathode define the channel. In some embodiments, the anode and the cathode are in contact with the channel that is configured to contain the electrolyte stream. The electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field that is provided by the plurality of electromagnetic coils.

In some embodiments, the plurality of electromagnet coils or a subset thereof may be arranged relative to each other and supplied with current as to provide one or more Helmholtz coils, one or more anti-Helmholtz coils, one or more two-coil Maxwell coils, and/or one or more three-coil Maxwell coils, as described herein, in the electrochemical reactor.

The remaining features (such as the iron metal, the electrolyte stream, operating temperature, cathode materials, anode materials, etc.) of the electrochemical reactor that includes a plurality of electromagnetic coils that are disposed around the electrochemical cell are as described herein for the electrochemical reactor that includes the first magnetic field source and the second magnetic field source.

In some embodiments, the electrochemical reactor that includes a plurality of electromagnetic coils that are disposed around the electrochemical cell includes a channel that is separated by a separator to provide a catholyte channel and an anolyte channel, wherein the catholyte channel is configured to contain a catholyte stream comprising the iron-containing feedstock, and the anolyte channel is configured to contain an anolyte stream. The details of the catholyte stream, anolyte stream, and separator are as described herein for the electrochemical reactor that includes the first magnetic field source and the second magnetic field source.

In some embodiments, the electrochemical reactor that includes a plurality of electromagnetic coils that are disposed around the electrochemical cell has a configuration wherein at least one of the anode or the cathode is directly on the separator, preferably wherein at least one of the anode or the cathode contacts the separator. In other embodiments, a first distance between a surface of the anode and the separator is 0.001 cm to 2 cm, a second distance between a surface of the cathode and the separator is 0.001 cm to 2 cm, or a combination thereof.

In some embodiments, the electrochemical reactor includes a plurality of electromagnetic coils that are disposed around a plurality of electrochemical cells. For example, the plurality of electromagnetic coils may be disposed around a plurality of electrochemical cells having 2 to 500 electrochemical cells, preferably 5 to 200 electrochemical cells, or 50 to 170 electrochemical cells.

In some embodiments, the electrochemical reactor includes a plurality of electromagnetic coils that are disposed around a plurality of electrochemical cells, wherein a bipolar plate is disposed between a pair of adjacent electrochemical cells. For example, the electrochemical reactor that includes a plurality of electromagnetic coils that are disposed around a plurality of electrochemical cells may include (n−1) bipolar plates, wherein n is a number of electrochemical cells in the plurality of electrochemical cells. For example, the electrochemical reactor may include a bipolar plate between each pair of adjacent electrochemical cells. Each of the bipolar plates may include an anode side in electrical contact with the anode of a first electrochemical cell; and a cathode side in electrical contact with the cathode of a second electrochemical cell, wherein the first electrochemical cell and the second electrochemical cell are adjacent. In some embodiments, the plurality of electrochemical cells may be connected in series and configured to have a reactor potential applied between a cathode of an initial electrochemical cell and an anode of a final electrochemical cell, wherein the reactor potential is a cell potential multiplied by n, wherein n is the number of electrochemical cells in the plurality of electrochemical cells.

In some embodiments, the electrochemical reactor includes a plurality of electromagnetic coils that are disposed around a plurality of electrochemical cells, wherein adjacent electrochemical cells are arranged in a monopolar configuration such that the anodes of adjacent cells are adjacent and the cathodes of adjacent cells are adjacent. In such embodiments, the plurality of electrochemical cells may be connected in parallel and configured to have a same cell potential applied between the cathode and the anode of each electrochemical cell.

FIG. 9 shows a schematic diagram of an embodiment of an electrochemical reactor 900. The electrochemical reactor 900 includes an anode 910, e.g., a counter electrode, and a cathode 920, e.g., a working electrode, which are spaced apart and disposed in a channel 950 of the electrochemical reactor 900, wherein the anode 910 and the cathode 920 are in contact with an electrolyte stream including an iron-containing feedstock. The iron-containing feedstock includes a feedstock that is susceptible to magnetization. A plurality of electromagnetic coils 930 are disposed around the anode 910 and the cathode 920. In FIG. 9, there are seven such electromagnetic coils 930, with a first part of each respective electromagnetic coil 930 being shown in an upper portion of FIG. 9 and a second part of each respective electromagnetic coil being shown in a lower portion of FIG. 9. Of course, the total number of electromagnetic coils utilized may vary depending on the number of electrochemical cells and/or the configuration of the electrochemical cells (monopolar or bipolar) utilized in the electrochemical reactor 900. In operation, the feedstock (e.g., the iron-containing feedstock) is reduced to provide iron metal. The electrochemical reactor 900 may further include a separator 952.

The electrochemical reactor 900 in FIG. 9 includes a plurality of electrochemical cells that are disposed along an axis common to the plurality of electromagnetic coils 930. The electrochemical reactor 900 includes additional anodes 910a, 910b, 910c, etc., and additional anodes 920a, 920b, and 920c, etc. When the plurality of electrochemical cells are present, a first electrochemical cell may be formed by anode 910 and cathode 920, a second electrochemical cell may be formed by anode 910a and cathode 920a, a third electrochemical cell may be formed by anode 910b and cathode 920b, and a fourth electrochemical cell may be formed by anode 910c and cathode 920c. The electrochemical reactor 900 may further include separators 952, 954, 956, and 958. In FIG. 9, for clarity of illustration, four electrochemical cells are shown, although as indicated above the electrochemical reactor may comprise any suitable number of electrochemical cells, e.g., 2 to 500 cells.

The configuration shown in FIG. 9 is a monopolar configuration, wherein the first and second cells have adjacent cathodes 920 and 920a, the second and third cells have adjacent anodes 910a and 910b, and the third and fourth cells have adjacent cathodes 920b and 920c. In operation, the electrochemical reactor 900 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathodes 920, 920a, 920b, and 920c in a magnetic field provided by the plurality of electromagnetic coils 930.

FIG. 10 shows a schematic diagram of an embodiment of an electrochemical reactor 1000. The electrochemical reactor 1000 includes an anode 1010, e.g., a counter electrode, and a cathode 1020, e.g., a working electrode, which are spaced apart and disposed in a channel 1050 of the electrochemical reactor 1000, wherein the anode 1010 and the cathode 1020 are in contact with an electrolyte stream including an iron-containing feedstock. The iron-containing feedstock includes a feedstock that is susceptible to magnetization. A plurality of electromagnetic coils 1030 are disposed around the anode 1010 and the cathode 1020. In FIG. 10, there are seven such electromagnetic coils 1030, with a first part of each respective electromagnetic coil 1030 being shown in an upper portion of FIG. 10 and a second part of each respective electromagnetic coil being shown in a lower portion of FIG. 10. Of course, the total number of electromagnetic coils utilized may vary depending on the number of electrochemical cells and/or the configuration of the electrochemical cells (monopolar or bipolar) utilized in the electrochemical reactor 1000. In operation, the feedstock (e.g., the iron-containing feedstock) is reduced to provide iron metal. The electrochemical reactor 1000 may further include a separator 1052.

The electrochemical reactor 1000 in FIG. 10 includes a plurality of electrochemical cells that are disposed along an axis common to the plurality of electromagnetic coils 1030. The electrochemical reactor 1000 includes additional anodes 1010a, 1010b, etc. and additional cathodes 1020a, 1020b, etc. When the plurality of electrochemical cells are present, a first electrochemical cell may be formed by anode 1010 and cathode 1020a, a second electrochemical cell may be formed by anode 1010a and cathode 1020b, and a third electrochemical cell may be formed by anode 1010b and cathode 1020. The electrochemical reactor 1000 may further include separators 1052, 1054, and 1056. In FIG. 10, for clarity of illustration, three electrochemical cells are shown, although as indicated above the electrochemical reactor may comprise any suitable number of electrochemical cells, e.g., 2 to 500 cells.

The configuration shown in FIG. 10 is a bipolar configuration, wherein bipolar plates 1040 and 1042 are disposed between the respective adjacent electrochemical cells. The bipolar plate 1040 has a cathode side that is in electrical contact with cathode 1020a and an anode side that is in electrical contact with anode 1010a. The bipolar plate 1042 has a cathode side that is in electrical contact with cathode 1020b and an anode side that is in electrical contact with anode 1010b. In operation, the electrochemical reactor 1000 may reduce at least a portion of the iron-containing feedstock to iron metal at the cathodes 1020, 1020a, and 1020b in a magnetic field provided by the plurality of electromagnetic coils 1030.

FIG. 12 shows a perspective view of a first electromagnetic coil 1210 and a second electromagnetic coil 1220 arranged in a Helmholtz coil configuration. In this regard, the first electromagnetic coil 1210 and the second electromagnetic coil 1220 are positioned along an axis, a, common to each other, are configured to receive current in the same direction, have the same radius, r, (and thus the same diameter) and the same number of turns as each other, and are spaced apart a distance, d, that is equal to the radius, r. In this illustrative embodiment, the first electromagnetic coil 1210 and the second electromagnetic coil 1220 each have two turns. Of course, the number of turns in the first electromagnetic coil 1210 and the second electromagnetic coil 1220 can be adjusted to affect the magnetic field produced thereby and better accommodate different electrochemical cell configurations within an electrochemical reactor. The first electromagnetic coil 1210 and the second electromagnetic coil 1220 are operably connected to a current source 1230, such that the current source 1230 can be activated to supply the first electromagnetic coil 1210 and the second electromagnetic coil 1220 with current, which causes the first electromagnetic coil 1210 and the second electromagnetic coil 1220 to generate a magnetic field. In this illustrative embodiment, the first electromagnetic coil 1210 and the second electromagnetic coil are operably connected to the same current source 1230 in series. It is appreciated, however, that a Helmholtz coil configuration can still be realized in instances where the first electromagnetic coil 1210 and the second electromagnetic coil 1220 are operably connected to separate current sources.

FIG. 13 is a perspective view of the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12 generating a magnetic field in response to being supplied current in the same direction. Referring now to FIGS. 12 and 13, when the first electromagnetic coil 1210 and the second electromagnetic coil 1220 are supplied with current, i, from the current source 1230 in the same direction, the first electromagnetic coil 1210 and the second electromagnetic coil 1220 generate a magnetic field with a high degree of uniformity in a direction transverse to the planes in which the first electromagnetic coil 1210 and the second electromagnetic coil 1220 are provided, especially in an area between the first electromagnetic coil 1210 and the second electromagnetic coil 1220. In this illustrative embodiment, the first electromagnetic coil 1210 and the second electromagnetic coil 1220 are each provided current in a first rotational direction (e.g., counterclockwise), as shown in FIG. 12, that causes the first electromagnetic coil 1210 and the second electromagnetic coil 1220 to generate a magnetic field with a left-to-right direction, as shown in FIG. 13. Of course, the first electromagnetic coil 1210 and the second electromagnetic coil 1220 can each alternatively be provided with current in a second rotational direction (e.g., clockwise) that is opposite of the first rotational direction to cause the first electromagnetic coil 1210 and the second electromagnetic coil 1220 to generate a magnetic field with a right-to-left direction. As further discussed below with reference to FIGS. 14-18, 19A, and 19B, the magnetic field generated by the first electromagnetic coil 1210 and the second electromagnetic coil 1220 while provided in a Helmholtz coil arrangement and supplied with current in the same direction can be leveraged to help direct and maintain ore particles, such as iron ore particles, in proximity to the cathodes of electrochemical cells present in an electrochemical reactor.

It is appreciated, that the radii of the first electromagnetic coil 1210 and the second electromagnetic coil 1220, the number of turns in the first electromagnetic coil 1210 and the second electromagnetic coil 1220, the distance between the first electromagnetic coil 1210 and the second electromagnetic coil 1220, and the direction in which current is applied to both the first electromagnetic coil 1210 and the second electromagnetic coil 1220 can be adjusted to provide a magnetic field suitable for directing and maintaining ore particles in proximity to the cathodes of electrochemical cells present in an electrochemical reactor. In other words, the foregoing characteristics can be modified to accommodate different electrochemical reactor constructions and still provide a Helmholtz coil that generates a magnetic field consistent with that illustrated in FIG. 13.

