ELECTROCHEMICAL MEMBRANE REACTOR SYSTEMS FOR REMOVING LITHIUM FROM A LITHIUM-CONTAINING SOLUTION AND RELATED METHODS
20250257491 ยท 2025-08-14
Inventors
Cpc classification
B01D61/445
PERFORMING OPERATIONS; TRANSPORTING
B01D61/463
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
Systems and methods for removing lithium from a lithium-containing solution producing a lithium-enriched stream. The system includes a first electrochemical membrane reactor including one or more working electrodes, one or more counter electrodes, one or more ion exchange membranes, one or more optional bipolar membranes, and a power source configured to apply a voltage to the first electrochemical membrane reactor. A second electrochemical membrane reactor is configured to remove lithium from the lithium enriched stream. The first electrochemical membrane reactor may be coupled to the second electrochemical membrane reactor. The second electrochemical membrane reactor includes one or more working electrodes, one or more counter electrodes, one or more ion exchange membranes, and a power source configured to apply a voltage to the second electrochemical membrane reactor.
Claims
1. A system comprising: a first electrochemical membrane reactor configured to process a solution comprising lithium and one or more elements, the first electrochemical membrane reactor configured to remove at least one of the one or more elements and to form a lithium enriched stream, the first electrochemical membrane reactor comprising: one or more working electrodes in a first chamber; one or more anion exchange membranes in the first chamber; one or more cation exchange membranes in the second chamber; a second chamber between one of the one or more anion exchange membranes and one of the one or more cation exchange membranes; a third chamber between one of the one or more cation exchange membranes and a reactor wall; one or more counter electrodes in the third chamber; an inlet for introducing one or more of nitrogen, argon, air, and oxygen into the solution comprising lithium and one or more elements; and a power source configured to apply a voltage to the first electrochemical membrane reactor; and a second electrochemical membrane reactor configured to remove lithium from the lithium enriched stream, the first electrochemical membrane reactor coupled to the second electrochemical membrane reactor, the second electrochemical membrane reactor comprising: one or more working electrodes; one or more counter electrodes; one or more bipolar membranes; and a power source configured to apply a voltage to the second electrochemical membrane reactor.
2. The system of claim 1, wherein the first electrochemical membrane reactor configured to process the solution comprising lithium and one or more elements comprises the first electrochemical membrane reactor configured to process one or more of brine, seawater, oil produced water, gas produced water, a leachate of spent lithium ion batteries, a leachate of mines, a leachate of mine tailings, and wastewater.
3. The system of claim 1, wherein the one or more working electrodes in the first electrochemical membrane reactor comprise one or more of a plate working electrode and a porous working electrode.
4. The system of claim 1, wherein the one or more working electrodes in the first electrochemical membrane reactor comprise one or more plate working electrodes comprising a material formulated to suppress a hydrogen gas evolution reaction.
5. The system of claim 1, wherein the one or more working electrodes in the first electrochemical membrane reactor comprise one or more plate working electrodes comprising one or more of lead, bismuth, and titanium.
6. The system of claim 1, wherein the one or more working electrodes in the first electrochemical membrane reactor comprise one or more porous working electrodes comprising one or more of stainless steel, titanium, nickel alloy, carbon, and copper.
7. The system of claim 1, wherein the one or more working electrodes in the first electrochemical membrane reactor comprise one or more porous working electrodes exhibiting a coating on a surface of the porous working electrode, the coating comprising carbon nanoparticles bonded to the surface of the porous working electrode by one or more of polyvinylidene fluoride, polytetrafluoroethylene, sulfonated tetrafluoroethylene-based fluoropolymer copolymer, cation exchange ionomers, and anion exchange ionomers.
8. The system of claim 1, wherein the one or more counter electrodes in the first electrochemical membrane reactor comprise one or more plate counter electrodes comprising one or more of titanium, titanium coated with iridium oxide, titanium coated ruthenium oxide, platinum, gold, carbon and silver, lead, nickel, iron and copper.
9. The system of claim 1, wherein the first electrochemical membrane reactor further comprises: one or more of one or more additional plate electrodes and additional porous working electrodes in one or more additional chambers; one or more additional anion exchange membranes; one or more additional cation exchange membranes; one or more additional counter electrodes; and one or more additional chambers between the one or more additional anion exchange membranes, the one or more additional cation exchange membranes, and one or more reactor walls.
10. The system of claim 1, wherein the second electrochemical membrane reactor further comprises: one or more of one or more additional working electrodes; one or more additional counter electrodes; and one or more additional bipolar membranes.
11. The system of claim 1, wherein the one or more working electrodes in the second electrochemical membrane reactor comprise one or more of a plate working electrode and a porous working electrode.
12. The system of claim 1, wherein the one or more counter electrodes in the second electrochemical membrane reactor comprise one or more of a plate counter electrode and a porous counter electrode.
13. A system comprising: a first electrochemical membrane reactor configured to process a solution comprising lithium and one or more elements, the first electrochemical membrane reactor configured to remove at least one of the one or more elements and to form a lithium enriched stream, the first electrochemical membrane reactor comprising: one or more working electrodes in a first chamber; one or more anion exchange membranes in the first chamber; one or more bipolar membranes in a second chamber, the second chamber between one of the one or more anion exchange membranes and one of the one or more bipolar membranes; a third chamber between one of the one or more bipolar membranes and a reactor wall; one or more counter electrodes in the third chamber; and an inlet for introducing one or more of nitrogen, argon, air, and oxygen into the solution comprising lithium and one or more elements; and a power source configured to apply a voltage to the first electrochemical membrane reactor; and a second electrochemical membrane reactor configured to remove lithium from the lithium enriched stream, the first electrochemical membrane reactor coupled to the second electrochemical membrane reactor, the second electrochemical membrane reactor comprising: one or more working electrodes; one or more counter electrodes; one or more bipolar membranes; and a power source configured to apply a voltage to the second electrochemical membrane reactor.
14. The system of claim 13, wherein the one or more working electrodes in the first electrochemical membrane reactor comprise one or more of a plate working electrode and a porous working electrode; and wherein the one or more counter electrodes in the first electrochemical membrane reactor comprise one or more of a plate counter electrode and a porous counter electrode.
15. A system comprising an electrochemical membrane reactor, the electrochemical membrane reactor comprising: one or more counter electrodes in one or more counter electrode chambers; one or more working electrodes in one or more working electrode chambers adjacent the one or more counter electrode chambers; at least one ionic exchange membrane between at least one of the one or more counter electrode chambers and the one or more working electrode chambers; an inlet for supplying a leaching solution to the one or more working electrode chambers; a power source electrically coupled to the one or more counter electrodes and the one or more working electrodes for applying a current between the one or more counter electrodes and the one or more working electrodes; a purging system for introducing one or more of N.sub.2, argon, air and O.sub.2, to the electrochemical membrane reactor; a pH measurement system coupled to the electrochemical membrane reactor; and an outlet for discharging a purified leaching solution.
16. A method for recovering lithium from a lithium-containing solution, comprising: introducing a solution comprising lithium and one or more elements to a first electrochemical membrane reactor; applying a voltage to the first electrochemical membrane reactor to ionize one or more of the one or more elements; reducing the one or more ionized elements to form one or more reduced elements; adjusting a pH of the solution to precipitate the one or more elements; removing the one or more precipitated elements from the solution comprising lithium and one or more elements to form a lithium enriched stream; introducing the lithium enriched stream to a second electrochemical membrane reactor; suspending one or more of battery material, MnO.sub.2, graphite, FePO.sub.4, Li.sub.2-xTiO.sub.3, Li.sub.1-x, Ni.sub.xMn.sub.yCo.sub.zO.sub.2 in the lithium enriched stream to form a first suspension; suspending one or more of lithiated MnO.sub.2, graphite, FePO.sub.4, Li.sub.2-x TiO.sub.3, Li.sub.1-xNi.sub.xMn.sub.yCo.sub.zO.sub.2 (x+y+z=1) particles in a LiOH solution to form a second suspension; subjecting the first suspension and the second suspension to one or more of mechanical stirring, Vortex shaking, or ultrasound; passing the first suspension through a working electrode chamber of the second electrochemical membrane reactor; passing the second suspension through a counter electrode chamber of the second electrochemical membrane reactor; applying a voltage to the second electrochemical membrane reactor to extract lithium from the first suspension forming a lithium depleted stream, releasing lithium into the second suspension forming a concentrated LiOH solution; and recovering the lithium from the concentrated LiOH solution to form a residual stream of LiOH that is substantially free of lithium.
17. The method of claim 16, wherein reducing the one or more ionized elements to form one or more reduced elements comprises electroplating one or more of Cu, Zn, Pb, Co, Ni, Fe, Ag, Cd, Sb, and Sn on a working electrode of the first electrochemical membrane reactor; and wherein adjusting a pH of the solution to precipitate the one or more reduced elements comprises adjusting the pH of the solution to precipitate one or more of Fe.sup.3+, Ga.sup.3+, Co.sup.2+, Ni.sup.2+, U.sup.4+, Th.sup.4+, Al.sup.3+, Be.sup.2+, Cr.sup.3+, Zr.sup.4+, Cd.sup.2+, Mg.sup.2+, and REEs ions and oxidize Mn.sup.2+ ions to MnO.sub.2, and deposit the one or more of Fe.sup.3+, Ga.sup.3+, Co.sup.2+, Ni.sup.2+, U.sup.4+, Th.sup.4+, Al.sup.3+, Be.sup.2+, Cr.sup.3+, Zr.sup.4+, Cd.sup.2+ ions, and MnO.sub.2 on a working electrode of the first electrochemical membrane reactor.
18. The method of claim 16, wherein removing the one or more precipitated elements from the solution to form a lithium enriched stream comprises removing one or more of uranium, thorium, silver, cadmium, aluminum, iron, manganese, copper, magnesium, lead, zinc, nickel, cobalt, chromium, zirconium, gallium, gold, platinum, and rare earth elements.
19. The method of claim 18, wherein removing the one or more of uranium, thorium, silver, cadmium, aluminum, iron, manganese, copper, magnesium, lead, zinc, nickel, cobalt, chromium, zirconium, gallium, gold, platinum, and rare earth elements comprises producing the lithium enriched stream comprising less than or equal to about 1 ppm of one or more of uranium, thorium, silver, cadmium, aluminum, iron, manganese, copper, magnesium, lead, zinc, nickel, cobalt, chromium, zirconium, gallium, gold, platinum, and rare earth elements.
20. The method of claim 16, further comprising: introducing one or more of an NaCl solution, an HCl solution, an H.sub.2SO.sub.4 solution, and an Na.sub.2SO.sub.4 solution to the first electrochemical membrane reactor; one or more of applying a voltage to the first electrochemical membrane reactor and adjusting a pH of the solution comprising lithium and one or more elements to form one or more of H.sub.2SO.sub.4, NaCl, HCl, U(OH).sub.4, Th(OH).sub.4, Ga(OH).sub.3, Cr(OH).sub.3, Al(OH).sub.3, Fe(OH).sub.3, Co(OH).sub.3, Ni(OH).sub.3, Zr(OH).sub.4, Cd(OH).sub.2, Sc(OH).sub.3, Y(OH).sub.3, lanthanides(OH).sub.3, Mn(OH).sub.2, and Mg(OH).sub.2; and removing the one or more of H.sub.2SO.sub.4, NaCl, HCl, U(OH).sub.4, Th(OH).sub.4, Ga(OH).sub.3, Cr(OH).sub.3, Al(OH).sub.3, Fe(OH).sub.3, Co(OH).sub.3, Ni(OH).sub.3, Zr(OH).sub.4, Cd(OH).sub.2, Sc(OH).sub.3, Y(OH).sub.3, lanthanides(OH).sub.3, Mn(OH).sub.2, and Mg(OH).sub.2 from the solution to form the lithium enriched stream.
21. The method of claim 16, wherein one or more of Al.sub.2O.sub.3 and ZrO.sub.2 forms a layer on particles of the one or more of battery material, MnO.sub.2, graphite, FePO.sub.4, Li.sub.2-x TiO.sub.3, Li.sub.1-xNi.sub.xMn.sub.yCo.sub.zO.sub.2.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a detailed understanding of the disclosure, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements have generally been designated with like numerals, and wherein:
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DETAILED DESCRIPTION
[0031] The illustrations presented herein are not actual views of any electrochemical membrane reactor system, or any component thereof, but are merely idealized representations, which are employed to describe embodiments of the present invention.
[0032] As used herein, the singular forms following a, an, and the are intended to include the plural forms as well, unless the context clearly indicates otherwise.
[0033] As used herein, the term may with respect to a material, structure, feature, or method act indicates that such is contemplated for use in implementation of an embodiment of the disclosure, and such term is used in preference to the more restrictive term is so as to avoid any implication that other compatible materials, structures, features, and methods usable in combination therewith should or must be excluded.
[0034] As used herein, any relational term, such as first, second, top, bottom, upper, lower, above, beneath, side, upward, downward, etc., is used for clarity and convenience in understanding the disclosure and accompanying drawings, and does not connote or depend on any specific preference or order, except where the context clearly indicates otherwise. For example, these terms may refer to an orientation of elements of any electrochemical reactor when utilized in a conventional manner. Furthermore, these terms may refer to an orientation of elements of any electrochemical membrane reactor as illustrated in the drawings.
[0035] As used herein, the term substantially in reference to a given parameter, property, or condition means and includes to a degree that one skilled in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing tolerances. By way of example, depending on the particular parameter, property, or condition that is substantially met, the parameter, property, or condition may be at least 90.0% met, at least 95.0% met, at least 99.0% met, or even at least 99.9% met.
[0036] As used herein, the term about used in reference to a given parameter is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the given parameter, as well as variations resulting from manufacturing tolerances, etc.).
[0037] As used herein, the terms comprising, including, containing, characterized by, and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method acts, but also include the more restrictive terms consisting of and consisting essentially of and grammatical equivalents thereof. The term containing, as used to describe embodiments herein, is not meant to be exclusive. For example, a lithium-containing solution may include additional chemical elements or chemical compounds.
