Method and apparatus for extracting metal from materials

Abstract

This disclosure relates to apparatus and methods for selectively recovering a target metal or mineral from a mixture / solution containing a metal or mineral.

Description

[Technical Field]

[0001] The present invention relates generally to the technical field of extracting metals from industrial streams in the fields of mining, metal refining, waste treatment and valuation, and recycling of critical materials, and more specifically to apparatus and methods for recovering metals and minerals from materials. [Background technology]

[0002] Streams containing metals and minerals are generated from a variety of sources, including batteries, mining processes, and recycling and refining operations.

[0003] The global mining, refining, and recycling industries are facing increasing pressure to reduce their environmental impact. These industries rely on concentrators to produce concentrates containing complex mixtures of base materials or metals and other materials for shipment to smelters. In mining, this process leaves a significant amount of finely ground minerals and / or toxic chemicals in the tailings left on the mine site, which can leach into the environment. Such tailings often pose an environmental hazard and require substantial costs for maintenance and / or restoration by mining companies or governments. In refining and recycling, large amounts of chemical inputs and energy are consumed to recover relatively small amounts of high-value, critical materials.

[0004] Copper, silver, and gold are generally extracted from sulfide ores and each possesses unique physicochemical properties, making them essential commodities for industrial applications in addition to their monetary or decorative value. All three metals are excellent electrical conductors. Copper is the third most widely used metal, after iron and aluminum. Naturally occurring copper sulfide deposits are usually found alongside iron, nickel, lead, zinc, and molybdenum sulfides, often containing trace amounts of silver and gold. Chalcopyrite is one of the most common ores from which copper is extracted. Copper has a wide range of applications, such as electrical wires, roofing materials and pipes, and industrial machinery.

[0005] Conventional extraction metallurgical processes for copper extraction generally involve dry metallurgy to recover copper from copper sulfide. Many known recovery processes involve crushing the ore, froth flotation (which selectively separates minerals from gangue by utilizing differences in hydrophobicity) to obtain ore concentrate, and then roasting and reduction with carbon or electrolytic extraction. However, such processes often require expensive mining and beneficiation steps to concentrate the sulfides. Furthermore, the process of producing copper from copper sulfide ore using known techniques generates large amounts of sulfur dioxide, carbon dioxide, and cadmium vapor. Smelting slag and other process residues also contain considerable amounts of heavy metals.

[0006] Turning to the battery sector, as battery technology becomes an indispensable element in today's society, the need for recycling batteries, battery components, and critical battery materials is rapidly increasing. Of particular importance are lithium (Li), cobalt (Co), manganese (Mn), and nickel (Ni). Current methods generally involve crushing critical battery components (e.g., anodes and cathodes) to produce "black mass," leaching the black mass by exposing it to strong acids (e.g., H2SO4 and HCl), adding neutralizing agents (e.g., sodium compounds such as sodium carbonate and sodium hydroxide) to precipitate the valuable materials. Solvent extraction and thermal crystallization are also common process steps to enable further separation and purification of critical materials.

[0007] While these methods are useful, they are not optimal in terms of capital investment costs, operating costs, and environmental impact. Furthermore, chemical precipitation techniques inevitably contaminate the black mass due to residual sodium and other chemicals, making lithium extraction difficult. Therefore, in the field of battery recycling using wet metallurgy, there is a need for novel and useful systems and methods that enable low-cost, environmentally sustainable extraction of critical materials while minimizing chemical precipitation, thermal crystallization, and solvent exchange. [Overview of the Initiative]

[0008] One aspect of this disclosure is an apparatus for extracting a target metal or mineral from a mixture / solution containing a metal or mineral. The apparatus is an electrochemical reactor.

[0009] In one embodiment, the electrochemical reactor includes a flow cell having a plurality of electrodes. The electrodes include one or more anodes and one or more cathodes. In one embodiment, each electrode includes a non-porous or porous electrode material having a roughened surface and includes a voltage source configured to apply a voltage between one or more anodes and one or more cathodes. In some embodiments, the one or more cathodes and anodes form an array in which anodes and cathodes are arranged alternately. In another embodiment, the flow cell is configured to receive a metal-containing solution. In yet another embodiment, the flow cell is a closed-loop or partially closed-loop configuration. The metal-containing solution may optionally originate from a lithium-ion battery recycling stream, a mining production stream (including, but not limited to, heap leachate or pregnant leach solution), a waste stream, a refining stream, or a mining-affected water source.

[0010] In some embodiments, the metal or mineral in question may include, but is not limited to, lithium, manganese, cobalt, nickel, aluminum, iron, copper, lead, zinc, silver, cadmium, precious metals (e.g., gold, silver), platinum group metals (e.g., platinum, palladium, rhodium, ruthenium, osmium, iridium, rhenium), rare earth elements (e.g., lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium), mercury, thallium, selenium, bismuth, lead, uranium, polonium, oxides or hydroxides thereof, or combinations thereof.

[0011] In some embodiments, the electrode material includes silicon, carbon, stainless steel, ferroalloy, lead alloy, or a combination thereof. In other embodiments, at least one of the electrodes is a silicon electrode. In one embodiment, the recovered metal is periodically peeled off from the silicon electrode, and the silicon electrode is reusable.

[0012] In some embodiments of the present disclosure, the electrodes are in a series flow configuration or a parallel flow configuration.

[0013] In some embodiments of the present disclosure, the distance between the electrodes ranges from about 1 mm to about 100 cm.

[0014] In other embodiments of the present disclosure, the thickness of the electrode ranges from about 200 μm to about 1 cm.

[0015] Another embodiment of the present disclosure includes a method for extracting metal from a metal-containing mixture / solution. The method includes: providing an electrochemical reactor; feeding a metal-containing solution to the electrochemical reactor to flow along the surfaces of a plurality of electrodes or pass through the plurality of electrodes; applying a voltage between the plurality of electrodes; transferring the metal from the metal-containing solution to the plurality of electrodes by electrolytic deposition; selectively depositing the corresponding metal or the corresponding metal oxide or hydroxide on the electrode; and recovering the corresponding metal or the corresponding metal-containing species in situ in the chemical reactor or by removing the electrodes from the reactor by mechanical separation, chemical separation, electrochemical separation, or a combination thereof. including.

[0016] In some embodiments, the electrochemical reactor includes a flow cell having a plurality of electrodes. The electrodes include one or more anodes and one or more cathodes. Each electrode may be a porous or non-porous electrode material having a roughened surface.

[0017] In one embodiment, the applied voltage is in the range of approximately 0V to approximately 20V.

[0018] In one embodiment, the pH of the metal-containing solution ranges from approximately -1 to less than 10.

[0019] In another embodiment, the method further includes maintaining the temperature of the flow cell from about 0°C to about 120°C.

[0020] In one embodiment, the method involves placing approximately 0 to approximately 2Acm between the electrodes. -2 This further includes applying a current density in the range up to .

[0021] In one embodiment, mechanical separation includes air or water jetting, ultrasonic treatment, or mechanical shearing.

[0022] In one embodiment, the chemical separation includes the acidic dissolution of the recovered metal.

[0023] In one embodiment, a silicon electrode coated with the recovered material is combined with a counter electrode made of the same material as the recovered material, and the target metal or mineral is recovered by electrochemical purification in an electrochemical reactor. In another embodiment, the counter electrode for recovery does not have to contain the same material as the recovered target material, but the target material may be selectively recovered by electrochemical purification. [Brief explanation of the drawing]

[0024] Figure 1 is a schematic top view of an example of an electrochemical reactor for extracting metals from a mixture / solution containing metals or minerals.

[0025] Figure 2 is a schematic top view of another example of an electrochemical reactor for extracting metals from a mixture / solution containing metals or minerals.

[0026] Figure 3A is a schematic top view of an assembled flow cell having comb-like interlocking electrodes in one embodiment of the present disclosure.

[0027] Figure 3B is a schematic diagram of a separated electrode for metal recovery in one embodiment of the present disclosure.

[0028] Figure 4A is a schematic cross-sectional view of the silicon anode-cathode combination inside the flow cell / reactor.

[0029] Figure 4B shows a different view of the same cell / reactor as in Figure 4A.

[0030] Figure 5A shows an example of a stream path for a solution / mixture passing through a silicon electrode in an electrochemical reactor.

[0031] Figure 5B shows an example of a flow path for a solution / mixture around a silicon electrode in an electrochemical reactor.

[0032] Figure 6A is a graph of voltage against time in a relevant operating environment for an example platinum-clad silicon anode.

[0033] Figure 6B is a graph of voltage against time in the relevant operating environment for an example platinum / iridium-coated silicon anode.

[0034] Figure 7 shows the results of copper extraction from a complex acidic aqueous stream in one example.

[0035] Detailed explanation The following description of embodiments of the present invention is not intended to limit the invention to these embodiments, but rather to enable those skilled in the art to implement and use the invention.

[0036] overview Apparatus and methods for extracting metals from materials include electrochemical flow cell reactors. Materials may be primary mining streams such as heap leachate or pregnant leach solution, waste materials, or materials to be purified. Materials may be solvents, solutions, slurries, suspensions, or mixtures containing other mixtures containing the material of interest (e.g., the metal or mineral of interest). Solutions containing metals and minerals may originate from battery recycling, mining, refining, or other processes that produce metal and / or mineral materials. Metals and minerals include, but are not limited to, lithium, manganese, cobalt, nickel, copper, lead, zinc, silver, cadmium, precious metals (e.g., gold, silver), platinum group metals (e.g., platinum, palladium, rhodium, ruthenium, osmium, iridium, rhenium), rare earth elements (e.g., lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium), mercury, thallium, selenium, bismuth, lead, uranium, polonium, ions thereof, or mixtures thereof.

[0037] Disclosed herein are electrochemical flow cell reactors having reusable anode and cathode electrode arrays for the extraction of important metals and minerals. In some examples, the flow cell reactor may utilize reusable silicon electrodes as cathode, anode, or both to electrodeposit target metals or metal oxides or hydroxides from acidic solutions (e.g., battery recycling leachate, primary mining heapleach leachate, purification stream, or mining water). The acidic solution may flow through alternating anode and cathode electrode arrays configured in parallel or series flow configurations (see Figures 1 and 2) and circulate in a closed-loop or partially closed-loop configuration. While it is advantageous that the electrochemical flow cell reactors disclosed herein can operate with acidic solutions (e.g., pH < 7.0), and even highly acidic solutions (e.g., pH < 2.0), it is also envisioned that the reactors will be compatible with basic solutions (e.g., pH > 7.0). In a partially closed-loop configuration, the process flow may circulate a predetermined number of times, and then, after the circulation is complete, flow to another stage downstream. A voltage / current may be applied between the cathode and anode to selectively electrolyze a specific target metal or mineral from a solution. Selectivity may be based on the electrochemical potential of reduction of the target material. In broader processes, it may be necessary to combine several extraction stages to first remove contaminants to be extracted at a lower voltage. A feedback loop may be used to adjust the voltage in real time based on sensor data to reach the ideal voltage for the extraction of a specific target material.

[0038] After electrodeposition, the electrodes may be removed from the flow cell, and the target metal may be recovered by mechanical separation (e.g., sonication, mechanical shearing, air jet, water jet), chemical separation (e.g., acidic dissolution of the recovered metal), or electrochemical separation (e.g., applied voltage / current, electrolytic refining). This recovery of the target material may be carried out in situ within the electrochemical reactor.

[0039] In some modifications, the electrodes may be a comb-like interlocking anode and cathode that can be easily disassembled and reassembled to quickly recover the electrodeposited material. In various examples, the electrodeposited material may include, but is not limited to, lithium, manganese, cobalt, nickel, copper, lead, zinc, silver, cadmium, precious metals (e.g., gold, silver), platinum group metals (e.g., platinum, palladium, rhodium, ruthenium, osmium, iridium, rhenium), rare earth elements (e.g., lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium), mercury, thallium, selenium, bismuth, lead, uranium, polonium, their oxides or hydroxides, or combinations thereof.

[0040] The apparatus and methods may be particularly applicable to the extraction of target materials from battery leaching solutions (e.g., those applied to battery recycling). That is, the systems and methods may be applicable to the extraction of typical battery compounds (e.g., lithium carbonate, lithium hydroxide, cobalt sulfate, nickel sulfate, manganese oxide) from batteries or battery leaching solutions (e.g., black mass leaching solutions). In some examples, the main black mass components include, but are not limited to, Al, Co, Cu, Fe, Li, Ni, Ag, Zn, Mn, graphite, F, P, and their ions.

[0041] The apparatus and methods may be applicable to the extraction of target materials from heap leachate or pregnant leach solution in the production of primary metals, including but not limited to copper, cobalt, nickel, gold, platinum, and palladium.

[0042] The apparatus and methods may be applicable, in particular, to the extraction of target materials from metal refining or recycling streams, specifically from the refining or recycling of precious metals or platinum group metals.

[0043] The apparatus and methods disclosed herein offer advantages over currently used electrodes or extraction methods. For example, at least one of the anode / cathode may be silicon, which can be reused after the recovery of the target material / metal. Silicon electrodes offer improved extraction of important materials in terms of durability, cost, efficiency, and performance compared to common electrode materials such as carbon, titanium, platinum, and stainless steel. Furthermore, the comb-like interlocking electrodes allow for rapid assembly / disassembly for the recovery of electrodeposited metals / metal oxides. In some examples, silicon is more durable than common electrode materials, and using silicon as both the anode and cathode allows for use in highly acidic solutions such as concentrated sulfuric acid, nitric acid, and hydrochloric acid, as well as more difficult mixtures such as aqua regia (nitric acid + hydrochloric acid). When using silicon electrodes, the target material can be electrolyzed directly from the acidic stream, eliminating the need for neutralizing chemicals in the electro-extraction process. Moreover, the acid may be reused. Electroextraction at low pH (e.g., pH < 2.0) also offers several unique performance advantages, such as enabling highly selective separation of Co and Ni (e.g., Co is extracted while Ni remains), which does not occur at higher pH levels (where they are almost always extracted together).

[0044] In some embodiments, silicon anodes / cathodes may be coated or functionalized with one or more coating materials that serve to improve the durability, efficiency, and performance of the electrodes. In one example, coating a silicon anode has the effect of lowering the anode voltage, thereby increasing extraction efficiency. Coating also increases the long-term chemical and electrochemical stability of the electrodes. Coating materials include, but are not limited to, Ti, Ni, Co, Cu, Ag, Pt, Pd, Au, Ir, Hf, Pb, Sb, Ca, Ru, Rh, or combinations thereof. Coating materials may exist as metals or as compounds such as oxides or silicides thereof. The coating may consist of a combination of two or more coating materials. The thickness of the coating may range from about 1 nm to about 500 nm.

[0045] The coating material may be deposited by physical vapor deposition (e.g., magnetron sputtering, electron beam deposition, thermal deposition, pulsed laser deposition), electroplating, ion implantation, thermal spray deposition, or chemical vapor deposition. The coating may then be further refined by thermal annealing. In some examples, the electrode surface may be pretreated prior to deposition by ion beam etching or immersion in hydrofluoric acid with a HF concentration range of about 0.1% to about 50% by weight in water. electrochemical reactor An electrochemical reactor for extracting metals from waste materials includes a flow cell. The flow cell includes multiple electrodes in a closed-loop or partially closed-loop configuration. The electrodes may consist of one or more cathodes and / or one or more anodes.

[0046] In some embodiments, an electrochemical reactor may have multiple alternating anodes and cathodes. Figure 1 shows an exemplary electrochemical reactor 100 in which cathode 102 and anode 104 may be arranged in a series flow configuration. The flow of a solution containing a metal or mineral may alternately change direction as it flows between the multiple alternating cathodes 102 and anode 104, as indicated by the arrows in Figure 1. Figure 2 shows an exemplary electrochemical reactor 200 in which cathode 202 and anode 204 may be arranged in a parallel flow configuration. The flow of a solution containing a metal or mineral may be in the same direction as it flows between the multiple alternating cathodes and anodes, as indicated by the arrows in Figure 2. In various examples, an electrochemical reactor may include 1, 2, 3, 4, 5, or more anodes and 1, 2, 3, 4, 5, or more cathodes. An electrochemical reactor may contain approximately 1 to 5, approximately 5 to 10, approximately 10 to 50, approximately 50 to 100, approximately 100 to 500, or approximately 500 to 100 anodes / cathodes. An electrochemical reactor may contain an equal number of anodes and cathodes. For example, an electrochemical reactor may contain 4 anodes and 4 cathodes arranged alternately in a parallel flow configuration. In another example, an electrochemical reactor may contain 4 anodes and 4 cathodes arranged alternately in a series flow configuration. In yet another example, an electrochemical reactor may contain a different number of anodes and cathodes. In yet another example, electrochemical reactor 300 may contain a comb-shaped interlocking cathode 302 and a comb-shaped interlocking anode 304, as shown in Figure 3A.

[0047] Figure 4A is a schematic cross-sectional view of an exemplary electrochemical reactor 400 having a single silicon anode-cathode pair. The electrochemical reactor 400 may include an anode 402, a cathode 404, energizing leads 406 positioned in electrode holders 408 for each of the anode 402 and cathode 404, and a housing 410 forming a flow cell 411. The electrode holders 408 may further include conductive metal pads 412 and O-rings 414 for securing the leads 406 to the anode 402 or cathode 404. The energizing leads 406 may be electrically connected to a power source (not shown) and to the anode 402 or cathode 404 via the conductive metal pads 412. The housing 410 of the electrochemical reactor 400 may further include an inlet 416 for a metal or mineral-containing solution, an outlet 418 for a metal or mineral-containing solution, and one or more openings 420 for sensor insertion.

[0048] The electrochemical reactor 400 may include one or more sensors (not shown). Non-limiting examples of sensors include pH sensors, conductivity sensors, temperature sensors, UV-visible spectroscopic sensors, oxidation-reduction potential (ORP) sensors, X-ray fluorescence (XRF) sensors, pressure sensors, flow sensors, liquid level sensors, inductively coupled plasma (ICP) sensors, and specific detectors for hazardous materials such as Cl, Br, or F that may be produced as byproducts. In some examples, one or more sensors may be placed directly within the cell. In other examples, a small portion of the stream may be led externally from the main process flow and pass through connected measuring instruments including one or more sensors. In some examples, one or more sensors may be used to signal adjustment of the voltage in the flow cell in a feedback loop to improve selectivity for the material of interest.

[0049] In one example, the reactor shown in Figure 4A can be a subunit of a much larger cell by repeatedly increasing the number of anode / cathode pairs. Figure 4B shows a different view of the same cell / reactor as in Figure 4A.

[0050] In some embodiments, the electrochemical reactor is configured such that a solution containing a metal or mineral flows between or through multiple electrodes. Figures 5A and 5B show exemplary flow paths of a solution / mixture passing through (Figure 5A) or flowing around (Figure 5B) a silicon electrode in an electrochemical reactor. Referring to Figure 5A, the solution containing a metal or mineral enters the electrochemical reactor 500 through the inlet 516, passes through the porous electrode 502, and exits through the outlet 518. Referring to Figure 5B, the solution containing a metal or mineral enters the electrochemical reactor 500 through the inlet 516, flows around the non-porous electrode 502, and exits through the outlet 518.

[0051] The anode and / or cathode may be porous or nonporous. In some examples, if the electrode is porous, the mixture / solution may pass through the pores in the electrode (e.g., Figure 5A), and the target metal may precipitate in the pores. The pores in the porous electrode may be in the following size ranges: about 1 μm to about 1 cm, about 1 μm to about 100 μm, about 100 μm to about 1 mm, about 1 mm to about 2 mm, about 2 mm to about 3 mm, about 3 mm to about 4 mm, about 4 mm to about 5 mm, about 5 mm to about 6 mm, about 6 mm to about 7 mm, about 7 mm to about 8 mm, about 8 mm to about 9 mm, or about 9 mm to about 1 cm. In other examples, if the electrode is nonporous, the mixture / solution may flow along the surface of the electrode between at least one anode and at least one cathode (e.g., Figure 5B). In some examples, the flow of a solution containing a metal or mineral may be perpendicular to the applied voltage when passing between non-porous electrodes. In yet another example, the flow of a solution containing a metal or mineral may be parallel to the applied voltage when passing through porous electrodes.

[0052] In some embodiments of the electrochemical reactor, the anode and cathode may include silicon, carbon, stainless steel, iron alloy, lead alloy, or a combination thereof. In one embodiment, at least one of the anode or cathode may be silicon. In at least one example, at least one anode and at least one cathode include silicon. Without being limited to any one theory, silicon electrodes can reduce H2 gas generation compared to standard stainless steel electrodes, resulting in improved efficiency. In various embodiments, silicon electrodes may be up to 1%, up to 5%, up to 10%, up to 15%, up to 20%, or more than 20% more efficient than stainless steel electrodes when recovering target metals from highly acidic (pH < 2.0) solutions. For example, a silicon cathode may be about 20% more efficient (in terms of kWh / kg) than a stainless steel cathode when extracting copper from an acidic solution containing multiple metals and salts.

[0053] In embodiments, the electrode may consist solely of monolithic silicon. Therefore, the electrode may be a single continuous silicon piece. The monolithic silicon electrode may be modified to be porous. In some examples, the electrode may consist solely of a porous monolithic silicon body without any further layers or coatings (i.e., the monolithic silicon body may lack a coating). In one example, the electrode may be non-laminated. In another example, the electrode may not contain substantially any elements other than silicon. In yet another example, the electrode may be pure silicon. In yet another example, the monolithic structure may not be hindered or blocked by non-silicon components. In one example, the silicon may be substantially free to interact with ions. Alternatively, the silicon body may consist of multiple pieces (e.g., layers of silicon, layers of silicon with other materials, coatings, etc.). In various examples, the electrode may contain at least 98% by weight, at least 99% by weight, at least 99.5% by weight, at least 99.9% by weight, or 100% by weight of silicon.

[0054] In some embodiments of this disclosure, the silicon anode or cathode is N-type doped with a group V element. In some embodiments, the element is phosphorus or arsenic. In some embodiments, the silicon anode or cathode is P-type doped with boron. In some embodiments, the silicon anode and / or cathode is a wafer or plate. For example, electrodes in an electrochemical reactor may be monolithic silicon wafers. In some embodiments, the silicon surface may be roughened, porous, non-porous, polished, or a combination thereof. Non-porous electrodes are easy to manufacture, while porous electrodes provide a larger surface area. The surface may be treated by mechanical roughening, laser cutting, metal-assisted chemical etching, sandblasting, or a combination thereof. Roughening results in an increased surface area for electrodeposition or improved adhesion of electrodeposition material to the electrode. The electrode roughness (Rz) can range from approximately 1 nm to approximately 10 μm, approximately 1 nm to approximately 1 μm (e.g., smoothed / polished silicon), approximately 2 μm to approximately 5 μm (e.g., rough, unpolished silicon), approximately 3 μm to approximately 10 μm (e.g., laser-roughened silicon), or approximately 1 μm to approximately 10 μm (e.g., sandblasted silicon). In some examples, the electrode roughness may be measured by a profilometer.

[0055] In some embodiments, the silicon anode and / or cathode may be coated or functionalized with one or more coating materials that serve to improve the durability, efficiency, and performance of the electrodes. For example, without being limited to any one theory, coatings can improve the electrochemical stability of the electrode material over time, which may result in a longer lifespan and higher electrochemical efficiency. Furthermore, coating the silicon anode may act to lower the anode voltage, thereby improving extraction efficiency. In some examples, both the anode and cathode may be coated, the anode may be coated but the cathode may not, the cathode may be coated but the anode may not, or both the anode and cathode may be coated.

[0056] Figures 6A and 6B compare a Pt-coated Si anode (Figure 6A) and a Pt / Ir-coated Si anode (Figure 6B) in terms of voltage over time in the relevant operating environment. Higher stability of the coated anode leads to a longer lifespan, and lower voltages lead to higher efficiency. The stability of the coated electrode can be maintained over long periods. For example, a coated silicon electrode can maintain voltage stability (e.g., the voltage does not exceed the initially applied voltage) for at least 100 hours, at least 200 hours, at least 300 hours, at least 400 hours, at least 500 hours, at least 600 hours, or at least 700 hours.

[0057] The coating material may, but is not limited to, include Ti, Ni, Co, Cu, Ag, Pt, Pd, Au, Ir, Hf, Pb, Sb, Ca, Ru, Rh, C, W, Bi, or combinations thereof. For example, the coating material may, but is not limited to, include Ti, Ni, Co, Cu, Ag, Pt, Pd, Au, Ir, Hf, Pb, Sb, Ca, Ru, Rh, or combinations thereof. The coating material may exist as a metal, or as a compound such as an oxide or silicide.For example, coatings include Ti / Ni, Ti / Co, Ti / Cu, Ti / Ag, Ti / Pt, Ti / Pd, Ti / Au, Ti / Ir, Ti / Hf, Ti / Pb, Ti / Pb, Ti / Sb, Ti / Ca, Ti / Ru, Ti / Rh, Ni / Co, Ni / Cu, Ni / Ag, Ni / Pt, Ni / Pd, Ni / Au, Ni / Ir, Ni / Hf, Ni / Pb, Ni / Sb, Ni / Ca, Ni / Ru, Ni / Rh, Co / Cu, Co / Ag, Co / Pt, Co / Pd, C o / Pd, Co / Au, Co / Ir, Co / Hf, Co / Pb, Co / Sb, Co / Ca, Co / Ru, Co / Rh, Cu / Ag, Cu / Pt, Cu / Pd, Cu / Au, Cu / Ir, Cu / Hf, Cu / Pb, Cu / Sb, Cu / Ca, Cu / Ru, Cu / Rh, Ag / Pt, Ag / Pd, Ag / Au, Ag / Ir, Ag / Hf, Ag / Pb, Ag / Sb, Ag / Ca, Ag / Ru, Ag / Rh, Pt / Pd, Pt / Au, Pt / Ir, Pt / Hf , Pt / Pb, Pt / Sb, Pt / Ca, Pt / Ru, Pt / Rh, Pd / Au, Pd / Ir, Pd / Hf, Pd / Pb, Pd / Sb, Pd / Ca, Pd / Ru, Pd / Rh, Au / Ir, Au / Hf, Au / Pb, Au / S b, Au / Ca, Au / Ru, Au / Rh, Ir / Hf, Ir / Pb, Ir / Sb, Ir / Ca, Ir / Ru, Ir / Rh, Hf / Pb, Hf / Sb, Hf / Ca, Hf / Ru, Hf / Rh, Pb / Sb, Pb / Ca, Pb / The coating may be Ru, Pb / Rh, Sb / Ca, Sb / Ru, Sb / Rh, Ca / Ru, Ca / Rh, Ru / Rh, Pt / Ni, Pt / Pb / Sb, Pt / Pb / Sb / Ca, Pt / Ir, Pt / Ru, Pt / Bi, Pt / W, Au / Ni, Au / Pb / Sb, Au / Pb / Sb / Ca, Au / Ir, Au / Ru, Au / Ni, Au / W, Au / Bi, C / Ni, Cu / Pb / Sb, C / Pb / Sb / Ca, C / Ir, C / Ru, C / W, or C / Bi. In one example, the coating may be Pt / N. In one example, the coating may be Pt / Pb / Sb. In one example, the coating may be Pt / Pb / Sb / Ca. In one example, the coating may be Pt / Ir. In one example, the coating may be Pt / Ru. In another example, the coating may be Pt / Bi. In another example, the coating may be Pt / W. In another example, the coating may be Au / Ni.In one example, the coating may be Au / Pb / Sb. In one example, the coating may be Au / Pb / Sb / Ca. In one example, the coating may be Au / Ir. In one example, the coating may be Au / Ru. In one example, the coating may be Au / Ni. In one example, the coating may be Au / W. In one example, the coating may be Au / Bi. In one example, the coating may be C / Ni. In one example, the coating may be Cu / Pb / Sb. In one example, the coating may be C / Pb / Sb / Ca. In one example, the coating may be C / Ir. In one example, the coating may be C / Ru. In one example, the coating may be C / W. In one example, the coating may be C / Bi.

[0058] Many coating materials are very expensive, and therefore their use is not scalable. Thus, instead of using these materials for the entire electrode material, a thin coating can be applied only to the silicon electrode, thereby leveraging the properties of the coating material without cost or scalability issues. The thickness of the material coating can range from approximately 0.5 nm to approximately 500 nm. For example, a coating consisting of one or more coating materials on a silicon anode or silicon cathode may have a thickness of approximately 0.5 nm to approximately 1 nm, approximately 1 nm to approximately 10 nm, approximately 10 nm to approximately 50 nm, approximately 50 nm to approximately 100 nm, approximately 100 nm to approximately 150 nm, approximately 150 nm to approximately 200 nm, approximately 200 nm to approximately 250 nm, approximately 250 nm to approximately 300 nm, approximately 300 nm to approximately 350 nm, approximately 350 nm to approximately 400 nm, approximately 400 nm to approximately 450 nm, or approximately 450 nm to approximately 500 nm. In at least one example, the coating may have a thickness of approximately 50 nm to approximately 100 nm.

[0059] In some embodiments, silicon can have resistivity ranging from about 0.0001 Ω·cm to about 100 Ω·cm. For example, resistivity ranges from about 0.001 Ω·cm to about 0.005 Ω·cm, from about 0.0005 Ω·cm to about 95 Ω·cm, from about 0.001 Ω·cm to about 90 Ω·cm, from about 0.005 Ω·cm to about 85 Ω·cm, from about 0.001 Ω·cm to about 80 Ω·cm, from about 0.05 Ω·cm to about 75 Ω·cm, from about 0.01 Ω·cm to about 70 Ω·cm, from about 0.5 Ω·cm to about 65 Ω·cm, from about 0.1 Ω·cm to about 60 Ω·cm, from about 1.0 Ω·cm to about 55 Ω·cm, and about The resistivity can range from 1.5 Ω·cm to approximately 50 Ω·cm, from approximately 2.0 Ω·cm to approximately 45 Ω·cm, from approximately 2.5 Ω·cm to approximately 40 Ω·cm, from approximately 3.0 Ω·cm to approximately 35 Ω·cm, from approximately 3.5 Ω·cm to approximately 30 Ω·cm, from approximately 4.0 Ω·cm to approximately 25 Ω·cm, from approximately 4.5 Ω·cm to approximately 20 Ω·cm, from approximately 5.0 Ω·cm to approximately 15 Ω·cm, from approximately 5.5 Ω·cm to approximately 10 Ω·cm, from approximately 6.0 Ω·cm to approximately 9.0 Ω·cm, or from approximately 7.0 Ω·cm to approximately 8.0 Ω·cm. In some examples, the resistivity can be measured using a four-point probe.

[0060] In some embodiments of this disclosure, the silicon electrode may be reusable. The metal may be recovered from the electrode in situ within a flow cell or in a separate recovery tank. In some embodiments, the target metal or mineral is electrochemically purified by pairing a silicon electrode coated with the recovered material with a counter electrode in an electrochemical cell. The recovered target metal selectively migrates from the electrode to the counter electrode, thereby further purifying the target metal, and the silicon may be regenerated for further use. In one embodiment, the counter electrode may be composed of the target material. In one embodiment, the counter electrode may contain the pure target metal. For example, a silicon electrode electrodeocted with copper after recovery is placed in an electrochemical cell with a counter electrode made of pure copper foil, and the recovered copper selectively migrates from the silicon to the pure copper, thereby further purifying the copper, and the silicon may be regenerated for further use. In other embodiments, the counter electrode for recovery does not have to contain the same material as the recovered target material, but the target material can still be selectively recovered. A counter electrode having the same or different material as the target material may be configured to achieve both the removal of the target material from Si and an improvement in purity (e.g., electrolytic refining).

[0061] In some embodiments of this disclosure, either the anode or the cathode may include carbon. In some examples, the carbon may be graphitic, glassy, ​​or a combination thereof. In other embodiments, the carbon may be felt, paper, or a plate.

[0062] In some aspects of this disclosure, the spacing between consecutive electrodes may range from about 0.1 cm to about 100 cm. For example, the spacing may range from about 0.1 cm to about 100 cm, about 0.5 cm to about 90 cm, about 1 cm to about 80 cm, about 1.5 cm to about 70 cm, about 2 cm to about 60 cm, about 2.5 cm to about 50 cm, about 3 cm to about 40 cm, about 3.5 cm to about 30 cm, about 4 cm to about 20 cm, about 4.5 cm to about 10 cm, about 5 cm to about 8.0 cm, and about 0.6 cm to about 7 cm. It could be approximately 0.1 cm to 1 cm, approximately 1 cm to 5 cm, approximately 5 cm to 10 cm, approximately 10 cm to 20 cm, approximately 20 cm to 30 cm, approximately 30 cm to 40 cm, approximately 40 cm to 50 cm, approximately 50 cm to 60 cm, approximately 60 cm to 70 cm, approximately 70 cm to 80 cm, approximately 80 cm to 90 cm, or approximately 90 cm to 100 cm.

[0063] In some aspects of this disclosure, the electrode thickness may range from about 0.2 mm to about 1 cm. For example, the thickness may range from about 0.3 mm to about 9.5 mm, about 0.4 mm to about 9.0 mm, about 0.5 mm to about 8.5 mm, about 0.6 mm to about 8.0 mm, about 0.7 mm to about 7.5 mm, about 0.8 mm to about 7.0 mm, about 0.9 mm to about 6.5 mm, about 1.0 mm to about 6.0 mm, about 1.5 mm to about 5.5 mm, about 2.0 mm to about 5.0 mm, about 2.5 mm to about 4.5 mm, about 3.0 mm to about 4.0 mm, about 3.2 mm to about 3.8 mm, about 0.2 mm to about 1 mm, about 1 mm to about 3 mm, about 2 mm to about 4 mm, about 3 mm to about 5 mm, about 4 mm to about 6 mm, about 5 mm to about 7 mm, about It could be 6mm to approximately 8mm, approximately 7mm to approximately 9mm, approximately 8mm to approximately 10mm, approximately 10mm to approximately 15mm, approximately 15mm to approximately 20mm, approximately 20mm to approximately 25mm, approximately 25mm to approximately 30mm, approximately 30mm to approximately 35mm, approximately 35mm to approximately 40mm, approximately 40mm to approximately 45mm, approximately 45mm to approximately 50mm, approximately 50mm to approximately 55mm, approximately 55mm to approximately 60mm, approximately 60mm to approximately 65mm, approximately 65mm to approximately 70mm, approximately 70mm to approximately 75mm, approximately 75mm to approximately 80mm, approximately 80mm to approximately 85mm, approximately 85mm to approximately 90mm, approximately 90mm to approximately 95mm, or approximately 95mm to approximately 1cm.

[0064] In one embodiment, the electrodes are arranged to interlock in a comb-like manner for rapid removal and retrieval. Figure 3A shows an example of a comb-like interlocking cathode and a comb-like interlocking anode. In some embodiments, the cathode and anode are in an interlocking comb-like arrangement. Each electrode may have one, two, three, four, five, or more protrusions, with the cathode protrusions and anode protrusions alternating. In some embodiments, the electrodes may have the same or different numbers of protrusions. In various examples, the gaps between the protrusions may be the same distance as the spacing between consecutive electrodes described above.

[0065] In some embodiments, the electrochemical reactor may be easily assembled and easily disassembled. For example, the comb-like interlocking electrodes may be easily separated from each other, as shown in Figure 3B, and placed in separate recovery tanks for the recovery of the electrodeposited metal or metal oxide.

[0066] In some embodiments, the electrochemical reactor may further include a voltage source connected to the electrodes. In some embodiments, the voltage applied between the anode and cathode may range from about 0.1V to about 5V. Applying a voltage between the electrodes generates an electric field. The electric field facilitates the electrodeposition of the target metal or metal oxide onto the cathode and / or anode. The electric field is adjustable to select the desired metal.

[0067] In some examples, the voltage can be from about 0.1V to about 20V. For example, the voltage can be from about 0.1V to about 0.5V, from about 0.5V to about 1V, from about 1V to about 1.5V, from about 1.5V to about 2V, from about 2V to about 2.5V, from about 2.5V to about 3V, from about 3V to about 3.5V, from about 3.5V to about 4V, from about 4V to about 4.5V, from about 4.5V to about 5V, from about 5V to about 6V, from about 6V to about 7V, from about 7V to about 8V, from about 8V to about 9V, from about 9V to about 10V, from about 10V to about 11V, from about 11V to about 12V, from about 12V to about 13V, from about 13V to about 14V, from about 14V to about 15V, from about 15V to about 16V, from about 16V to about 17V, from about 17V to about 18V, from about 18V to about 19V, or from about 19V to about 20V. In one aspect, the current density can be in the range of about 0 to about 2A cm -2 In some examples, the current density can be 0.1A cm -2 0.2A cm -2 0.3A cm -2 0.4A cm -2 0.5A cm -2 0.6A cm -2 0.7A cm -2 0.8A cm -2 0.9A cm -2 1.0A cm -2 1.1A cm -2 1.2A cm -2 1.3A cm -2 1.4A cm -2 1.5A cm -2 1.6A cm -2 1.7A cm -2 1.8A cm -2 1.9A cm -2 or 2.0A cm -2 It can be.

[0068] In some embodiments, the electrochemical reactor may further include an external heat source, such as a heating coil or other heating mechanism known in the field. The heat source may be configured to heat the electrochemical reactor to a temperature in the range of about 0°C to about 120°C, about 0°C to about 10°C, about 10°C to about 20°C, about 20°C to about 30°C, about 30°C to about 40°C, about 40°C to about 50°C, about 50°C to about 60°C, about 60°C to about 70°C, about 70°C to about 80°C, about 80°C to about 85°C, about 85°C to about 90°C, about 90°C to about 95°C, about 95°C to about 100°C, about 100°C to about 110°C, or about 110°C to about 120°C.

[0069] [method] A method for extracting metals from waste material may include the following steps: supplying a mixture or a solution containing a metal or mineral to an electrochemical reactor having multiple electrodes; flowing the metal-containing solution through the multiple electrodes; applying a voltage between the multiple electrodes to transfer the target metal from the mixture or metal-containing solution to the electrodes by electrolytic extraction; depositing the target metal or an oxide of the target metal on the electrodes; and recovering the target metal or an oxide of the target metal by mechanical separation, chemical separation, electrochemical separation, or a combination thereof. In some embodiments, the method may further include assembling an electrochemical reactor having a flow cell with multiple electrodes. In other embodiments, the electrochemical reactor may already be assembled with multiple electrodes.

[0070] The metals or minerals covered may include, but are not limited to, lithium, manganese, cobalt, nickel, copper, lead, zinc, silver, cadmium, precious metals (e.g., gold, silver), platinum group metals (e.g., platinum, palladium, rhodium, ruthenium, osmium, iridium, rhenium), rare earth elements (e.g., lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium), mercury, thallium, selenium, bismuth, lead, uranium, polonium, their oxides or hydroxides, or combinations thereof.

[0071] The electrodes of this disclosure are as described above. In some embodiments, the method may further include coating a plurality of electrodes before supplying a solution containing a metal or mineral to an electrochemical reactor. The silicon electrode material may be coated with the coating material. The coating material is not limited to, but includes titanium, nickel, cobalt, copper, silver, platinum, palladium, gold, iridium, hafnium, ruthenium, rhodium, lead, calcium, antimony, combinations thereof, and oxides or silicides thereof (e.g., M x O y Or M x S iy Herein, M is a metal, and x and y may vary depending on the stoichiometry of the metal used for coating. The thickness of these materials may range from 0.5 nm to 500 nm.

[0072] The coating material may be deposited by physical vapor deposition (e.g., magnetron sputtering, electron beam deposition, thermal deposition, pulsed laser deposition), electroplating, ion implantation, thermal spraying, or chemical vapor deposition. In at least one example, the coating material is deposited by magnetron sputtering, a method that provides throughput / scalability and controllability, and allows for high-precision variation of thickness over a wide range. In some embodiments, the steps for coating may include, but are not limited to, roughening the Si surface (by laser rastering or sandblasting), cleaning the Si surface by immersion in hydrofluoric acid (wet chemical treatment) or oxygen / hydrogen plasma (ion beam etching), and subsequently performing sputtering or other deposition methods. Roughening can help the coating material adhere to the electrodes and, further, to the adhesion of the target material to be subsequently extracted. Depending on the circumstances, the coating may be further refined by thermal annealing.

[0073] The hydrofluoric acid (HF) used to clean the Si surface before film formation may be in the following concentration ranges in water: approximately 0.1% to approximately 50% by weight, approximately 0.1% to approximately 1% by weight, approximately 1% to approximately 5% by weight, approximately 5% to approximately 10% by weight, approximately 10% to approximately 15% by weight, approximately 15% to approximately 20% by weight, approximately 20% to approximately 25% by weight, approximately 25% to approximately 30% by weight, approximately 30% to approximately 35% by weight, approximately 35% to approximately 40% by weight, approximately 40% to approximately 45% by weight, or approximately 45% to approximately 50% by weight.

[0074] In one embodiment, the mixture or metal-containing solution may be acidic. In one embodiment, the metal-containing waste liquid may have a pH of about -1 to about 10.0, about -1 to about 2.0, about 1.0 to about 3.0, about 2.0 to about 4.0, about 3.0 to about 5.0, about 4.0 to about 6.0, about 5.0 to about 7.0, about 6.0 to about 8.0, about 7.0 to about 9.0, or about 8.0 to about 10.0.

[0075] The mixture may contain the target metal and a solvent. In one embodiment, the solvent may be an acid. In one embodiment of this method, an acid may be added to the metal-containing solution. The acid may include, but is not limited to, sulfuric acid, hydrochloric acid, nitric acid, or a combination thereof. For example, the pH of the acid may be less than 7, less than 6, less than 5, less than 4, less than 3, less than 2, less than 1, or less than 0.5.

[0076] In some aspects of this method, the voltage applied between the anode and cathode is in the range of approximately 0.1V to approximately 20V. For example, the voltage can be approximately 0.1V to approximately 0.5V, approximately 0.5V to approximately 1V, approximately 1V to approximately 1.5V, approximately 1.5V to approximately 2V, approximately 2V to approximately 2.5V, approximately 2.5V to approximately 3V, approximately 3V to approximately 3.5V, approximately 3.5V to approximately 4V, approximately 4V to approximately 4.5V, approximately 4.5V to approximately 5V, approximately 5V to approximately 6V, approximately 6V to approximately 7V, or approximately 7V. The voltage may be approximately 8V, 8V to 9V, 9V to 10V, 10V to 11V, 11V to 12V, 12V to 13V, 13V to 14V, 14V to 15V, 15V to 16V, 16V to 17V, 17V to 18V, 18V to 19V, or 19V to 20V. When a voltage is applied between the electrodes, an electric field is generated, which promotes the electrodeposition of metal ions onto the electrodes. The electric field is adjustable to select the desired target material. Selectivity is obtained based on the electrochemical potential for reduction of the target material. A feedback loop may be used to adjust or improve the voltage in real time based on sensor data to reach the optimal voltage for extraction of a specific target material.

[0077] In one embodiment, the current density ranges from approximately 0 to approximately 2 A / cm². 2 It is within this range. In some examples, the current density is 0.1 A / cm². 2 , 0.2 A / cm 2 , 0.3 A / cm 2 , 0.4 A / cm 2 , 0.5 A / cm 2 , 0.6 A / cm 2 , 0.7 A / cm 2 , 0.8 A / cm 2 , 0.9 A / cm2 , 1.0 A / cm 2 , 1.1 A / cm 2 , 1.2 A / cm 2 , 1.3 A / cm 2 , 1.4 A / cm 2 , 1.5 A / cm 2 , 1.6 A / cm 2 , 1.7 A / cm 2 , 1.8 A / cm 2 , 1.9 A / cm 2 , or 2.0 A / cm 2 That's fine.

[0078] In some embodiments of this method, the voltage is applied over a period of time ranging from 0.5 hours to 24 hours, about 0.5 hours to about 1 hour, about 1 hour to about 6 hours, about 6 hours to about 12 hours, about 12 hours to about 24 hours, about 24 hours to about 144 hours, about 24 hours to about 48 hours, about 48 hours to about 72 hours, about 72 hours to about 96 hours, about 96 hours to about 120 hours, or about 120 hours to about 144 hours. In some embodiments of this method, the voltage is applied semi-continuously, with short pauses to recover the metal product. In other embodiments, the voltage is applied continuously for one cycle, and the metal product is recovered between cycles. Recovery may include mechanical recovery (scraping), sonication, chemical recovery, or electrochemical recovery. In some examples, the entire electrode rack may be lifted out of the reactor for product recovery, or recovery may be performed in situ within the reactor. Mechanical recovery can take minutes, while electrochemical recovery or electrolytic purification can take hours.

[0079] In some embodiments, the metal or mineral-containing solution circulates continuously through a flow cell while a voltage is applied. For example, the metal or mineral-containing solution may be continuously recirculated through the flow cell for approximately 0.5 to 24 hours, approximately 0.5 to approximately 1 hour, approximately 1 to approximately 6 hours, approximately 6 to approximately 12 hours, approximately 12 to approximately 24 hours, approximately 24 to approximately 144 hours, approximately 24 to approximately 48 hours, approximately 48 to approximately 72 hours, approximately 72 to approximately 96 hours, approximately 96 to approximately 120 hours, or approximately 120 to approximately 144 hours.

[0080] Heat may be supplied to the electrochemical reactor via an external heat source, such as a heating coil or other heating mechanism known in the field. In some embodiments of this disclosure, the temperature is in the range of about 0°C to about 120°C. In some examples, the temperature may be about 0°C to about 120°C, about 0°C to about 10°C, about 10°C to about 20°C, about 20°C to about 30°C, about 30°C to about 40°C, about 40°C to about 50°C, about 50°C to about 60°C, about 60°C to about 70°C, about 70°C to about 80°C, about 80°C to about 85°C, about 85°C to about 90°C, about 90°C to about 95°C, about 95°C to about 100°C, about 100°C to about 110°C, or about 110°C to about 120°C.

[0081] In some embodiments, the method may further include measuring one or more states or properties within a flow cell during the operation of an electrochemical reactor. In some examples, the method may include measuring pH, conductivity, temperature, ultraviolet-visible spectroscopy, oxidation-reduction potential (ORP), X-ray fluorescence (XRF), pressure, flow rate, liquid level, inductively coupled plasma (ICP), or the concentration of hazardous substances such as Cl, Br, or F that may be produced as by-products. One or more states or properties may be measured by one or more sensors. In some examples, one or more sensors may be placed directly within the cell to continuously or periodically measure the state or properties of the solution, flow cell, or electrode while a voltage is applied within the flow cell. In other examples, a small volume of a portion of the flow may be branched from the main process flow and directed to pass through a connected measuring instrument including one or more sensors. The method may further include adjusting the voltage applied between the anode and cathode to selectively deposit the material of interest onto the electrode. In some examples, one or more states or characteristics obtained from one or more sensors may be used to inform a feedback loop that adjusts the voltage in the flow cell in order to adjust / improve the selectivity for the material of interest.

[0082] When the corresponding metal or metal oxide is deposited on the electrode, the corresponding metal is deposited on the cathode and the corresponding metal oxide is deposited on the anode.

[0083] In some embodiments, recovery may be carried out by passing different liquids through a flow cell for chemical separation. For example, the method may involve passing an acidic, aqueous, or solvent-based recovery solution through a flow cell to recover the target metal, target metal oxide, and / or target metal hydroxide without removing the electrodes by mechanical, chemical, or electrochemical separation. In some non-limiting examples, the recovery solution may be sulfuric acid, nitric acid, hydrochloric acid, or aqua regia.

[0084] The metal may be recovered from the electrodes in situ within the electrochemical reactor or in a separate recovery tank. In some embodiments, the method may further include removing the electrodes from the electrochemical reactor to recover the target metal or the corresponding target metal oxide. For example, the target metal or target metal oxide may be recovered by mechanical separation (e.g., sonication, mechanical shearing, mechanical peeling / scraping, water jet, air jet), chemical separation (e.g., acidic dissolution of the recovered metal), electrochemical separation (e.g., application of voltage / current, electrolytic refining), or a combination thereof. The recovery method may be selected based on the properties of the starting mixture / solution and the specific target metal or mineral. In some examples, the mixture / solution may contain a large amount of incorporated liquid, as a result the target metal or mineral may adhere loosely to the electrodes. In this example, mechanical scraping may be used to recover the target metal or mineral. In other examples, the target metal or mineral may form a more continuous layer or foil on the electrode surface, which may be mechanically peeled off. After the electrodes are removed from the electrochemical reactor, they may be placed in a recovery tank. In some examples, the cathode may be placed in one recovery tank, and the anode may be placed in a separate recovery tank.

[0085] In other embodiments, the target metal or the corresponding target metal oxide may be recovered in situ within an electrochemical reactor. In-situ electrochemical purification may be used to achieve a higher purity of the recovered target material or because the product is excessively strongly bonded to silicon. In some embodiments, the target metal or mineral is electrochemically purified by placing a silicon electrode coated with the recovered material in an electrochemical cell in combination with a counter electrode made of the target material. For example, a silicon electrode electrodeocted with copper after recovery is placed in an electrochemical cell together with a counter electrode made of pure copper foil to selectively transfer the recovered copper from silicon to pure copper. This further purifies the material and regenerates the silicon for further use.

[0086] In some cases, the target metal or metal oxide recovered from the cathode may be different from the target metal or metal oxide recovered from the anode.

[0087] This method may include recovering the target metal or mineral in a yield of up to 100%. In various examples, the yield of the target metal or mineral by this method may be about 90% to about 100%, about 90% to about 92%, about 92% to about 94%, about 94% to about 96%, about 96% to about 98%, about 98% to about 100%, about 99% to about 100%, greater than 99%, greater than 99.5%, or greater than 99.9%. The yield can be defined as the absence of any detectable amount of the target material remaining in the mixture / solution after electrolytic extraction. The yield may be improved to approach or reach 100% by increasing the number of electrodes arranged in series, or by circulating the flow of the mixture / solution in a closed loop through a set of electrodes for a certain period of time. The purity of the recovered target metal or mineral may be greater than 95%, greater than 96%, greater than 97%, greater than 98%, greater than 99%, greater than 99.5%, greater than 99.9%, or 100%.

[0088] In this example, a single silicon anode / cathode combination was used in a flow-around configuration (non-porous electrode) to extract copper from a complex acidic (pH approximately 2) solution containing metal. The anode was coated with Pt, while the cathode was not. The metal-containing solution was continuously recirculated through a flow cell, resulting in the depletion of copper over time. Figure 7 shows the yield of copper extracted from the solution over 25 hours, demonstrating that the extraction rate decreases as the yield approaches 100%. Figure 7 further shows that the yield reaches over 90% after approximately 15 hours and over 99% after approximately 22 hours.

[0089] The copper was mechanically recovered from the electrodes by scraping them. definition

[0090] As used herein, the term "about" is used to provide flexibility in the endpoints of a numerical range by specifying that a given value may be "slightly above" or "slightly below" the endpoint. For example, the endpoint may be within 10%, 8%, 5%, 3%, 2%, or 1% of the stated value. Furthermore, for convenience and brevity, the numerical range "about 50 mg / mL to about 80 mg / mL" should be understood as also providing support for the range "50 mg / mL to 80 mg / mL". The endpoint may also be based on the variability permitted by the appropriate regulatory body, such as the FDA or USP.

[0091] The terms “comprises,” “comprising,” “containing,” and “having” as used herein have the meanings given under U.S. patent law and may mean “includes,” “including,” etc., and are generally interpreted as open-ended terms. The terms “consisting of” or “consists of” are closed terms and include only the components, structures, processes, etc. explicitly listed with the term, as well as those subject to U.S. patent law. The terms “consisting essentially of” or “consists essentially of” have the meanings generally given under U.S. patent law. In particular, these terms are generally closed terms, except that they allow for the inclusion of additional items, materials, components, processes, or elements that do not substantially affect the basic and novel properties or functions. For example, trace components present in a composition but not affecting its properties or characteristics are permitted to exist under the phrase "substantially consisting of," even if they are not explicitly listed in the list of items following the term. Where open-ended terms such as "contain" or "include" are used herein, it is understood that the phrases "substantially consisting of" and "consisting of" should be given the same direct support as they would be given, and vice versa.

[0092] The terms 1, 2, 3, etc., used herein are used to characterize and distinguish various elements, components, regions, layers, and / or sections. These elements, components, regions, layers, and / or sections should not be limited by these terms. Numerical terms may be used to distinguish one element, component, region, layer, and / or section from another. Such use of numerical terms does not imply order or arrangement unless explicitly indicated by the context. Such numerical references may be used interchangeably without departing from the teachings of the embodiments and variations described herein.

[0093] The terms “battery leachate solution,” “black mass leachate,” “mixture solution,” “mixture,” “solution,” “metal or mineral containing solution,” and “feed solution” as used herein may be used interchangeably to refer to a solution flowing into an electrochemical reactor. The solution may be a mixture containing a solvent, slurry, or suspension, or any solution having a viscosity that allows it to flow through the electrochemical reactor.

[0094] As used herein, the terms “material,” “compound,” “product,” and “component” are used to refer to any type of material without prejudice to the generality of the material in question. That is, “compound” may refer to any metal, element, ion, molecule, composite structure, or combination thereof (e.g., metal oxides, metal sulfides).

[0095] As used herein, "roughened" may refer to a surface that has an uneven, uneven, or asymmetrical surface shape.

[0096] As used herein, the terms "electrochemical reactor," "reactor," "flow cell," and "electrochemical flow cell reactor" may be used interchangeably to refer to a system comprising a voltage-applied electrode to which a solution flows around or inside the electrode.

[0097] As those skilled in the art will understand from the above detailed description, as well as from the drawings and claims, various modifications and changes can be made to aspects of the present invention without departing from the scope of the invention as defined by the following claims.

[0098] [Example Clause] [Clause 1] An electrochemical reactor for extracting a target metal or mineral from a solution containing a metal or mineral, wherein the electrochemical reactor comprises the following: A flow cell comprising a plurality of electrodes comprising one or more anodes and one or more cathodes, each electrode comprising electrode material; and A voltage source configured to apply a voltage between one or more anodes and one or more cathodes. Includes, One or more cathodes and anodes form an array in which anodes and cathodes are arranged alternately. A flow cell is configured to extract a target metal or mineral from a solution containing a metal or mineral. Electrochemical reactor. [Clause 2] The flow cell is an electrochemical reactor as described in Clause 1, which is in a closed-loop configuration or a partially closed-loop configuration. [Clause 3] An electrochemical reactor as described in Clause 1, wherein a solution containing a metal or mineral passes between or through multiple electrodes. [Clause 4] The electrochemical reactor described in Clause 3, wherein the flow of a solution containing a metal or mineral is perpendicular to the applied voltage. [Clause 5] The electrochemical reactor described in Clause 1 contains a solution containing metals or minerals from a lithium-ion battery recycling stream, a mining production stream, a mining waste stream, a refining stream, or a water source affected by mining. [Clause 6] The target metal or mineral is selected from the group consisting of lithium, manganese, cobalt, nickel, copper, lead, zinc, silver, cadmium, precious metals (gold, silver), rare earth elements (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium), platinum, palladium, iridium, ruthenium, rhodium, osmium, rhenium, mercury, thallium, selenium, bismuth, lead, uranium, polonium, combinations thereof, and their oxides or hydroxides, as described in Clause 1. [Clause 7] The coating is Pt / N, as described in Clause 6 of the electrochemical reactor. [Clause 8] The coating is Pt / Pb / Sb, as specified in Clause 6 of the electrochemical reactor. [Clause 9] The coating is Pt / Pb / Sb / Ca, as described in Clause 6 of the electrochemical reactor. [Clause 10] The coating is Pt / Ir, as described in Clause 6 of the electrochemical reactor. [Clause 11] The coating is Pt / Ru, as described in Clause 6 of the electrochemical reactor. [Article 12] The coating is Pt / Bi, as described in Clause 6 of the electrochemical reactor. [Clause 13] The coating is Pt / W, as described in Clause 6 of the electrochemical reactor. [Clause 14] The electrochemical reactor as described in Clause 6, the coating may be Au / Ni. [Article 15] The coating is an electrochemical reactor as described in Clause 6, containing Au / Pb / Sb. [Clause 16] The coating is an electrochemical reactor as described in Clause 6, containing Au / Pb / Sb / Ca. [Article 17] The coating is Au / Ir, as described in Clause 6 of the electrochemical reactor. [Clause 18] The coating is Au / Ru, as described in Clause 6 of the electrochemical reactor. [Article 19] The coating is Au / Ni, as described in Clause 6 of the electrochemical reactor. [Clause 20] The coating is an electrochemical reactor as described in Clause 6, including Au / W. [Article 21] The coating is Au / Bi, as described in Clause 6 of the electrochemical reactor. [Article 22] The coating is C / Ni, as described in Clause 6 of the electrochemical reactor. [Article 23] The coating is Cu / Pb / Sb, as described in Clause 6 of the electrochemical reactor. [Article 24] The coating is C / Pb / Sb / Ca, as described in Clause 6 of the electrochemical reactor. [Article 25] The coating is C / Ir, as described in Clause 6 of the electrochemical reactor. [Article 26] The coating is C / Ru, as described in Clause 6 of the electrochemical reactor. [Article 27] The coating is an electrochemical reactor as described in Clause 6, including C / W. [Article 28] The coating is C / Bi, as described in Clause 6 of the electrochemical reactor. [Article 29] The electrochemical reactor as described in Clause 1, wherein the electrode material includes silicon, carbon, stainless steel, iron alloy, lead alloy, or a combination thereof. [Clause 30] The electrochemical reactor according to Clause 29, wherein at least one of the multiple electrodes is a silicon electrode. [Article 31] The silicon electrodes are reusable, as described in Clause 30 of the electrochemical reactor. [Article 32] The electrochemical reactor according to Clause 30, wherein the silicon electrodes are coated with a coating material selected from the group consisting of titanium, nickel, cobalt, copper, silver, platinum, palladium, gold, iridium, hafnium, ruthenium, rhodium, lead, antimony, calcium, and their oxides or silicides. [Article 33] The coating has a thickness ranging from approximately 0.5 nm to approximately 500 nm, as described in Clause 32 of the electrochemical reactor. [Article 34] The electrochemical reactor described in Clause 32, wherein the coating material is formed by physical vapor deposition (magnetron sputtering, electron beam deposition, thermal deposition, pulsed laser deposition), electroplating, ion implantation, thermal spraying, or chemical vapor deposition, and further modified by thermal annealing. [Article 35] The electrochemical reactor according to Clause 1, wherein at least one surface of a plurality of electrodes is treated before coating by ion beam etching or immersion in HF from 0.1% to 50% by weight in water. [Article 36] The electrode material is nonporous, as described in Clause 1 of the electrochemical reactor. [Article 37] The electrode material is porous, as described in Clause 1 of the electrochemical reactor. [Article 38] The electrochemical reactor as described in Clause 1, wherein the surface of the electrode material is roughened by mechanical methods such as polishing, sandblasting, laser roughening, or ion etching, as well as by chemical, thermal, or photon-based methods. [Article 39] The electrochemical reactor according to Clause 1, wherein the multiple electrodes are in a series or parallel flow configuration, and a solution containing a metal or mineral flows through or around the porous electrodes. [Clause 40] The electrochemical reactor as described in Clause 1, wherein the distance between multiple electrodes is in the range of approximately 1 mm to approximately 100 cm. [Article 41] The electrochemical reactor according to Clause 1, wherein the multiple electrodes have a thickness ranging from approximately 200 μm to approximately 1 cm. [Article 42] A method for extracting a target metal from a solution containing a metal or mineral, the method being: To provide an electrochemical reactor comprising a flow cell containing a plurality of electrodes, each electrode having a roughened surface and including one or more anodes and one or more cathodes; A solution containing a metal or mineral is supplied to an electrochemical reactor, thereby causing the metal or mineral-containing solution to flow along the surface of multiple electrodes or to pass through multiple electrodes; Applying a voltage between multiple electrodes; The process of transferring a target metal from a solution containing a metal or mineral to multiple electrodes by electrolysis; Depositing the target metal, the corresponding target metal oxide, or the corresponding target metal hydroxide onto multiple electrodes, and To recover the target metal or the corresponding target metal oxide and / or corresponding target metal hydroxide by mechanical separation, chemical separation, electrochemical separation, or a combination thereof. A method that includes this. [Article 43] The silicon electrode is nonporous, according to the method of clause 42. [Article 44] The silicon electrode is porous, according to the method of clause 42. [Article 45] The method according to Clause 42, wherein the applied voltage is in the range of approximately 0V to approximately 20V. [Article 46] The method according to Clause 42, wherein the pH of the metal-containing solution is approximately -1 to less than 10. [Article 47] The method according to clause 42, further comprising maintaining the temperature of the flow cell in a range of about 0°C to about 120°C. [Clause 48] Between multiple electrodes, approximately 0 to approximately 2 Acm -2 The method according to clause 42, further comprising applying a current density in the range up to . [Article 49] The method according to Clause 42, wherein the target metal is selected from the group consisting of lithium, manganese, cobalt, nickel, copper, lead, zinc, silver, cadmium, precious metals (gold, silver), rare earth elements (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium), platinum, palladium, iridium, ruthenium, rhodium, osmium, rhenium, mercury, thallium, selenium, bismuth, lead, uranium, polonium, combinations thereof, and their oxides or hydroxides. [Clause 50] The coating is as described in Clause 49, including Pt / N. [Article 51] The coating is as described in Clause 49, including Pt / Pb / Sb. [Article 52] The coating is as described in Clause 49, including Pt / Pb / Sb / Ca. [Article 53] The coating is as described in Clause 49, including Pt / Ir. [Article 54] The coating is as described in Clause 49, including Pt / Ru. [Article 55] The coating is as described in Clause 49, including Pt / Bi. [Article 56] The coating is as described in Clause 49, including Pt / W. [Article 57] The coating may be Au / Ni, as described in Clause 49. [Article 58] The coating is as described in Clause 49, including Au / Pb / Sb. [Article 59] The coating is as described in Clause 49, including Au / Pb / Sb / Ca. [Clause 60] The coating is as described in Clause 49, including Au / Ir. [Article 61] The coating is as described in Clause 49, including Au / Ru. [Article 62] The coating is as described in Clause 49, including Au / Ni. [Article 63] The coating is as described in Clause 49, including Au / W. [Article 64] The coating is as described in Clause 49, including Au / Bi. [Article 65] The coating is as described in Clause 49, including C / Ni. [Article 66] The coating is as described in Clause 49, including Cu / Pb / Sb. [Article 67] The coating is as described in Clause 49, including C / Pb / Sb / Ca. [Article 68] The coating is as described in Clause 49, including C / Ir. [Article 69] The coating is as described in Clause 49, including C / Ru. [Article 70] Coatings are as described in Clause 49, including C / W. [Article 71] The coating is as described in Clause 49, including C / Bi. [Article 72] The method according to Clause 42, further comprising flowing an acidic solution, an aqueous solution, or a solvent system solution through a flow cell to recover the target metal, the corresponding target metal oxide, and / or the corresponding target metal hydroxide without removing multiple electrodes by mechanical, chemical, or electrochemical separation. [Article 73] The method according to Clause 42, further comprising disassembling the electrochemical reactor by removing the electrodes and recovering the target metal, the corresponding target metal oxide and / or the corresponding target metal hydroxide. [Article 74] The method according to Clause 42, further comprising recovering the target metal, the corresponding target metal oxide and / or the corresponding target metal hydroxide in situ within an electrochemical reactor. [Article 75] The method according to Clause 74, wherein the target metal, the corresponding target metal oxide and / or the corresponding target metal hydroxide are recovered in situ by placing a counter electrode in an electrochemical reactor, the recovered target metal is selectively moved from multiple electrodes to the counter electrode, thereby further purifying the target metal and regenerating silicon for further use. [Article 76] Mechanical separation is the method according to Clause 42, including ultrasonic treatment, mechanical shearing or mechanical peeling, air jet or water jet. [Article 77] Chemical separation is carried out according to the method of Clause 42, including the acidic dissolution of the recovered metal. [Article 78] Electrochemical separation, including electrolytic purification, as described in Clause 42.

Claims

1. An electrochemical reactor for extracting a target metal or mineral from a solution containing a metal or mineral, wherein the electrochemical reactor comprises the following: A flow cell comprising a plurality of electrodes comprising one or more anodes and one or more cathodes, each electrode comprising electrode material; and A voltage source configured to apply a voltage between one or more anodes and one or more cathodes. Includes, One or more cathodes and anodes form an array in which anodes and cathodes are arranged alternately. A flow cell is configured to extract a target metal or mineral from a solution containing a metal or mineral. Electrochemical reactor.

2. The electrochemical reactor according to claim 1, wherein the flow cell has a closed-loop configuration or a partially closed-loop configuration.

3. The electrochemical reactor according to claim 1, wherein a solution containing a metal or mineral passes between or through a plurality of electrodes.

4. The electrochemical reactor according to claim 3, wherein the flow of a solution containing a metal or mineral is perpendicular to the applied voltage.

5. The electrochemical reactor according to claim 1, wherein the solution containing metals or minerals is from a lithium-ion battery recycling stream, a mining production stream, a mining waste stream, a refining stream, or a water source affected by mining.

6. The electrochemical reactor according to claim 1, wherein the target metal or target mineral is selected from the group consisting of lithium, manganese, cobalt, nickel, copper, lead, zinc, silver, cadmium, precious metals (gold, silver), rare earth elements (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium), platinum, palladium, iridium, ruthenium, rhodium, osmium, rhenium, mercury, thallium, selenium, bismuth, lead, uranium, polonium, combinations thereof, and oxides or hydroxides thereof.

7. The electrochemical reactor according to claim 6, wherein the coating comprises Pt / N.

8. The electrochemical reactor according to claim 6, wherein the coating comprises Pt / Pb / Sb.

9. The electrochemical reactor according to claim 6, wherein the coating comprises Pt / Pb / Sb / Ca.

10. The electrochemical reactor according to claim 6, wherein the coating comprises Pt / Ir.

11. The electrochemical reactor according to claim 6, wherein the coating comprises Pt / Ru.

12. The electrochemical reactor according to claim 6, wherein the coating comprises Pt / Bi.

13. The electrochemical reactor according to claim 6, wherein the coating comprises Pt / W.

14. The electrochemical reactor according to claim 6, wherein the coating may be Au / Ni.

15. The electrochemical reactor according to claim 6, wherein the coating comprises Au / Pb / Sb.

16. The electrochemical reactor according to claim 6, wherein the coating comprises Au / Pb / Sb / Ca.

17. The electrochemical reactor according to claim 6, wherein the coating comprises Au / Ir.

18. The electrochemical reactor according to claim 6, wherein the coating comprises Au / Ru.

19. The electrochemical reactor according to claim 6, wherein the coating comprises Au / Ni.

20. The electrochemical reactor according to claim 6, wherein the coating comprises Au / W.

21. The electrochemical reactor according to claim 6, wherein the coating comprises Au / Bi.

22. The electrochemical reactor according to claim 6, wherein the coating comprises C / Ni.

23. The electrochemical reactor according to claim 6, wherein the coating comprises Cu / Pb / Sb.

24. The electrochemical reactor according to claim 6, wherein the coating comprises C / Pb / Sb / Ca.

25. The electrochemical reactor according to claim 6, wherein the coating comprises C / Ir.

26. The electrochemical reactor according to claim 6, wherein the coating comprises C / Ru.

27. The electrochemical reactor according to claim 6, wherein the coating includes C / W.

28. The electrochemical reactor according to claim 6, wherein the coating comprises C / Bi.

29. The electrochemical reactor according to claim 1, wherein the electrode material includes silicon, carbon, stainless steel, iron alloy, lead alloy, or a combination thereof.

30. The electrochemical reactor according to claim 29, wherein at least one of the multiple electrodes is a silicon electrode.

31. The electrochemical reactor according to claim 30, wherein the silicon electrode is reusable.

32. The electrochemical reactor according to claim 30, wherein the silicon electrode is coated with a coating material selected from the group consisting of titanium, nickel, cobalt, copper, silver, platinum, palladium, gold, iridium, hafnium, ruthenium, rhodium, lead, antimony, calcium, and oxides or silicides thereof.

33. The electrochemical reactor according to claim 32, wherein the coating has a thickness ranging from about 0.5 nm to about 500 nm.

34. The electrochemical reactor according to claim 32, wherein the coating material is formed by a physical vapor deposition method (magnetron sputtering, electron beam deposition, thermal deposition, pulsed laser deposition), electroplating, ion implantation, thermal spraying, or chemical vapor deposition, and is further modified by a thermal annealing treatment.

35. The electrochemical reactor according to claim 1, wherein at least one surface of a plurality of electrodes is treated before coating by ion beam etching or immersion in 0.1% to 50% by weight of HF in water.

36. The electrochemical reactor according to claim 1, wherein the electrode material is non-porous.

37. The electrochemical reactor according to claim 1, wherein the electrode material is porous.

38. The electrochemical reactor according to claim 1, wherein the surface of the electrode material is roughened by a mechanical method such as polishing, sandblasting, laser roughening, or ion etching, a chemical method, a thermal method, or a method using photons.

39. The electrochemical reactor according to claim 1, wherein the multiple electrodes are arranged in a series or parallel flow configuration, and a solution containing a metal or mineral flows through a porous electrode or around a non-porous electrode.

40. The electrochemical reactor according to claim 1, wherein the distance between multiple electrodes is in the range of approximately 1 mm to approximately 100 cm.

41. The electrochemical reactor according to claim 1, wherein the multiple electrodes have a thickness ranging from about 200 μm to about 1 cm.

42. A method for extracting a target metal from a solution containing a metal or mineral, the method being: To provide an electrochemical reactor comprising a flow cell containing a plurality of electrodes, each having one or more anodes and one or more cathodes, wherein each electrode is made of silicon having a roughened surface; A solution containing a metal or mineral is supplied to an electrochemical reactor, thereby causing the metal or mineral-containing solution to flow along the surface of multiple electrodes or to pass through multiple electrodes; Applying a voltage between multiple electrodes; The process of transferring a target metal from a solution containing a metal or mineral to multiple electrodes by electrolysis; Depositing the target metal, the corresponding target metal oxide, or the corresponding target metal hydroxide onto multiple electrodes, and To recover the target metal or the corresponding target metal oxide and / or corresponding target metal hydroxide by mechanical separation, chemical separation, electrochemical separation, or a combination thereof. A method that includes this.

43. The method according to claim 42, wherein the silicon electrode is non-porous.

44. The method according to claim 42, wherein the silicon electrode is porous.

45. The method according to claim 42, wherein the applied voltage is in the range of approximately 0V to approximately 20V.

46. The method according to claim 42, wherein the pH of the metal-containing solution is approximately -1 to less than 10.

47. The method according to claim 42, further comprising maintaining the temperature of the flow cell in a range of about 0°C to about 120°C.

48. Between multiple electrodes, approximately 0 to approximately 2 A cm －２ The method according to claim 42, further comprising applying a current density in the range up to .

49. The method according to claim 42, wherein the target metal is selected from the group consisting of lithium, manganese, cobalt, nickel, copper, lead, zinc, silver, cadmium, precious metals (gold, silver), rare earth elements (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium), platinum, palladium, iridium, ruthenium, rhodium, osmium, rhenium, mercury, thallium, selenium, bismuth, lead, uranium, polonium, combinations thereof, and oxides or hydroxides thereof.

50. The method according to claim 49, wherein the coating comprises Pt / N.

51. The method according to claim 49, wherein the coating comprises Pt / Pb / Sb.

52. The method according to claim 49, wherein the coating comprises Pt / Pb / Sb / Ca.

53. The coating according to claim 49, comprising Pt / Ir.

54. The method according to claim 49, wherein the coating comprises Pt / Ru.

55. The method according to claim 49, wherein the coating comprises Pt / Bi.

56. The method according to claim 49, wherein the coating comprises Pt / W.

57. The method according to claim 49, wherein the coating may be Au / Ni.

58. The method according to claim 49, wherein the coating comprises Au / Pb / Sb.

59. The method according to claim 49, wherein the coating comprises Au / Pb / Sb / Ca.

60. The method according to claim 49, wherein the coating comprises Au / Ir.

61. The method according to claim 49, wherein the coating comprises Au / Ru.

62. The method according to claim 49, wherein the coating comprises Au / Ni.

63. The method according to claim 49, wherein the coating comprises Au / W.

64. The method according to claim 49, wherein the coating comprises Au / Bi.

65. The method according to claim 49, wherein the coating comprises C / Ni.

66. The method according to claim 49, wherein the coating comprises Cu / Pb / Sb.

67. The method according to claim 49, wherein the coating comprises C / Pb / Sb / Ca.

68. The coating according to claim 49, comprising C / Ir.

69. The method according to claim 49, wherein the coating comprises C / Ru.

70. The method according to claim 49, wherein the coating includes C / W.

71. The method according to claim 49, wherein the coating comprises C / Bi.

72. The method according to claim 42, further comprising flowing an acidic solution, an aqueous solution, or a solvent system through a flow cell to recover the target metal, the corresponding target metal oxide, and / or the corresponding target metal hydroxide without removing multiple electrodes by mechanical, chemical, or electrochemical separation.

73. The method according to claim 42, further comprising disassembling the electrochemical reactor by removing the electrodes and recovering the target metal, the corresponding target metal oxide and / or the corresponding target metal hydroxide.

74. The method according to claim 42, further comprising recovering the target metal, the corresponding target metal oxide and / or the corresponding target metal hydroxide in situ within an electrochemical reactor.

75. The method according to claim 74, wherein a target metal, a corresponding target metal oxide and / or a corresponding target metal hydroxide are recovered in situ by placing a counter electrode in an electrochemical reactor, and the recovered target metal is selectively moved from a plurality of electrodes to the counter electrode, thereby further purifying the target metal and regenerating silicon for further use.

76. The method according to claim 42, wherein the mechanical separation includes ultrasonic treatment, mechanical shearing or mechanical peeling, air jet or water jet.

77. The method according to claim 42, wherein the chemical separation includes the acidic dissolution of the recovered metal.

78. The method according to claim 42, wherein the electrochemical separation includes electrolytic purification.

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