FIG. 14 shows a schematic diagram of a cell assembly 1400, including: a first electromagnetic coil 1402; a second electromagnetic coil 1404; and an electrochemical cell 1405 positioned between the first electromagnetic coil 1402 and the second electromagnetic coil 1404. The first electromagnetic coil 1402 and the second electromagnetic coil 1404 are arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a Helmholtz coil. The cell assembly 1400 can be implemented in and form part of an electrochemical reactor as provided herein. As shown, the electrochemical cell 1405 includes an anode 1410, a cathode 1420, and a separator 1430 positioned between anode 1410 and the cathode 1420. The cathode 1420 and the anode 1410 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 1410 and the cathode 1420 are configured to contact the electrolyte stream. Current, i, can be supplied to the first electromagnetic coil 1402 and the second electromagnetic coil 1404 from a current source (not shown) in the first rotational direction to generate a magnetic field consistent with that shown in FIG. 13. Accordingly, when the cell assembly 1400 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the magnetic field generated by virtue of current being supplied to the first electromagnetic coil 1402 and the second electromagnetic coil 1404 in the first rotational direction serves to direct and maintain at least a portion of the iron-containing feedstock present in the electrochemical cell 1405 at the cathode 1420 of the electrochemical cell 1405. In operation, an electrochemical reactor including the cell assembly 1400 of FIG. 14 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1420.

FIG. 15 shows a schematic diagram of a cell assembly 1500, including: a first electromagnetic coil 1502; a second electromagnetic coil 1504; and an electrochemical cell 1505 positioned between the first electromagnetic coil 1502 and the second electromagnetic coil 1504. The first electromagnetic coil 1502 and the second electromagnetic coil 1504 are arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a Helmholtz coil. The cell assembly 1500 can be implemented in and form part of an electrochemical reactor as provided herein. As shown, the electrochemical cell 1505 includes an anode 1510, a cathode 1520, and a separator 1530 positioned between anode 1510 and the cathode 1520. The cathode 1520 and the anode 1510 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 1510 and the cathode 1520 are configured to contact the electrolyte stream. In this embodiment, the electrochemical cell 1505 is a zero-gap cell. Current, i, can be supplied to the first electromagnetic coil 1502 and the second electromagnetic coil 1504 from a current source (not shown) in the first rotational direction to generate a magnetic field consistent with that shown in FIG. 13. Accordingly, when the cell assembly 1500 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the magnetic field generated by virtue of current being supplied to the first electromagnetic coil 1502 and the second electromagnetic coil 1504 in the first rotational direction serves to direct and maintain at least a portion of the iron-containing feedstock present in the electrochemical cell 1505 at the cathode 1520 of the electrochemical cell 1505. In operation, an electrochemical reactor including the cell assembly 1500 of FIG. 15 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1520.

FIG. 16 shows a schematic diagram of a cell assembly 1600, including: a first electromagnetic coil 1602; a second electromagnetic coil 1604; a first electrochemical cell 1610; and a second electrochemical cell 1620; and a bipolar plate 1630 that is positioned between the first electrochemical cell 1610 and the second electrochemical cell 1620. The first electromagnetic coil 1602 and the second electromagnetic coil 1604 are arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a Helmholtz coil. As shown, the first electrochemical cell 1610, the second electrochemical cell 1620, and the bipolar plate 1630 are each positioned between the first electromagnetic coil 1602 and the second electromagnetic coil 1604. The cell assembly 1600 can be implemented in and form part of an electrochemical reactor as provided herein. As shown, the first electrochemical cell 1610 includes an anode 1612, a cathode 1614, and a separator 1616 positioned between the anode 1612 and the cathode 1614. The cathode 1614 and the anode 1612 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 1612 and the cathode 1614 are configured to contact the electrolyte stream. Similarly, the second electrochemical cell 1620 includes an anode 1622, a cathode 1624, and a separator 1626 positioned between the anode 1622 and the cathode 1624. The cathode 1624 and the anode 1622 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 1622 and the cathode 1624 are configured to contact the electrolyte stream. The bipolar plate 1630 has a cathode side that is in electrical contact with cathode 1614 and an anode side that is in electrical contact with anode 1622. Accordingly, in this embodiment, the first electrochemical cell 1610 and the second electrochemical cell 1620 are in a bipolar configuration.

Referring still to FIG. 16, current, i, can be supplied to the first electromagnetic coil 1602 and the second electromagnetic coil 1604 from a current source (not shown) in the first rotational direction to generate a magnetic field consistent with that shown in FIG. 13. Accordingly, when the cell assembly 1600 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the magnetic field generated by virtue of current being supplied to the first electromagnetic coil 1602 and the second electromagnetic coil 1604 in the first rotational direction serves to direct and maintain iron-containing feedstock at the cathodes 1614, 1624 of the cell assembly 1600. In operation, an electrochemical reactor including the cell assembly 1600 of FIG. 16 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1614 and may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1624.

FIG. 17 shows a schematic diagram of a cell assembly 1700, including: a first electromagnetic coil 1702; a second electromagnetic coil 1704; a first electrochemical cell 1710; and a second electrochemical cell 1720. The first electromagnetic coil 1702 and the second electromagnetic coil 1704 are arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a Helmholtz coil. As shown, the first electrochemical cell 1710 and the second electrochemical cell 1720 are each positioned between the first electromagnetic coil 1702 and the second electromagnetic coil 1704. The cell assembly 1700 can be implemented in and form part of an electrochemical reactor as provided herein. As shown, the first electrochemical cell 1710 includes an anode 1712, a cathode 1714, and a separator 1716 positioned between the anode 1712 and the cathode 1714. The cathode 1714 and the anode 1712 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 1712 and the cathode 1714 are configured to contact the electrolyte stream. Similarly, the second electrochemical cell 1720 includes an anode 1722, a cathode 1724, and a separator 1726 positioned between the anode 1722 and the cathode 1724. The cathode 1724 and the anode 1722 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 1722 and the cathode 1724 are configured to contact the electrolyte stream. In this embodiment, the first electrochemical cell 1710 and the second electrochemical cell 1720 are in a monopolar configuration.

Referring still to FIG. 17, current, i, can be supplied to the first electromagnetic coil 1702 and the second electromagnetic coil 1704 from a current source (not shown) in the first rotational direction to generate a magnetic field consistent with that shown in FIG. 13. Accordingly, when the cell assembly 1700 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the magnetic field generated by virtue of current being supplied to the first electromagnetic coil 1702 and the second electromagnetic coil 1704 in the first rotational direction serves to direct and maintain iron-containing feedstock at the cathodes 1714, 1724 of the cell assembly 1700. In operation, an electrochemical reactor including the cell assembly 1700 of FIG. 17 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1714 and may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1724.

FIG. 18 shows a schematic diagram of a cell assembly 1800 and a second cell assembly 1830, which can be implemented in and form part of an electrochemical reactor as provided herein. As indicated by the ellipsis in FIG. 18, in various embodiments, one or more components of the electrochemical reactor, such as additional cell assemblies, may be provided between the first cell assembly 1800 and the second cell assembly 1830. As shown, the first cell assembly 1800 includes: a first electromagnetic coil 1802; a second electromagnetic coil 1804; a first electrochemical cell 1810; a second electrochemical cell 1820; and a first bipolar plate 1815 positioned between the first electrochemical cell 1810 and the second electrochemical cell 1820. The first electromagnetic coil 1802 and the second electromagnetic coil 1804 are arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a first Helmholtz coil. As shown, the first electrochemical cell 1810 and the second electrochemical cell 1820 are each positioned between the first electromagnetic coil 1802 and the second electromagnetic coil 1804. The first electrochemical cell 1810 includes an anode 1812, a cathode 1814, and a separator 1816 positioned between the anode 1812 and the cathode 1814. The cathode 1814 and the anode 1812 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 1622 and the cathode 1624 are configured to contact the electrolyte stream. Similarly, the second electrochemical cell 1820 includes an anode 1822, a cathode 1824, and a separator 1826 positioned between the anode 1822 and the cathode 1824. The cathode 1824 and the anode 1822 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 1822 and the cathode 1824 are configured to contact the electrolyte stream. In this embodiment, the first electrochemical cell 1810 and the second electrochemical cell 1820 are in a bipolar configuration.

Referring still to FIG. 18, the second cell assembly 1830 includes: a third electromagnetic coil 1806; a fourth electromagnetic coil 1808; a third electrochemical cell 1840; a fourth electrochemical cell 1850; and a second bipolar plate 1845 positioned between the third electrochemical cell 1840 and the fourth electrochemical cell 1850. The third electromagnetic coil 1806 and the fourth electromagnetic coil 1808 are arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a second Helmholtz coil. As shown, the third electrochemical cell 1840 and the fourth electrochemical cell 1850 are each positioned between the third electromagnetic coil 1806 and the fourth electromagnetic coil 1808. The third electrochemical cell 1840 includes an anode 1842, a cathode 1844, and a separator 1846 positioned between the anode 1842 and the cathode 1844. Similarly, the fourth electrochemical cell 1850 includes an anode 1852, a cathode 1854, and a separator 1856 positioned between the anode 1852 and the cathode 1854. In this embodiment, the third electrochemical cell 1840 and the fourth electrochemical cell 1850 are also in a bipolar configuration.

Referring still to FIG. 18, current, i, can be supplied to the first electromagnetic coil 1802 and the second electromagnetic coil 1804 from a current source (not shown) in the first rotational direction to generate a first magnetic field consistent with that shown in FIG. 13. Similarly, current, i, can be supplied to the third electromagnetic coil 1806 and the fourth electromagnetic coil 1808 from a current source (not shown) in the first rotational direction to generate a second magnetic field consistent with that shown in FIG. 13. Accordingly, when the first cell assembly 1800 and the second cell assembly 1830 are implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the first Helmholtz coil provided by the first electromagnetic coil 1802 and the second electromagnetic coil 1804 and the second Helmholtz coil provided by the third electromagnetic coil 1806 and the fourth electromagnetic coil 1808 can be selectively activated (by supplying current to the electromagnetic coils defining the first Helmholtz coil and the second Helmholtz coil) to direct and maintain iron-containing feedstock at the cathodes 1814, 1824 of the first cell assembly 1800 and the cathodes 1844, 1854 of the second cell assembly 1830.

In various embodiments and implementations, the first Helmholtz coil corresponding to the first cell assembly 1800 and the second Helmholtz coil corresponding to the second cell assembly 1830 may be activated at the same time, different times, or a combination thereof. In operation, an electrochemical reactor including the first cell assembly 1800 and the second cell assembly 1830 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1814, may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1824, may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1844, and may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1854. Although the first cell assembly 1800 and the second cell assembly 1830 are each illustrated as including multiple electrochemical cells arranged in a bipolar configuration, alternative embodiments in which the electrochemical cells 1810, 1820 of the first cell assembly 1800 and/or the electrochemical cells 1840, 1850 of the second cell assembly 1830 are arranged in a monopolar configuration are also contemplated herein.

FIGS. 19A and 19B show schematic diagrams of a cell assembly 1900 at a first time and a second time. The cell assembly 1900 can be implemented in and form part of an electrochemical reactor as provided herein. As shown, the cell assembly 1900 includes: a first electromagnetic coil 1902; a second electromagnetic coil 1904; a third electromagnetic coil 1906; a first electrochemical cell 1910; a second electrochemical cell 1920; a first bipolar plate 1915 positioned between the first electrochemical cell 1910 and the second electrochemical cell 1920; a third electrochemical cell 1930; a fourth electrochemical cell 1940; and a second bipolar plate 1935 positioned between third electrochemical cell 1930 and the fourth electrochemical cell 1940. The first electromagnetic coil 1902 and the second electromagnetic coil 1904 are arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a first Helmholtz coil when supplied with current in the same direction. The second electromagnetic coil 1904 and the third electromagnetic coil 1906 are also arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a second Helmholtz coil. The first electrochemical cell 1910 and the second electrochemical cell 1920 are each positioned between the first electromagnetic coil 1902 and the second electromagnetic coil 1904, while the third electrochemical cell 1930 and the fourth electrochemical cell 1940 are positioned between the second electromagnetic coil 1904 and the third electromagnetic coil 1906. As shown, each respective electrochemical cell 1910, 1920, 1930, 1940 of the cell assembly 1900 includes: an anode 1912, 1922, 1932, 1942; a cathode 1914, 1924, 1934, 1944; and a separator 1916, 1926, 1936, 1946 positioned between the anode 1912, 1922, 1932, 1942 and the cathode 1914, 1924, 1934, 1944 of the electrochemical cell 1910, 1920, 1930, 1940. The cathodes 1914, 1924, 1934, 1944 and the anodes 1912, 1922, 1932, 1942 of each electrochemical cell 1910, 1920, 1930, 1940 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the cathodes 1914, 1924, 1934, 1944 and the anodes 1912, 1922, 1932, 194 are configured to contact the electrolyte stream. In this embodiment, the first electrochemical cell 1910 and the second electrochemical cell 1920 are arranged in a bipolar configuration, and the third electrochemical cell 1930 and the fourth electrochemical cell 1940 are also arranged in a bipolar configuration. Alternative embodiments in which the first electrochemical cell 1910 and the second electrochemical cell 1920 are arranged in a monopolar configuration and/or in which the third electrochemical cell 1930 and the fourth electrochemical cell 1940 are arranged in a monopolar configuration are also contemplated herein.

