WO2025199364A1 - Metal extraction from clays and metal ores using faradaic processes - Google Patents

Abstract

This disclosure provides systems, methods, and apparatus related to metal extraction from clays and metal ores. In one aspect, a metal-rich clay and carbon or a metal ore and the carbon are ball milled to form a powder mixture. The powder mixture and water are mixed to form an aqueous mixture. A first electrode and a second electrode are inserted in the aqueous mixture. A bias is applied between the first electrode and the second electrode to drive metal ions out of the metal-rich clay or the metal ore and into the aqueous mixture.

Description

Metal Extraction From Clays and Metal Ores Using Faradaic Processes

Inventors: Andrew Haddad, Robert Kostccki

RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/568,323, filed 21 March 2024, and to U.S. Provisional Patent Application No. 63/772,960, filed 17 March 2025, both of which are hereby incorporated by reference.

STATEMENT OF GOVERNMENT SUPPORT

[0002] This invention was made with government support under Contract No. DE-AC02- 05CH11231 awarded by the U.S. Department of Energy. The government has certain rights in this invention.

BACKGROUND

[0003] Historically, ore refinement has been dominated by thermally coupled hydrometallurgical processes or pyro-metallurgy. For example, the Bayer process is used to extract alumina from bauxite; the sulfuric acid roast process and the limestone gypsum roast (LGR) process are used to extract lithium from spodumene or phyllosilicate ores, respectively; the high-pressure acid leach process (HPAL) is used to extract nickel from laterite nickel oxide ores; and pyrometallurgical processing of both copper and nickel sulfide ores is used to recover nickel and copper. These types of thermochemical processes have dominated critical material and base metal extraction technologies for over a century, the totality responsible for supplying raw materials that are integral to many technologies used in energy storage applications, aviation, building materials, and consumer products.

[0004] As global demand for stationary electrical energy storage and electric transport continues to increase, projected to reach 4600 GWh by 2040, so too will the demand for the critical elements needed to power this shift. For example, estimates suggest a need for more than 100,000 metric tons (t) of lithium (elemental) per year by 2025, a 300% increase from 2018 levels, and by 2100 413,000-704,0001 of Li per year. The trend is similar for copper, nickel, cobalt, phosphate, vanadium, and rare earth elements (REEs). This dramatic surge in mineral demand complicates efforts to reach net zero targets by the second half of the century, further exacerbating the materials production carbon footprint problem, and may lead to materials supply implications. Despite the ubiquity of orc processing and its increasing importance in sustaining a clean energy future, they have had little change since their inception.

[0005] Recently, lithium reserves were identified near the McDermitt caldera (USA) at Thacker Pass, with estimates suggesting -20-40 Mt (million metric tonnes) of lithium contained within the whole caldera. These reserves are recognized as both Illite- bearing Miocene lacustrine sediments that can have grades up to 1 weight % lithium, and smectite-rich claystones, such as hectorite, and other lithium-bearing claystones that can have up to 0.4 weight % of lithium.

These sedimentary Li resources are also found in other areas such as the Mojave Desert, southern Nevada, Mexico, and Serbia, and are attracting numerous large-scale commercial mining and extraction ventures employing traditional thermal-based LGR processes or concentrated acid leaching.

SUMMARY

[0006] One innovative aspect of the subject matter described in this disclosure can be implemented in method including ball milling a metal-rich clay and carbon or a metal ore and the carbon to form a powder mixture. The powder mixture and water are mixed to form an aqueous mixture. A first electrode and a second electrode are inserted in the aqueous mixture. A bias is applied between (or to) the first electrode and the second electrode to drive metal ions out of the metal-rich clay or the metal ore and into the aqueous mixture.

[0007] Another innovative aspect of the subject matter described in this disclosure can be implemented in a method including providing two horizontal subsurface wells. A horizontal portion of each of the horizontal subsurface wells are substantially parallel. A fluid is injected in at least one of the horizontal subsurface wells to fracture the material between the two horizontal subsurface wells. The material includes a metal-rich clay or a metal ore. The fluid includes water and carbon. An electrode is inserted in each of the two horizontal subsurface wells. A bias is applied between (or to) the electrodes. The bias drives metal ions out of the metal-rich clay or the metal ore and into the fluid. The fluid is pumped out of the two horizontal subsurface wells.