[0038] Systems and methods including a flowing electrochemical membrane reactor (EMR) are described. In the flowing EMR, a liquid (e.g., a solution) is passed (e.g., pumped) through the reactor, and reactions occur as the solution flows past an electrode of the EMR. The systems and methods may be utilized to remove (e.g., extract electrochemically) lithium from a lithium-containing solution. The lithium-containing solution may include one or more of brine, seawater, oil and gas produced water (e.g., water that is extracted from the ground during the process of oil- and gas-production), a leachate of spent lithium ion batteries (e.g., a liquid solution created when valuable metals such as lithium, cobalt, nickel, and manganese are extracted from a cathode material of used lithium-ion batteries through a chemical process called leaching, where the metals dissolve in a solvent, typically an acidic solution, leaving behind the remaining non-dissolved components), a leachate of mining (e.g., a liquid that comes from water passing through waste materials from mining), a leachate of mine tailings (e.g., mine tailings being a leftover material from the process of extracting minerals from the earth), and wastewater, which are collectively referred to herein as a lithium-containing solution. In embodiments of the disclosure, the lithium-containing solution may include lithium at from about 10 ppm to about 1,000 ppm, or from about 10 ppm to about 200 ppm, or from about 100 ppm to about 200 ppm. Alternatively, the lithium-containing solution may include a greater concentration of lithium. The systems and methods may provide advantages such as one or more of a high lithium selectivity, a high lithium recovery (e.g., extraction) efficiency, and a high durability for cycling (e.g., long cyclability) compared to conventional electrodialysis methods. The lithium may be recovered in a lithium enriched stream. While embodiments described herein may refer to recovering lithium from brine, other lithium-containing solutions may be processed similarly.
[0039] The electrochemical membrane reactor systems and methods may use a small amount of reagents (e.g., chemicals), may avoid the degradation mechanism of MnO.sub.2 particles that may occur with Al based ion exchange sorbent methods, and may accurately and precisely enable control of the electrode potential to extract the lithium without also extracting sodium and potassium from the lithium-containing solution. The electrochemical membrane reactor systems and methods may overcome the limit of lithium ion diffusion in the liquid and may mitigate or overcome reactor mechanical and thermal instability.
[0040] In embodiments of the disclosure, the electrochemical membrane reactor (EMR) systems and methods may include two electrochemical membrane reactors (EMRs, such as a first EMR and a second EMR). The first EMR and the second EMR may be coupled (e.g., connected) by a conduit suitable for flowing a lithium enriched stream, which is produced in the first EMR, to the second EMR. Alternatively, the lithium enriched stream produced in the first EMR may be contained in a vessel and subsequently introduced (e.g., poured) into the second EMR. The EMR systems and methods according to embodiments of the disclosure may be utilized to lower the amounts of desired chemical elements in the lithium-containing solution (e.g., a solution comprising lithium and one or more of the elements). The first EMR may be configured to reduce the amounts of certain elements in the lithium-containing solution, such as one or more of chloride, silver, cadmium, aluminum, iron, manganese, copper, gallium, chromium, zirconium, ruthenium, magnesium, lead, antimony, tin, platinum, gold, cobalt, nickel, magnesium, zinc, and rare earth elements (Cl, Ag, Cd, Al, Fe, Mg, Cu, Ga, Cr, Zr, Ru, Mg, Pb, Sb, Sn, Pt, Au, Co, Ni, Mg, Zn, and rare earth elements (REEs), respectively). The rare earth elements may include one or more of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). The rare earth elements may include one or more of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y). The lithium-containing solution may also include chlorine (Cl). In embodiments of the disclosure, the EMR systems and methods may reduce the amount of these elements to concentrations of less than or equal to about 1 ppm while increasing a concentration or weight percentage of Li for recovery in a concentrated Li stream (also referred to herein as the lithium enriched stream). Lowering the concentrations of these elements may eliminate the interference of their ions on subsequent Li extraction. The first EMR may be configured to remove chlorine (Cl) (e.g., Cl ions or Cl-containing compounds) from the lithium-containing solution to generate byproducts such as sulfuric acid (H.sub.2SO.sub.4) with NaCl or HCl. The first EMR may also be configured to generate byproducts such as metal, metal oxide compounds including, but not limited to, one or more of Cu, Ni, Zn, Co, Pb, Al(OH).sub.3, Fe(OH).sub.3, REEs(OH).sub.3, Mn(OH).sub.2, MnO.sub.2, and Mg(OH).sub.2. In embodiments of the disclosure, the first EMR may be configured to generate Mn(OH).sub.2, MnO.sub.2, and Mg(OH).sub.2 byproducts having a purity of greater than about 95% by weight. By comparison with conventional technologies, which may conduct several acts including chemical precipitation, solvent extraction, and ion exchange to extract similar elements, and that may introduce impurities into the liquid during the process, using the first EMR may remove impurities and concentrate lithium to produce the lithium enriched stream in a single process and consume only electricity, air, and water, while introducing few reagents or zero extra reagents or impurities into the lithium-containing solution.
[0041] The systems and methods may include recovering lithium from the lithium-containing solution in the first electrochemical membrane reactor to form the lithium enriched stream. The lithium enriched stream may be processed in the second electrochemical membrane reactor to remove (e.g., extract) lithium from the lithium enriched stream. Embodiments of the first electrochemical membrane reactor are shown in
[0042] As shown in
[0043] The working electrode (e.g., cathode) may comprise one or more of a plate electrode and a metal frame porous electrode. The working electrode (e.g., cathode) may be selected and configured so as to not introduce extra impurities into the lithium-containing solution. The working electrode (e.g., cathode) material may be selected from, but is not limited to, one or more of lead, bismuth, nickel, copper, steel, carbon, and titanium. The metal frame porous electrode may desirably be easily operated and washable. The metal frame porous electrode may be selected from one or more of porous metal, foam, and mesh, although not limited thereto. Electrode materials may be selected depending on factors including, but not limited to, the potential distribution on the MFPE, electrode pore density, electrochemical reactions, and their rate. An electrode with an optimized pore density may be selected to process the lithium-containing solution at a fast rate through the first EMR. In embodiments of the disclosure, the plate working electrode comprises a material formulated to suppress a hydrogen gas evolution reaction. For example, the plate working electrode may comprise one or more of lead, bismuth, and titanium. The porous working electrode may comprise a chemically resistant material. For example, the porous working electrode may comprise one or more of stainless steel, titanium, nickel alloy, carbon, and copper. The porous working electrode may exhibit a coating on a surface of the porous working electrode, the coating comprising carbon nanoparticles bonded to the surface of the porous working electrode by one or more of polyvinylidene fluoride, polytetrafluoroethylene, sulfonated tetrafluoroethylene-based fluoropolymer copolymer, cation exchange ionomers, and anion exchange ionomers.
[0044] The counter electrode (e.g., anode) may comprise an inert metal, such as one or more of titanium, titanium coated with iridium oxide, titanium coated ruthenium oxide, platinum, gold, carbon, and silver, although not limited. The counter electrode (e.g., anode) may comprise an active metal, such as one or more of lead, nickel, iron, and copper, although not limited. In embodiments of the disclosure, a material of the counter electrode (e.g., anode) may be selected in accordance with factors including the maximum current density the electrodes supply and the oxidation reaction happening on the electrode surface. The dimension and arrangement of the counter electrodes may be selected depending on the configuration of the reactor(s). The configuration of the reactor(s) may be arranged to maximize the electrode/electrolyte interface of the working electrode, and with consideration of the extraction sequence of the elements.
[0045] The electrode potential distribution on the MFPE may be controlled to enable extraction of Li.sup.+ ions without extracting Mg.sup.2+, Na.sup.+, K.sup.+ ions and other ions. Cyclic voltammetry and chronopotentiometry tests may be performed on MFPE, and the potential distribution may be measured by using a three-electrode system. Applied current, pore density of MFPE and its potential distribution, may be controlled by selecting the foam thickness, pore density, current value, among other properties.
[0046] The lithium enriched stream produced by the first electrochemical membrane reactor may be transferred to the second electrochemical membrane reactor to remove (e.g., extract) lithium from the lithium enriched stream. The second electrochemical membrane reactor may directly remove (e.g., extract) the lithium from the lithium enriched stream formed in the first electrochemical membrane reactor to form a lithium hydroxide (LiOH) solution through an intercalation/deintercalation reaction, with exemplary reactions shown in equations (1) and (2).
2-MnO.sub.2+Li.sup.++e.sup..fwdarw.LiMn.sub.2O.sub.4(1)
LiMn.sub.2O.sub.4.fwdarw.2-MnO.sub.2+Li.sup.++e.sup.(2)
The LiOH solution may include one or more of the lithium ion battery materials, such as MnO.sub.2 particles and LiMn.sub.2O.sub.4 particles. The lithium may be recovered from the LiOH solution and a residual stream that is substantially free of lithium may be produced.
[0047] The second EMR may be configured to extract the lithium by selecting the arrangement of the MFPEs (e.g., MFPC, MFPA) and BPM(s), the thickness of the metal foams, their pore density, the length of the foam, the flowing rate and direction of the suspension, and the placement of the reactor. When the suspension flows through the second EMR, desirably all or substantially all of the particles of lithium ion battery material, such as MnO.sub.2 and LiMn.sub.2O.sub.4 particles, may be involved in the intercalation and deintercalation completely. The particles desirably do not aggregate and not block the pore inside the foam. These factors may optimize the flow rate of the suspension. Agitation (e.g., stirring, Vortex shaking, ultrasound) may be introduced to the reactor to minimize or prevent nanoparticles from aggregation.
[0048] As shown in
[0049] As shown in
[0050] As shown in
[0051] As shown in
Chambers 122a may connect with chamber 122a (connections not shown). First electrochemical membrane reactor 110f may include a first counter electrode 126a (e.g., anode), a second counter electrode 126b (e.g., anode), and, optionally, one or more additional counter electrodes (e.g., anodes) (not shown). An inlet 130 (e.g., tubing) for introducing one or more of nitrogen, argon, air, and oxygen into a solution (e.g., a solution comprising lithium and one or more elements, the lithium-containing solution) is connected to first chamber 114.
[0052] Turning to
[0053] Thus, in embodiments of the disclosure, a flowing EMR system including the first EMR (e.g., 100a, 100b, 100c, 100f) and the second EMR (e.g., 210a, 210b) and a process is described that may efficiently extract about 95% of lithium from lithium-containing solutions, such as geothermal brine, leachates of mines, and leachates of spent lithium ion batteries, without consuming chemicals and while also generating valuable by-products, including one or more of Cu, Ni, Co, Pb, Zn, Ag, Pt, Au, U(OH).sub.4, Th(OH).sub.4, Ga(OH).sub.3, Cr(OH).sub.3, Al(OH).sub.3, Fe(OH).sub.3, Zr(OH).sub.4, Cd(OH).sub.3, REEs(OH).sub.3, Mg(OH).sub.2, Mn(OH).sub.2, NaCl, H.sub.2SO.sub.4, or HCl. With a purity of greater than or equal to about 99%, the extracted LiOH may be used as battery grade LiOH with a relatively low amount of additional handling. The whole process may involve a smaller chemical footprint than any conventional Li extraction technologies. An electrolysis protocol that sequentially removes the elements may be designed for the elements' extraction. By using the protocol, the processing time may be shortened over processing times of conventional techniques. By way of example only, Ag, Cu, Cd, Fe, Al, Zn, Pb, Co, Ni, Ga, Zr, REEs, Mn and Mg may be effectively extracted to less than about 1 ppm, and Mn(OH).sub.2 and Mg(OH).sub.2 purity may be greater than about 95%.
[0054] In embodiments of the disclosure, methods for recovering lithium from the lithium-containing solution 115 comprising lithium and one or more elements may comprise introducing the lithium-containing solution 115 to the first electrochemical membrane reactor. A voltage may be applied across the electrodes of the first electrochemical membrane reactor to ionize (e.g., reduce or oxidize) the one or more elements. By way of example only, a voltage of from about 2.0 V to about 3.5 V may be applied. A voltage range that is greater than the foregoing range may be used depending on the size of the EMR (e.g., when the EMR is scaled up). A voltage range for the second EMR may be smaller than the voltage range for the first EMR. The one or more ionized elements are reduced (e.g., chemically reduced) to produce one or more reduced elements. The one or more ionized elements are reduced to metallic form, which may be electroplated on the surface of the working electrode. By way of example only, Cu.sup.2+ ions in the lithium-containing solution 115 may be reduced to Cu, which is electroplated on the surface of the working electrode. The one or more ionized elements may be oxidized to metal oxide form, which may be deposited on the surface of the working electrode. By way of example only, Mn.sup.2+ ions in the lithium-containing solution 115 may be oxidized to MnO.sub.2, which is deposited on the surface of the working electrode. The one or more reduced elements may be removed (that is, precipitated) from the lithium-containing solution 115 to produce a lithium enriched stream 140. The pH of the lithium-containing solution 115 may be sequentially adjusted to different values to precipitate the one or more elements. The one or more reduced elements may be precipitated by, for example, adjusting the pH of the lithium-containing solution 115. For example, the pH may be increased/decreased from a pH of about 0 to a pH of about 13. The method may further comprise introducing one or more of an NaCl solution, an HCl solution, and a Na.sub.2SO.sub.4 solution to the second chambers 118a, 118b, and the third chambers 122a, 122b of the first electrochemical membrane reactor. Introducing the one or more solutions (e.g., one or more of NaCl, HCl, Na.sub.2SO.sub.4 solution) may adjust solution concentration to prevent the solution from having a high concentration (e.g., maintaining a relatively dilute solution). A voltage may be applied to the first electrochemical membrane reactor, causing one or more of Cu.sup.2+, Zn.sup.2+, Co.sup.2+, Ni.sup.2+, Pb.sup.2+, Ag.sup.+, Pt.sup.2+, and Au.sup.3+ ions to electroplate in their metallic form, causing Mn.sup.2+ ions to oxidize to MnO.sub.2, and the pH of the lithium-containing solution 115 to be adjusted to generate one or more of H.sub.2SO.sub.4, NaCl, HCl, U(OH).sub.4, Th(OH).sub.4, Ga(OH).sub.3, Cr(OH).sub.3, Al(OH).sub.3, Fe(OH).sub.3, Co(OH).sub.3, Ni(OH).sub.3, Zr(OH).sub.4, Cd(OH).sub.2, Sc(OH).sub.3, Y(OH).sub.3, lanthanides(OH).sub.3 (hydroxide compounds of lanthanide elements), Mn(OH).sub.2, and Mg(OH).sub.2. One or more of Cl.sup., U.sup.4+, Th.sup.4+, Cu.sup.2+, Zn.sup.2+, Pb.sup.2+, Co.sup.2+, Ni.sup.2+, Ag.sup.+, Pt.sup.2+, Au.sup.3+, Fe.sup.3+, Pb.sup.2+, Cr.sup.3+, Al.sup.3+, Ga.sup.3+, Zr.sup.4+, Cd.sup.2+, Sc.sup.3+, Y.sup.3+, lanthanides.sup.3+, Mn.sup.2+, and Mg.sup.2+ ions may be removed from the lithium-containing solution 115 (e.g., in the form of compounds of one or more of these ions) to produce the lithium enriched stream 140. The lithium enriched stream 140 may be introduced into the second electrochemical membrane reactor (second EMR). A voltage may be applied across the electrodes of the second electrochemical membrane reactor to produce a LiOH solution from the lithium enriched stream 140. The lithium in the lithium-containing solution, which may include one or more of the lithium-ion battery materials, such as MnO.sub.2 particles and LiMn.sub.2O.sub.4 particles, may be removed to produce a residual stream that is substantially free of lithium. The generated, concentrated LiOH solution may be separated from the delithiated battery materials and the lithium in the LiOH solution is recovered. The process may further comprise suspending lithium-ion battery materials, such as MnO.sub.2 particles, in the lithium-enriched stream and suspending lithiated materials, such as LiMn.sub.2O.sub.4, in the diluted LiOH solution. Lithiated materials, such as LiMn.sub.2O.sub.4, may come from the cathode chamber from the last extraction. If it is a first use of the second EMR to extract lithium from a lithium-containing solution, LiMn.sub.2O.sub.4 may come from a sysnthese process, such as calcinating LiOH with MnO.sub.2 particles. The suspension of the lithium-ion battery material and the lithiated battery material, such as MnO.sub.2 and LiMn.sub.2O.sub.4 suspensions, may be formed by one or more of applying vortex shaking, mechanical stirring, and ultra-sonication to the second electrochemical membrane reactor. The two suspensions (e.g., the MnO.sub.2 and LiMn.sub.2O.sub.4 suspensions) may be passed through the second electrochemical membrane reactor. The lithium may be recovered from the lithium-containing solution 115 and used as a starting material in a process or product that includes lithium. By way of example only, the recovered lithium may be used as a starting material or a component of lithium ion batteries.
[0055] As shown in
[0056] In order to remove the precipitates (e.g., Zn.sup.2+, Co.sup.2+, Ni.sup.2+, Fe.sup.3+, Ga.sup.3+, Cr.sup.3+, Al.sup.3+, Zr.sup.4+, Cd.sup.2+, Sc.sup.3+, Y.sup.3+, lanthanides.sup.3+, Mn.sup.2+, and Mg.sup.2+ ions) from the MFPE(s) and clean the MFPE(s), in embodiments of the disclosure, the MFPE(s) may be coated with a layer of nanocarbon particles, which is bonded on the surface of the electrode with a polymer binder, e.g., one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), NAFION (sulfonated tetrafluoroethylene-based fluoropolymer copolymer), cation exchange ionomers, and anion exchange ionomers. One or more of ultrasound cleaning and calcination can be utilized to clean the carbon layer and remove any residual precipitation remaining on the MFPE(s).
[0057] Brine is a complex composition of elements or analytes. If the lithium-containing solution 115 is brine, the elements or analytes shown in Table 1 may be present. By way of example only, the geothermal brine composition of Table 1 may be from the Salton Sea.
TABLE-US-00001 TABLE 1 Salton Sea Geothermal Brine Chemical Composition Element or Mean Element or Mean Analyte (mg/L) Analyte (mg/L) Cl 142,015 Br 91 Na 49,249 Pb 84 Ca 25,684 Cs 20 K 14,467 I 17 Fe 1347 F 15 Mn 1201 As 9.0 Zn 463 Cu 4.1 Sr 434 Al 2.4 B 298 Cd 1.9 Ba 205 Ag 1.6 Li 202 SiO.sub.2 342 Rb 110 NH.sub.4 311 Mg 109 SO.sub.4 58.6
[0058] Table 2 shows examples of extraction reactions, their thermal dynamic electroplating potentials, and the pH ranges where targeted materials precipitate from a lithium-containing solution, such as brine. The brine may be a geothermal brine from the Salton Sea, which includes the elements shown in Table 1.
TABLE-US-00002 TABLE 2 Reaction mechanisms of elements extracted from a lithium-containing solution using the first EMR Thermodynamic potential for electroplating or pH Reaction mechanism precipitation Electroplating Pt.sup.2+ + 2e.sup. .fwdarw. Pt (1) Pt.sup.2+/Pt: E.sub.0 = 1.88 + 0.02951 log.sub.pt+ Au.sup.3+ + 3e.sup. .fwdarw. Au (2) Au.sup.3+/Au: E.sub.0 = 1.498 + 0.0197log.sub.Au3+ Ag.sup.+ + e.sup. .fwdarw. Ag (3) Ag.sup.+/Ag: E.sub.0 = 0.799 + 0.0591log.sub.Ag+ Cu.sup.2+ + 2e.sup. .fwdarw. Cu (4) Cu.sup.2+/Cu: E.sub.0 = 0.337 + 0.0295logC.sub.Cu2+ Pb.sup.2+ + 2e.sup. .fwdarw. Pb (5) Pb.sup.2+/Pb: E.sub.0 = 0.126 + 0.0295logC.sub.Pb2+ Cd.sup.2+ + e.sup. .fwdarw. Cd (6) Cd.sup.2+/Cd: E.sub.0 = 0.403 + 0.0295logC.sub.Cd2+ Fe.sup.2+ + e.sup. .fwdarw. Fe (7) Fe.sup.2+/Fe: E.sub.0 = 0.44 + 0.0295logC.sub.Fe2+ Zn.sup.2+ + e.sup. .fwdarw. Zn (8) Zn.sup.2+/Zn: E.sub.0 = 0.763 + 0.0295logC.sub.Zn2+ Ni.sup.2+ + 2e.sup. .fwdarw. Ni (9) Ni.sup.2+/Ni: E.sub.0 = 0.25 + 0.0295logC.sub.Ni2+ Co.sup.2+ + 2e.sup. .fwdarw. Co (10) Co.sup.2+/Co: E.sub.0 = 0.277 + 0.0295log C.sup.Co2+ Electrochemical 2H.sub.2O + 4e.sup. .fwdarw.H.sub.2 + 2OH.sup.(11) H.sup.+/H.sub.2: E.sub.0 = 0.0591 pH precipitation 2H.sub.2O + O.sub.2 + 4e.sup. .fwdarw.4OH.sup.(12) O.sub.2/H.sub.2O: E.sub.0 = 1.228 0.0591 pH U.sup.4+ + 4OH.sup..fwdarw.U(OH).sub.4(13) K.sub.sp, U(OH)4 = 6.31 10.sup.53, precipitate: pH >~1.2 Th.sup.4+ + 4OH.sup..fwdarw.Th(OH).sub.4(14) K.sub.sp, Th(OH)4 = 2.951 10.sup.49, precipitate: pH >~2.12 Ga.sup.3+ + 4OH.sup..fwdarw.Ga(OH).sub.3(15) K.sub.sp, Ga(OH)3 = 7.28 10.sup.36, precipitate: pH >~2.6 Al.sup.3+ + 3OH.sup..fwdarw.Al(OH).sub.3(16) K.sub.sp, Al(OH)3 = 1.9 10.sup.33, precipitate: pH >~3.5 Zn.sup.2+ + 2OH.sup..fwdarw.Zn(OH).sub.2(17) K.sub.sp, Zn(OH)2 = 4.5 10.sup.17, precipitate: pH >~6.32 Fe.sup.2+ + 2OH.sup..fwdarw.Fe(OH).sub.2(18) K.sub.sp, Fe(OH)2 = 7.9 10.sup.15, precipitate: pH >~7.5 Fe.sup.3+ + 2OH.sup..fwdarw.Fe(OH).sub.3(19) K.sub.sp, Fe(OH)3 = 2.5 10.sup.39, precipitate: pH >~147 Mn.sup.2+ + 2OH.sup..fwdarw.Mn(OH).sub.2(20) K.sub.sp, Mn(OH)2 = 1.6 10.sup.13, precipitate: pH >~8.1 Mg.sup.2+ + 2OH.sup..fwdarw.Mg(OH).sub.2(21) K.sub.sp, Mg(OH)2 = 1.5 10.sup.11, precipitate: pH >~1.37 Zr.sup.4+ + 4OH.sup..fwdarw.Zr(OH).sub.4(22) K.sub.sp, Zr(OH)4 = 3.2 10.sup.63, precipitate: pH >~9 Cr.sup.3+ + 2OH.sup..fwdarw.Cr(OH).sub.4(23) K.sub.sp, Cr(OH)3 = 6.7 10.sup.31, precipitate: pH >~4.28 Ni.sup.2+ + 2OH.sup..fwdarw.Ni(OH).sub.4(24) K.sub.sp, Ni(OH)2 = 2.8 10.sup.16, precipitate: pH >~6.72 Co.sup.2+ + 2OH.sup..fwdarw.Co(OH).sub.2(25) K.sub.sp, Co(OH)2 = 5.92 10.sup.16, precipitate: pH >~6.89 Sc.sup.3+ + 2OH.sup..fwdarw.Sc(OH).sub.3(26) K.sub.sp, Sc(OH)3 = 2.22 10.sup.31, precipitate: pH >~4.11 Y.sup.3+ + 2OH.sup..fwdarw.Y(OH).sub.3(27) K.sub.sp, Y(OH)3 = 1.0 10.sup.22, precipitate: pH > ~7 Lanthanides.sup.3+ + 3OH.sup. K.sub.sp, Lanthanides(OH)3 = 1.0 10.sup.20 to ~1.00 10.sup.24, .fwdarw.Y(OH).sub.3(28) precipitate: pH >~7 = 6.4
[0059] Cl.sup. ions from the brine may coordinate with metal ions, affecting their precipitation. For example, Cl.sup. ions may coordinate with Al.sup.3+ and Fe.sup.3+ ions to form [AlCl.sub.4].sup. and [FeCl.sub.4].sup. complex ions. The pH of the brine may be raised higher than the pH values stated in Table 2 in order to precipitate some of the metal ions. Air may be introduced (e.g., sparged) into the brine to aerate the solution and thus oxidize Fe.sup.2+ to Fe.sup.3+ ions. At a pH of about 7, about 99% of Fe.sup.2+ ions may be oxidized in less than about 50 minutes, and Mn.sup.2+ ion oxidation may be negligible. Dissolved O.sub.2 (naturally occurring from air sparging) may also be electrochemically reduced to produce OH ions, which may increase the pH of the brine solution. After the oxidation of Fe.sup.2+ to Fe.sup.3+ ions, air sparging may not be used and the pH of the brine solution may be increased by electrochemically reducing H.sub.2O and O.sub.2 to produce OH.sup.. When the pH of the brine is adjusted, in embodiments to about 8.5, by the first electrochemical membrane reactor, the concentrations of those elements, including one or more of Cu.sup.2+, Ga.sup.3+, Zn.sup.2+, Co.sup.2+, Ni.sup.2+, Ag.sup.+, Pt.sup.2+, Au.sup.3+, Fe.sup.3+, Fe.sup.2+, Pb.sup.2+, Cr.sup.3+, Al.sup.3+, Zr.sup.4+, Cd.sup.2+, Sc.sup.3+, Y.sup.3+, lanthanides.sup.3+, Mn.sup.2+, and Mg.sup.2+ ions, may be reduced to less than about 1 ppm through one or more of the electroplating reactions or electrochemical precipitation reactions. When the pH is further elevated in the electrochemical membrane reactor to greater than about pH 8.5, Mn.sup.2+ ions may start to precipitate as hydroxides. When the pH reaches about 10, greater than about 99% of Mn.sup.2+ ions may be extracted as hydroxides and less than about 10 ppm of Mn.sup.2+ ions may remain soluble in the brine. With the pH continuously increasing above about pH 10, Mg.sup.2+ ions may further precipitate and less than about 1 ppm of Mg.sup.2+ ions may remain in the brine by about pH 11.5. The electrochemical membrane reactor may not only extract metal ions, but may also generate valuable byproducts including one or more of Ga(OH).sub.3, REEs(OH).sub.3, Mn(OH).sub.2, Mg(OH).sub.2, NaCl, HCl, Na.sub.2SO.sub.4, and H.sub.2SO.sub.4, which may be recovered.
[0060] The purified solution 140 (e.g., lithium enriched stream) produced by (e.g., prepared with) the first electrochemical membrane reactor may be introduced (e.g., poured) into the cathode chamber 212 of the second electrochemical membrane reactor 210a, as shown in
[0061] In embodiments of the disclosure, the lithium enriched stream 140 from the first EMR may be introduced into the second electrochemical membrane reactor. One or more of MnO.sub.2, graphite, FePO.sub.4, Li.sub.2-xTiO.sub.3, and Li.sub.1-xNi.sub.xMn.sub.yCo.sub.zO.sub.2 (x+y+z=1) particles may be suspended in the lithium enriched stream. Mechanic stirring, Vortex shaking, or ultrasound may maintain the stability of the suspension. One or more of the lithiated particles, such as LiMn.sub.2O.sub.4, Li-graphite, LiFePO.sub.4, Li.sub.2TiO.sub.3, and LiNi.sub.xMn.sub.yCo.sub.zO.sub.2 (x+y+z=1), which may be obtained, for example, from the last lithium extraction or from calcination of MnO.sub.2, graphite, FePO.sub.4, Li.sub.2-xTiO.sub.3, and Li.sub.1-xNi.sub.xMn.sub.yCo.sub.zO.sub.2 (x+y+z=1) particles with LiOH, may form in the suspension. When suspending the MnO.sub.2, graphite, FePO.sub.4, Li.sub.2-xTiO.sub.3, and Li.sub.1-xNi.sub.xMn.sub.yCo.sub.zO.sub.2 (x+y+z=1) particles in the lithium enriched stream, and suspending LiMn.sub.2O.sub.4, Li-graphite, LiFePO.sub.4, Li.sub.2TiO.sub.3, and LiNi.sub.xMn.sub.yCo.sub.zO.sub.2 (x+y+z=1) in dilute LiOH solution, pouring those suspensions into the cathode and anode chambers of the second EMR, applying voltage to the second EMR, the lithium from the lithium-enriched stream is extracted and the lithium in the lithiated battery particles is released into the dilute LiOH solution. Optionally, the suspensions inside the EMR may be stabilized, such as through one or more of Vortex shaking, stirring, and ultrasound treatment. or more of Al.sub.2O.sub.3 and ZrO.sub.2 can coat on to the particles of battery material, MnO.sub.2, graphite, FePO.sub.4, Li.sub.2-xTiO.sub.3, Li.sub.1-xNi.sub.xMn.sub.yCo.sub.zO.sub.2 (e.g., can form a layer on the particles of battery material) to increase their durability and stability.
[0062] In the meantime, water may be split into H.sup.+ and OH.sup. ions by the BPMs, while H.sup.+ ions may travel to the cathode side and OH.sup. ions may travel to the anode side. Alternately, water may be produced by the BPMs, while H.sup.+ ions may travel from the anode side and OH.sup. ions may travel from the cathode side. The nanoparticles in the nanoparticle stream 252 may be homogenously suspended in the lithium enriched stream 140 (e.g., enriched brine) produced in the first electrochemical membrane reactor 110a, and this may reduce the diffusion distance of Li.sup.+ ions inside the metal frame porous electrode, as shown in
[0063]
[0064]
[0065] Elements comprising one or more of U, Th, Ga, Cr, Zr, Ag, Cu, Cd, Fe, Al, Zn, Pb, Mn, Mg, REEs, Li, and some amount of the Cl may be removed (e.g., extracted) in the methods utilizing the first and second electrochemical membrane reactors and may generate valuable byproducts. By way of example only, natural brine may be processed in the first electrochemical membrane reactor using extraction to remove one or more elements, such as one or more of U, Th, Ga, Cr, Zr, Ag, Cu, Cd, Fe, Al, Zn, Pb, Mn, Mg, and REEs, to produce the lithium enriched solution (e.g., lithium enriched brine). The lithium enriched stream generated by the first electrochemical membrane reactor may be processed in the second electrochemical membrane reactor and lithium may be recovered (e.g., extracted) from the lithium enriched solution in the second electrochemical membrane reactor. The lithium enriched solution is processed in the second electrochemical membrane reactor, the lithium may be extracted therefrom, and the residual stream (which may be substantially free of lithium) may be safely discharged into the environment. The lithium recovered from the method 400 may then be used as a starting material in a new process or product.
[0066] After processing in the first EMR, the lithium enriched stream may contain less than or equal to about 1 ppm of the above elements (such as less than about 1 ppm of one or more of uranium, thorium, gallium, silver, cadmium, aluminum, iron, manganese, copper, magnesium, lead, zinc, rare earth elements, nickel, cobalt, chromium, zirconium, chromium, gold, and platinum) and may be in an improved form for extraction of Li with high purity as compared to unprocessed liquid. As described herein, the first EMR may be utilized to process the lithium enriched stream prepared with the first EMR.
[0067] MnO.sub.2 nanoparticles may be synthesized having different sizes and their electrochemical properties may be determined to determine the stability time of those particles suspended inside natural brine. The configuration of first electrochemical membrane reactor may be selected considering the ionic conductivity of the lithium-containing solution (e.g., brine) in the metal frame foams with different pore densities. The electrochemical properties of the MnO.sub.2 nano-particles suspension in the reactor both static way and flowing way may be considered. The second electrochemical membrane reactor having a semi-solid flowing structure may extract Li with one or more of about 99% purity, greater than about 95% extraction efficiency/cycle, greater than about 75.06 mg.Math.g.sup.1.Math.h.sup.1 extraction rate, and greater than about 500 cyclability at the Li extraction capacity retention of about 80%.
[0068] MnO.sub.2 nanoparticles may be synthesized by chemical reaction between aqueous KMnO.sub.4 solution and 2,3-butanediol, and the particle size may be controlled by adjusting the 2,3-butanediol/KMnO.sub.4 ratio. MnO.sub.2 may be fabricated to prepare an ink electrode to test its electrochemical properties in LiCl, NaCl and KCl solution measuring the Li extraction capacity. The synthesized battery material particles, such as MnO.sub.2 particles, may be coated with a Al.sub.2O.sub.3 layer, or a ZrO.sub.2 layer, to increase battery material stability, especially at low voltage conditions.
[0069] Different size MnO.sub.2 nanoparticles may be suspended inside a solution (e.g., brine) such as by Vortex shaking, mechanical stirring, and/or ultra-sonication. The sedimentation dynamics may be characterized by measuring the suspension's transmission value with a photo-centrifuge device, and the relationship between stability time of the suspension and particle size determined.
[0070] The following examples serve to explain embodiments of the disclosure in more detail. These examples are not to be construed as being exhaustive or exclusive as to the scope of the disclosure.
EXAMPLES
Example 1
[0071] A benchtop scale first EMR electrochemical membrane reactor was employed to extract elements, including but not limited to, one or more of uranium, thorium, gallium, silver, silver, cadmium, aluminum, iron, manganese, copper, magnesium, lead, zinc, rare earth elements, nickel cobalt, chromium, zirconium, gold, and platinum, from a lithium-containing solution (e.g., an aqueous solution), to produce a lithium enriched stream.
[0072]
[0073] Variations of a benchtop scale first electrochemical membrane reactor were employed to extract Cu, Al and Fe from a complex aqueous solution containing Mn, Co, Ni, Cu, Al and Fe. In one embodiment, a plate working electrode was utilized in the first electrochemical membrane reactor. In another embodiment, a porous electrode was utilized in place of the plate electrode. The porous electrode accelerated the extraction process and reduced the extraction time as compared with the plate electrode. The main body of the first electrochemical membrane reactor comprised a three-cylinder H cell with two pieces of anion exchange membrane (FUMASEP FAA-3-PK-130) sandwiched between two of the three adjacent cylinders. A Ni foam (5 cm30 cm, pore density 110 ppi, MTI Corporation) was coiled and inserted into the middle cylinder, functioning as a cathode, and two Ni plates or platinum foils were applied as the counter electrodes in both sides of the cylinders. 0.2 mol/l.sup.1 Na.sub.2SO.sub.4 solution was used as the anolyte inside the two side cylinders. The two-anode design significantly increased the uniformity of the potential distribution on the cathode, improving Cu, Fe and Al extraction selectivity, and reducing the processing time. Two different aqueous solutions were tested. The composition of Solution 1 was: 9,782 ppm Co, 11,740 ppm Ni, 43,920.0 ppm Mn, 3,240.8 ppm Cu, 2,536.1 ppm Al, and 1,117 ppm Fe, and the anions were SO.sub.4.sup.2 ions. Solution 2 had the same composition as Solution 1 except for 46,952 ppm Ni, 10,988 ppm Mn, and 3,240.8 ppm Cu. Solution 1 was electrolyzed in the first electrochemical membrane reactor by using Ni plates as the anode. Cu from the solution electroplated on the coiled Ni foam from the outside to the inside layer.
