Patent Application
20250146155
The iron and 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 is the electrolytic reduction of iron oxide in alkaline solutions at moderate temperatures.
There remains a continuing need for improved systems and methods to produce iron metal from iron-containing feedstocks, such as iron ores.
An electrochemical reactor system includes: an electrochemical cell, having: an anode; a cathode disposed opposite the anode; an electrolyte stream contacting the cathode, the electrolyte stream including an electrolyte and an iron-containing feedstock including feedstock particles; and a channel that contains the electrolyte stream within the electrochemical cell; and a magnetic field source positioned to provide a magnetic field of at least one gauss, preferably 25 to 10,000 gauss, more preferably 300 to 3,000 gauss to the cathode, or to provide a magnetic field of 0.0025 to 1 Tesla, preferably 0.03 to 1 Tesla, more preferably 0.03 to 0.3 Tesla at the surface of the cathode, or a combination thereof. The electrochemical cell is configured to electrochemically reduce at least a portion of the iron-containing feedstock to form iron particles including iron metal at a surface of the cathode and in the magnetic field. The feedstock particles have an average particle size in at least one dimension of 10 micrometers or less, preferably 0.1 to 10 micrometers, and the iron particles have an average particle size in at least one dimension of 50 to 1,000 micrometers, preferably 50 to 200 micrometers, or the feedstock particles have an average particle size in at least one dimension of 25 micrometers or greater, preferably 25 to 500 micrometers, and the iron particles have an average particle size in at least one dimension of 0.1 to 20 micrometers, preferably 0.1 to 10 micrometers.
A method of processing an iron-containing feedstock to produce iron particle includes: providing an above described electrochemical rector system; flowing the electrolyte stream through the channel or the catholyte channel of the electrochemical cell; applying the magnetic field to the cathode; and electrochemically reducing at least a portion of the iron-containing feedstock in the magnetic field to produce the iron particles at the surface of the cathode.
The following figures are exemplary embodiments, where like elements are numbered alike.
The present subject matter relates to an electrochemical reactor system and a corresponding method for producing iron metal from an iron-containing feedstock. In particular, the disclosed subject matter provides for an electrochemical reactor system and a corresponding method for the production of iron metal particles through the reduction of an iron-containing feedstock comprising feedstock particles (preferably solid feedstock particles) by an electrolysis reaction. The produced iron metal particles may be removed from an electrochemical cell before all the feedstock particles are reduced. While the unreduced feedstock particles may be separated from the produced iron metal particles via magnetic separation so that the unreduced feedstock particles can be recycled for further reduction cycles, there is a continuing need for improved system and method that allow for more efficient separation of the produced iron metal particles from the feedstock particles that are not reduced during a reduction cycle.
The inventors have discovered that the particle size of the iron-containing feedstock influences the particle size of the iron metal produced via electrolysis as described herein. In particular, the inventors have found that by controlling the particle size of the starting feedstock, iron metal produced through alkaline electrolysis can have distinct sizes and morphology compared to the starting feedstock particles. The discovery can allow for a separation based on particle size to harvest iron metal powder from solution while enabling recirculation of unreduced feedstock.
As used herein, an electrochemical reactor system can refer to a system that includes a unit such as an electrochemical cell where electrochemical reactions occur and optionally other units (e.g. separation units) that do not involve any electrochemical reactions.
An aspect provides an electrochemical reactor system including an electrochemical cell, where the cell has an anode, a cathode disposed opposite the anode, an electrolyte stream that contacts the cathode, preferably both the anode and the cathode, and a channel that contains the electrolyte stream within the electrochemical cell. The electrochemical reactor system also includes a magnetic field source positioned in proximity to the cathode. The magnetic field and the source thereof will be described in detail herein below.
As used herein, the electrolyte stream comprises an electrolyte and an iron-containing feedstock. The iron-containing feedstock can include iron-containing feedstock particles (also referred to as “feedstock particles”), which are solid particles suspended or dispersed in the electrolyte stream.
The electrochemical cell electrochemically reduces at least a portion of the iron-containing feedstock to form iron particles comprising iron metal at a surface of the cathode and in the magnetic field provided by the magnetic field source. As used herein, the term “iron metal” refers to Fe(0), which is iron with an oxidation state of zero. In particular, the produced iron metal is presented in the form of particles with discrete particle size and is distinct from other forms such as plates. The iron particles produced on the surface of the cathode and in the magnetic field can comprise greater than 90 weight percent (wt %), greater than 95 wt %, or greater than 98 wt %, or 100 wt % of iron metal, based on a total weight of the iron particles.
As discussed herein, the inventors have discovered that the size of the iron-containing feedstock particles influences the size of the final iron particles generated through iron electrolysis in a magnetic field. When using feedstocks with very small particle size, on the order of 1 micron, iron crystallites can grow in a magnetic field forming long needles, much larger than the feedstock particle in at least one dimension. For this embodiment, the feedstock is also referred to as the “first feedstock,” and the produced iron particles are also referred to as the “first iron product.” The iron particles can have a needle-like shape with a high aspect ratio. For example, the iron particles may have an aspect ratio (length versus width) of 2 to 50, 3 to 20, or 5 to 15.
In particular, it has been found that when the feedstock particles have an average particle size in at least one dimension of greater than 0 and less than or equal to 10 micrometers (μm), greater than 0 and less than or equal to 5 μm, preferably 0.1 μm to 10 μm or 0.1 μm to 5 μm (first feedstock), the produced iron particles have an average particle size in at least one dimension of 50 μm to 1,000 μm, preferably 50 μm to 500 μm, and more preferably 50 μm to 200 μm (first iron product).
It has also been found that when greater than 90 volume percent (vol %), greater than 95 vol %, greater than 99 vol %, or 100 vol % of the feedstock particles in the electrolyte stream contained within the electrochemical cell have a largest dimension of 0.1 μm to 10 μm, preferably 0.1 μm to 5 μm, based on a total volume of the feedstock particles in the electrolyte stream contained within the electrochemical cell (first feedstock), then greater than 90 vol %, greater than 95 vol %, greater than 99 vol %, or 100 vol % of the iron particles formed at the surface of the cathode and in the magnetic field have a largest dimension of 50 μm to 300 μm, and preferably 50 μm to 200 μm, based on a total volume of the iron particles formed at the surface of the cathode and in the magnetic field (first iron product).
As a specific example, when greater than 95 vol %, greater than 98 vol %, or 100 vol % of the feedstock particles in the electrolyte stream contained in the electrochemical cell have a largest dimension of 0.1 μm to 5 μm, based on a total volume of the feedstock particles in the electrolyte stream contained within the electrochemical cell (first feedstock), then greater than 95 vol %, greater than 98 vol %, or 100 vol % of the iron particles formed at the surface of the cathode and in the magnetic field have a largest dimension of 50 μm to 200 μm, based on a total volume of the iron particles formed at the surface of the cathode and in the magnetic field (first iron product).
Surprisingly, the inventors have also found that in the presence of larger feedstock particles with diameter on the order of 10 μm, iron crystallites grow as smaller polyhedra which are easily dispersed. For this embodiment, the feedstock can also be referred to as the “second feedstock,” and the produced iron particles can also be referred to as the “second iron product.” In particular, when the feedstock particles have an average particle size in at least one dimension of 25 μm or greater, preferably 25 μm to 500 μm, or 25 μm to 100 μm, or 25 μm to 50 μm (second feedstock), the iron particles produced through electrolysis have an average particle size in at least one dimension of 0.1 μm to 20 μm, preferably 0.1 μm to 10 μm, and more preferably 1 μm to 10 μm (second iron product). The iron particles can be faceted particles with aspect ratios approaching unity.
Alternatively or in addition, it has been found that when greater than greater 90 wt %, greater than 95 vol %, greater than 99 vol %, or 100 vol % of the feedstock particles in the electrolyte stream contained within the electrochemical cell have a largest dimension of 25 μm or greater, for example, 25 μm to 500 μm or 25 μm to 400 μm, preferably 25 μm to 200 μm, 25 μm to 100 μm, 25 μm to 45 μm, based on a total volume of the feedstock particles in the electrolyte stream contained within the electrochemical cell (second feedstock), then greater than 90 vol %, greater than 95 vol %, greater than 99 vol %, or 100 vol % of the iron particles formed at the surface of the cathode and in the magnetic field have a largest dimension of 0.1 μm to 20 μm, preferably 0.1 μm to 10 μm, and more preferably 1 μm to 10 μm, based on a total volume of the iron particles formed at the surface of the cathode and in the magnetic field (second iron product).
As a specific example, when greater than 95 vol %, greater than 98 vol %, or 100 vol % of the feedstock particles in the electrolyte stream contained in the electrochemical cell have a largest dimension of 25 μm to 50 μm, or 25 μm to 45 μm, based on a total volume of the feedstock particles in the electrolyte stream contained within the electrochemical cell (second feedstock), then greater than 95 vol %, greater than 98 vol %, or 100 vol % of the iron particles formed at the surface of the cathode and in the magnetic field have a largest dimension of 0.1 μm to 10 μm or 1 μm, based on a total volume of the iron particles formed at the surface of the cathode and in the magnetic field (second iron product).
As used herein, the “at least one dimension” preferably refers to the largest dimension of a particle. The average particle size refers to the number or volume average particle size, and in particular volume average particle size. The average particle size and the largest dimension can be measured by laser diffraction, dynamic light scattering, or image analysis (e.g., analysis based on scanning electron microscope images). The average particle size of at least one dimension and the largest dimension can be determined, for example, with a HORIBA instrument.
Due to the distinct particle size ranges of the produced iron particles and the starting feedstock particles, the produced iron particles can be conveniently and efficiently and optionally continuously separated from the feedstock particles that are not reduced (residual feedstock), using methods such as sieving, filtering, screening, hydrocyclone, and/or centrifugation. The electrochemical reactor system and the corresponding method can be particularly advantageous for separating iron metal particles from magnetite- and/or maghemite-based ores as iron, magnetite, and maghemite all have high intrinsic susceptibility and can be challenging to separate with certain magnetic methods.
The electrochemical cell has a channel that contains the electrolyte stream within the electrochemical cell. The cathode or both the cathode and the anode are disposed in the channel. Optionally, at least one of the anode or the cathode can define the channel.
The channel can have an inlet for receiving an original electrolyte stream, and an outlet for discharging an electrolyte product stream after at least a portion of the iron-containing feedstock is electrochemically reduced to form iron particles comprising iron metal at the surface of the cathode and in the magnetic field. The electrochemical reactor system is configured to flow the electrolyte stream through the channel in a unidirectional flow from the inlet of the channel to the outlet of the channel.
The electrochemical cell can further include a separator between the cathode and the anode. When the separator is present, the electrochemical cell can include a catholyte channel that contains a catholyte stream, an anolyte channel configured to contain an anolyte stream, where the cathode is positioned in the catholyte channel, and the anode is positioned in the anolyte channel. Preferably, the catholyte channel contains the catholyte stream, the anolyte channel contains the anolyte stream, and cathode contacts the catholyte stream, and the anode contacts the anolyte stream.
The electrolyte stream comprises an iron-containing feedstock, an electrolyte, and various optional additives.
In terms of the materials, as used herein, the iron-containing feedstock refers to an iron-containing material that is capable of undergoing reduction reactions during operation of the electrochemical cell. For convenience, the term “iron ore” may be substituted or interchanged for the term “iron-containing feedstock.” “Iron ores” and “iron-containing feedstocks” may include iron in any form, such as iron oxides, hydroxides, oxyhydroxides, carbonates, or 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(s), rock(s), natural rock(s), sediment(s), natural sediment(s), mineral, and/or natural mineral(s), whether in naturally-occurring states or in otherwise purified or modified states. The iron-containing feedstock can be any suitable material, such as an iron-containing fluid from another process. Some embodiments of methods and electrochemical reactor systems described herein may be particularly useful for iron-containing feedstocks including hematite, maghemite, goethite, magnetite, limonite, 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.
The iron-containing feedstock may be 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 weight percent (wt %) iron, 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 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 comprise greater than 50%, 75 to 99 wt %, 80 to 98 wt %, or 85 to 95 wt % of iron oxides or hydroxides, based on total weight of the iron-containing feedstock. the iron-containing feedstock may include Fe(OH)2, Fe(OH)3, Fe2O3, Fe3O4, FeOOH, or a combination thereof.
The iron-containing feedstock may be a magnetite ore. As used herein, “magnetite ore” refers to an iron-containing feedstock that contains greater than 80 wt % of Fe3O4 based on total content of iron oxides and/or hydroxides in the iron-containing feedstock, more preferably greater than 90 wt % of Fe304 or greater than 95 wt % of Fe3O4 based on total content of iron oxides and/or hydroxides in the iron-containing feedstock. For example, the iron-containing feedstock may include a magnetite ore containing greater than 80 wt % of Fe3O4, greater than 90 wt % of Fe3O4, or greater than 95 wt % of Fe3O4 based on a total content of iron oxides (Fe3O4 and Fe2O3) in the iron-containing feedstock. The electrochemical reactor system may be used for the reduction of magnetite ore to iron metal. The iron-containing feedstock can also consist essentially of magnetite, which can mean that the iron-containing feedstock comprises greater than 90 wt % or greater than 95 wt % of magnetite based on a total weight of the iron-containing feedstock.
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. A content of the impurities or minor components may be less than 30 wt %, less than 10 wt %, less than 5 wt %, less than 1 wt %, 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 impurities or minor components 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.
In the electrolyte stream contained within the electrochemical cell, a content of the iron-containing feedstock may be 0.1 to 30 wt %, preferably 0.1 to 15 wt %, or 0.2 to 10 wt %, more preferably 0.2 to 2 wt %, or 0.1 to 5 wt % based on a total weight of the electrolyte stream contained within the electrochemical cell. 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 contained within the electrochemical cell 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 contained within the electrochemical cell. In some embodiments, the iron-containing feedstock may include magnetite, wherein the electrolyte stream contained within the electrochemical cell may include 0.1 to 30 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 contained within the electrochemical cell.
As described herein, the electrolyte stream includes an electrolyte. The electrolyte can include an aqueous solution of an alkali hydroxide, ammonium hydroxide, an organic hydroxide, or a combination thereof. The electrolyte may be a solution including water as a solvent and one or more dissolved hydroxides. For example, the electrolyte may include an aqueous solution of NaOH, KOH, LiGH, CsOH, ammonium hydroxide (NH4OH), or a combination thereof. Preferably, the electrolyte may include an aqueous solution of NaOH.
In the electrolyte including the aqueous solution, the alkali hydroxide, ammonium hydroxide, the organic hydroxide, or the combination thereof 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 electrolyte. Preferably 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 electrolyte.
In addition to the iron-containing feedstock and the electrolyte, the electrolyte stream may optionally contain additives to promote or inhibit certain desired or undesirable reactions. A combination of additives may be used. 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 suppressors), an iron activator (e.g., a sulfide salt, such as bismuth sulfide (Bi2S3) or sodium sulfide (Na2S)), or the like, or a combination thereof. Alternatively or in addition, the electrolyte stream may further include an alkali metal sulfide or a polysulfide including one or more of lithium sulfide (Li2S) or polysulfide (Li2Sx, x=2 to 6), sodium sulfide (Na2S) or polysulfide (Na2Sx, x=2 to 6), potassium sulfide (K2S) or polysulfide (K2Sx, x=2 to 6), cesium sulfide (Cs2S) or polysulfide (Cs2Sx, x=2 to 6), or the like. Non-limiting examples of additives include sodium sulfide (Na2S), potassium sulfide (K2S), lithium sulfide (Li2S), iron sulfides (FeSx, 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 additive 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.
Optionally, 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.
Unless specified otherwise, the electrolyte stream refers to the stream contained in the electrochemical cell. The electrolyte stream that is introduced into the electrochemical cell can be referred to an original electrolyte stream. The electrolyte steam that is discharged from the electrochemical cell after at least a portion of the iron-containing feedstock is reduced forming iron particles on a surface of the cathode and in the magnetic field is referred to as an electrolyte product stream which may contain feedstock particles that are not reduced.
The electrolyte stream can be prepared by combining the iron-conducting feedstock, the electrolyte, and the optional additives. The order of the combination is not particularly limited. For example, the additives, if used, can be added to the electrolyte, or the iron-conducting feedstock, then the electrolyte and the iron-conducting feedstock are combined to prepare the electrolyte stream.
When the separator is present, the electrochemical cell can include a catholyte stream contained in a catholyte channel and an anolyte stream contained in an anolyte channel. The anolyte stream and the catholyte stream may be different. For example, the catholyte stream may be alkaline (basic) and the anolyte stream may be acidic.
The catholyte stream can be the same as the electrolyte stream contained in the electrochemical cell as described herein which comprises an iron-containing feedstock and an electrolyte and optional additives.
The anolyte stream may include one or more strong acids, optionally one or more supporting electrolyte compounds for conductivity, and water. Representative anolyte stream includes an aqueous solution of a strong acid having a pKa of 2 or less, such as an aqueous solution of HCl, HNO3, H2SO4, HClO4, H3PO4, or a combination thereof. The optional supporting electrolyte compounds can include MClO4, MNO3, M2SO4, MF, MCl, MBr, or MI, where M=Li, Na, or K, or tetra-n-butylammonium X (N(C4H9)4X), where X is F, Cl, Br, I, or hexafluorophosphate. Optionally, the anolyte stream can further include a nonaqueous solvent, such as acetonitrile, dimethylsulfoxide, dimethylformamide, methanol, ethanol, 1-propanol, isopropanol, ether, diglyme, tetrahydrofuran, glycerol, or the like, or a combination thereof.
As a specific example, the anolyte stream may include an aqueous solution of a strong 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.
The electrochemical cell includes a cathode and an anode, and optionally a separator between the cathode and the anode. The distance between the anode and the cathode (interelectrode gap) may be varied, with an impact on the ohmic drop. The interelectrode gap may be 1 millimeters (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.
For an electrochemical cell with a separator, the 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. For example, at least one of the anode or the cathode is directly on the separator, i.e., the at least one of the anode or the cathode contacts the separator. For a zero-gap cell having one electrode in contact with the separator and another electrode that is not in contact with the separator, the electrode that is not in contact with the separator can have an electrode surface to separator distance of 0.001 cm to 2 cm, or 0.01 cm to 1 cm. The electrodes in zero-gap electrochemical cells are preferably porous to enable ion transport between the catholyte stream, the anolyte stream, and the separator.
Alternatively, the electrochemical cell with a separation can have a “non-zero gap cell” configuration, which means that both the anode and the cathode have a non-zero gap between the electrode surface and the separator, such as an electrode surface to separator distance of 0.001 cm to 2 cm, or 0.01 cm to 1 cm. In an exemplary cell with a separator, the cathode may be separated from the separator by a distance of 0.001 cm to 2 cm, or 0.01 to 1 cm, and the anode may be situated at an offset from the separator.
The electrochemical cell 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, nickel, copper, titanium, iron, chromium, an alloy thereof, or a combination thereof. For example, the cathode may include a stainless steel alloy such as 316, 316L, 304, or the like. In some embodiments, the cathode current collector may include steel, graphite, nickel, iron, a nickel-iron alloy, or a combination thereof. Optionally, 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.
Optionally, the cathode may further include one or more additive(s) to enhance the electronic and/or physical properties of the cathode. 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.
The cathode may further include one or more binder compound(s). 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. Optionally, the cathode current collector may be at least partially porous.
The electrochemical cell includes an anode. The anode can include a suitable anode current collector. The anode current collector may be a metal, a metal alloy, or a combination thereof. The anode may include carbon, titanium, lead, nickel, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof. The anode current collector may be coated with mixed metal oxides of iridium, ruthenium, tantalum, or the like, or a combination thereof.
Optionally, the anode may include a catalyst. Exemplary catalysts include metal oxide catalysts, such as manganese oxide (MnO2, Mn2O3, Mn3O4, MnxOy (where x=1 to 3 and y=1 to 8)), nickel-doped manganese oxide (Ni—MnxOy), nickel oxide (NiOx), nickel oxyhydroxide (NiOx(OH)y), iron oxide (FeOx), iron oxyhydroxide (FeOx(OH)y (where x=0 to 2 and y=0 to 3)), cobalt oxide (Co3O4, CoxOy (where x=1 to 3 and y=1 to 8)), manganese cobalt oxide (MnCo2O4, Mn1+xCo2-xO4 (where x=0 to 2)), cobalt manganese oxide (CoMn2O4), nickel manganese oxide (NiMnOx (where x=2 to 4)), manganese iron oxide (MnFe2O4, Mn1+xFe2-xO4 (where x=0 to 1)), nickel-doped manganese oxide (Ni—MnxOy (where x=1 to 3 and y=1 to 8)), manganese cobalt iron oxide (MnxCoyFezO4 (where x=0 to 4 and y=0 to 4 and z=0 to 4)), zinc cobalt manganese oxide (ZnCoMnO4, ZnxCoyMnzO4 (where x=0 to 4 and y=0 to 4 and z=0 to 4)), cobalt nickel oxide (CoNiOx (where x=0 to 4)), calcium manganese oxide (CaMnOx (where x=0 to 4)), lanthanum manganese oxide (LaMnO3), lanthanum cobalt oxide (LaCo2O4, La1+xCo2-xO4 (where x=0 to 2), lanthanum nickel oxide (LaNiO3), lanthanum calcium aluminum manganese oxide (LaxCayAlzMnvO3 (where x=0 to 3 and y=0 to 3 and z=0 to 2 and v=0 to 3)), nickel iron oxide (NizFe1-zOx (where z=0 to 1 and x=0.5 to 2.5)), manganese ferrite (MnFe2O4), zinc ferrite (ZnFe2O4), nickel cobaltite (NiCo2O4), lanthanum strontium manganate (La0.8Sr0.2MnO3), or the like, other transition metal oxides or nitrides (such as Fe3N, FeCN, ZrN, Mn4N, or a combination thereof), or a combination thereof. 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. The anode current collector may be at least partially porous.
When the anolyte stream is acidic, acid compatible anode materials may be used. Representative materials for the anode when an acidic anolyte is used include carbon, titanium, platinum, iridium, ruthenium, titanium, 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 one or more binder compound(s), 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.
Optionally, a separator may be used to provide a physical barrier between the anode and the cathode, while facilitating ion transport in electrochemical cell.
The separator may be in the form of a membrane, such as a microporous polyolefin membrane; or a paper, an ion-exchange membrane, or may be a porous compact separator such a glass frit; a glass fiber mat; a cotton fabric; a rayon fabric; or cellulose acetate, for example.
The separator in the electrochemical cell may be a passive separator, such as a diaphragm separator, or may be an active separator, such as an ion exchange membrane.
A 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, some separator membranes are ion-selective and allow the transfer of negative (or positive) ions while substantially preventing transfer of positive (or negative) ions. In other examples, separator materials may be chosen based on an ability to allow or prevent the cross-over of gas bubbles from one side (associated with one electrode) to the opposite side (associated with the counter-electrode).
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 permeable to negative ions, such as hydroxide ions, or the like. The separator may be impermeable or effectively impermeable to active materials that are needed for the electrochemical reactions at an electrode.
The separator may be formed of a polymer, 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.
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).
The separator may include a composite membrane including an inorganic material and an organic material. The inorganic material may include a metal oxide or a ceramic material. 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.
The electrochemical cell can further include a voltage source that is electrically connected to the anode and the cathode. The voltage source may be configured to apply a voltage to the electrochemical cell to provide the iron particle.
The voltage of the electrochemical cell (with or without separator) 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. For example, the voltage of the electrochemical cell may be from 2.6 to 5.0 V, or from 2.8 to 4.0 V. 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 current density at the cathode may be selected to promote the formation of iron particles at the surface of the cathode. 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. The current density may be periodically pulsed, modulated, or a combination of pulsing and modulation to control the iron metal dendrite growth or to limit the competing HER at the cathode.
The electrochemical cell may be operated at a temperature of 50° C. to 140° C., 50° C. to 70° C., 70° C. to 120° C., or 85° C. to 110° C. The temperature may refer to the temperature of the electrolyte stream (catholyte stream and the anolyte stream if separator is used) in the electrochemical cell (collectively “electrolyte streams”). For example, electrolyte streams may be at a temperature of 50° C. to 140° C., 50° C. to 70° C., 70° C. to 120° C., or 85° C. to 110° C. before the electrolyte streams are introduced into the electrochemical cell, such that the temperature of the electrolyte streams in the electrochemical cell may be 50° C. to 140° C., 50° C. to 70° C., 70° C. to 120° C., or 85° C. to 110° C. The operating temperature of the electrochemical cell may refer to the temperature during which a magnetic field is applied to the electrochemical cell.
The operating temperature of the electrolyte streams in the electrochemical cell 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 streams in the electrochemical cell may be achieved through self-heating of the electrochemical cell 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.
The electrochemical cell may operate with a suitable fluid flow, which may be varied based on operating conditions. As used herein, a fluid flow can refer to a flow of the electrolyte stream, the catholyte stream, and/or the anolyte stream. 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.
The flow of the electrolyte streams may be in a direction from a top of the electrochemical cell to a bottom of the electrochemical cell. Alternatively, the flow of the electrolyte streams may be in a direction from the bottom of the electrochemical cell to the top of the electrochemical cell. The channels (channel if a separator is not used, catholyte channel and anolyte channel if a separator is used) may be arranged vertically. For example, the channels may be arranged to provide vertical flow channels relative to the ground.
The electrochemical cell may be configured to flow the electrolyte streams through the channels in a unidirectional flow from a region of the channels upstream of the cathode and the anode to a region of the channels downstream of the cathode and the anode during electrochemical reduction of the iron-containing feedstock. For example the electrochemical cell may be configured to flow the electrolyte streams through the channels in a unidirectional flow from inlets that receive the electrolyte streams (original streams) to outputs that discharge the electrolyte streams (electrolyte product streams). The flow direction can be controlled using pumps, for example.
The electrochemical cell may include a mechanical stirrer or other means of agitating the electrolyte streams within the electrochemical cell (e.g., within the channels).
The electrolyte streams may be agitated by the flow of the these streams through the electrochemical cell, by magnetohydrodynamic flow, or a combination thereof. In an aspect, the electrochemical cell does not include any additional means to stir or agitate the electrolyte streams in addition to the flow of the electrolyte streams through the electrochemical reactor and/or magnetohydrodynamic flow.
The electrochemical reactor system can include a plurality of electrochemical cells. For example, the electrochemical cell may include 2 to 500 electrochemical cells, more preferably 5 to 200 electrochemical cells, or 50 to 170 electrochemical cells. 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 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.
The plurality of electrochemical cells may be arranged in series or parallel. In an aspect, the plurality of electrochemical cells may be connected in series and may be configured to have a reactor potential that is applied between a cathode of an initial electrochemical cell and an anode of a final electrochemical cell, wherein the reactor potential is defined as a cell potential multiplied by n, wherein n is a number of electrochemical cells in the plurality of electrochemical cells (wherein n is 2 to 1000, preferably 4 to 500). In another aspect, the plurality of electrochemical cells may be connected in parallel and may be configured to have a same cell potential that is applied between the cathode and the anode of each electrochemical cell in the plurality of cells.
The electrochemical reactor system includes a magnetic field source that is positioned in proximity to the cathode of the electrochemical cell. In proximity means that a magnetic field source is positioned to provide a magnetic field of at least one gauss, preferably 25 to 10,000 gauss, more preferably 300 to 3,000 gauss or 350 to 2,500 gauss to the cathode, or to provide a magnetic field of 0.0025 to 1 Tesla, preferably 0.05 to 1 Tesla or 0.03 to 0.3 Tesla, more preferably 0.035 to 0.25 Tesla at the surface of the cathode, or a combination thereof.
Any suitable magnetic field source may be used. For example, the magnetic field source may include a permanent magnet, an electromagnet, or an electropermanent magnet. Electromagnets may include, for example, current coils. Permanent magnets may include, for example, neodymium iron boron (NdFeB or NIB) magnets, samarium cobalt (SmCo) magnets, alnico magnets, or ceramic or ferrite magnets. An electropermanent magnet is a permanent magnet in which 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. An electropermanent magnet can contain two magnetic materials, one magnetically hard (high coercivity, e.g. Nd—Fe—B) and one semi-hard (mid coercivity, e.g. Alnico, aluminum-iron-nickel-cobalt-copper), capped at both ends with a magnetically soft material (low coercivity, e.g. Iron) and wrapped with a coil.
Preferably, the magnetic field source is not a current collector of the cathode, such that the reduction of the iron-containing feedstock does not occur on a surface of the magnetic field source.
The strength of the magnetic field source may be selected based on the amount of iron-containing feedstock in the electrolyte streams, for example to limit the thickness of any layers formed from unreduced iron-conducting feedstock (e.g. magnetite) on the cathode current collector.
The magnetic field can be a modulated. As used herein, a modulated magnetic field is a magnetic field whose strength or direction can be varied over time. For example, the magnetic field source may be selected/configured to provide a magnetic field that varies over time, such as a rotating magnetic field or an alternating magnetic field. A rotating magnetic field can be produced by coils symmetrically placed and supplied with polyphase currents. An alternating magnetic field can be created by passing an alternating current through a coil.
The magnetic field source may be positioned to modify the deposition kinetics of the iron-containing feedstock on the cathode (e.g. 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 particular positions. For example, the magnetic field source may enhance deposition over substantially the entire surface of the cathode, such as by providing a magnet having a size substantially correlating to a size of the surface of the cathode. To control the deposition kinetics in particular locations, one or more magnetic field sources (e.g. magnets) may be positioned at particular locations of the cathode to preferentially pull materials susceptible to magnetization to those locations. As another example, one or more current coils may be associated with the cathode, and a power source or signal generator may be associated with those current coils. By turning on the power source or signal generator, the magnetic field of the coil can be activated, and the amount of the deposited material may be varied over a surface through the use of selectively positioned coils.
The orientation of the magnetic field with respect to the electrical field may be chosen to minimize the adhesion of the reduced iron metal to the cathode current collector.
The magnetic field source may be positioned external to the channels that include the electrolyte streams, wherein the magnetic field source does not contact the electrolyte streams. In this embodiment, the reduction of the iron-containing feedstock may not occur on a surface of the magnetic field source, since the magnetic field source is not in physical contact with the electrolyte streams.
Alternatively, at least a portion of the magnetic field source may be positioned within the channels comprising the electrolyte streams, such that at least a portion of the magnetic field source (e.g., 10%, 20%, 30%, 50%, 70%, 80%, 90%, or 100%) may be in physical contact with the electrolyte streams. For example, at least a portion of the magnetic field source that is in contact with the electrolyte streams may be enclosed within a protective sheath to prevent corrosion from the electrolyte streams. In some embodiments, the entire source may be positioned with the channels including the electrolyte streams, and the source may be enclosed within a protective sheath. Exemplary materials that may be used to provide the protective sheath to the magnetic field source include, for example, polymeric materials, metal-containing materials (e.g., such as those having a similar composition to the cathode current collector), or a combination thereof.
The electrochemical reactor system further includes a separation unit that is disposed downstream of the channels of the electrochemical cell. The separation unit can receive an electrolyte product stream discharged from the channel or the catholyte channel. The electrolyte product stream can contain the iron particles, a residual feedstock comprising the feedstock particles that are not reduced in the electrochemical cell, and a liquid. The separation unit is configured to separate the iron particles from the residual feedstock in the electrolyte product stream based on a particle size difference between the iron particles and the feedstock particles. The system and method disclosed herein can have very high separation efficiency. For example, the isolated iron product can retain less than 10 wt %, less than 8 wt %, less than 6 wt %, less than 5 wt %, less than 3 wt %, or less than 1 wt % of the residual feedstock based on a total weight of the iron product.
The separation unit can comprise a sieve, a filter, a screen, a hydrocyclone, a centrifuge, or a combination thereof for the separation based on the size differences between the iron particles and the feedstock particles.
The separation unit can include two or more subunits (e.g., 2). In an aspect, the separation unit has two subunits. The first subunit is configured to separate the iron particles from the electrolyte product stream, generating a first stream comprising the residual feedstock and a liquid, and a second stream comprising the iron particles. The second subunit is configured to separate the residual feedstock from the liquid in the first stream. Optionally the first subunit is a sieve, a filter, a screen, a hydrocyclone, or a centrifuge, and the second subunit is a magnetic separator or a physical separator. Any magnetic or physical separator can be used. The separator for magnetic and/or physical separation can include a clarifier, a spiral classifier, other screw-type devices, a countercurrent decantation (CCD) circuit, a thickener, a filter, a sieve, a conveyor-type device, a gravity separation device, a magnet, a hydrocyclone, a centrifuge, or other suitable apparatus.
In another aspect, the first subunit is configured to separate the residual feedstock from the electrolyte product stream, generating a first stream comprising the iron particles and a liquid, and a second stream comprising the residual feedstock, and the second subunit is configured to separate the iron particles from the liquid in the first stream. The first subunit can be a sieve, a filter, a screen, a hydrocyclone, or a centrifuge, and the second subunit can be a magnetic separator or a physical separator as described herein.
When the electrolyte stream in the electrochemical cell comprises the first feedstock as described herein, the product electrolyte stream can include the first iron product as described herein, a residual feedstock comprising feedstock particles that are not reduced, and a liquid. As an example, when the electrolyte product stream flows through the first subunit, which is a sieve or screen, the iron particles can be collected on the sieve or screen, and the remaining electrolyte stream, which includes the residual feedstock and the liquid, can be further separated in the second subunit. When the first subunit is a centrifuge or a hydrocyclone, the separation can generate a first stream comprising iron particles and a second stream comprising the residual feedstock and the liquid, which can be further separated in the second subunit.
As a specific example, when the feedstock particles have an average particle size in at least one dimension of 10 micrometers or less, preferably 0.1 to 10 micrometers, the separation unit can be configured to separate the feedstock particles from the iron particles having an average particle size in at least one dimension of 50 to 1000 micrometers, preferably 50 to 200 micrometers. In an aspect, the separation unit can comprise a sieve or screening having openings with a diameter less than the average particle size of the iron particles in at least one dimension but greater than the average particle size of the feedstock particles in at least one dimension. For example, the sieve or screen can have openings with a diameter of 15 micrometers to 45 micrometers, preferably 20 micrometers to 45 micrometers, or 30 to 45 micrometers. When the electrolyte product stream flows through such a sieve or screen, the iron particles can be collected on the sieve or screen, and the remaining electrolyte stream, which includes the residual feedstock and a liquid, can be further separated in the second subunit as described herein.
When the electrolyte stream in the electrochemical cell comprises the second feedstock as described herein, the product electrolyte stream can include the second iron product as described herein, a residual feedstock comprising feedstock particles that are not reduced, and a liquid. As an example, the first subunit can be a sieve or screen. The sieve or screen can have openings with a diameter less than the average particle size of the feedstock particles that are not reduced in at least one dimension but greater than the average particle size of the iron particles in at least one dimension. The sieve or screen can also have openings with a diameter less than the particle size of the feedstock particles but greater than the particle size of the feedstock particles that are not reduced. When the electrolyte product stream flows through such a first subunit, the residual feedstock can be collected on the sieve or screen, and the remaining electrolyte stream, which includes the iron particles and the liquid, can be further separated in the second subunit. When the first subunit is a centrifuge or a hydrocyclone, the separation in the first subunit can generate a first stream comprising iron particles and a second stream comprising the residual feedstock and the liquid. And the second stream can be further treated at the second subunit to separate the residual feedstock from the liquid.
As a specific example, when the feedstock particles have an average particle size in at least one dimension of 25 micrometers or greater, preferably 25 to 500 micrometers, the separation unit can be configured to separate the feedstock particles from iron particles having an average particle size in at least one dimension of 0.1 to 20 micrometers, preferably 0.1 to 10 micrometers. In an aspect, the separation unit can comprise a sieve or screening having openings with a diameter less than the average particle size of the feedstock particles in at least one dimension but greater than the average particle size of the iron particles in at least one dimension. When the electrolyte product stream flows through a sieve or screen, the feedstock particles can be collected on the sieve or screen, and the remaining electrolyte stream, which includes iron particles and a liquid, can be further separated in a second subunit, which can be a magnetic separator or a physical separator as described herein.
Regardless of the separation unit used, the recovered residual feedstock and the recovered liquid can be recycled and used in the next electrolysis cycle, and the iron particles can be washed, and/or dried, and/or densified.
The electrochemical reactor system further include an electrolyte reservoir, and the electrolyte streams can be provided to the channels of the electrochemical cell by the electrolyte reservoir. The electrolyte reservoir can be a mixing tank that mixes an ore slurry (e.g., the recovered residual feedstock and/or any fresh iron-containing feedstock) with a recovered electrolyte (the liquid in the electrolyte product stream) and optionally a fresh electrolyte.
The electrochemical reactor system can optionally include an electrolyte purification unit that provides electrolyte purification. The electrolyte to be purified can include an electrolyte recovered from separation unit. The electrolyte purification unit 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 as described herein the context of the electrolyte stream.
The electrochemical reactor system can also include an iron product post processing unit, where the separated iron particles can be washed, and/or dried, and/or densified.
A method of processing an iron-containing feedstock to produce iron particles includes: providing an electrochemical reactor system as described herein, flowing the electrolyte stream through the channel or catholyte channel of the electrochemical cell, applying a magnetic field to the cathode, and electrochemically reducing at least a portion of the iron-containing feedstock in the magnetic field to produce the iron particles at the surface of the cathode, wherein the feedstock particles and the iron particles have the sizes as described herein. Preferably, the iron particles are collected from the surface of the cathode using the electrolyte stream.
The electrochemically reducing can be carried out at a current efficiency of at least 0.6, wherein the current efficiency is a ratio of charge used for the reduction of the iron-containing feedstock to a total charge provided to the cathode.
In some embodiments, the iron-containing feedstock is not electrochemically reduced before the magnetic field is applied at the cathode.
The iron particles (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 and flushing the iron particles from the surface of the cathode using the electrolyte stream. Any suitable method may be used to harvest the iron particles 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 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.
The harvesting may further include stopping the electrochemical reduction of the iron-containing feedstock. For example, the step of stopping the electrochemical reduction may include substantially reducing the applied voltage 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.
The electrolyte stream may be continuously flowed through the electrochemical cell during the step of electrochemically reducing the iron-containing feedstock to the iron particles, which may maintain a substantially constant concentration of iron-containing feedstock species during the reduction step. The iron particles and the feedstock particles that are not reduced can be separated in the separation unit as described herein.
As shown in
The electrolyte stream 130 is provided to the channel 150 of the electrochemical reactor 100 by an electrolyte reservoir (210). The electrolyte reservoir (210) can be a mixing tank, where a concentrated ore slurry from a concentrated ore unit 220 can be mixed with an electrolyte from an electrolyte unit 230. An iron-containing feedstock 290 may be in fluid communication with the concentrated ore unit 220 (as shown in
From the electrochemical cell 100 an electrolyte product stream 310 including a liquid, the iron particles, and a residual feedstock comprising feedstock particles that are not reduced, can be provided to a separation unit 300. The separation unit may include a first separation unit 320a (as shown in
The separation unit 300 may also optionally include a second separation unit 340a (as shown in
The system may optionally include a post processing unit 330. The post processing unit 330 may wash and/or dry and/or densify the iron product. The post processing unit 330 may be fluidly connected to the first separation unit 320a or the second separation unit 320b via product post-processing stream 280.
A separator may be provided in an electrochemical cell between the cathode and the anode as shown in
The anolyte stream 3110 may be provided from an anolyte reservoir 3120. The catholyte stream 130a may be provided by an electrolyte reservoir 210 similar to the one described for
Shown in
Harvesting the iron product may be facilitated by reducing the voltage and/or reducing the magnetic field, as shown in step 4C. When the magnetic field is reduced or the source is turned off, the iron metal product may release from the cathode, facilitating recovery of the product. As shown in step 4C with arrow 2020, the electrolyte, unreacted ore, and the product may exit the electrochemical cell for separation of the product and recycling of the unreacted ore and the electrolyte to the electrochemical cell. 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 4C, while illustrated to have the magnetic field decreased after the voltage is decreased, also disclosed is an aspect in which the voltage is decreased after the magnetic field is decreased or removed. Alternatively, in step 4C, the magnetic field may be stopped entirely during the harvesting step.
An amount of magnetite powder equivalent to 1% the mass of the total electrolyte slurry was added to a 40 wt % NaOH solution while stirred by an overhead mixer at 400 RPM. The slurry was heated to 90° C. using a cuff heater around the PTFE beaker. The anode was a nickel mesh, and the cathode current collector was a polished nickel foil. The electrodes were inserted into a custom frame, maintaining an electrode gap of 1 cm. An alnico horseshoe magnet rated at 9 lbs-pull was secured on the outside of the beaker, adjacent to the cathode current collector positioned on the other side of the beaker wall. A constant current of 250 mA/cm2 was applied between the electrodes for an amount of time sufficient to theoretically reduce 80% of the available magnetite powder in the slurry. When the experiment was complete, the iron product and remaining magnetite powders were collected using a magnetic wand, washed with deionized water, and dried under vacuum before weighing. The amount of metallic iron was determined via potentiometric titration.
The table below,
An amount of magnetite powder equivalent to 0.25% the mass of the total electrolyte slurry was added to a 40 wt % NaOH solution while stirred by an overhead mixer at 250 RPM. The slurry was heated to 90° C. using an immersion heater. The anode was a nickel mesh, and the cathode current collector was a polished AISI 304 stainless steel sheet. The electrodes were inserted into a custom frame, maintaining an electrode gap of 1.5 cm. A neodymium permanent magnet was secured on the outside of the vessel, adjacent to the cathode current collector positioned on the other side of the vessel wall. The strength of the magnetic field at the cathode current collector was 1600 G. A constant current of 100 mA/cm2 was applied between the electrodes for an amount of time sufficient to theoretically reduce 80% of the available magnetite powder in the slurry. When the experiment was complete, the iron product and remaining magnetite powders were collected using a magnetic wand, washed with deionized water, and dried under nitrogen before weighing. The amount of metallic iron was determined via potentiometric titration. The mass-basis current efficiency was 79.5%.
An amount of magnetite powder equivalent to 0.25% the mass of the total electrolyte slurry was added to a 40 wt % NaOH solution while stirred by an overhead mixer at 250 RPM. The slurry was heated to 90° C. using an immersion heater. The anode was a nickel mesh, and the cathode current collector was a polished AISI 304 stainless steel sheet. The electrodes were inserted into a custom frame, maintaining an electrode gap of 1.5 cm. A neodymium permanent magnet was secured on the outside of the vessel, adjacent to the cathode current collector positioned on the other side of the vessel wall. The strength of the magnetic field at the cathode current collector was 1600 G. A constant current of 100 mA/cm2 was applied between the electrodes for an amount of time sufficient to theoretically reduce 80% of the available magnetite powder in the slurry. When the experiment was complete, the iron product and remaining magnetite powders were collected using a magnetic wand, washed with deionized water, and dried under nitrogen before weighing and particle size analysis. The amount of metallic iron was determined via potentiometric titration. The mass-basis current efficiency was 78.4%.
The results of Examples 1-4 are summarized in the table below.
This disclosure further encompasses the following aspects.
Aspect 1. An electrochemical reactor system, comprising: an electrochemical cell, comprising: an anode; a cathode disposed opposite the anode; an electrolyte stream contacting the cathode, the electrolyte stream comprising an electrolyte and an iron-containing feedstock comprising feedstock particles; and a channel that contains the electrolyte stream within the electrochemical cell; and a magnetic field source positioned to provide a magnetic field of at least one gauss, preferably 25 to 10,000 gauss, more preferably 300 to 3,000 gauss to the cathode, or to provide a magnetic field of 0.0025 to 1 Tesla, preferably 0.03 to 1 Tesla, more preferably 0.03 to 0.3 Tesla at the surface of the cathode, or a combination thereof, and wherein the electrochemical cell is configured to electrochemically reduce at least a portion of the iron-containing feedstock to form iron particles comprising iron metal at a surface of the cathode and in the magnetic field, and wherein the feedstock particles have an average particle size in at least one dimension of 10 micrometers or less, preferably 0.1 to 10 micrometers, and the iron particles have an average particle size in at least one dimension of 50 to 1,000 micrometers, preferably 50 to 200 micrometers, or wherein the feedstock particles have an average particle size in at least one dimension of 25 micrometers or greater, preferably 25 to 500 micrometers, and the iron particles have an average particle size in at least one dimension of 0.1 to 20 micrometers, preferably 0.1 to 10 micrometers.
Aspect 2. The electrochemical reactor system of aspect 1, further comprising a separator disposed between the anode and the cathode.
Aspect 3. The electrochemical reactor system of aspect 2, wherein the channel comprises a catholyte channel and an anolyte channel, and the separator is disposed between the catholyte channel and the anolyte channel; the catholyte channel contains the electrolyte stream; the anolyte channel is configured to contain an anolyte stream; the cathode is positioned in the catholyte channel; and the anode is position in the anolyte channel.
Aspect 4. The electrochemical reactor system of aspect 3, further comprising the anolyte stream in the anolyte channel, wherein the cathode contacts the electrolyte stream and the anode contacts the anolyte stream.
Aspect 5. The electrochemical reactor system of aspect 4, wherein the anolyte stream comprises an aqueous solution comprising: an acid having a pKa of 2 or less; and optionally a supporting electrolyte compound.
Aspect 6. The electrochemical reactor system of any one of aspects 2 to 5, wherein the separator comprises an anion exchange membrane, a cation exchange membrane, a zwitterionic membrane, a porous membrane having an average pore diameter of less than 10 nanometers, a polybenzimidazole-containing membrane, a polysulfone-containing membrane, a polycarboxylic-containing membrane, a polyetherketone-containing membrane, a membrane comprising a polymer of intrinsic microporosity, or a combination thereof.
Aspect 7. The electrochemical reactor system of any one of the preceding aspects, wherein the channel or the catholyte channel has an inlet for receiving the electrolyte stream and an outlet for discharging an electrolyte product stream after at least a portion of the iron-containing feedstock is reduced to form iron particles comprising iron metal at the surface of the cathode and in the magnetic field.
Aspect 8. The electrochemical rector system of aspect 7, wherein the electrochemical rector system is configured to flow the electrolyte stream through the channel or the catholyte channel in a unidirectional flow from the inlet to the outlet of the channel or the catholyte channel.
Aspect 9. The electrochemical reactor system of aspect 7 or 8, further comprising a separation unit disposed downstream of the channel or the catholyte channel, wherein the separation unit is configured to separate at least a portion of the iron particles from the electrolyte product stream.
Aspect 10. The electrochemical reactor system of aspect 8 or 9, wherein the electrolyte product stream comprises the iron particles and a residual feedstock comprising the feedstock particles that are not reduced in the electrochemical cell, and the separation unit is configured to separate the iron particles from the residual feedstock in the electrolyte product stream based on a particle size difference between the iron particles and the residual feedstock to provide an iron product, and optionally wherein the iron product comprises less than 10 wt % of the residual feedstock based on a total weight of the iron product.
Aspect 11. The electrochemical reactor system of aspect 10, wherein the separation unit comprises a sieve, a filter, a screen, a hydrocyclone, a centrifuge, or a combination thereof.
Aspect 12. The electrochemical reactor system of aspect 10 or 11, wherein the separation unit has two subunits, the first subunit is configured to separate the iron particles from the electrolyte product stream, generating a first stream comprising the residual feedstock and a liquid, and a second stream comprising the iron particles, and the second subunit is configured to separate the residual feedstock from the liquid in the first stream, and optionally wherein the first subunit is a sieve, a filter, a screen, a hydrocyclone, or a centrifuge, and the second subunit is a magnetic separator or a physical separator.
Aspect 13. The electrochemical reactor system of aspect 10 or 11, wherein the separation unit has two subunits, the first subunit is configured to separate the residual feedstock from the electrolyte product stream, generating a first stream comprising the iron particles and a liquid, and a second stream comprising the residual feedstock, and the second subunit is configured to separate the iron particles from the liquid in the first stream, and optionally wherein the first subunit is a sieve, a filter, a screen, a hydrocyclone, or a centrifuge, and the second subunit is a magnetic separator or a physical separator.
Aspect 14. The electrochemical reactor system of aspects 10 or 11, wherein the feedstock particles have an average particle size in at least one dimension of 10 micrometers or less, preferably 0.1 to 10 micrometers, and the separation unit is configured to separate the residual feedstock in the electrolyte product stream from the iron particles having an average particle size in at least one dimension of 50 to 1000 micrometers, preferably 50 to 200 micrometers.
Aspect 15. The electrochemical reactor system of aspect 14, wherein the separation unit comprises a sieve or screening having openings with a diameter less than the average particle size of the iron particles in at least one dimension but greater than the average particle size of the feedstock particles in at least one dimension.
Aspect 16. The electrochemical reactor system of aspect 14 or 15, wherein the sieve or screen has openings with a diameter of 15 micrometers to 45 micrometers, preferably 20 micrometers to 45 micrometers, or 30 to 45 micrometers.
Aspect 17. The electrochemical reactor system of any one of aspects 10 to 11, wherein the feedstock particles have an average particle size in at least one dimension of 25 micrometers or greater, preferably 25 to 500 micrometers, and the separation unit is configured to separate the residual feedstock in the electrolyte product stream from iron particles having an average particle size in at least one dimension of 0.1 to 20 micrometers, preferably 0.1 to 10 micrometers.
Aspect 18. The electrochemical reactor system of any one of the preceding aspects, wherein the electrolyte stream contained within the electrochemical cell comprises from 0.1 to 30 wt % of the iron-containing feedstock, based on a total weight of the electrolyte stream contained within the electrochemical cell.
Aspect 19. The electrochemical reactor system of any one of the preceding aspects, wherein: (i) the iron-containing feedstock comprises hematite, maghemite, magnetite, goethite, limonite, or a combination thereof; or (ii) the iron-containing feedstock comprises magnetite; or (iii) the iron-containing feedstock comprises greater than 90 wt %, greater than 95 wt %, or greater than 98 wt % of magnetite based on a total weight of the iron-containing feedstock.
Aspect 20. The electrochemical reactor system of any one of the preceding aspects, wherein: (i) the electrolyte stream comprises an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof; or (ii) the electrolyte stream comprises an aqueous solution of an alkali hydroxide, an organic hydroxide, or a combination thereof, and the alkali 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 electrolyte stream.
Aspect 21. The electrochemical reactor system of any one of the preceding aspects, wherein the iron particles comprise greater than 90 wt %, greater than 95 wt %, or greater than 98 wt % of iron metal, preferably consists of iron metal.
Aspect 22. The electrochemical reactor system of any one of the preceding aspects, wherein the magnetic field source comprises a permanent magnet, an electromagnet, or an electropermanent magnet.
Aspect 23. The electrochemical reactor system of any one of aspects 1 to 22, wherein the magnetic field source is positioned external to the channel or the catholyte channel, and the magnetic field source does not contact the electrolyte stream.
Aspect 24. The electrochemical reactor system of any one of aspects 1 to 22, wherein at least a portion of the magnetic field source is positioned within the channel or the catholyte channel.
Aspect 25. The electrochemical reactor system of any one of the preceding aspects, wherein: (i) the cathode comprises aluminum, carbon, molybdenum, nickel, copper, titanium, iron, chromium, an alloy thereof, or a combination thereof; (ii) The electrochemical reactor system of any one of the preceding aspects, wherein the anode comprises carbon, titanium, lead, nickel, platinum, iridium, ruthenium, tantalum, niobium, zirconium, vanadium, hafnium, aluminum, cobalt, antimony, tungsten, an alloy thereof, an oxide thereof, or a combination thereof; or (iii) a combination thereof.
Aspect 26. The electrochemical reactor system of any one of the preceding aspects, wherein a current density at the cathode for the reduction of the iron-containing feedstock is from 40 to 5,000 milliamperes per square centimeter.
Aspect 27. The electrochemical reactor system of any one of the preceding aspects, wherein the at least a portion of the iron-containing feedstock is electrochemically reduced to form the iron particles at a current efficiency of at least 0.6, wherein the current efficiency is a ratio of charge used for the reduction of the iron-containing feedstock to a total charge provided to the cathode.
Aspect 28. The electrochemical reactor system of any one of the preceding aspects, wherein the channel or the catholyte channel is arranged vertically.
Aspect 29. A method of processing an iron-containing feedstock to produce iron particle, the method comprising: providing an electrochemical rector system of any one of aspects 1 to 28; flowing the electrolyte stream through the channel or the catholyte channel of the electrochemical cell; applying the magnetic field to the cathode; and electrochemically reducing at least a portion of the iron-containing feedstock in the magnetic field to produce the iron particles at the surface of the cathode.
Aspect 30. The method of aspect 29, further comprising maintaining a temperature of the electrolyte stream contained within the electrochemical cell at a temperature of 50° C. to 140° C. when at least a portion of the iron-containing feedstock in the magnetic field is electrochemically reducing to produce the iron particles at the surface of the cathode and in the magnetic field.
Aspect 31. The method of aspect 29 or 30, wherein the electrolyte stream is flowed unidirectionally from a region of the channel or the catholyte channel upstream of the cathode and the anode to a region of the channel or the catholyte channel downstream of the cathode and the anode.
Aspect 32. The method of any one of aspects 29 to 31, further comprising collecting the iron particles at the surface of the cathode using the electrolyte stream.
Aspect 33. The method of any one of aspects 29 to 32, further comprising separating the iron particles from a residual feedstock comprising the feedstock particles that are not reduced in the electrochemical cell based on particle size.
Aspect 34. The method of any one of aspects 29 to 32, further comprising collecting the iron particles at the surface of the cathode using the electrolyte stream, generating an electrolyte product stream comprising the iron particles and a residual feedstock comprising the feedstock particles that are not reduced; flowing the electrolyte product stream out of the electrochemical cell; separating the iron particles from the residual feedstock in the electrolyte product stream at a separation unit comprising a sieve, a filter, a screen, a hydrocyclone, a centrifuge, or a combination thereof based on a size difference of the iron particles and the feedstock particles that are not reduced.
Aspect 35. An iron metal powder produced using the system of aspects 1, or the method of aspect 29, wherein the iron metal has (i) 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; (ii) a carbon emission intensity of less than 1100 kilograms of CO2 per ton of the iron metal, when determined according to ISO 14404; (iii) 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; (iv) 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; (v) 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; (vi) 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; (vii) 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 (viii) a combination thereof.
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 so as 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.
This application is based on and claims priority to U.S. Provisional Application No. 63/547,803, filed on Nov. 8, 2023, in the U.S. Patent and Trademark Office, and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which are incorporated herein in its entirety by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63547803 | Nov 2023 | US |