Referring still to FIGS. 19A and 19B, current, i, can be supplied to the first electromagnetic coil 1902 and the second electromagnetic coil 1904 from a current source (not shown) in the first rotational direction to provide a Helmholtz coil that generates a first magnetic field consistent with that shown in FIG. 13. Similarly, current, i, can be supplied to the second electromagnetic coil 1904 and the third electromagnetic coil 1906 from a current source (not shown) in the first rotational direction to provide a second Helmholtz coil that generates a second magnetic field consistent with that shown in FIG. 13. As evidenced by viewing FIGS. 19A and 19B in sequence, current can be supplied to the first electromagnetic coil 1902 and the second electromagnetic coil 1904 at a first time, and current can be supplied to the second electromagnetic coil 1904 and the third electromagnetic coil 1906 at a second time. Accordingly, in this embodiment, the second electromagnetic coil 1904 of the cell assembly 1900 may act in conjunction with the first electromagnetic coil 1902 as a component of the first Helmholtz coil at a first time and act in conjunction with the third electromagnetic coil 1906 as a component of the second Helmholtz coil at a second time. Accordingly, when the cell assembly 1900 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the first Helmholtz coil can be activated (by supplying current to the first electromagnetic coil 1902 and the second electromagnetic coil 1904 in the same direction) to direct and maintain iron-containing feedstock at the cathodes 1914, 1924 of the first electrochemical cell 1910 and the second electrochemical cell 1920. Similarly, when the cell assembly 1900 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the second Helmholtz coil can be activated (by supplying current to the second electromagnetic coil 1902 and third electromagnetic coil 1904 in the same direction) to direct and maintain iron-containing feedstock at the cathodes 1934, 1944 of the third electrochemical cell 1930 and the fourth electrochemical cell 1940. In operation, an electrochemical reactor including the cell assembly 1900 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1914, may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1924, may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1934, and may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 1944.

In some embodiments of the electrochemical reactors disclosed herein, the respective electromagnetic coils of the cell assemblies 1400, 1500, 1600, 1700, 1800, 1900 described above with reference to FIGS. 14-18, 19A, and 19B may serve as the first magnetic field source, the second magnetic field source, or an additional magnetic field source of the electrochemical reactor.

FIG. 20 is a perspective view of a first electromagnetic coil 2010 and a second electromagnetic coil 2020 arranged in an anti-Helmholtz coil configuration. In this regard, the first electromagnetic coil 2010 and the second electromagnetic coil 2020 are positioned along an axis, a, common to each other, are configured to receive current in opposite directions, have the same radius, r, (and thus the same diameter) and the same number of turns as each other, and are spaced apart a distance, d, equal to the radius, r. In this illustrative embodiment, the first electromagnetic coil 2010 and the second electromagnetic coil 2020 each have two turns. Of course, the number of turns in the first electromagnetic coil 2010 and the second electromagnetic coil 2020 can be adjusted to affect the magnetic field produced thereby and better accommodate different electrochemical cell configurations within an electrochemical reactor. The first electromagnetic coil 2010 is operably connected to a first current source 2030, such that the first current source 2030 can be activated to supply the first electromagnetic coil 2010 with current. The second electromagnetic coil 2020 is operably connected to a second current source 2040, such that the second current source 2040 can be activated to supply the second electromagnetic coil 2020 with current.

Referring still to FIG. 20, as shown, when the first electromagnetic coil 2010 and the second electromagnetic coil 2020 are supplied with equal amounts of current, i, in opposing directions, the first electromagnetic coil 2010 and the second electromagnetic coil 2020 generate opposing magnetic fields which crate a fairly uniform magnetic field gradient in an area between the first electromagnetic coil 2010 and the second electromagnetic coil 2020. In this illustrative embodiment, the first electromagnetic coil 2010 is provided current from the first current source 2030 in a first rotational direction (e.g., counterclockwise) and the second electromagnetic coil 2020 is provided current from the second current source 2040 in a second rotational direction (e.g., clockwise) that causes the first electromagnetic coil 2010 to generate a magnetic field with a left-to-right direction and the second electromagnetic coil 2020 to generate a magnetic field in a right-to-left direction. As further discussed below with reference to FIGS. 21-23, the magnetic field gradient generated by virtue of the first electromagnetic coil 2010 and the second electromagnetic coil 2020 while in an anti-Helmholtz coil configuration and supplied with current in opposing directions can be leveraged to help direct and maintain ore particles, such as iron ore particles, in proximity to the cathodes of electrochemical cells present in an electrochemical reactor.

It is appreciated, that the radii of the first electromagnetic coil 2010 and the second electromagnetic coil 2020, the number of turns in the first electromagnetic coil 2010 and the second electromagnetic coil 2020, and the distance between the first electromagnetic coil 2010 and the second electromagnetic coil 2020 can be adjusted to provide a magnetic field suitable for directing and maintaining ore particles in proximity to the cathodes of electrochemical cells present in an electrochemical reactor. In other words, the foregoing characteristics can be modified to accommodate different electrochemical reactor constructions and still provide an anti-Helmholtz coil that generates a magnetic field gradient consistent with that illustrated in FIG. 12.

FIG. 21 shows a schematic diagram of a cell assembly 2100, including: a first electromagnetic coil 2102; a second electromagnetic coil 2104; and an electrochemical cell 2105 positioned between the first electromagnetic coil 2102 and the second electromagnetic coil 2104. The first electromagnetic coil 2102 and the second electromagnetic coil 2104 are arranged in similar fashion as the first electromagnetic coil 2010 and the second electromagnetic coil 2020 of FIG. 20, and thus provide an anti-Helmholtz coil. The cell assembly 2100 can be implemented in and form part of an electrochemical reactor as provided herein. As shown, the electrochemical cell 2105 includes an anode 2110, a cathode 2120, and a separator 2130 positioned between anode 2110 and the cathode 2120. The cathode 2120 and the anode 210 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 2110 and the cathode 2120 are configured to contact the electrolyte stream. Current, i, can be supplied to the first electromagnetic coil 2102 from a current source (not shown) in the first rotational direction and current, i, can be supplied to the second electromagnetic coil 2104 in the second rotational direction to generate a magnetic field gradient consistent with that shown in FIG. 20. Accordingly, when the cell assembly 2100 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the magnetic field gradient generated by virtue of current being supplied to the first electromagnetic coil 2102 and the second electromagnetic coil 2104 in opposing directions serves to direct and maintain at least a portion of the iron-containing feedstock present in the electrochemical cell 2105 at the cathode 2120 of the electrochemical cell 2105. In operation, an electrochemical reactor including the cell assembly 2100 of FIG. 21 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 2120.

FIG. 22 shows a schematic diagram of a cell assembly 2200, including: a first electromagnetic coil 2202; a second electromagnetic coil 2204; and an electrochemical cell 2205 positioned between the first electromagnetic coil 2202 and the second electromagnetic coil 2204. The first electromagnetic coil 2202 and the second electromagnetic coil 2204 are arranged in similar fashion as the first electromagnetic coil 2010 and the second electromagnetic coil 2020 of FIG. 20, and thus provide an anti-Helmholtz coil. The cell assembly 2200 can be implemented in and form part of an electrochemical reactor as provided herein. As shown, the electrochemical cell 2205 includes an anode 2210, a cathode 2220, and a separator 2230 positioned between anode 2210 and the cathode 2220. The cathode 2220 and the anode 2210 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 2210 and the cathode 2220 are configured to contact the electrolyte stream. In this embodiment, the electrochemical cell 2205 is a zero-gap cell. Current, i, can be supplied to the first electromagnetic coil 2202 from a current source (not shown) in the first rotational direction and current, i, can be supplied to the second electromagnetic coil 2204 in the second rotational direction to generate a magnetic field gradient consistent with that shown in FIG. 20. Accordingly, when the cell assembly 2200 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the magnetic field gradient generated by virtue of current being supplied to the first electromagnetic coil 2202 and the second electromagnetic coil 2204 in opposing directions serves to direct and maintain at least a portion of the iron-containing feedstock present in the electrochemical cell 2205 at the cathode 2220 of the electrochemical cell 2205. In operation, an electrochemical reactor including the cell assembly 2200 of FIG. 22 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 2220.

FIG. 23 shows a schematic diagram of a cell assembly 2300 and a second cell assembly 2320, which can be implemented in and form part of an electrochemical reactor as provided herein. As indicated by the ellipsis in FIG. 23, in various embodiments, one or more components of the electrochemical reactor, such as additional cell assemblies, may be provided between the first cell assembly 2300 and the second cell assembly 2320. As shown, the first cell assembly 2300 includes: a first electromagnetic coil 2302; a second electromagnetic coil 2304; and a first electrochemical cell 2310 positioned between the first electromagnetic coil 2302 and the second electromagnetic coil 2304. The first electromagnetic coil 2302 and the second electromagnetic coil 2304 are arranged in similar fashion as the first electromagnetic coil 2010 and the second electromagnetic coil 2020 of FIG. 20, and thus provide a first anti-Helmholtz coil. The first electrochemical cell 2310 includes an anode 2312, a cathode 2314, and a separator 2316 positioned between the anode 2312 and the cathode 2314. The cathode 2314 and the anode 2312 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 2312 and the cathode 2314 are configured to contact the electrolyte stream. The second cell assembly 2320 includes: a third electromagnetic coil 2306; a fourth electromagnetic coil 2308; and a second electrochemical cell 2330 positioned between the third electromagnetic coil 2306 and the fourth electromagnetic coil 2308. The third electromagnetic coil 2306 and the fourth electromagnetic coil 2308 are arranged in similar fashion as the first electromagnetic coil 2010 and the second electromagnetic coil 2020 of FIG. 20, and thus provide a second Helmholtz coil. The second electrochemical cell 2330 includes an anode 2332, a cathode 2334, and a separator 2336 positioned between the anode 2332 and the cathode 2334. The cathode 2334 and the anode 2332 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anode 2332 and the cathode 2334 are configured to contact the electrolyte stream. In this embodiment, the first electrochemical cell 2310 and the second electrochemical cell 2330 are each arranged in a zero-gap configuration. It is appreciated, however, that alternative embodiments in which the first electrochemical cell 2310 and/or the second electrochemical cell 2330 are arranged in a non-zero-gap configuration are also contemplated herein.

Referring still to FIG. 23, current, i, can be supplied to the first electromagnetic coil 2302 from a current source (not shown) in the first rotational direction and current, i, can be supplied to the second electromagnetic coil 2304 in the second rotational direction by a current source (not shown) to generate a magnetic field gradient consistent with that shown in FIG. 20. Similarly, current, i, can be supplied to the third electromagnetic coil 2322 from a current source (not shown) in the first rotational direction and current, i, can be supplied to the fourth electromagnetic coil 2324 from a current source (not shown) in the second rotational direction to generate a magnetic field gradient consistent with that shown in FIG. 20. Accordingly, when the first cell assembly 2300 and the second cell assembly 2320 are implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the first anti-Helmholtz coil provided by the first electromagnetic coil 2302 and the second electromagnetic coil 2304 and the second Helmholtz coil provided by the third electromagnetic coil 2322 and the fourth electromagnetic coil 2324 can be selectively activated (by supplying current to the electromagnetic coils defining the first anti-Helmholtz coil and the second anti-Helmholtz coil) to direct and maintain iron-containing feedstock at the cathode 2314 of the first cell assembly 2300 and the cathode 2334 of the second cell assembly 2320.

FIG. 24 shows a schematic diagram of a cell assembly 2400 which can be implemented in and form part of an electrochemical reactor as provided herein. The cell assembly 2400 includes: a first electromagnetic coil 2402; a second electromagnetic coil 2404; first electrochemical cell 2410 positioned between the first electromagnetic coil 2402 and the second electromagnetic coil 2404; a third electromagnetic coil 2406; and a second electrochemical cell positioned between the second electromagnetic coil 2404 and the third electromagnetic coil 2406. The first electromagnetic coil 2402 and the second electromagnetic coil 2404 are arranged in similar fashion as the first electromagnetic coil 1210 and the second electromagnetic coil 1220 of FIG. 12, and thus provide a Helmholtz coil. The second electromagnetic coil 2404 and the third electromagnetic coil 2406 are arranged in similar fashion as the first electromagnetic coil 2010 and the second electromagnetic coil 2020 of FIG. 20, and thus provide an anti-Helmholtz coil. The first electrochemical cell 2410 and the second electrochemical cell 2420 each include: an anode 2412, 2422; a cathode 2414, 2424; and a separator 2416, 2426 positioned between the anode 2412, 2422 and the cathode 2414, 2424. The cathodes 2414, 2424 and the anodes 2412, 2422 of the electrochemical cells 2410, 2420 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the cathodes 2414, 2424 and the anodes 2412, 2422 are configured to contact the electrolyte stream. In this embodiment, the first electrochemical cell 2410 and the second electrochemical cell 2420 are each arranged in a zero-gap configuration. It is appreciated, however, that alternative embodiments in which the first electrochemical cell 2410 and/or the second electrochemical cell 2420 are arranged in a non-zero-gap configuration are also contemplated herein.

Referring still to FIG. 24, current, i, can be supplied to the first electromagnetic coil 2402 and the second electromagnetic coil 2404 from a current source (not shown) in the first rotational direction to generate a magnetic field consistent with that shown in FIG. 13. Current, i, can be supplied to the second electromagnetic coil 2404 from current source (not shown) in the first rotational direction while current, i, is also supplied to the third electromagnetic coil 2406 from a current source (not shown) in the second rotational direction to generate a magnetic field gradient consistent with that shown in FIG. 20. In some embodiments and implementations, the first electromagnetic coil 2402 and the second electromagnetic coil 2404 are supplied current, i, at a first time when the third electromagnetic coil 2406 is not supplied with current, and the second electromagnetic coil 2404 and the third electromagnetic coil 2406 are supplied with current at a second time when the first electromagnetic coil 2402 is not supplied with current. Accordingly, in this embodiment, the second electromagnetic coil 2404 of the cell assembly 2400 may act in conjunction with the first electromagnetic coil 2402 as a component of a Helmholtz coil at a first time and act in conjunction with the third electromagnetic coil 2406 as a component of an anti-Helmholtz coil at a second time. In some embodiments, the first electromagnetic coil 2402, the second electromagnetic coil 2404, and the third electromagnetic coil 2406 are each operably connected to a separate current source.

Referring still to FIG. 24, when the cell assembly 2400 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the Helmholtz coil can be activated (by supplying current to the first electromagnetic coil 2402 and the second electromagnetic coil 2404 with current in the same direction) to direct and maintain iron-containing feedstock at cathode 2414 of the first electrochemical cell 2410. Similarly, when the cell assembly 2400 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the anti-Helmholtz coil can be activated (by supplying the second electromagnetic coil 2404 and the third electromagnetic coil 2406 with current in opposing directions) to direct and maintain iron-containing feedstock at the cathode 2424 of the second electrochemical cell 2420. In operation, an electrochemical reactor including the cell assembly 2400 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 2414 and may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 2424 of the second electrochemical cell 2420.

Although the cell assemblies 2100, 2200, 2300, 2320, 2400 described above with reference to FIGS. 21-24 are illustrated as including only a single electrochemical cell between opposing electromagnetic coils, it should be appreciated that alternative embodiments in which one or more additional electrochemical cells are positioned between some or all of the opposing electromagnetic coils in some or all of the cell assemblies 2100, 2200, 2300, 2320, 2400 are also contemplated herein. Furthermore, in some embodiments of the electrochemical reactors disclosed herein, the respective electromagnetic coils of the cell assemblies 2100, 2200, 2300, 2320, 2400 described above with reference to FIGS. 21-24 may serve as the first magnetic field source, the second magnetic field source, or an additional magnetic field source of the electrochemical reactor.

FIG. 25 shows a perspective view of a first electromagnetic coil 2510, a second electromagnetic coil 2520, and a third electromagnetic coil 2530 arranged in a three-coil Maxwell coil configuration. In this regard, the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 are positioned along an axis, a, common to each other and are configured to receive current in the same direction. As shown, the first electromagnetic coil 2510 and the third electromagnetic coil 2530 have the same radius, r′, (and thus the same diameter) while the second electromagnetic coil has a larger radius, r. In this embodiment, the radii, r′, of the first electromagnetic coil 2510 and the third electromagnetic coil 2530 are each approximately equal to the radius, r, of the second electromagnetic coil 2520 multiplied by the square root of 4/7. As shown, the second electromagnetic coil 2520 is positioned between the first electromagnetic coil 2510 and the third electromagnetic coil 2530. In this embodiment, the first electromagnetic coil 2510 is spaced a distance, d₁, from the second electromagnetic coil 2520 that is approximately equal to the radius, r, of the second electromagnetic coil 2520 multiplied by the square root of 3/7. Similarly, in this embodiment, the third electromagnetic coil 2530 is spaced a distance, d₂, from the second electromagnetic coil 2520 that is approximately equal to the radius, r, of the second electromagnetic coil 2520 multiplied by the square root of 3/7.

Referring still to FIG. 25, it is appreciated that while the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 are each illustrated as having the same number of turns, in this case, that the number of turns present in the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 can be adjusted to affect the magnetic field produced thereby and better accommodate different electrochemical cell configurations within an electrochemical reactor. For instance, in some embodiments, the number of turns of the first electromagnetic coil 2510 and the third electromagnetic coil 2530 may be approximately equal to 49/64 of the second electromagnetic coil 2520. The first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 are operably connected to a current source 2540, such that the current source 2540 can be activated to supply the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 with current, which causes the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 to generate a magnetic field. In this illustrative embodiment, the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 are operably connected to the same current source 2540 in series. It is appreciated, however, that a three-coil Maxwell coil configuration can still be realized in instances where the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 are operably connected to multiple current sources. For instance, in some embodiments, the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 may each be operably connected to a separate current source.

FIG. 26 shows a schematic side view of the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 of FIG. 25 generating magnetic field in response to current being supplied to the second electromagnetic coil 2520, and the third electromagnetic coil 2530 in the same direction. Referring now to FIGS. 25 and 26, when the first electromagnetic coil 2510, the second electromagnetic coil 2520, and third electromagnetic coil 2530 are supplied with current, i, 2540 from the current source 2540 in the same direction. In this illustrative embodiment, the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 are each provided current in a first rotational direction (e.g., counterclockwise), as shown in FIG. 25, that causes the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 to generate a magnetic field with a left-to-right direction, as shown in FIG. 26. Of course, the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 can each alternatively be provided with current in a second rotational direction (e.g., clockwise) that is opposite of the first rotational direction to cause the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 to generate a magnetic field with a right-to-left direction. As further discussed below with reference to FIG. 27, the magnetic field generated by the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 while provided in a three-coil Maxwell coil arrangement and supplied with current in the same direction can be leveraged to help direct and maintain ore particles, such as iron ore particles, in proximity to the cathodes of electrochemical cells present in an electrochemical reactor.

It is appreciated, that the radii of the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530, the number of turns in the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530, the distance between the first electromagnetic coil 2510 and the second electromagnetic coil 2430 relative to the second electromagnetic coil 2520, and the direction in which current is applied to the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 can be adjusted to provide a magnetic field suitable for directing and maintaining ore particles in proximity to the cathodes of electrochemical cells present in an electrochemical reactor. In other words, the foregoing characteristics can be modified to accommodate different electrochemical reactor constructions and still provide a three-coil Maxwell coil that generates a magnetic field consistent with that illustrated in FIG. 26.

FIG. 27 shows a schematic diagram of a cell assembly 2700, including a first electromagnetic coil 2702; a second electromagnetic coil 2704; a third electromagnetic coil 2706; a first electrochemical cell 2710; a second electrochemical cell 2720; a first bipolar plate 2715 positioned between the first electrochemical cell 2710 and the second electrochemical cell 2720; a third electrochemical cell 2730; a fourth electrochemical cell 2740; and a second bipolar plate 2735 positioned between the third electrochemical cell 2730 and the fourth electrochemical cell. The first electromagnetic coil 2702, the second electromagnetic coil 2704, and the third electromagnetic coil 2706 are arranged in similar fashion as the first electromagnetic coil 2510, the second electromagnetic coil 2520, and the third electromagnetic coil 2530 in FIG. 25, and thus provide a three-coil Maxwell coil. The cell assembly 2700 can be implemented and form part of an electrochemical reactor as provided herein. As shown, each respective electrochemical cell 2710, 2720, 2730, 2740 of the cell assembly 2700 includes: an anode 2712, 2722, 2732, 2742; a cathode 2714; 2724; 2734; 2744; and a separator 2716, 2726, 2736, 2746 positioned between the anode 2712, 2722, 2732, 2742 and the cathode 2714, 2724, 2734, 2744. The cathodes 2714, 2724, 2734, 2744 and the anodes 2712, 2722, 2732, 2742 of the electrochemical cells 2710, 2720, 2730, 2740 are provided in a channel configured to contain an electrolyte stream that includes an iron-containing feedstock, wherein the anodes 2712, 2722, 2732, 2742 and the cathodes 2714, 2724, 2734, 2744 are configured to contact the electrolyte stream. In this embodiment, the first electrochemical cell 2710 and the second electrochemical cell 2720 are arranged in a bipolar configuration, and the third electrochemical cell 2730 and the fourth electrochemical cell 2740 are arranged in a bipolar configuration. It is appreciated, however, that alternative embodiments in which the first electrochemical cell 2710 and the second electrochemical cell 2720 are arranged in monopolar configuration and/or the third electrochemical cell 2730 and the fourth electrochemical cell 2740 are arranged in a monopolar configuration are also contemplated herein.

Referring still to FIG. 27, current, i, can be supplied to the first electromagnetic coil 2702, the second electromagnetic coil 2704, and the third electromagnetic coil 2706 from a current source (not shown) in the first rotational direction to generate a magnetic field consistent with that shown in FIG. 26. Accordingly, when the cell assembly 2700 is implemented in an electrochemical reactor as provided herein and the electrochemical reactor is in operation, the magnetic field generated by virtue of current being supplied to the first electromagnetic coil 2702, the second electromagnetic coil 2704, and the third electromagnetic coil 2706 in the first rotational direction serves to direct and maintain iron-containing feedstock at the cathodes 2714, 2724, 2734, 2744 of the cell assembly 2700. In operation, an electrochemical reactor including the cell assembly 2700 of FIG. 27 may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 2714, may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 2724, may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 2734, and may reduce at least a portion of the iron-containing feedstock to iron metal at cathode 2744.

FIG. 28 shows a perspective view of a first electromagnetic coil 2810 and a second electromagnetic coil 2820 arranged in a two-coil Maxwell coil configuration. In this regard, the first electromagnetic coil 2810 and the second electromagnetic coil 2820, are positioned along an axis, a, common to each other, are configured to receive current in opposing directions, have the same radius, r, (and thus diameter) and the same number of turns as each other, and are spaced apart a distance, d, that is greater than half diameter of the coils. In this embodiment, the distance, d, between the first electromagnetic coil 2810 and the second electromagnetic coil 2820 is approximately equal to the radius, r, multiplied by the square root of three. The first electromagnetic coil 2810 is operably connected to a first current source 2830, such that the first current source 2830 can be activated to supply the first electromagnetic coil 2810 with current, i. The second electromagnetic coil 2820 is operably connected to a second current source 2840, such that the second current source 2840 can be activated to supply the second electromagnetic coil 2820 with current, i.

Referring still to FIG. 28, in this illustrative embodiment, the first electromagnetic coil 2810 is provided current, i, from the first current source 2830 in a first rotational direction (e.g., counterclockwise) and the second electromagnetic coil 2820 is provided current, i, from the second current source 2840 in a second rotational direction (e.g., clockwise) that causes the first electromagnetic coil 2810 to generate a magnetic field with a left-to-right direction and the second electromagnetic coil 2820 to generate a magnetic field in a right-to-left direction. The magnetic field gradient generated by virtue of the first electromagnetic coil 2810 and the second electromagnetic coil 2820 while in a two-coil Maxwell coil configuration and supplied with current is thus similar to that illustrated in FIG. 20 and described above with reference to the cell assemblies 2100, 2200, 2300, 2330, 2400 utilizing one or more anti-Helmholtz coils. As such, cell assemblies including electromagnetic coils providing one or more two-coil Maxwell coils can be utilized in the same manner as the cell assemblies 2100, 2200, 2300, 2330, 2400 described above with reference to FIGS. 21-24 to help direct and maintain ore particles, such as iron ore particles, in proximity to the cathodes of electrochemical cells present in an electrochemical reactor.

It is appreciated, that the radii of the first electromagnetic coil 2810 and the second electromagnetic coil 2820, the number of turns in the first electromagnetic coil 2810 and the second electromagnetic coil 2820, and the distance between the first electromagnetic coil 2810 and the second electromagnetic coil 2820 can be adjusted to provide a magnetic field suitable for directing and maintaining ore particles in proximity to the cathodes of electrochemical cells present in an electrochemical reactor. In other words, the foregoing characteristics can be modified to accommodate different electrochemical reactor constructions and still provide a two-coil Maxwell coil that generates a magnetic field gradient similar to that illustrated in FIG. 20.

The cell assemblies 1400, 1500, 1600, 1700, 1800, 1830, 1900, 2100, 2200, 2300, 23202400, 2700 shown in FIGS. 14-18, 19A, 19B, 21-24, and 27 and described can be utilized in various combinations within an electrochemical reactor.