[0008] Details of one or more embodiments of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figures 1A-1C show examples of flow diagrams illustrating methods using Faradaic processes for metal extraction from metal-rich clays or metal ores. Figure ID shows an example of a schematic illustration of a setup for in-situ metal extraction using Faradaic processes from metal-rich clays or metal ores.

[0010] Figure 2A shows CVs of HCCE composite electrode cycled three times between 2.5 and 3.75 V showing the first, second, and third cycles. Figure 2B shows five CV cycles of HCCE between 2.5 and 4.3 V showing the first, second, third, fourth, and fifth cycles. Figure 2C shows galvanostatic charge and discharge curves of HCCE at a current density of 0.72 mA g^-1 between 2.9 and 4.5 V. WE: HCCE; CE: Li; RE: Li; Electrolyte: LiPaste generation-2 LIB electrolyte.

[0011] Figure 3A shows Lils high-resolution XPS spectra of pristine and polarized HCCE’s. Figure 3B shows Fe2p high-resolution XPS spectra of pristine and polarized HCCE’s. Figure 3C shows diffraction patterns of pristine HCCE and HCCE after Galvanostatic polarization; SiCL and CaCOa references. Figure 3D shows ATR-FTIR spectra of pristine HCCE and polarized HCCE; R = Li⁺, Mg²⁺, or Fe²⁺.

[0012] Figure 4A shows a SEM image of pristine HCCE. Figure 4B shows a SEM image of polarized HCCE held at 4.5 V for 1 h. Figure 4C shows a SEM image of polarized HCCE held at 4.5 V for 6 days showing enhanced surface film formation. Figure 4D shows a cross-sectional FIB analysis of pristine HCCE (50,000x magnification). Figure 4E shows a cross-sectional FIB analysis HCCE polarized at 4.5 V for 24 h showing surface film layer formation on the surface of the electrode (50,000x magnification). Figure 4F shows a cross-sectional FIB analysis of polarized HCCE at 4.5 V for 6 days showing large surface film (50,000x magnification).

DETAILED DESCRIPTION

[0013] Reference will now be made in detail to some specific examples of the invention including the best modes contemplated by the inventors for carrying out the invention. Examples of these specific embodiments are illustrated in the accompanying drawings. While the invention is described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to the described embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

[0014] In the following description, numerous specific details arc set forth in order to provide a thorough understanding of the present invention. Particular example embodiments of the present invention may be implemented without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.

[0015] Various techniques and mechanisms of the present invention will sometimes be described in singular form for clarity. However, it should be noted that some embodiments include multiple iterations of a technique or multiple instantiations of a mechanism unless noted otherwise.

[0016] The terms “about” or “approximate” and the like are synonymous and are used to indicate that the value modified by the term has an understood range associated with it, where the range can be ± 20%, ± 15%, ± 10%, ± 5%, or ± 1%. The terms “substantially” and the like are used to indicate that a value is close to a targeted value, where close can mean, for example, the value is within 80% of the targeted value, within 85% of the targeted value, within 90% of the targeted value, within 95% of the targeted value, or within 99% of the targeted value.

[0017] Electrochemical leaching is an emerging field that utilizes electrochemical reactions, electrical fields, or a combination of chemical and electrochemical reactions to facilitate metal ion dissolution from host lattices. Various iterations of electrochemical leaching have been successfully deployed in electronic waste remediation, LIB recycling, and ore dissolution. Compared to chemical and thermochemical approaches, electrochemical leaching removes the need for high temperatures or high acid concentrations and can integrate seamlessly with renewable electrons. However, given the heterogeneous nature of the electrochemical reaction and the insulating properties of many oxide-bearing lithium ores, electrochemical leaching strategies are limited by large overpotentials, side reactions, and poor Faradaic efficiency.

[0018] To this end and in pursuit of developing additional mineral processing technologies, described herein are methods for electrochemical activation-enabled ion release using mineral ore-carbon composites. Li⁺ (and other metal ions) can be electrochemically deintercalated from a variety of inorganic host 2D and 3D mineral materials. [0019] Described herein are electrochemical-based lithium extraction methods, termed Faradaic leaching, that can eject lithium ions from lithium-rich clays or orcs to produce a Li+ brine. Lithium-rich clays, such as hectorite or sepiolite, for example, are predominantly composed of magnesium-silicate layers. In their pristine form, the insulating nature of the clays makes them unfeasible for any electrochemical manipulations. The embodiments described herein function by creating conductive composites (e.g., both static film and aqueous slurry composites) that contain carbon and a lithium-rich clay (e.g., such as hectorite) that can be used as an electrode and subjected to voltage and current density bias. The electrochemical bias is sufficient drive lithium ions out of the composite into the surrounding electrolyte.

[0020] Further embodiments include a subsurface mining method: electrochemically fracked leaching to extract lithium directly from subsurface lithium-rich clay resources using in situ subsurface electrochemical charging processes. Horizontal fractures using a fracturing fluid composed of water and carbon (and in some embodiments, sand) in subsurface of regions where lithium-rich clays are present will prompt dissolution of fine particles of lithium-rich clays into the fracking electrode medium. Electrodes are inserted into the fracking holes. Currents are applied to the electrodes to create an electric field that drives ions (e.g., lithium and sodium) out of fractured clays. The fracking fluids, now containing high levels of alkali metals, can be withdrawn and sent for further processing. Application of acoustic frequencies also improves the fracture of the clay lattice to assist in ion release.

[0021] Yet further embodiments include metal extraction using a battery-like device.

[0022] The methods can also be used to extract other metals (e.g., alkali metals, alkaline metals, and transition metals, including Na, Mg, Mn, Ni, Fe, Zn, Al, Co, In, Ga, Ir, Pt, Au, Ag, Cr, V, Ti, Ru, Re, Cd, W, Nb, Tc, Mo, and rare earth elements) from clays or ores to generate a metal rich brine. The method can also be used to extract Si CL from clays or ores to generate a SiCL rich brine.

[0023] Figures 1A-1C show examples of flow diagrams illustrating methods using Faradaic processes for metal extraction from metal-rich clays or metal ores. Figure 1A shows an example of a flow diagram illustrating method using Faradaic processes for metal extraction from metalrich clays or metal ores that have been removed from the ground.

[0024] Starting at block 105 of the method 100 shown in Figure 1A, a metal-rich clay and carbon or a metal ore and the carbon are ball-milled to form a powder mixture. In some embodiments, the carbon is electrically conductive. The carbon serves to makes the metal-rich clay or the metal orc more conductive, which is important in the faradic process.

[0025] In some embodiments, a metal of the metal-rich clay or the metal ore is a metal from a group an alkali metal, an alkaline metal, a transition metal, and a rare earth element. In some embodiments, a metal of the metal-rich clay or the metal ore is a metal from a group Li, Na, Mg, Mn, Ni, Fe, Zn, Al, Co, In, Ga, Ir, Pt, Au, Ag, Cr, V, Ti, Ru, Re, Cd, W, Nb, Tc, and Mo. In some embodiments, a metal of the metal-rich clay or the metal ore is lithium.

[0026] In some embodiments, the metal-rich clay comprises a lithium-rich clay. In some embodiments, the lithium-rich clay is a clay from a group hectorite, swinefordite, tainiolite, smectite, laterite, bauxite, antigorite, kaolinite, illite, montmorillonite, chlorite, vermiculite, biotite, muscovite, phlogopite, lepidolite, margarite, glauconite, spodumene, nambulite, augite, pezzottaite, sugilite, tourmaline, petalite, willemite, tephroite, staurolite, clinohumite, jadarite, and mixtures thereof.

[0027] In some embodiments, the carbon is carbon is a carbon from a group carbon powder, activated carbon powder, carbon black, graphite, carbon nanotubes, graphite nanotubes, graphene, and mixtures thereof. In some embodiments, a weight % of the carbon in the powder mixture is about 0.1 weight % to 50 weight percent, about 5 weight % to 15 weight %, or about 10 weight %. In some embodiments, the carbon is in the form of particles that are about 50 microns to 100 microns prior to the ball milling.

[0028] Too much carbon in the powder mixture may impede the coating of particles of the metal-rich clay or the metal ore with particles of the carbon. Too much carbon in the powder mixture may also yield particles of the metal-rich clay or the metal ore having an uneven distribution of carbon on the surfaces of the particles. Both of these effects may impede the rate of electron percolation into the metal-rich clay or the metal ore at block 120, reducing the rate at which metal ions are driven out of the metal-rich clay or the metal ore.

[0029] In some embodiments, the ball milling is performed for about 15 minutes to 1 hour. A longer ball milling time generates smaller particles of the metal-rich clay and the carbon or the metal ore and the carbon. Particle sizes of the metal-rich clay and the carbon or the metal ore and the carbon of about 1 micron to 10 microns can be achieved in about in 15 minutes of ball milling, in some instances. In some embodiments, particle sizes of the metal-rich clay and the carbon or the metal ore and the carbon are about 50 nanometers to 10 microns after the ball milling. Tn some embodiments, after the ball milling, particles of the metal-rich clay or the metal orc arc coated with particles of the carbon. In some embodiments, stainless steel balls arc used in the ball milling.

[0030] In some embodiments, during the ball milling, the metal-rich clay and the carbon or the metal ore and the carbon further include a liquid. In some embodiments, the liquid comprises an alcohol (e.g., ethanol) or water. When the liquid comprises an alcohol, the alcohol may be allowed to evaporate after the ball milling at block 105. In some embodiments, when the liquid comprises water, the water may include sulfuric acid, hydrochloric acid, and mixtures thereof. In some embodiments, a molarity of a solution of the acid and water is about 0.05 molar to 0.3 molar, or about 0.125 molar. In some embodiments, including acid during the ball milling operation begins to breakdown the structure of the metal-rich clay or the metal ore. This may improve the process of driving metal ions out of the metal-rich clay or the metal ore at block 120. When the ball milling includes water, the operation at block 110 may be skipped, depending on the amount of water included in the ball milling. Alternatively, when the ball milling includes water, less water may need to be added at block 110 to form the aqueous mixture, depending on the amount of water included in the ball milling.

[0031] Returning to the method 100 shown in Figure 1 A, at block 110 the powder mixture and water are mixed to form an aqueous mixture. In some embodiments, a loading of powder mixture to water is about 25 grams per liter of water to 500 grams per liter of water, or about 100 grams per liter of water.

[0032] In some embodiments, the water includes an acid. In some embodiments, the acid is an acid from a group sulfuric acid, hydrochloric acid, and combinations thereof. In some embodiments, a molarity of a solution of the acid and water is about 0.05 molar to 0.3 molar, or about 0.125 molar. The acid makes the water more conductive, serving as an electrolyte (i.e., a dilute acidic electrolyte). There is a dependence on the rate of the reaction at block 120 with acid concentration. Generally, the higher the acid concentration, the faster the reaction rate.

[0033] At block 115, a first electrode and a second electrode are inserted in the aqueous mixture. In some embodiments, the electrode to which a negative bias is applied (i.e., the cathode) comprises graphite or an acid-resistant metal (e.g., stainless steel, such as stainless steel 315). In some embodiments, the electrode to which a positive bias is applied (i.e., the anode) comprises graphite or an acid-resistant metal (e.g., stainless steel, such as stainless steel 315, or a mixed metal oxide (titanium/tantalum/iridium or titanium/tantalum/ruthenium). Any of the electrode materials to which a positive bias is applied may also be coated with hafnium oxide. [0034] In some embodiments, there is no membrane between the first electrode and the second electrode. Not including a membrane between the first electrode and the second electrode simplifies the method 100 and reduces the cost of performing the method.

[0035] At block 120, a bias is applied between (or to) the first electrode and the second electrode to drive metal ions out of the metal-rich clay or the metal ore and into the aqueous mixture (i.e., electrochemical leaching). In some embodiments, the bias applied between the first electrode and the second electrode is about 0.3 V to 2.5 V. In some embodiments, the bias is applied between the first electrode and the second electrode for about 6 hours to 36 hours, or about 24 hours.

[0036] In some embodiments, the process in which the bias is applied between the first electrode and the second electrode is a batch process. For example, the aqueous mixture may be in a container, with the aqueous mixture being stirred when the bias is applied. In some embodiments, the bias is applied between the first electrode and the second electrode while the aqueous mixture is flowed past the electrodes. For example, the aqueous mixture may be in a closed loop flowing past the electrodes. This implementation is similar to a flow cell, for example. When the method 100 is complete (i.e., most or all of the metal ions have been driven out of the metal-rich clay or the metal ore), the method 100 may be repeated with a new batch of the metal-rich clay or the metal ore.

[0037] In some embodiments, the method 100 further includes processing the water to remove the metal ions from the aqueous mixture. Processes to remove metal ions from water are well-known industrial processes.

[0038] For example, when lithium ions are to be removed from the aqueous mixture, transition metals arc first removed from the aqueous mixture by raising the pH of the aqueous mixture (i.e., making the aqueous mixture more basic). Raising the pH of the aqueous mixture precipitates the transition metals out of the aqueous mixture. Ion exchange resins are then used to remove alkali metals and alkaline metals from the aqueous mixture, including K, Na, Mg, and Ca. The remaining aqueous mixture generally includes Li and Na in the form of lithium sulfate and sodium sulfate, respectively. The sodium sulfate is remove from the aqueous mixture via inverse temperature crystallization by adding sodium carbonate to the aqueous mixture. [0039] Further, in some embodiments, the carbon is removed from the aqueous mixture. The carbon can then be reused in the method 100. The carbon may be removed using centrifugal separation or a flotation method. The residual ore or clay may be used as a component of concrete.

[0040] In some embodiments, the method 100 further includes irradiating the metal-rich clay or the metal ore with micro waves prior to block 105. The micro waves may change the crystal structure of the metal-rich clay or the metal ore and make it easier to separate metal ions from the metal-rich clay or the metal ore.

[0041] In some embodiments, the method 100 further includes applying acoustic frequencies to the metal-rich clay or the metal ore. In some embodiments, the acoustic frequency is about 1 microHz to 1 gigaHz. The acoustic frequencies may change the crystal structure of the metal-rich clay or the metal ore and make it easier to separate metal ions from the metal-rich clay or the metal ore. The acoustic frequencies may be applied prior to or after the ball milling at block 105, or when applying the bias at block 120. For example, in some embodiments, acoustic frequencies are applied to the powder mixture during the ball milling at block 105.

[0042] In some embodiments, the method 100 further includes homogenizing the powder mixture and the water after block 110. Carbon is generally hydrophobic and may not mix with the water when forming the aqueous mixture. In some embodiments, the powder mixture and the water are homogenized for about 15 minutes to 45 minutes. In some embodiments, the powder mixture and the water are homogenized with a homogenizer (e.g., a rotor-stator homogenizer) or a homogenizing stirrer.

[0043] Figure IB shows an example of a flow diagram illustrating an in-situ method using Faradaic processes for metal extraction from metal-rich clays or metal ores. Starting at block 135 of the method 130 shown in Figure IB, two horizontal subsurface wells are provided. A horizontal portion of each of the horizontal subsurface wells are substantially parallel to one another. In some embodiments, the method 130 further includes drilling the two horizontal subsurface wells prior to block 135.

[0044] At block 140, a fluid is injected in at least one of the horizontal subsurface wells to fracture the material between the two horizontal subsurface wells. The material between the two horizontal subsurface wells includes a metal rich-clay or a metal ore. The fluid includes water and carbon (i.e., water mixed with carbon). The fluid serves as a hydraulic fracking fluid. In some embodiments, the fluid includes sand. Injecting the fluid into at least one of the horizontal subsurface wells creates fissures in the material (i.c., the earth) proximate the well and between the two horizontal subsurface wells. These fissures form a percolation network between the two horizontal subsurface wells. In some embodiments, the fluid is injected into each of the two horizontal subsurface wells.

[0045] In some embodiments, a metal of the metal-rich clay or the metal ore is a metal from a group an alkali metal, an alkaline metal, a transition metal, and a rare earth element. In some embodiments, a metal of the metal-rich clay or the metal ore is a metal from a group Li, Na, Mg, Mn, Ni, Fe, Zn, Al, Co, In, Ga, Ir, Pt, Au, Ag, Cr, V, Ti, Ru, Re, Cd, W, Nb, Tc, and Mo. In some embodiment, a metal of the metal-rich clay or the metal ore is lithium.

[0046] In some embodiments, the metal-rich clay comprises a lithium-rich clay. In some embodiments, the lithium-rich clay is a clay from a group hectorite, swinefordite, tainiolite, smectite, laterite, bauxite, antigorite, kaolinite, illite, montmorillonite, chlorite, vermiculite, biotite, muscovite, phlogopite, lepidolite, margarite, glauconite, spodumene, nambulite, augite, pezzottaite, sugilite, tourmaline, petalite, willemite, tephroite, staurolite, clinohumite, jadarite, and mixtures thereof.

[0047] In some embodiments, the carbon is a carbon from a group carbon powder, activated carbon powder, carbon black, graphite, carbon nanotubes, graphite nanotubes, graphene, and mixtures thereof. In some embodiments, the carbon is electrically conductive. The carbon polarizes the metal-rich clay or the metal ore lying between the two horizontal subsurface wells. In some embodiments, a loading of carbon in the water is about 25 grams per liter of water to 500 grams per liter of water, or about 100 grams per liter of water.

[0048] In some embodiments, the water includes an acid. In some embodiments, the acid is an acid from a group sulfuric acid, hydrochloric acid, and combinations thereof. In some embodiments, a molarity of a solution of the acid and water is about 0.05 molar to 0.3 molar, or about 0.125 molar. The acid makes the water more conductive, serving as an electrolyte (i.e., a dilute acidic electrolyte). There is a dependence on the rate of the reaction at block 150 with acid concentration. Generally, the higher the acid concentration, the faster the reaction rate.

[0049] Returning to the method 130 shown in Figure IB, at block 145 an electrode is inserted in each of the two horizontal subsurface wells. The electrode may comprise the same or similar materials as the electrodes used in the method 100, as described with respect to Figure 1 A.

[0050] At block 150, a bias is applied between (or to) the electrodes. A metal-rich clay or a metal ore is between the two horizontal subsurface wells. The bias drives metal ions out of the metal-rich clay or the metal ore and into the fluid.

[0051] During the operation at block 150, the two horizontal subsurface wells are in fluid communication. Further, each of the electrodes in each of the two horizontal subsurface wells are in contact with the fluid injected into at least one of the wells. When the fluid is injected into only one of the two horizontal subsurface wells, the fluid may percolate to the other of the two horizontal subsurface wells such that the two wells are in fluid communication.

[0052] Figure ID shows an example of a schematic illustration of a setup for in-situ metal extraction using Faradaic processes from metal-rich clays or metal ores. As shown in Figure ID, there are two horizontal subsurface wells 182 and 184. Between the two horizontal subsurface wells 182 and 184 is a metal-rich clay or a metal ore 186. There are fissures 188 generated at block 140 in the metal-rich clay or the metal ore 186 between the two horizontal subsurface wells 182 and 184. Electrodes 192 and 194 are inserted into each of the two horizontal subsurface wells 182 and 184, respectively.

[0053] Returning to the method 130 shown in Figure IB, at block 155 the fluid is pumped out of the two horizontal subsurface wells. In some embodiments, the method 130 further includes processing the fluid to remove the metal ions from the water.

[0054] In some embodiments, method 130 further includes injecting water into at least one of the two horizontal subsurface wells after inserting the electrodes or while applying a bias between the electrodes. For the bias to drive metal ions out of the metal-rich clay or the metal ore, there needs to be fluid spanning between the two wells. I.e., there mush be fluid communication between the two wells.

[0055] Figure 1C shows an example of a flow diagram illustrating a method using Faradaic processes for metal extraction from metal-rich clays or metal ores in a battery-like device. Starting at block 165 of the method 160 shown in Figure 1C, a cell is provided. The cell includes a cathode, an anode, a separator positioned between the cathode and the anode, and an electrolyte. The electrolyte serves to conduct ions between the cathode and the anode. The cathode includes a metal-rich clay and carbon or a metal ore and the carbon. In some embodiments, the metal-rich clay and the carbon or the metal ore and the carbon are disposed on a metal foil or a metal mesh. In some embodiments, the metal foil or the metal mesh comprises aluminum.

[0056] In some embodiments, the anode is a material from a group platinum, palladium, nickel graphite, stainless steel, and iridium oxide (e.g., DSA-IrO2). In some embodiments, the separator is a separator from a group polypropylene, PVDF, a cation exchange membrane, and a ceramic material. In some embodiments, the electrolyte is an electrolyte from a group ethylene and ethyl methyl carbonate, an alkali metal sulfate (e.g., Na2SO4, Li2SO4), an alkali metal tetrafluroborate (e.g., LiBF4, NaBF4), a potassium iron ferro(ferri)cyanide (e.g., K4Fe(II)CN6 / K3Fe(III)CN6), and an alkali metal perchlorate (e.g., LiC104, or NaC104).

[0057] In some embodiments, a metal of the metal-rich clay or the metal ore is a metal from a group an alkali metal, an alkaline metal, a transition metal, and a rare earth element. In some embodiments, a metal of the metal-rich clay or the metal ore is a metal from a group Li, Na, Mg, Mn, Ni, Fe, Zn, Al, Co, In, Ga, Ir, Pt, Au, Ag, Cr, V, