Patent Application
20240035112
The present disclosure relates generally to apparatuses for dissolving or leaching metal from metal-containing substances. The dissolved or leached metal may be useful for production of consumer, industrial, or agricultural products.
Metal-dissolving equipment is used for dissolution or leaching of metal from metal-containing substances. Once dissolved or leached, the metal may be further processed and/or isolated for use in the production of different chemicals, or materials such as for batteries, electroplating, animal feeds, fertilizers, toothpaste, agricultural sprays, etc.
Conventional metal dissolution processes are either batch or continuous.
For a conventional batch process, conventional metal-dissolving equipment comprises an agitated batch tank. The tank is filled with metal and a dissolving solution, and left to sit for a period of time (which may include periodic or continuous stirring). Once the metal has been sufficiently dissolved, the contents of the tank are all removed.
In a stirred tank system, however, the large particles do not stir well and become unevenly distributed relative to the dissolving solution, with a tendency for the large particles to sink towards the bottom of the tank due to weight.
In a conventional continuous process, a dissolver column is filled with the metal-containing substance. The dissolving solution is provided into the column at a certain location, flowed past the metal-containing materials within the column to dissolve the metals in the solution that is passing by, then removed from the column at another location. The solution being removed from the column contains the dissolved metals. The solution may be processed to extract the dissolved metals, then re-circulated back into the column in a continuous-loop process.
To maximize the amount of metal that is dissolved, it is desirable for the reactor to contain a packed bed of metal components. A challenge with dissolving metals using dissolving solution in a process comprising a packed bed of metal components (also referred to as a packed bed process), irrespective of whether it is a batch or a continuous process, is ensuring mixing and even distribution across the column of the chemical components of the metal-dissolving solution. The typical design practice for dissolving columns to help achieve this uniformity of mixing and distribution for all chemicals of the solution, both horizontally and vertically within a column, is to size the column diameter to be approximately 10 times the largest metal-containing particle size, and then to size the column height to be approximately 4 to 8 times the diameter of the column. Accordingly, the height-to-diameter ratio of a conventional column is typically between four-to-one and eight-to-one, where a ratio is calculated by dividing the height by the diameter. The column diameter (width) is constant throughout. This practice is generally known and relied upon in the field of art to help try to achieve a sufficient uniformity of mixing and distributions of all the chemicals of the solution across the column (both horizontally and vertically). Without such uniformity of mixing and distribution of the solution, there may be areas of the column where the solution is at lower concentration of reactants, and/or largely unreacted metal dissolution solution may pass out of the column. This can result in a reduced or otherwise hindered ability to dissolve metal to a desired amount or target. The slender column helps, in part, prevent the solution from back-flowing in the column.
To be effective and efficient at dissolving or leaching metal-containing substances, dissolver columns also need to be of a sufficient height to allow for a sufficiently high flow rate, and also a sufficiently high target residence time, of the solution in the column. For example, a column may need to be at least 6 to 8 meters in height. Such heights are required for metal-dissolving kinetics: the solution must be flowed by the metal-containing materials at a threshold rate/velocity to encourage dissolution of the metal; and the solution must reside in the column a threshold amount of time to remain in contact with the metal-containing containing substances so as to dissolve a sufficient amount of metal before the solution exits the column (otherwise the full dissolution capacity of the solution is not utilized).
For these reasons, conventional columns must be tall to allow for the solution to be flowed within the column at an optimal rate for an optimal residence time, while still maintaining the correct height-to-diameter ratio to ensure uniformity of mixing and distribution of all the chemical of the solution across the column.
In certain process conditions, however, the optimal height to help achieve uniform mixing and distribution may be different than the optimal height to achieve the minimum solution velocity and residence time. Furthermore, although there is an incentive to use taller columns to increase the amount of metal-containing substances that can be processed at one time, if the column is too tall, the solution reagent concentrations can drop to lower levels in upper portions of a column making the dissolution reaction slower, and therefore not effectively utilizing the entire volume of metal containing substances in the column for dissolution.
Because of the foregoing design requirements, columns are typically symmetrical and of a continuous diameter (with sometimes a conical section at the bottom), and they are assembled onsite with supports external to the reactor itself to prevent the tall, slender, columns from falling over.
A solution which resolves the challenges and trade-offs of using columns to dissolve or leach metal from metal-containing substances is desired.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the attached Figures.
Described herein is a metal-dissolving system, apparatus, and process.
The metal-dissolving apparatus has a height that is less than its length. The metal-dissolving apparatus may be a box. The apparatus may comprise a reactant distribution device 170 to help hydraulically force uniformity of flow of chemical components of the dissolving solution. The distribution device may be, for example, perforated pipes, penetrating nozzles, or a false bottom.
The term height as used herein refers to the vertical dimension of the apparatus. The term length as used herein refers to the longest, non-diagonal, horizontal dimension of the apparatus. The term width as used herein refers to the shortest horizontal dimension of the apparatus.
The apparatus may have a height that is less than that of equivalent capacity dissolver columns (e.g., less than about 6 to 8 meters). The apparatus may have a height-to-length ratio of less than one (1), where a ratio is calculated by dividing the height by the length. In an embodiment, the metal-dissolving apparatus is a box.
The height, length, and width of the apparatus may be proportional to one another such that the apparatus is self-supporting. For example, to be self-supporting, the apparatus may have a height-to-length ratio of 1 or less. This means the apparatus will not overturn even if the apparatus base is tilted up to 45 degrees from horizontal even when the apparatus is in use (containing metal-containing materials and dissolving solution). In an embodiment, the self-supporting apparatus must be able to safely remain standing when in use without any structural supports outside of the space defined by the apparatus. In an embodiment, the self-supporting apparatus is configured to have a center of mass that is of a height that is less than half of the width of the apparatus. The term self-supporting does not preclude the apparatus from being anchored to a foundation or supporting structure to help prevent horizontal/lateral movement and/or for added safety.
The apparatus may comprise a sufficiently flat, large base. The height and base of the apparatus may be dimensioned so that the apparatus can be installed on flat surfaces, such as a structural foundation, without requiring peripheral infrastructure to install, secure, support, and/or stabilize apparatus, such as elevated structural elements, external supports, etc. The apparatus may also be configured to fit within a standard shipping container. Generally, shipping containers have dimensions of about 4 meters in height, by 5 meters in width, by 12 meters in length. As such, the apparatus may be sized and shaped to be transportable within the envelope of a standard shipping container. For example, the apparatus may be substantially rectangular in shape, and may be 4 m height×4 m width×11 m length. The reactor 110 may be rectangular in plan view.
The metal-dissolving apparatus may be a reactor. The reactor may have a simple, modular substantially rectangular design. Generally, a modular structure refers to a structure that may be largely manufactured and/or assembled off-site from its intended destination; may be readily transportable to its intended site; may require relatively less installation, finishing work, and/or assembly on-site; and/or may be readily assembled once on-site. A modular reactor may be configured to have a shape that integrates or interlocks with an inverse shape of an identical modular reactor. The reactor may comprise eight corners. Such substantially rectangular designs may allow for maximizing the dissolution-processing volume obtainable from a dimensional size that can be efficiently shop-fabricated and readily shipped through standard transportation means. The metal-dissolving apparatus may provide a reactor having a substantially box-shaped configuration. Apparatuses having such configurations may have a height low enough to facilitate maintaining uniform leaching process conditions within the apparatus reactor.
The metal-dissolving apparatus may comprise one or more dividers, where the divider(s) divide the apparatus into a plurality of reactors. Each of the plurality of reactors may define a separate dissolving section or zone of the apparatus. The reactor may be divided or segmented width-wise and/or length-wise. The reactor may comprise a plurality of dividers. By forming these separate dissolving sections or zones with dividers, the metal-dissolving apparatus may be configured to separately dissolve or leach different metal-containing substances, and may be able to separately collect loaded metal-dissolving solutions.
Alternatively, the metal-dissolving apparatus may be comprised of a plurality of reactors. Each of the plurality of reactors may be a modular reactor that is physically separate and not connected to any of the other modular reactors. In such an embodiment, an individual reactor may not necessarily be self-supporting or have a height-to-length ratio of less than one, but the apparatus as a whole may comprise multiple reactors arranged adjacent to one-another in such a way that the entire apparatus itself, when taken is a whole, is self-supporting or have a height-to-length ratio of less than 1. In an embodiment, each reactor may be a separate module which can be individually transported and/or affixed to other reactors. In another embodiment, the reactors may be placed and arranged within a container, the apparatus comprising the combination of the container and the arranged reactors therewithin.
Apparatuses as described herein may include a reactant distribution device 170 for helping hydraulically force a uniform flow of metal-dissolving solution throughout the apparatus. The reactant distribution devices 170 may help avoid needing to rely on back pressure created by packed beds of metal-containing substance (which is used in conventional dissolver columns) to provide uniformity of flow (for example, columns having a height-to-diameter ratio of between about four-to-one and eight-to-one, where a ratio is calculated by dividing the height by the diameter). Apparatuses according to the present disclosure may have a low enough height that, when coupled with the distribution device to help hydraulically force uniformity of reactant flow, they can maintain spatially uniform process conditions on a scale that is of commercial size-relevance, such as achieving scale-up. Maintaining uniformity of conditions at scale can be important, as the leaching processes described herein may be stable within a narrow operating envelope of acidity, pH, peroxide to acid ratio, temperature, metal strength (otherwise referred to as metal concentration in solution), etc. Reactant distribution devices 170 that may enable such uniformity of conditions may comprise perforated pipes, penetrating nozzles, false bottoms that may be perforated or coupled to penetrating nozzles, a series of metal-dissolving solution inlets, or a combination thereof. The reactant distribution device 170 may be located within the body of the reactor which also contains the leaching solution.
In an embodiment of the present disclosure, a metal-dissolving apparatus, comprises: a reactor; a metal inlet at a first location for providing into the reactor a metal-containing substance; a solution inlet at a second location for providing into the reactor a metal-dissolving solution; a solution outlet at a third location for discharging from the reactor the metal-dissolving solution; and a ventilation port at a fourth location; wherein the apparatus comprises a length and a height, the height being less than the length. The apparatus may be the reactor. The apparatus may comprise a plurality of reactors. Each of the plurality of reactors may have a length and a height, the height being less than the length, or the height being greater than the length. The apparatus may further comprise a divider defining a plurality of reactors within the apparatus. The metal-dissolving apparatus may further comprise a reactant distribution device disposed within the apparatus for receiving the solution and distributing the solution with substantially spatial uniformity throughout the reactor. The apparatus may further comprise a delivery system coupled to the apparatus for providing the metal-containing substance to the metal inlet. The apparatus may comprise a height to width ratio of less than one. The apparatus may be self-supporting. The reactor may be configured to fit within a standard shipping container, such as a shipping container having dimensions of about 4×4×12 m. The reactor may be substantially a rectangular in shape. The reactor may be modular. The metal inlet may be at a first location along an upper portion of the reactor. The solution inlet may be at a second location along the height and length of the reactor, and optionally extend along the length of the reactor; or the solution inlet may be at a second location along the height and width of the reactor, and optionally extend along the width of the reactor. The solution outlet may be at a third location along the height and length of the reactor, and optionally extend along the length of the reactor; or the solution outlet may be at a third location along the height and width of the reactor, and optionally extend along the width of the reactor. Along the length of the reactor, the solution inlet may be within a lower portion of the reactor and the solution outlet may be within an upper portion of the reactor for providing flow of solution countercurrent to flow of metal-containing substance. Along the length of the reactor, the solution inlet may be within an upper portion of the reactor and the solution outlet may be within a lower portion of the reactor for providing flow of solution co-current to flow of metal-containing substance. Along the width of the reactor, the solution inlet may be at one end the reactor and the solution outlet may be at an opposing end of the reactor for providing flow of solution crosscurrent to flow of metal-containing substance. The solution inlet may comprise a series of inlets extending along an outside length of the reactor coupled to a series of perforated pipes extending across an inside width of the reactor for distributing the metal-leaching solution with substantially spatial uniformity throughout the reactor. The solution inlet comprises a tapered manifold. The ventilation system may comprise a gas outlet for providing gas flow out of the reactor, and optionally further comprise a gas inlet for providing gas flow into the reactor and optionally further comprise a gas-capturing system. The reactant distribution device may comprise a perforated pipe disposed within the apparatus for receiving the solution from the inlet and distributing the solution with substantially spatial uniformity throughout the reactor.
In an embodiment, a metal-dissolving apparatus comprises: a reactor; a metal inlet at a first location in the reactor for receiving a metal-containing substance; a solution inlet at a second location in the reactor for receiving a metal-dissolving solution; a solution outlet at a third location in the reactor for discharging from the reactor the metal-dissolving solution with dissolved metal therein; and a re-circulation loop comprising a re-circulation tank connecting the solution outlet to the solution inlet for providing all of the metal dissolving solution from the solution outlet to the solution inlet.
In an embodiment, a metal-dissolving process comprises: providing with substantially spatial uniformity a metal-dissolving solution into a first location of a metal-dissolving apparatus comprising metal-containing substances; flowing the metal-dissolving solution through the apparatus under a relatively low hydrostatic load while maintaining substantially uniform metal-dissolving conditions across the length, width and height of the apparatus; dissolving metal from the metal-containing substances into the metal-dissolving solution; and discharging the metal-dissolving solution from a second location of the apparatus. The first location may be a lower portion of the apparatus, and the second location is an upper portion of the apparatus. The process may be a continuous process or a batch process. The solution may be provided into the apparatus through a plurality of perforated pipes to more evenly distributed the solution across the apparatus. The metal-dissolving solution may be re-circulated or recycled, or a portion of the solution may be recirculated or recycled. The metal-dissolving conditions may comprise pH, leaching-reagent ratios, temperature, dissolved metal concentration, or a combination thereof. The apparatus may comprise a rectangular reactor having a shorter height relative to length. The solution may be provided into a reactant distribution device within the apparatus to more evenly distribute the solution across the apparatus.
In an embodiment, use of a metal-dissolving apparatus having a shorter height relative to length for dissolving metal from metal-containing substances.
In an embodiment, a metal-dissolving process, comprising: providing metal-containing substances into a reactor; receiving and mixing a fresh metal-dissolving solution and a second solution to form a third solution being a metal-dissolving solution, the second solution having an amount of dissolved metals therein that is less than a threshold amount; providing the third solution into the reactor; flowing the third solution through the reactor to dissolve metal from the metal-containing substances to form a semi-loaded solution; providing all of the semi-loaded solution back into the reactor as the second solution of the third solution. The second solution may be initially water. The process may further comprise providing water into a recirculation tank, and providing the second solution from the re-circulation tank. The process may further comprise re-circulating through the reactor all of the semi-loaded solution as the second solution of the third solution until the semi-loaded solution contains the target threshold amount of dissolved metals therein to form a pregnant leach solution. The process may further comprise ceasing receiving the fresh metal dissolving solution in response to the semi-loaded solution forming the pregnant leach solution. The process may further comprise providing the pregnant leach solution downstream. The process may further comprise providing the pregnant leach solution downstream comprises providing the pregnant leach solution to a buffer tank. The process may further comprise receiving water from a second recirculation tank after all of the pregnant leach solution has been provided downstream. The process may further comprise mixing the pregnant leach solution of the process with pregnant leach solution(s) of one or more other metal-dissolving processes to form a fourth solution with a desired level of dissolved metal therein.
Referring to
Further, the reactor 110 may comprise a ventilation system (e.g., see ventilation air outlet 160, shown in
The ventilation system may be an off-gassing system. The ventilation system may further comprise a gas-capturing system. Gases such as hydrogen, oxygen, or a combination thereof may be released during dissolution or leaching of the metal-containing substance. Gases may be released due to corrosion of the metal-containing substance with acid (e.g., may release hydrogen). Gases may be released from reactions involving oxidants such as peroxide (e.g., may release oxygen). Resulting gases may carry aerosols of liquid in the reactor 110, and may need to be cleaned in a gas-cleaning device (e.g., such as a scrubber or mist eliminator). Generation of hydrogen often needs to be diluted before being released into the atmosphere, recovered, or captured for use in order to maintain concentrations below hydrogen's lower explosive limit. Alternatively, air may need to be kept out to enable hydrogen to be recovered and/or captured for use.
The reactor 110 may comprise a delivery system such as the delivery system 150 shown in
The reactor 110 that has a height that is less than the length of the reactor. With respect to the reactor 110, the term height as used herein refers to the vertical dimension of the reactor. The term length as used herein refers to the longest, non-diagonal, horizontal dimension of the reactor. The term width as used herein refers to the shortest horizontal dimension of the reactor. The reactor 110 may have a height that is less than that of dissolver columns (e.g., less than about 6 to 8 meters). The reactor 110 may be have a height to length ratio of less than one (1), where a ratio is calculated by dividing the height by the length.
The height, length, and weight of the reactor may be proportional to one another such that the reactor 110 is self-supporting. For example, to be self-supporting, the reactor 110 may have a length-to-height ratio of 1 or larger. This means the reactor 110 will not overturn even if the reactor 110 base is tilted up to 45 degrees from horizontal even when the reactor 110 is in use (containing metal-containing materials and dissolving solution). In an embodiment, the self-supporting reactor 110 must be able to safely remain standing when in use without any structural supports outside of the space defined by the reactor. In an embodiment, the self-supporting reactor is configured to have a center of mass that is of a height that is less than half of the width of the reactor. Despite being self-supporting, the reactor 110 may nonetheless be certainly anchored to a foundation or supporting structure to help prevent horizontal/lateral movement and for safety. The reactor 100 may comprise a sufficiently flat, large base. The height and base of the reactor 110 may be dimensioned so that the reactor 110 can be installed on flat surfaces, such as a structural foundation, without requiring peripheral infrastructure to install, secure, support, and/or stabilize the reactor 110, such as elevated structural elements, external supports, etc. The reactor 110 may also be configured to fit within a standard shipping container. Generally, shipping containers have dimensions of about 4 meters in height, by 5 meters in width, by 12 meters in length. As such, the reactor 110 may be sized and shaped to be transportable within the envelope of a standard shipping container. For example, the reactor 110 may be substantially rectangular in shape, and may be 4 m height×4 m width×11 m length. The reactor 110 may be rectangular in plan view.
In an embodiment, the reactor 110 is modular (not shown in
A reactor of the present disclosure may be formed out of metal, cement, plastic, or a combination thereof. The reactor may be formed out of fibre reinforced plastic (FRP), high density polyethylene (HDPE), crosslinked HDPE, polyvinyl chloride (PVC), chlorinated PVC (CPVC), polypropylene (PP), etc. The reactor may be formed out of metal or concrete, and, lined with FRP, rubber, or other plastics.
The reactor 110 comprises a solution inlet 130, and a solution outlet 140. The solution inlet 130 and outlet 140 may each comprise a plurality of openings within the outside walls of the reactor 110. The solution inlet 130 may be at a second location along the height and length of the reactor 110, optionally extending along the length of the reactor including with openings that are positioned along the length of the reactor a certain distance apart; or along the height and width of the reactor 110, optionally extending along the width with the openings positioned a certain distance apart. The solution outlet 140 may be at a third location along the height and length of the reactor, optionally extending along the length of the reactor; or along the height and width of the reactor, optionally extending along the width.
As depicted in
Alternatively, the solution inlet 130 may extend along the length of the reactor 110 within an upper or top portion 112 of the reactor, and the solution outlet 140 may extend along the length of the reactor within a lower or bottom portion 111. So positioned, the inlet 130 and the outlet 140 may provide for a flow of metal-dissolving solution going from the upper portion of the reactor downward through to the lower portion of the reactor. The flow of the solution may be co-current to the flow of the metal-containing substance, where the solution can flow into the reactor 110 at the upper portion, and flow downwards through any metal-containing substance also moving down with gravity as substance in a lower portion within the reactor 110 dissolves and shrinks, and then the solution may be discharged from the lower portion of the reactor. Optionally, the solution inlet 130 and the solution outlet 140 may be positioned along opposing widths, or ends of the reactor 110, where each may be respectively positioned in the upper 112 or lower 111 portions of the reactor. So positioned, the inlet 130 and outlet 140 may help provide for a flow of metal-dissolving solution that is cross-current to the flow of the metal-containing substance, where the solution can flow into the reactor 110 from one end, and flow across any metal-containing substance moving down with gravity as substance in a lower portion within the reactor 110 dissolves and shrinks, and then the solution may be discharged from the other side.
The solution inlet 130 may comprise a series of openings that extend along an outside length of the reactor 110. The solution inlet 130 openings may receive the solution from a manifold 131. The manifold 131 may taper as it extends along the length of the reactor 110. The taper may help provide even flow of the solution to each of the openings of the inlet 130. The manifold 131 may have individual conduits which connect the manifold 131 to each of the openings of the solution inlet 130.
Referring to
The metal-dissolving apparatus described herein may be used to implement a metal-dissolving process. That process may comprise one or more of the following steps. A metal-containing substance may be introduced into a metal-dissolving apparatus as described herein, via a metal inlet. A metal-dissolving solution may be provided with substantially spatial uniformity into a lower portion of the apparatus when the apparatus contains the metal-containing substance. The solution may be provided into the apparatus through a plurality of perforated pipes to more evenly distributed the solution across the apparatus. The metal-dissolving solution may be flowed through the apparatus under a relatively low hydrostatic load, while maintaining substantially uniform metal-dissolving conditions across the length and height of the apparatus. The size and shape of the apparatus, wherein the apparatus has a height that is less than its length, may result in the relatively low hydrostatic load, and may allow the metal-dissolving conditions to be maintained substantially uniformly across the length and height of the apparatus, due to lower vertical gradients. The metal-dissolving conditions may comprise pH, leaching-reagent ratios, temperature, dissolved metal concentration, or a combination thereof, and are maintained within a desired range for dissolving metal.
The process as described herein may be a batch process. The term “batch” is generally understood by persons skilled in the present field of art of the present application to refer to a process that does not have a steady state of (also referred to as stable) process conditions. As used herein, a “batch” process refers to one where one or more process conditions are changing over time, such process conditions including any one or more of (i) ratios of metal-dissolving solution to metal-containing substance, (ii) concentrations of reagents in the metal-dissolving solution, (iii) temperatures, pressures, pH, or flow rates, (iv) concentrations of dissolved metal within metal-dissolving solution, and (v) concentrations of metal ions within the leach solution re-circulating to the reactor.
The process as described herein may be a continuous process. The term “continuous” is generally understood by persons skilled in the present field of art of the present application to refer to a process that achieves or is intended to achieve a relatively steady state (such that it has stable process conditions) over the entire period of operation. For a metal dissolving process to be continuous, the following process conditions must all eventually achieve stability (i) amounts and concentrations of reagents in the metal-dissolving solution being introduced into a metal-dissolving apparatus, (ii) minimum or larger amounts and/or surface area of metal containing substances to be dissolved within the apparatus, (iii) amounts and concentrations of metal ions within the leach solution re-circulating to the reactor; and (iv) amounts and concentrations of loaded metal-dissolving solution exiting the apparatus. Each process condition must remain stable generally, or relative to each of the other process conditions. It is recognized that despite there being fluctuations in process conditions, they are still considered steady state or stable when within experimental error/operational tolerances. Such fluctuations do not detract from the leaching process being continuous.
The metal of the metal-containing substance may be dissolved or leached into the metal-dissolving solution. So loaded with dissolved or leached metal, the metal-dissolving solution may then be discharged from an upper portion of the apparatus. The metal-dissolving solution may be re-circulated or recycled back into the apparatus. The apparatus may comprise a pump to help circulate, and optionally help re-circulate, the metal-dissolving solution in the apparatus.
The metal-containing substance (also referred to as feedstock) described herein may comprise relatively pure metals that dissolve readily; impure metals; metal alloys; full or cut cathodes or cathode sheets; metal pellets, rounds, or crowns; metal shot, scrap, or shredded metal; metal powder or briquettes; or a combination thereof. The metals may include nickel, cobalt, nickel/cobalt alloys, ferronickel, manganese, copper, or a combination thereof. The apparatus and process described herein may receive a quite pure metal feedstock as the metal-containing substance. The apparatus and process described herein may be configured to receive other types of feedstock as the metal-containing substance(s), including electrowon or hydrogen reduced or carbonyl process produced pure metals, less pure metals produced pyrometallurgically or by other means, mixtures of different metals, metal alloys such as ferronickel or as may be derived from spent catalyst treatment, or other metallic feedstocks.
The metal-dissolving solution described herein may comprise an acid in aqueous solution. The metal-dissolving solution described herein may comprise an acid and an oxidant in aqueous solution. The acid may be sulfuric acid, hydrochloric acid, nitric acid, or a combination thereof. The oxidant may be added as a solid, liquid, or gas. The oxidant may be SO2/oxygen; peroxide; oxygen; oxidants that have cations comprising or consisting of H+ or the metal being dissolved, oxidants that have an anion comprising or consisting of sulfate, or a combination thereof; or a combination thereof. Oxidants that comprise cations consisting of H+ or the metal being dissolved, and comprise anions consisting of sulfate may be selected when producing metal-comprising battery chemicals. The metal-dissolving solution described herein may comprise sulfuric acid with or without an oxidant in aqueous solution. The metal-dissolving solution may comprise an aqueous solution of sulfuric acid and peroxide.
The metal dissolved or leached from the metal-containing substance may be used in production of consumer products (e.g., batteries, toothpastes), industrial products or processes (e.g., batteries, electroplating), or agricultural products (e.g., feeds, fertilizers, sprays, etc.). Metal sulfates may form from the metal dissolved or leached from the metal-containing substance. The metal sulfates may include nickel sulfate, zinc sulfate, cobalt sulfate, manganese sulfate, copper sulfate, or a combination thereof. So formed, the metal sulfates may be further processed and/or recovered via processes occurring downstream of the metal-dissolving apparatus, and may be used in production of batteries (e.g., nickel sulfate); used in electroplating (e.g., nickel sulfate); used in animal feeds, fertilizers, toothpaste, or agricultural sprays (e.g., zinc sulfate); or as mineral processing flotation reagents (copper sulfate) or a combination thereof.
Any one or more of the metal-dissolving apparatus, processes, and uses of the present disclosure may provide any one or more of the following.
The metal-dissolving apparatus may provide a reactor having a simple, modular substantially rectangular design. The modular reactor may be configured to have a shape that integrates or interlocks with an inverse shape of an identical modular reactor. The reactor may comprise eight corners. Such substantially rectangular designs may allow for maximizing the dissolution-processing volume obtainable from a dimensional size that can be efficiently shop-fabricated and readily shipped through standard transportation means. The metal-dissolving apparatus may provide a reactor having a substantially box-shaped configuration. Reactors having such configurations may have a low enough height that, coupled with a distributed series of metal-dissolving solution inlets or other device for helping hydraulically force a uniformity of metal-dissolving solution flow, may provide an ability to maintain spatially uniform process conditions on a scale that is of commercial size-relevance, such as achieving scale-up. As mentioned above, maintaining uniformity of conditions at scale can be important, as the processes described herein may be stable within a narrow operating envelope of acidity, pH, peroxide to acid ratio, temperature, metal strength (otherwise referred to as metal concentration in solution), etc.
As a result of the size and shape of the reactor, the metal-dissolving apparatus may require less interconnecting piping, feed systems, instrumentation, valving, etc. Further, the metal-dissolving apparatus may result in a high metal-dissolution capacity throughput module/per unit cost (e.g., up to 40,000 t/a metal eq., depending on feedstock type).
The low height of the reactor relative to its length may result in the metal-dissolving apparatus requiring less complicated material feeding systems (e.g., the solution inlet), lower building heights (e.g., less than 6 meters), lower pressure drop/pumping power, lower hydro/geostatic loads (from the pressure of the metal-containing substances and solution when the reactor is in use), lower elevation conveyors for loading metal or a combination thereof. Further, the metal-dissolving apparatus may achieve more uniform process conditions due to lower vertical gradients, may be easier to operate and/or maintain, may be easier and/or faster to install, may be able to handle a broad range of variable feedstocks & sizes of metal-containing substances (pellets, cathodes, rounds, crowns, etc.), or a combination thereof.
Described herein are metal-dissolving systems, and processes for dissolving metals. The systems comprise metal-dissolving apparatus according to embodiments of the present disclosure. The systems may further comprise additional structures, such as recirculation tanks, buffer tanks, holding tanks, or a combination thereof.
The metal-dissolving system 300 depicted in
Systems as described herein, such as the system depicted in
In an embodiment, the metal-dissolving batch process comprises circulating a metal-dissolving solution through a metal-dissolving apparatus comprising metal-containing substances. The metal-dissolving solution may be circulated through the apparatus with substantially spatial uniformity. The metal-dissolving solution may be circulated through the apparatus with substantially spatial uniformity, under a relatively low hydrostatic load while maintaining substantially uniform metal-dissolving conditions across the length, width and height of the apparatus. The metal-dissolving solution may be provided into the apparatus through a reactant distribution device within the reactor such as a plurality of perforated pipes to more evenly distributed the solution across the apparatus. Other reactant distribution devices are possible, such as manifolds internally to the reactor, injection nozzles penetrating through the floor or side walls of the reactor, etc. The metal-dissolving conditions may comprise pH, leaching-reagent ratios, temperature, dissolved metal concentration, or a combination thereof. The process may comprise dissolving metal from the metal-containing substances into the circulating metal-dissolving solution. The metal-dissolving solution may be circulated into the apparatus at a first location and circulated out of the apparatus as a second location. The first location may be positioned at a lower portion of the apparatus, and the second location may be positioned at an upper portion of the apparatus. The process may further comprise circulating the metal-dissolving solution through a recirculation loop. The recirculation loop may comprise circulating the metal-dissolving solution from the reactor at the second location (with dissolved metal ions therein) to a recirculation tank, and from the recirculation tank to the reactor at the first location. The process may further comprise providing metal-dissolving reagents into the metal-dissolving solution as the solution circulates from the recirculation tank to the reactor at the first location. The process may further comprise circulating the metal-dissolving solution through the recirculation loop, dissolving metal from the metal-containing substances into the metal-dissolving solution thereby incrementally increasing dissolved or leached metal concentration within the metal-dissolving solution, and eventually forming a loaded metal-dissolving solution. The loaded metal-dissolving solution may comprise dissolved or leached metal at a specific, or desired concentration. Once the loaded metal-dissolving solution is formed, the batch process is complete. The process may then comprise flowing the loaded metal-dissolving solution from the recirculation tank to a buffer tank. The process may further comprise flowing the loaded metal-dissolving solution from the buffer tank for further processing downstream.
In an embodiment, the metal-dissolving system 300 depicted in
The process involves feeding metal-containing substances (Metal Feed) into the reactor 310 through an upper portion 380 of the reactor 310, and filling the recirculation tank 320 with water (
Once the recirculating solution has reached a desired dissolved or leached metal concentration, the loaded metal-dissolving solution is deemed formed. Recirculation and addition of fresh metal-dissolving solution may be stopped (
The metal-dissolving system 400 depicted in
Systems as described herein, such as the system depicted in
The first or second metal-dissolving solution may be circulated through the apparatus with substantially spatial uniformity. The first or second metal-dissolving solution may be circulated through the apparatus with substantially spatial uniformity, under a relatively low hydrostatic load while maintaining substantially uniform metal-dissolving conditions across the length, width and height of the apparatus. The first or second metal-dissolving solution may be provided into the apparatus through a plurality of perforated pipes to more evenly distributed the solution across the apparatus. The metal-dissolving conditions may comprise pH, leaching-reagent ratios, temperature, dissolved metal concentration, or a combination thereof.
The process comprises dissolving metal from the metal-containing substances into the circulating first or second metal-dissolving solution. The first or second metal-dissolving solution may be circulated into the apparatus at a first location and circulated out of the apparatus as a second location. The first location may be positioned at a lower portion of the apparatus, and the second location may be positioned at an upper portion of the apparatus. The process comprises circulating the first metal-dissolving solution through a first recirculation loop, and separately circulating the second metal-dissolving solution through a second recirculation loop. The first recirculation loop may comprise circulating the first metal-dissolving solution from the reactor at the second location to a first recirculation tank, and from the first recirculation tank to the reactor at the first location. The second recirculation loop may comprise circulating the second metal-dissolving solution from the reactor at the second location to a second recirculation tank, and from the second recirculation tank to the reactor at the first location. The process may further comprise providing metal-dissolving reagents into the first or second metal-dissolving solution as the solution circulates from the first or second recirculation tank to the reactor at the first location. The process may further comprise circulating the first or second metal-dissolving solution through the first or second recirculation loop, increasing dissolved or leached metal concentration, and forming a first or second loaded metal-dissolving solution. The first or second loaded metal-dissolving solution comprise dissolved or leached metal at a specific, or desired concentration. Once the first or second loaded metal-dissolving solution is formed, the batch process is complete. The process then comprises flowing the first or second loaded metal-dissolving solution from the first or second recirculation tank for further processing downstream. The process comprises flowing the first loaded metal-dissolving solution downstream while circulating the second metal-dissolving solution through the second recirculation loop. The process further comprises flowing the second loaded metal-dissolving solution downstream while circulating the first metal-dissolving solution through the first recirculation loop.
In an embodiment, the metal-dissolving system 400 depicted in
The process involves feeding metal-containing substances (Metal Feed) into the reactor 410 through an upper portion 480 of the reactor 410, and filing the first recirculation tank 420 with water (
Once the recirculating solution has reached a desired dissolved or leached metal concentration, a first loaded metal-dissolving solution is deemed to have been formed. Recirculation is then diverted from the first recirculation loop 460 to the second recirculation loop 461, where water from the second recirculation tank 430 is circulated through the system 400 using the second recirculation loop 461 with fresh metal dissolving solution added thereto. Concurrently, the first loaded metal-dissolving solution from the recirculation tank 420 is sent downstream for further processing (
In both the systems and process of 300 and 400, recirculation of the semi-pregnant leach solution helps dilute the acidity of the fresh leach solution prior to the reactor and also helps with mass transfer to encourage dissolution of the metal through a greater volume of solution passing through the bed of metal in the reactor.
An embodiment of the present disclosure is a metal-dissolving batch process which comprises recirculating all of a semi-pregnant leach solution through a reactor while simultaneously adding fresh leach solution to the reactor to help leach metal from metal-containing substances within the reactor through mixing. The fresh leach solution and the re-circulated semi-pregnant leach solution may be mixed before being provided into the reactor. The recirculation of the semi-pregnant leach solution may be stopped in response to the amount of metal dissolved in the semi-pregnant leach solution reaching a threshold amount so as to form a pregnant leach solution. The pregnant leach solution may be discharged downstream. While the pregnant leach solution is discharged downstream, the addition of fresh leaching solution to the reactor may be stopped.
The pregnant leach solution from a reactor may be mixed/blended with the pregnant leach solution(s) of one or more other reactors to form a final pregnant leach solution that has a desired level of dissolved metals therein. By using multiple batch metal dissolving processes as described herein, and combining the resulting pregnant leach solutions of those individual batch processes in certain amounts, it may be possible to better control the final amount of dissolved metal being sent downstream. Furthermore, this mixing of PLSs may allow the reactors to collectively process a wider variety of metal-containing substances, including without the need to pre-blend the metal-containing substances prior to providing into the reactor(s). The types and amounts of metal in the metal-containing substances that is provided into a reactor may vary significantly over time.
A system and method for controlling the metal-dissolving apparatus as described herein may comprise one or more of the following considerations or limitations. Systems and methods for controlling the apparatuses described in
The apparatuses or systems as described herein, for example the apparatuses described in
Use of such instrumentation and corresponding readings may enable controlling the herein described apparatuses or systems to affect discharge solution composition, and/or to help avoid a large recirculation tank. An example is outlined in the table below of a method (including selected parameters) for controlling herein described apparatuses/reactors using said aforementioned readings according to a “pull” control strategy. A similar method exists for a “push” based control strategy.
The above control method is representative only. With the instrumentation scheme, an automated control scheme may be enacted to keep the composition of the stream from this system to the next process stage within tight bounds.
This application claims priority to and the benefit of, and incorporates by reference the entire contents of, U.S. Provisional Application App. No. 63/392,641 filed Jul. 27, 2022.
| Number | Date | Country | |
|---|---|---|---|
| 63392641 | Jul 2022 | US |