Although the electromagnetic coils of the cell assemblies 1400, 1500, 1600, 1700, 1800, 1830, 1900, 2100, 2200, 2300, 23202400, 2700 shown in FIGS. 14-18, 19A, 19B, 21-24, and 27 and described above are illustrated and/or described as being oriented in-line with the electrochemical cells of such cell assemblies, such that the electromagnetic coils and the electrochemical cells are arranged in a row, it is appreciated that electrochemical reactors including such cell assemblies and made in accordance with the present disclosure are not necessarily limited to such construction. Rather, in some embodiments, some or all of the electromagnetic coils in the cell assemblies may be disposed about an exterior of an electrochemical cell in the cell assembly and each electrochemical cell may be positioned along an axis common to each of the electromagnetic coils in the cell assembly.

In still other aspects, the magnet configurations may be used in other types of electrochemical cells, for example in a chlor-iron process.

The net reaction for the “chlor-iron” process is provided below in Equation 4 and is described herein (see also US Patent Publication No. 2023-0392272, the contents of which are incorporated herein by reference in its entirety). Also provided are the reactions occurring at the cathode (Equation 5) and the anode (Equation 6).

Fe₂O₃+6NaCl+3H₂O→2Fe+6NaOH+3Cl₂  [4]

6NaCl→3Cl₂+6Na⁺+6e⁻  [5]

Fe₂O₃+3H₂O+6e⁻→2Fe+6OH⁻  [6]

The chemistry and operating conditions of the chlor-alkali process is shown in FIG. 11A, and the chlor-iron process is shown in FIG. 11B. Both reactions can operate at 85 to 100° C., and using a NaCl brine at a pH of 2, and 30% NaOH. The two processes differ significantly in the reduction reaction at the negative electrode. Hydrogen evolution occurs in the chlor-alkali process, whereas the reduction of iron oxide to iron metal occurs in the chlor-iron process. The electrochemical unit is defined as the ratio of electrochemical products generated during the electrolysis reaction. The electrochemical unit can be indexed to metric tons of chlorine gas produced. For chlor-alkali, the electrochemical unit is approximately 1 metric ton of chlorine gas, 1.13 metric tons of alkali hydroxide, and 0.03 metric tons of hydrogen gas. The electrochemical unit for the chlor-iron process is approximately 1 metric ton of chlorine gas, 1.13 metric tons of alkali hydroxide, and 0.5 metric tons of iron metal.

In another aspect, a method of processing an iron-containing feedstock to produce iron metal is provided. The method includes flowing an electrolyte stream including the iron-containing feedstock through an electrochemical cell of an electrochemical reactor as described herein, applying a magnetic field at the cathode of the electrochemical cell, electrochemically reducing at least a portion of the iron-containing feedstock to produce the iron metal at the cathode while the magnetic field is applied at the cathode, and collecting the iron metal powder from the cathode using the electrolyte stream.

In some embodiments, the step of collecting may further include stopping the electrochemical reduction of the iron-containing feedstock, releasing or partially releasing the magnetic field from the cathode, and flushing the iron metal from the surface of the cathode using the electrolyte stream. For example, the step of stopping the electrochemical reduction may include substantially reducing a voltage applied to the cathode. In some embodiments, the step of stopping the electrochemical reduction may include stopping the applied voltage to the cathode. In some embodiments, the step of stopping the electrochemical reduction may include reducing the voltage applied to the cathode to stop the electrochemical reduction of the iron-containing feedstock.

A continuous flow of the electrolyte stream may be maintained through the electrochemical cell during the step of electrochemically reducing the iron-containing feedstock to the iron metal, which may maintain a substantially constant concentration of iron-containing feedstock species during the reduction step. Any non-reduced iron oxide and/or iron hydroxide species in the iron-containing feedstock of the electrolyte stream may be separated from the iron metal collected on the cathode current collector during the collecting step. The unreduced iron-containing feedstock in the electrolyte stream may be returned to an input electrolyte stream that feeds the electrochemical cell.

Still another aspect provides a method of processing an iron-containing feedstock to produce iron metal that includes continuously flowing an electrolyte stream including the iron-containing feedstock through a channel of an electrochemical cell as provided herein, wherein the electrochemical cell includes an anode and a cathode disposed in the channel. A magnetic field is applied at the cathode of the electrochemical cell, at least a portion of the iron-containing feedstock is electrochemically reduced to produce the iron metal on a surface of the cathode while the magnetic field is applied at the cathode, and the iron metal powder is collected from the surface of the cathode using the electrolyte stream.

The iron metal (for example, the iron powder) that is formed in the electrochemical cell may be harvested or collected from the surface of the cathode, for example, by releasing or partially releasing the magnetic field from the surface of the cathode. Any suitable method may be used to harvest the iron metal product from the cathode in accordance with various aspects. The optimal harvesting mechanism will depend largely on a number of interrelated factors, primarily current density, iron concentration in the electrolyte, electrolyte flow rate, and electrolyte temperature. Other contributing factors include the level of mixing within the electrochemical reactor, the frequency and duration of the harvesting method, and/or the presence and amount of any process additives (such as, for example, flocculant, surfactants, or the like).

In situ harvesting configurations, either by self-harvesting (described below) or by other in situ devices, may be desirable to minimize or avoid the need to remove and handle cathodes to facilitate the removal of iron metal from the electrochemical cell. Moreover, in situ harvesting configurations may advantageously permit the use of fixed electrode cell designs. As such, any number of mechanisms and configurations may be used.

Examples of possible harvesting mechanisms include vibration (e.g., one or more vibration and/or impact devices affixed to one or more cathodes to displace iron metal from the cathode surface at predetermined time intervals), a pulse flow system (e.g., electrolyte flow rate increased dramatically for a short time to displace iron metal from the cathode surface), use of a pulsed power supply to the cell, use of ultrasonic waves, and/or use of other mechanical displacement means to remove iron metal from the cathode surface, such as intermittent or continuous air bubbles. Alternatively, under some conditions, “self-harvest” or “dynamic harvest” may be achievable, when the electrolyte flow rate is sufficient to displace iron metal from the cathode surface as it is formed, or shortly after reduction occurs.

In accordance with an aspect of an exemplary embodiment, an electrolyte mixture that includes an iron metal slurry from the channel may be subjected to an apparatus for separating at least a portion of the electrolyte from the iron metal, such as, for example, a clarifier, a spiral classifier, other screw-type devices, a countercurrent decantation (CCD) circuit, a thickener, a filter, a conveyor-type device, a gravity separation device, a magnet, or other suitable apparatus.

An embodiment provides an electrochemical reactor that includes a first magnetic field source; a second magnetic field source; a plurality of electrochemical cells between the first magnetic field source and the second magnetic field source, each electrochemical cell comprising an anode and a cathode; and a bipolar plate between each adjacent pair of electrochemical cells, each bipolar plate comprising an anode plate in electrical contact with the anode of a first electrochemical cell; and a cathode plate in electrical contact with the cathode of a second electrochemical cell, wherein the first electrochemical cell and the second electrochemical cell are adjacent, wherein the anode and the cathode of each electrochemical cell are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, and wherein the anode and the cathode of each of the electrochemical cells are configured to contact the electrolyte stream, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each electrochemical cell and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

An embodiment provides an electrochemical reactor that includes a first magnetic field source; a second magnetic field source; a plurality of electrochemical cells between the first magnetic field source and the second magnetic field source, each electrochemical cell comprising an anode and a cathode; and a bipolar plate between each adjacent pair of electrochemical cells, each bipolar plate comprising an anode plate in electrical contact with the anode of a first electrochemical cell; and a cathode plate in electrical contact with the cathode of a second electrochemical cell, wherein the first electrochemical cell and the second electrochemical cell are adjacent, wherein one or more of the bipolar plates further comprises a bipolar magnetic field source between adjacent anode and cathode plates, wherein the anode and the cathode of each electrochemical cell are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, and wherein the anode and the cathode of each of the electrochemical cells are configured to contact the electrolyte stream, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each electrochemical cell and in a magnetic field provided by the first magnetic field source, the second magnetic field source, the one or more bipolar magnetic field sources, or a combination thereof.

An embodiment provide an electrochemical reactor that includes a first magnetic field source; a second magnetic field source; and a plurality of electrochemical cells between the first magnetic field source and the second magnetic field source, each electrochemical cell comprising an anode and a cathode, wherein the anode and the cathode of each electrochemical cell are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, and wherein the anode and the cathode of each of the electrochemical cells are configured to contact the electrolyte stream, wherein adjacent electrochemical cells are arranged in a monopolar configuration such that the anodes of adjacent cells are adjacent and the cathodes of adjacent cells are adjacent, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each electrochemical cell and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

An embodiment provide an electrochemical reactor that includes a first magnetic field source; a second magnetic field source; a plurality of electrochemical cells between the first magnetic field source and the second magnetic field source, each electrochemical cell comprising an anode and a cathode; one or more monopolar magnetic field sources between adjacent electrochemical cells, wherein the anode and the cathode of each electrochemical cell are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, and wherein the anode and the cathode of each of the electrochemical cells are configured to contact the electrolyte stream, wherein adjacent electrochemical cells are arranged in a monopolar configuration such that the anodes of adjacent cells are adjacent and the cathodes of adjacent cells are adjacent, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each electrochemical cell and in a magnetic field provided by the first magnetic field source, the second magnetic field source, the one or more monopolar magnetic field sources, or a combination thereof.

An embodiment provide an electrochemical reactor that includes a first magnetic field source; a second magnetic field source; a terminal cathode proximate the first magnetic field source; a terminal anode proximate the second magnetic field source; and a bipolar cell assembly between the first magnetic field source and the second magnetic field source, wherein the bipolar cell assembly comprises an anode proximate to the first magnetic field source, a cathode opposite the cathode, a bipolar plate on a side of the anode opposite the cathode, wherein the cathode and the anode are in a channel configured to contain an electrolyte stream comprising an electrolyte and an iron-containing feedstock, and wherein the cathode and the anode are configured to contact the electrolyte stream, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

An embodiment provide an electrochemical reactor that includes a first magnetic field source; a second magnetic field source; a terminal cathode proximate the first magnetic field source; a terminal anode proximate the second magnetic field source; and a monopolar cell assembly between the first magnetic field source and the second magnetic field source, wherein the monopolar cell assembly comprises a cathode, an anode, wherein the cathode and the anode are in a channel configured to contain an electrolyte stream comprising an electrolyte and an iron-containing feedstock, and wherein the cathode and the anode are configured to contact the electrolyte stream, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

This disclosure further encompasses the following aspects.

Aspect 1. An electrochemical reactor including a first magnetic field source; a second magnetic field source; and an electrochemical cell between the first magnetic field source and the second magnetic field source, the electrochemical cell comprising an anode and a cathode. The anode and the cathode are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, and wherein the anode and the cathode are configured to contact the electrolyte stream. The electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

Aspect 2. The electrochemical reactor of aspect 1, wherein the first magnet component and the second magnet component are each independently a field generating device.

Aspect 3. The electrochemical reactor of aspect 1 or 2, wherein the first magnet component and the second magnet component each independently comprises a permanent magnet, an electromagnet, or an electropermanent magnet.

Aspect 4. The electrochemical reactor of any of aspects 1 to 3, wherein the magnetic field has a magnetic flux density of at least 250 gauss, preferably 1000 gauss to 10,000 gauss, and more preferably 1,000 gauss to 5,000 gauss.

Aspect 5. The electrochemical reactor of any of aspects 1 to 3, wherein the magnetic field has a gradient ranging from 0.1 to 1×10⁶ gauss per meter.

Aspect 6. The electrochemical reactor of any of aspects 1 to 5, wherein the first magnet component and the second magnet component are each an electromagnetic coil and are arranged in a Helmholtz coil configuration.

Aspect 7. The electrochemical reactor of any of aspects 1 to 5, wherein the first magnet component and the second magnet component are each an electromagnetic coil and are arranged in an anti-Helmholtz coil configuration.

Aspect 8. The electrochemical reactor of any of aspects 1 to 5, wherein the first magnetic field source and the second magnetic field source are each an electromagnetic coil and are arranged in a two-coil Maxwell coil configuration.

Aspect 9. The electrochemical reactor of any of aspects 1 to 5, wherein the first magnetic field source and the second magnetic field source are each an electromagnetic coil, and wherein an axis common to the first magnetic field source and the second magnetic field source is transverse to a surface of the cathode at which the at least a portion of the iron-containing feedstock is reduced to iron metal when the electrochemical reactor is in operation.

Aspect 10. The electrochemical reactor of aspect 1, wherein the first magnetic field source is a field generating device, and the second magnetic field source is a field propagating device.

Aspect 11. The electrochemical reactor of aspect 10, wherein the first magnetic field source comprises a permanent magnet, an electromagnet, or an electropermanent magnet.