TABLE-US-00003 TABLE 3 Impurity concentration and Ni, Co, and Mn recovery efficiency (RE) After the First EMR Processed the Simulated Leachate Simulated leachate Cu/ppm Al/ppm Fe/ppm Ni RE Co RE Mn RE Solution 1 (Ni anode) <0.5 0 0 99.5% 95.4% 99.14% Solution 1 (Ni anode) 0 0 5.0 95.5% 97.7% 99.3% Solution 1 (Pt anode) 1.0 2.3 0 96.3% 98.8% 99.9% Solution 2 (Ni anode) 0.01 3.7 0 94.3% 98.2% 99.4%
[0074] After the electrochemical extraction, the processed solution inside the middle cylinder was discharged, and replaced with 0.2 mol/l.sup.1 Na.sub.2SO.sub.4 solution. The polarity of the reactor was switched and the dissolved Ni.sup.2+ ions from the anode plate electroplated back to the Ni plate. Ni.sup.2+ ion concentrations in the two side cylinders were about 3105 ppm at the end of the extraction process and the concentration decreased to about 26.6 ppm after the dissolved Ni electroplated back to the anode. The capacity efficiency of Ni recovery was about 83.9%. After recovering Ni, the pH of the electrolyte in the middle cylinder decreased to 0.96, due to the H.sub.2SO.sub.4 byproduct. The reactor extracted Cu, Al, and Fe and kept Ni, Co, and Mn in solution. However, the first electrochemical membrane reactor may extract all the elements which can be electroplated and precipitated from brine, so there is much less complexity in the process. Based on the extraction of Cu, Al and Fe from Solution 1 and Solution 2, the first electrochemical membrane reactor was capable of extracting fifteen or more elements, including one or more of U, Th, Ga, Cr, Zr, Ag, Cu, Cd, Fe, Al, Zn, Pb, Mn, Mg and REEs, from brine, lowering their concentration to about 1 ppm, when the pH was increased to about 11.5.
[0075] The brine from Salton Sea may have greater than about 20 weight % of dissolved solids and may exhibit intrinsic ionic conductivity, especially when the temperature is high. The MFPE (MFPC and MFPA) may have pores of from micrometer to millimeter in size, such as from about 10 micrometers to 1,000 micrometers. The larger sized pores in the MFPE may allow ions and particles to easily travel through the electrode body. These two factors may impart excellent ionic conductivity to the MFPE. The metal frame of the MFPE (in embodiments, made from one or more of carbon, a metal, such as one or more of Ni, Ti, and Cu metal) may exhibit an excellent electrical conductivity.
[0076] The first electrochemical membrane reactor may have particles directly in contact with the metal frame porous electrode and may have a large surface area which may reduce ohmic resistance. The standard intercalation potentials for Li.sup.+, Na.sup.+, and K.sup.+ ions are 0.912-1.03 V (vs. SHE) (SHE=standard hydrogen electrode potential), 0.092 V (vs. SHE), and 0.045 V (vs. SHE), and 0.82 V difference is between the extraction reactions of Li.sup.+ and Na.sup.+ ions. Considering the influence of Li.sup.+, Na.sup.+, and K.sup.+ ions concentrations on the value of their intercalation potential, there is still around 0.67 V difference between the extraction reactions of Li.sup.+ and Na.sup.+ ions. Therefore, if potential distribution on the MFPE is less than 0.67 V, the reactor may only extract Li.sup.+ ions without extracting any Na.sup.+ and K.sup.+ ions. Because of its electric and ionic conductivity, the porous electrode may be fabricated very thick, such as to a thickness of about 1 millimeter to about 1,000 millimeters, and the potential distribution on the porous metal electrode may be under 0.67 V.
[0077] The second electrochemical membrane reactor may flow MnO.sub.x and LiMn.sub.2O.sub.4 nanoparticles through its MFPE, and the reactor configuration and process may overcome or alleviate one or more of the drawbacks associated with conventional electrodialysis reactors. The second electrochemical membrane reactor may be configured to accommodate a larger amount of battery materials and lithiated battery materials, such as MnO.sub.2 and LiMn.sub.2O.sub.4 particles, as compared to conventional reactors. The second electrochemical membrane reactor may be controlled to selectively extract Li.sup.+ ions without extracting K.sup.+ and Na.sup.+ ions by applying an appropriate voltage. For example, a potential of from about 0.9 V (vs. standard hydrogen electrode) to about 1.0 V (vs. standard hydrogen electrode) may be applied to the second electrochemical membrane reactor. The extraction process may be conducted by using the reaction of MnO.sub.2.Math.LiMn.sub.2O.sub.4 instead of the reaction of MnO.sub.2.Math.LiMn.sub.2O.sub.4.fwdarw.Mn.sup.2+. Because the lithium enriched stream which is produced by the first electrochemical membrane reactor may have a final pH value of about 12.5, such a high pH value may prevent LiMn.sub.2O.sub.4 from dissolving into the liquid. The second electrochemical membrane reactor may not use a thermally and mechanically unstable binder; and the BPM may block the diffusion of Cl.sup. ions from the cathode chamber to the anode chamber which may avoid corrosion of the anodes. In embodiments of the disclosure, the MFPE in the first and second electrochemical membrane reactor is free of binder and may be washed. Particles (e.g., MnO.sub.2) may be calcined and washed for recovery. The precipitates from the brine may be removed from the electrode by washing. In contrast, conventional electrodes, such as a paste electrode, cannot be washed and cleaned to remove precipitates because they are structurally fragile. Cl.sup. ions may not corrode the cathode because the cathode has a low potential. Dilute LiOH solution has a high pH and LiMn.sub.2O.sub.4 particles in the anode suspension are also insoluble as well. For at least the above reasons, the first electrochemical membrane reactor may be very robust and capable of being scaled up. The first electrochemical membrane reactor may exhibit one or more of a significantly higher Li.sup.+ selectivity, a greater extraction efficiency, and a higher yield, as compared with previous reactors. The cyclability of the second electrochemical membrane reactor may be 500 cycles at a lithium extraction capacity retention of about 80%. In embodiments of the disclosure, the second electrochemical membrane reactor may extract at least about 95% of lithium from the lithium enriched stream generated by the first electrochemical membrane reactor per cycle with the generated LiOH having a purity of greater than about 99%, with the Li extraction rate being greater than about >75.06 mg.Math.g.sup.1.Math.h.sup.1. Conventional electrodialysis employing paste electrodes, 3D flow-through electrodes, or packed-bed electrodes may operate for less than 50 cycles having a lithium to magnesium selectivity of about 50 and may not achieve both a high lithium extraction rate and a high lithium extraction efficiency simultaneously. The performances of these three electrodes are compared in Table 4. The paste electrode may have more MnO.sub.2 loading than the flow-through electrode, and it may extract more Li per cycle, but the Li extraction rate is much lower than the 3D flow-through electrode. Those electrodes may not have high enough selectivity to extract Li from brine, and the extracted Li may have less than about 25 wt. % purity. Their cyclability may be about 50 cycles in natural geothermal brines, for the reasons of electrode material degradation mechanisms and precipitate coating on the electrode.
TABLE-US-00004 TABLE 4 LiMn.sub.2O.sub.4 loading / Extraction Extraction rate / Li selectivity Type of electrodes mg .Math. cm.sup.2 efficiency / cycle mg .Math. g.sup.1 .Math. h.sup.1 to Mg Cyclability Paste electrode 75.06 ~29% 2.4 57 <50 3D flow-through 40 ~6.7% 75.06 46 <50 electrode Packed-bed porous unknown ~1.6% unknown unknown <50 electrode Metal Frame Porous 6.73 g .Math. L.sup.1 >95% >75.06 >28000 (to >500 Electrode In Accordance Mg, Na and With Embodiments Of K) The Disclosure
[0078] The embodiments of the disclosure described above and illustrated in the accompanying drawings do not limit the scope of the disclosure, which is encompassed by the scope of the appended claims and their legal equivalents. Any equivalent embodiments are within the scope of this disclosure. Indeed, various modifications of the disclosure, in addition to those shown and described herein, such as alternate useful combinations of the elements described, will become apparent to those of ordinary skill in the art from the description. Such modifications and embodiments also fall within the scope of the appended claims and equivalents.