Aspect 12. The electrochemical reactor of any of aspects 1 to 11, wherein the iron metal comprises an iron metal powder.

Aspect 13. The electrochemical reactor of any of aspects 1 to 12, wherein the iron-containing feedstock comprises hematite, maghemite, magnetite, goethite, limonite, pyrite, red mud, siderite, ankerite, turgite, bauxite, or a combination thereof.

Aspect 14. The electrochemical reactor of any of aspects 1 to 13, wherein the electrolyte stream comprises an aqueous solution of an alkali metal hydroxide, an organic hydroxide, or a combination thereof.

Aspect 15. The electrochemical reactor of aspect 14, wherein the alkali metal hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount of 20 to 50 weight percent, or 30 to 40 weight percent, based on a total weight of the aqueous solution.

Aspect 16. The electrochemical reactor of any of aspects 1 to 15, wherein the electrolyte stream comprises from 0.1 to 30 weight percent of the iron-containing feedstock, preferably 0.1 to 15 weight percent, more preferably 0.1 to 5 weight percent, based on a total weight of the electrolyte stream.

Aspect 17. The electrochemical reactor of any of aspects 1 to 16, wherein the electrochemical reactor is operated at a temperature of 50° C. to 140° C.

Aspect 18. The electrochemical reactor of any of aspects 1 to 17, wherein each cathode independently comprises aluminum, carbon, copper, molybdenum, nickel, titanium, iron, an alloy thereof, or a combination thereof.

Aspect 19. The electrochemical reactor of any of aspects 1 to 18, wherein each anode independently comprises carbon, titanium, lead, nickel, iron, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof.

Aspect 20. The electrochemical reactor of any of aspects 1 to 19, wherein the iron-containing feedstock is not subjected to electrochemical reduction before the electrochemical reduction in the magnetic field.

Aspect 21. The electrochemical reactor of any of aspects 1 to 20, wherein the channel is separated by a separator to provide a catholyte channel and an anolyte channel, the catholyte channel is configured to contain a catholyte stream comprising the iron-containing feedstock, and the anolyte channel is configured to contain an anolyte stream.

Aspect 22. The electrochemical reactor of aspect 21, wherein the catholyte stream comprises an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof.

Aspect 23. The electrochemical reactor of aspect 22, wherein the alkali metal hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount of 20 to 50 weight percent, or 30 to 40 weight percent, based on a total weight of the catholyte stream excluding the iron-containing feedstock.

Aspect 24. The electrochemical reactor of any of aspects 21 to 23, wherein the catholyte stream comprises from 0.1 to 30 weight percent of the iron-containing feedstock, based on a total weight of the catholyte stream.

Aspect 25. The electrochemical reactor of any of aspects 21 to 23, wherein the anolyte comprises an aqueous solution comprising a supporting electrolyte; and optionally a mineral acid.

Aspect 26. The electrochemical reactor of aspect 25, wherein the mineral acid comprises HCl, HNO₃, H₂SO₄, HClO₄, H₃PO₄, or a combination thereof.

Aspect 27. The electrochemical reactor of aspect 25 or 26, wherein the anolyte comprises the supporting electrolyte compound, and the supporting electrolyte compound comprises a compound of the formula MClO₄, MNO₃, M₂SO₄, MF, MCl, MBr, MI, or a combination thereof, wherein M is Li, Na, or K, or tetra-n-butylammonium X, wherein X is F, Cl, Br, I, or hexafluorophosphate, or a combination thereof.

Aspect 28. The electrochemical reactor of any of aspects 21 to 27, wherein at least one of the anode or the cathode is directly in contact with the separator.

Aspect 29. The electrochemical reactor of any of aspects 21 to 27, wherein a first distance between a surface of the anode and the separator is 0.001 cm to 2 cm; a second distance between a surface of the cathode and the separator is 0.001 cm to 2 cm; or a combination thereof.

Aspect 30. The electrochemical reactor of any of aspects 1 to 29, wherein the electrochemical cell is a plurality of electrochemical cells between the first magnetic field source and the second magnetic field source.

Aspect 31. The electrochemical reactor of aspect 30, wherein the plurality of electrochemical cells comprises 2 to 500 electrochemical cells, preferably 5 to 200 electrochemical cells, or 50 to 170 electrochemical cells.

Aspect 32. The electrochemical reactor of any of aspects 30 or 31, further comprising a bipolar plate between a pair of adjacent electrochemical cells.

Aspect 33. The electrochemical reactor of aspect 32, comprising (n−1) bipolar plates, wherein n is the number of electrochemical cells in the plurality of electrochemical cells.

Aspect 34. The electrochemical reactor of aspect 32 or 33, wherein the bipolar plate comprises: an anode side in electrical contact with an anode of a first electrochemical cell; and a cathode side in electrical contact with a cathode of a second electrochemical cell, wherein the first electrochemical cell and the second electrochemical cell are adjacent.

Aspect 35. The electrochemical reactor of any of aspects 32 to 34, wherein the plurality of electrochemical cells are connected in series and configured to have a reactor potential applied between a cathode of an initial electrochemical cell and an anode of a final electrochemical cell, wherein the reactor potential is a cell potential multiplied by n, wherein n is a number of electrochemical cells in the plurality of electrochemical cells.

Aspect 36. The electrochemical reactor of any of aspects 32 to 35, wherein an additional magnetic field source is disposed between adjacent electrochemical cells, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each of the electrochemical cells and in a magnetic field provided by the first magnetic field source, the second magnetic field source, the additional magnetic field source, or a combination thereof.

Aspect 37. The electrochemical reactor of aspect 36, comprising (n/m−1) additional magnetic field sources, wherein m is a number of the electrochemical cells that are influenced by the magnetic field provided by a single pair of magnetic field sources, preferably wherein m is an integer from 1 to 10, and wherein n is a number of electrochemical cells in the plurality of electrochemical cells.

Aspect 38. The electrochemical reactor of aspect 30 or 31, wherein adjacent electrochemical cells are arranged in a monopolar configuration such that the anodes of adjacent cells are adjacent and the cathodes of adjacent cells are adjacent.

Aspect 39. The electrochemical reactor of aspect 38, wherein the plurality of electrochemical cells are connected in parallel and configured to have a same cell potential applied between the cathode and the anode of each electrochemical cell.

Aspect 40. The electrochemical reactor of aspect 38 or 39, further comprising one or more additional magnetic field sources disposed between adjacent electrochemical cells, wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each of the electrochemical cells and in a magnetic field provided by the first magnetic field source, the second magnetic field source, the one or more additional magnetic field sources, or a combination thereof.

Aspect 41. The electrochemical reactor of aspect 40, comprising (n/m−1) additional magnetic field sources, wherein n is a number of electrochemical cells in the plurality of electrochemical cells; and m is a number of the electrochemical cells that are influenced by the magnetic field provided by a single pair of magnetic field sources, preferably wherein m is an integer from 1 to 10.

Aspect 42. The electrochemical reactor of aspect 36 or 37, wherein each additional magnetic field source is independently a field generating device or a field propagating device.

Aspect 43. The electrochemical reactor of aspect 42, wherein each additional magnetic field source independently comprises a permanent magnet, an electromagnet, or an electropermanent magnet.

Aspect 44. The electrochemical reactor of aspect 43, wherein an additional magnetic field sources and at least one of the first electromagnetic field source and the second electromagnetic field source are an electromagnetic coils, and wherein the additional magnetic field source and the at least one of the first electromagnetic field source and the second electromagnetic field source are arranged in a Helmholtz coil configuration, an anti-Helmholtz coil configuration, a two-coil Maxwell coil configuration, or a three-coil Maxwell coil configuration.

Aspect 45. The electrochemical reactor of aspect 43, further including a first additional magnetic field source and a second additional magnetic field source.

Aspect 46. The electrochemical reactor of aspect 45, wherein the first additional magnetic field source and the second additional magnetic field source are each an electromagnetic coil.

Aspect 47. The electrochemical reactor of aspect 46, wherein the first additional magnetic field source and the second additional magnetic field source are arranged in a Helmholtz coil configuration, an anti-Helmholtz coil configuration, or a two-coil Maxwell coil configuration.

Aspect 48. The electrochemical reactor of aspect 46, wherein the first additional magnetic field source, the second additional magnetic field source, and one of the first electromagnetic field source and the second electromagnetic field source are arranged in a three-coil Maxwell coil configuration, and wherein the one of the first electromagnetic field source and the second electromagnetic field source is an electromagnetic coil.

Aspect 49. The electrochemical reactor of any of aspects 44 or 46-48, wherein an axis common to each electromagnetic coil present in the electrochemical reactor is transverse to a surface of the cathode of the electrochemical cell at which the at least a portion of the iron-containing feedstock is reduced to iron metal when the electrochemical reactor is in operation.

Aspect 50. The electrochemical reactor of aspect 40 or 41, wherein each additional magnetic field source is independently a field generating device or a field propagating device.

Aspect 51. The electrochemical reactor of aspect 50, wherein each additional magnetic field source is independently a permanent magnet, an electromagnet, or an electropermanent magnet.

Aspect 52. The electrochemical reactor of aspect 51, wherein an additional magnetic field source and at least one of the first electromagnetic field source and the second electromagnetic field source are electromagnetic coils, and wherein the additional magnetic field source and the at least one of the first electromagnetic field source and the second electromagnetic field source are arranged in a Helmholtz coil configuration, an anti-Helmholtz coil configuration, a two-coil Maxwell coil configuration, or a three-coil Maxwell coil configuration.

Aspect 53. The electrochemical reactor of aspect 51, comprising a first additional magnetic field source and a second additional magnetic field source.

Aspect 54. The electrochemical reactor of aspect 53, wherein the first additional magnetic field source and the second additional magnetic field source are each an electromagnetic coil.

Aspect 55. The electrochemical reactor of aspect 54, wherein the first additional magnetic field source and the second additional magnetic field source are arranged in a Helmholtz coil configuration, an anti-Helmholtz coil configuration, or a two-coil Maxwell coil configuration.

Aspect 56. The electrochemical reactor of aspect 54, wherein the first additional magnetic field source, the second additional magnetic field source, and one of the first electromagnetic field source and the second electromagnetic field source are arranged in a three-coil Maxwell coil configuration, and wherein the one of the first electromagnetic field source and the second electromagnetic field source is an electromagnetic coil.

Aspect 57. The electrochemical reactor of any of aspects 52 or 54 to 56, wherein an axis common to each electromagnetic coil present in the electrochemical reactor is transverse to a surface of the cathode of the electrochemical cell at which the at least a portion of the iron-containing feedstock is reduced to iron metal when the electrochemical reactor is in operation.

Aspect 58. An electrochemical reactor, including an electrochemical cell including an anode and a cathode; and at least one electromagnetic coil disposed adjacent to the electrochemical cell, wherein the anode and the cathode are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, wherein the anode and the cathode are configured to contact the electrolyte stream, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the at least one electromagnetic coil.

Aspect 59. The electrochemical reactor of aspect 58, wherein the magnetic field has a magnetic flux density of at least 250 gauss, preferably 1000 gauss to 10,000 gauss, and more preferably 1,000 gauss to 5,000 gauss.

Aspect 60. The electrochemical reactor of aspect 58 or 59, wherein the magnetic field has a gradient ranging from 0.1 to 1×10⁶ gauss per meter.

Aspect 61. The electrochemical reactor of any of aspect 58 to 60, wherein a first electromagnetic coil of the plurality of electromagnetic coils and a second electromagnetic coil of the plurality of electromagnet coils are arranged in a Helmholtz coil configuration.

Aspect 62. The electrochemical reactor of any of aspects 58 to 60, wherein a first electromagnetic coil of the plurality of electromagnetic coils and a second electromagnetic coil of the plurality of electromagnet coils are in an anti-Helmholtz coil configuration.

Aspect 63. The electrochemical reactor of any of aspects 58 to 60, wherein a first electromagnetic coil of the plurality of electromagnetic coils, a second electromagnetic coil of the plurality of electromagnetic coils, and a third electromagnetic coil of the plurality of electromagnetic coils are in a three-coil Maxwell coil configuration.

Aspect 64. The electrochemical reactor of any of aspects 58 to 60, wherein a first electromagnetic coil of the plurality of electromagnetic coils and a second electromagnetic coil of the plurality of electromagnetic coils are in a two-coil Maxwell coil configuration.

Aspect 65. The electrochemical reactor of any of aspects 58 to 64, wherein the iron metal comprises an iron metal powder.

Aspect 66. The electrochemical reactor of any of aspects 58 to 64, wherein the iron-containing feedstock comprises hematite, maghemite, magnetite, goethite, limonite, pyrite, red mud, siderite, ankerite, turgite, bauxite, or a combination thereof.

Aspect 67. The electrochemical reactor of any of aspects 58 to 66, wherein the electrolyte stream comprises an aqueous solution of an alkali metal hydroxide, an organic hydroxide, or a combination thereof.

Aspect 68. The electrochemical reactor of aspect 67, wherein the alkali metal hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount from 20 to 50 weight percent, based on a total weight of the aqueous solution.

Aspect 69. The electrochemical reactor of any of aspects 58 to 68, wherein the electrolyte stream comprises from 0.1 to 30 weight percent of the iron-containing feedstock, based on a total weight of the electrolyte stream.

Aspect 70. The electrochemical reactor of any of aspects 58 to 69, wherein the electrochemical reactor is configured for operation at a temperature of 50° C. to 140° C.

Aspect 71. The electrochemical reactor of any of aspects 58 to 70, wherein each cathode independently comprises aluminum, carbon, copper, molybdenum, nickel, titanium, iron, an alloy thereof, or a combination thereof.

Aspect 72. The electrochemical reactor of any of aspects 58 to 71, wherein each anode independently comprises carbon, titanium, lead, nickel, iron, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof.

Aspect 73. The electrochemical reactor of any of aspects 58 to 72, wherein the iron-containing feedstock is not subjected to electrochemical reduction before the electrochemical reduction in the magnetic field.

Aspect 74. The electrochemical reactor of any of aspects 58 to 73, wherein the channel is separated by a separator to provide a catholyte channel and an anolyte channel, the catholyte channel is configured to contain a catholyte stream comprising the iron-containing feedstock, and the anolyte channel is configured to contain an anolyte stream.

Aspect 75. The electrochemical reactor of aspect 74, wherein the catholyte stream comprises an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof.

Aspect 76. The electrochemical reactor of aspect 75, wherein the alkali metal hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount from 20 to 50 weight percent, based on a total weight of the catholyte stream excluding the iron-containing feedstock.

Aspect 77. The electrochemical reactor of aspect 75 or 76, wherein the catholyte stream comprises from 0.1 to 30 weight percent of the iron-containing feedstock, based on a total weight of the catholyte stream.

Aspect 78. The electrochemical reactor of any of aspects 74 to 77, wherein the anolyte comprises an aqueous solution comprising a supporting electrolyte compound; and optionally a mineral acid.

Aspect 79. The electrochemical reactor of aspect 78, wherein the mineral acid comprises HCl, HNO₃, H₂SO₄, HClO₄, H₃PO₄, or a combination thereof.

Aspect 80. The electrochemical reactor of aspect 78 or 79, wherein the anolyte comprises the supporting electrolyte compound, and the supporting electrolyte compound comprises a compound of the formula MClO₄, MNO₃, M₂SO₄, MF, MCi, MBr, MI, or a combination thereof, wherein M is Li, Na, or K, or tetra-n-butylammonium X, and wherein X is F, Cl, Br, I, or hexafluorophosphate.

Aspect 81. The electrochemical reactor of any of aspects 74 to 80, wherein at least one of the anode or the cathode is directly on the separator.

Aspect 82. The electrochemical reactor of any of aspects 74 to 81, wherein a first distance between a surface of the anode and the separator is 0.001 cm to 2 cm; a second distance between a surface of the cathode and the separator is 0.001 cm to 2 cm; or a combination thereof.

Aspect 83. The electrochemical reactor of any of aspects 58 to 82, wherein the electrochemical cell is a plurality of electrochemical cells, and wherein the plurality of electromagnetic coils are disposed around the plurality of electrochemical cells.

Aspect 84. The electrochemical reactor of aspect 83, wherein the plurality of electrochemical cells comprises 2 to 500 electrochemical cells, preferably 5 to 200 electrochemical cells, or 50 to 170 electrochemical cells.

Aspect 85. The electrochemical reactor of any of aspects 83 or 84, further comprising a bipolar plate between a pair of adjacent electrochemical cells.

Aspect 86. The electrochemical reactor of aspect 85, comprising (n−1) bipolar plates, wherein n is a number of electrochemical cells in the plurality of electrochemical cells.

Aspect 87. The electrochemical reactor of aspect 85 or 86, wherein the bipolar plate comprises: an anode side in electrical contact with the anode of a first electrochemical cell; and a cathode side in electrical contact with the cathode of a second electrochemical cell, wherein the first electrochemical cell and the second electrochemical cell are adjacent.

Aspect 88. The electrochemical reactor of any of aspects 85 to 87, wherein the plurality of electrochemical cells are connected in series and configured to have a reactor potential applied between a cathode of an initial electrochemical cell and an anode of a final electrochemical cell, wherein the reactor potential is a cell potential multiplied by n.

Aspect 89. The electrochemical reactor of any of aspects 83 or 84, wherein adjacent electrochemical cells are in a monopolar configuration such that the anodes of adjacent cells are adjacent and the cathodes of adjacent cells are adjacent.

Aspect 90. The electrochemical reactor of aspect 89, wherein the plurality of electrochemical cells are connected in parallel and configured to have a same cell potential applied between the cathode and the anode of each electrochemical cell.

Aspect 91. The electrochemical cell of any of aspects 58 to 90, wherein the electrochemical cell is disposed along an axis common to the plurality of electromagnetic coils.

Aspect 92. A method of processing an iron-containing feedstock to produce iron metal, the method including flowing the electrolyte stream comprising the iron-containing feedstock through an electrochemical cell of the electrochemical reactor of any of aspects 1 to 91; applying a magnetic field at the cathode of the electrochemical cell; electrochemically reducing at least a portion of the iron-containing feedstock to produce the iron metal at the cathode while the magnetic field is applied at the cathode; and collecting the iron metal- to produce the iron metal, wherein the iron metal is optionally a powder.

Aspect 93. The method of aspect 92, wherein the step of collecting further comprises stopping the electrochemical reduction of the iron-containing feedstock, releasing the magnetic field from the cathode, and flushing the iron metal from the cathode using the electrolyte stream.

Aspect 94. The method of aspect 92 or 93, wherein the iron-containing feedstock comprises iron in an oxidized state before the magnetic field is applied at the cathode.

Aspect 95. The method of any of aspects 92 to 94, wherein at least a portion of the iron-containing feedstock is reduced at the cathode while the magnetic field is applied to the cathode.

Aspect 96. The method of any of aspects 92 to 95, further including: transporting the electrolyte stream to a separation unit located downstream of the channel; separating at least a portion of the iron metal from the electrolyte stream; and recirculating the electrolyte stream to an upstream region of the channel.

Aspect 97. An iron metal produced by the method of any of aspects 92 to 96, wherein the iron metal has

• • a specific total embedded emissions of less than 0.8 tons of CO₂ per ton of the iron metal, when determined according to the European Union simplified bubble approach method for determining specific embedded emissions under the Carbon Border Adjustment Mechanism;
  • a carbon emission intensity of less than 1100 kilograms of CO₂ per ton of the iron metal, when determined according to ISO 14404; a carbon emission intensity of less than 800 kilograms of CO₂ per ton of the iron metal, when determined according to the Intergovernmental Panel on Climate Change Methodology 2006 Guidelines for National Greenhouse Gas Inventories;
  • a carbon emission intensity of less than 1500 kilograms of CO₂ per ton of the iron metal, when determined according to the 2017 World Steel Life Cycle Inventory Methodology;
  • a carbon emission intensity of less than 1300 kilograms of CO₂ per ton of the iron metal, when determined according to the 2008 World Resource Institute Iron and Steel Greenhouse Gas Protocol;
  • a carbon emission intensity of less than 750 kilograms of CO₂ per ton of the iron metal, when determined according to European Union Commission Implementing Regulation 2018/2066;
  • a specific total embedded emissions of less than 0 tons of CO₂ per ton of the iron metal, when determined according to the European Union simplified bubble approach method for determining specific embedded emissions under the Carbon Border Adjustment Mechanism; or
  • a combination thereof.

Aspect 98. An electrochemical reactor system including the electrochemical reactor of any of aspects 1 to 91; a feedstock handling system, wherein optionally the feedstock handling system comprises a mixing tank; and a product handling system, wherein the product handling system comprises a separation unit.

Aspect 99. A method of operating the electrochemical reactor system of aspect 98, including flowing the electrolyte stream comprising the iron-containing feedstock from the feedstock handling system to the electrochemical reactor; applying a magnetic field at the cathode of the electrochemical cell; electrochemically reducing at least a portion of the iron-containing feedstock to produce the iron metal at the cathode while the magnetic field is applied at the cathode; collecting the iron metal from the cathode by flowing the electrolyte stream to a product handling system; separating the iron metal from unreacted iron-containing feedstock in the separation unit to produce iron metal.

Aspect 100. The method of aspect 99, further including: flowing the unreacted iron-containing feedstock to the feedstock handling system; and treating the unreacted iron-containing feedstock in the feedstock handling system to provide a replenished electrolyte stream.

Aspect 101. The method of aspect 100, wherein the treating the unreacted iron-containing feedstock comprises mixing the unreacted iron-containing feedstock with a concentrated ore, adjusting a pH of the electrolyte stream, adjusting a temperature of the electrolyte stream, adding an electrolyte additive, adjusting a water content of the electrolyte stream, or a combination thereof.

Aspect 102. The method of aspects 100 or 101, further including recirculating the electrolyte stream from the feedstock handling system to the electrochemical reactor. The compositions, methods, and articles can alternatively comprise, consist of, or consist essentially of, any appropriate materials, steps, or components herein disclosed. The compositions, methods, and articles can additionally, or alternatively, be formulated to be devoid, or substantially free, of any materials (or species), steps, or components, which are otherwise not necessary to the achievement of the function or objectives of the compositions, methods, and articles.

All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of “up to 25 wt %, or, more specifically, 5 wt % to 20 wt %”, is inclusive of the endpoints and all intermediate values of the ranges of “5 wt % to 25 wt %,” etc.). “Combinations” is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms “first,” “second,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” and “the” do not denote a limitation of quantity and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. “Or” means “and/or” unless clearly stated otherwise. Reference throughout the specification to “some embodiments,” “an embodiment,” “an aspect,” and so forth, means that a particular element described in connection with the embodiment and/or aspect is included in at least one embodiment and/or aspect described herein, and may or may not be present in other embodiments and/or aspects. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments and/or aspects. A “combination thereof” is open and includes any combination comprising at least one of the listed components or properties optionally together with a like or equivalent component or property not listed.

Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art.

Claims

1. An electrochemical reactor, comprising: a first magnetic field source;a second magnetic field source; andan electrochemical cell between the first magnetic field source and the second magnetic field source, the electrochemical cell comprising an anode and a cathode,wherein the anode and the cathode are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, and wherein the anode and the cathode are configured to contact the electrolyte stream, andwherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the first magnetic field source, the second magnetic field source, or a combination thereof.

2. The electrochemical reactor of claim 1, wherein the first magnetic field source and the second magnetic field source are each independently a field generating device, wherein the first magnetic field source and the second magnetic field source each independently comprises a permanent magnet, an electromagnet, or an electropermanent magnet,wherein the magnetic field has a magnetic flux density of at least 250 gauss,wherein the magnetic field has a gradient ranging from 10 to 1×106 gauss per meter, ora combination thereof.

3.-5. (canceled)

6. The electrochemical reactor of claim 1, wherein the first magnetic field source and the second magnetic field source are each an electromagnetic coil and are arranged in a Helmholtz coil configuration, wherein the first magnetic field source and the second magnetic field source are each an electromagnetic coil and are arranged in an anti-Helmholtz coil configuration,wherein the first magnetic field source and the second magnetic field source are each an electromagnetic coil and are arranged in a two-coil Maxwell coil configuration, orwherein the first magnetic field source and the second magnetic field source are each an electromagnetic coil, and wherein an axis common to the first magnetic field source and the second magnetic field source is transverse to a surface of the cathode at which the at least a portion of the iron-containing feedstock is reduced to iron metal when the electrochemical reactor is in operation.

7.-9. (canceled)

10. The electrochemical reactor of claim 1, wherein the first magnetic field source is a field generating device, and the second magnetic field source is a field propagating device.

11. The electrochemical reactor of claim 10, wherein the first magnetic field source comprises a permanent magnet, an electromagnet, or an electropermanent magnet.

12. The electrochemical reactor of claim 1, wherein the iron metal comprises an iron metal powder,wherein the iron-containing feedstock comprises hematite, machemite, magnetite, goethite, limonite, pyrite, red mud, siderite, ankerite, turgite, bauxite, or a combination thereof,wherein the electrolyte stream comprises an aqueous solution of an alkali metal hydroxide, an organic hydroxide, or a combination thereof,wherein the electrolyte stream comprises an aqueous solution of an alkali metal hydroxide, an organic hydroxide, or a combination thereof and wherein the alkali metal hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount of 20 to 50 weight percent, or 30 to 40 weight percent, based on a total weight of the aqueous solution,wherein the electrolyte stream comprises from 0.1 to 30 weight percent of the iron-containing feedstock,wherein the electrochemical reactor is operated at a temperature of 50° C. to 140° C. or a combination thereof.

13.-17. (canceled)

18. The electrochemical reactor of claim 1, wherein each cathode independently comprises aluminum, carbon, copper, molybdenum, nickel, titanium, iron, an alloy thereof, or a combination thereof, wherein each anode independently comprises carbon, titanium, lead, nickel, iron, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof, ora combination thereof.

19. (canceled)

20. The electrochemical reactor of claim 1, wherein the iron-containing feedstock is not subjected to electrochemical reduction before the electrochemical reduction in the magnetic field.

21. The electrochemical reactor ofany of claim 1, wherein the channel is separated by a separator to provide a catholyte channel and an anolyte channel,the catholyte channel is configured to contain a catholyte stream comprising the iron-containing feedstock, andthe anolyte channel is configured to contain an anolyte stream.

22. The electrochemical reactor of claim 21, wherein the catholyte stream comprises an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof, wherein the catholyte stream comprises an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof and wherein the alkali metal hydroxide, the organic hydroxide, or the combination thereof is present in the aqueous solution in an amount of 20 to 50 weight percent, or 30 to 40 weight percent, based on a total weight of the catholyte stream excluding the iron-containing feedstock,wherein the catholyte stream comprises from 0.1 to 30 weight percent of the iron-containing feedstock, based on a total weight of the catholyte stream,wherein the anolyte comprises an aqueous solution comprising a mineral acid; and optionally a supporting electrolyte compound,wherein the anolyte comprises an aqueous solution comprising a mineral acid; andoptionally a supporting electrolyte compound and wherein the mineral acid comprises HCl, HNO3, H2SO4, HClO4, H3PO4, or a combination thereof,wherein the anolyte comprises a supporting electrolyte compound, and the supporting electrolyte compound comprises a compound of the formula MClO4, MNO3, M2SO4, MF, MCl, MBr, MI, or a combination thereof, wherein M is Li, Na, or K, or tetra-n-butylammonium X, wherein X is F, CI, Br, I, or hexafluorophosphate, or a combination thereof, ora combination thereof.

23.-27. (canceled)

28. The electrochemical reactor of claim 21, wherein at least one of the anode or the cathode is directly in contact with the separator, orwhereina first distance between a surface of the anode and the separator is 0.001 cm to 2 cm;a second distance between a surface of the cathode and the separator is 0.001 cm to 2 cm; ora combination thereof.

29. (canceled)

30. The electrochemical reactor of claim 1, wherein the electrochemical cell is a plurality of electrochemical cells between the first magnetic field source and the second magnetic field source, and wherein the plurality of electrochemical cells comprises 2 to 500 electrochemical cells.

31. (canceled)

32. The electrochemical reactor of claim 30, further comprising a bipolar plate between a pair of adjacent electrochemical cells.

33. The electrochemical reactor of claim 32, wherein the electrochemical reactor comprises (n−1) bipolar plates, wherein n is the number of electrochemical cells in the plurality of electrochemical cells,wherein the bipolar plate comprises:an anode side in electrical contact with an anode of a first electrochemical cell; anda cathode side in electrical contact with a cathode of a second electrochemical cell,wherein the first electrochemical cell and the second electrochemical cell are adjacent, ora combination thereof.

34. (canceled)

35. The electrochemical reactor of any of claim 32, wherein the plurality of electrochemical cells are connected in series and configured to have a reactor potential applied between a cathode of an initial electrochemical cell and an anode of a final electrochemical cell, wherein the reactor potential is a cell potential multiplied by n, wherein n is a number of electrochemical cells in the plurality of electrochemical cells.

36. The electrochemical reactor of claim 32, wherein an additional magnetic field source is disposed between adjacent electrochemical cells, and wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each of the electrochemical cells and in a magnetic field provided by the first magnetic field source, the second magnetic field source, the additional magnetic field source, or a combination thereof.

37. The electrochemical reactor of claim 36, comprising (n/m−1) additional magnetic field sources, wherein m is a number of the electrochemical cells that are influenced by the magnetic field provided by a single pair of magnetic field sources.

38. The electrochemical reactor of claim 30, wherein adjacent electrochemical cells are arranged in a monopolar configuration such that the anodes of adjacent cells are adjacent and the cathodes of adjacent cells are adjacent.

39. The electrochemical reactor of claim 38, wherein the plurality of electrochemical cells are connected in parallel and configured to have a same cell potential applied between the cathode and the anode of each electrochemical cell.

40. The electrochemical reactor of claim 38, further comprising one or more additional magnetic field sources disposed between adjacent electrochemical cells, wherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode of each of the electrochemical cells and in a magnetic field provided by the first magnetic field source, the second magnetic field source, the one or more additional magnetic field sources, or a combination thereof.

41. The electrochemical reactor of claim 40, comprising (n/m−1) additional magnetic field sources, wherein n is a number of electrochemical cells in the plurality of electrochemical cells; andm is a number of the electrochemical cells that are influenced by the magnetic field provided by a single pair of magnetic field sources.

42. The electrochemical reactor of claim 40, wherein each additional magnetic field source is independently a field generating device or a field propagating device, wherein each additional magnetic field source independently comprises a permanent magnet, an electromagnet, or an electropermanent magnet,wherein an additional magnetic field source and at least one of the first electromagnetic field source and the second electromagnetic field source are an electromagnetic coil, and wherein the additional magnetic field source and the at least one of the first electromagnetic field source and the second electromagnetic field source are arranged in a Helmholtz coil configuration, an anti-Helmholtz coil configuration, a two-coil Maxwell coil configuration, or a three-coil Maxwell coil configuration, ora combination thereof.

43. (canceled)

44. (canceled)

45. The electrochemical reactor of claim 36, further comprising a first additional magnetic field source and a second additional magnetic field source.

46. The electrochemical reactor of claim 45, wherein the first additional magnetic field source and the second additional magnetic field source are each an electromagnetic coil, wherein the first additional magnetic field source and the second additional magnetic field source are each an electromagnetic coil and wherein the first additional magnetic field source and the second additional magnetic field source are arranged in a Helmholtz coil configuration, an anti-Helmholtz coil configuration, or a two-coil Maxwell coil configuration, orwherein the first additional magnetic field source and the second additional magnetic field source are each an electromagnetic coil and wherein the first additional magnetic field source, the second additional magnetic field source, and one of the first electromagnetic field source and the second electromagnetic field source are arranged in a three-coil Maxwell coil configuration, and wherein the one of the first electromagnetic field source and the second electromagnetic field source is an electromagnetic coil.

47. (canceled)

48. (canceled)

49. The electrochemical reactor of claim 44, wherein an axis common to each electromagnetic coil present in the electrochemical reactor is transverse to a surface of the cathode of the electrochemical cell at which the at least a portion of the iron-containing feedstock is reduced to iron metal when the electrochemical reactor is in operation.

50.-57. (canceled)

58. An electrochemical reactor, comprising: an electrochemical cell comprising an anode and a cathode; andat least one electromagnetic coil disposed adjacent to the electrochemical cell,wherein the anode and the cathode are in a channel configured to contain an electrolyte stream comprising an iron-containing feedstock, wherein the anode and the cathode are configured to contact the electrolyte stream, andwherein the electrochemical reactor is configured to electrochemically reduce at least a portion of the iron-containing feedstock to iron metal at the cathode and in a magnetic field provided by the at least one electromagnetic coil.

59. The electrochemical reactor of claim 58, wherein the magnetic field has a magnetic flux density of at least 250 gauss, wherein the magnetic field has a gradient ranging from 10 to 1×106 gauss per meter,comprising a plurality of electromagnetic coils wherein a first electromagnetic coil of the plurality of electromagnetic coils and a second electromagnetic coil of the plurality of electromagnet coils are arranged in a Helmholtz coil configuration,comprising a plurality of electromagnetic coils wherein a first electromagnetic coil of the plurality of electromagnetic coils and a second electromagnetic coil of the plurality of electromagnet coils are in an anti-Helmholtz coil configuration,comprising a plurality of electromagnetic coils wherein a first electromagnetic coil of the plurality of electromagnetic coils and a second electromagnetic coil of the plurality of electromagnet coils are in an anti-Helmholtz coil configuration,comprising a plurality of electromagnetic coils wherein a first electromagnetic coil of the plurality of electromagnetic coils, a second electromagnetic coil of the plurality of electromagnetic coils, and a third electromagnetic coil of the plurality of electromagnetic coils are in a three-coil Maxwell coil configuration,comprising a plurality of electromagnetic coils wherein a first electromagnetic coil of the plurality of electromagnetic coils and a second electromagnetic coil of the plurality of electromagnetic coils are in a two-coil Maxwell coil configuration, ora combination thereof.

60.-73. (canceled)

74. The electrochemical reactor of claim 58, wherein the channel is separated by a separator to provide a catholyte channel and an anolyte channel,the catholyte channel is configured to contain a catholyte stream comprising the iron-containing feedstock, andthe anolyte channel is configured to contain an anolyte stream.

75.-82. (canceled)

83. The electrochemical reactor of claim 58, wherein the electrochemical cell is a plurality of electrochemical cells, wherein a plurality of electromagnetic coils are disposed around the plurality of electrochemical cells and wherein the plurality of electrochemical cells comprises 2 to 500 electrochemical cells, wherein the electrochemical cell is disposed along an axis common to a plurality of electromagnetic coils, ora combination thereof.

84.-91. (canceled)

92. A method of processing an iron-containing feedstock to produce iron metal, the method comprising: flowing the electrolyte stream comprising the iron-containing feedstock through an electrochemical cell of the electrochemical reactor of claim 1;applying a magnetic field at the cathode of the electrochemical cell;electrochemically reducing at least a portion of the iron-containing feedstock to produce the iron metal at the cathode while the magnetic field is applied at the cathode; andcollecting the iron metal to produce the iron metal, wherein the iron metal is optionally a powder.

93. The method of claim 92, wherein the step of collecting further comprises stopping the electrochemical reduction of the iron-containing feedstock,releasing the magnetic field from the cathode, andflushing the iron metal from the cathode using the electrolyte stream.

94. The method of claim 92, wherein the iron-containing feedstock comprises iron in an oxidized state before the magnetic field is applied at the cathode, wherein at least a portion of the iron-containing feedstock is reduced at the cathode while the magnetic field is applied to the cathode, ora combination thereof.

95. (canceled)

96. The method of claim 92, further comprising: transporting the electrolyte stream to a separation unit located downstream of the channel;separating at least a portion of the iron metal from the electrolyte stream; andrecirculating the electrolyte stream to an upstream region of the channel.

97. An iron metal produced by the method of claim 92, wherein the iron metal has a specific total embedded emissions of less than 0.8 tons of CO2 per ton of the iron metal, when determined according to the European Union simplified bubble approach method for determining specific embedded emissions under the Carbon Border Adjustment Mechanism;a carbon emission intensity of less than 1100 kilograms of CO2 per ton of the iron metal, when determined according to ISO 14404; a carbon emission intensity of less than 800 kilograms of CO2 per ton of the iron metal, when determined according to the Intergovernmental Panel on Climate Change Methodology 2006 Guidelines for National Greenhouse Gas Inventories;a carbon emission intensity of less than 1500 kilograms of CO2 per ton of the iron metal, when determined according to the 2017 World Steel Life Cycle Inventory Methodology;a carbon emission intensity of less than 1300 kilograms of CO2 per ton of the iron metal, when determined according to the 2008 World Resource Institute Iron and Steel Greenhouse Gas Protocol;a carbon emission intensity of less than 750 kilograms of CO2 per ton of the iron metal, when determined according to European Union Commission Implementing Regulation 2018/2066;a specific total embedded emissions of less than 0 tons of CO2 per ton of the iron metal, when determined according to the European Union simplified bubble approach method for determining specific embedded emissions under the Carbon Border Adjustment Mechanism; or a combination thereof.

98. An electrochemical reactor system comprising: the electrochemical reactor of claim 1;a feedstock handling system, wherein optionally the feedstock handling system comprises a mixing tank; anda product handling system, wherein the product handling system comprises a separation unit.

99. A method of operating the electrochemical reactor system of claim 98, comprising: flowing the electrolyte stream comprising the iron-containing feedstock from the feedstock handling system to the electrochemical reactor;applying a magnetic field at the cathode of the electrochemical cell;electrochemically reducing at least a portion of the iron-containing feedstock to produce the iron metal at the cathode while the magnetic field is applied at the cathode;collecting the iron metal from the cathode by flowing the electrolyte stream to a product handling system;separating the iron metal from unreacted iron-containing feedstock in the separation unit to produce iron metal.

100.-102. (canceled)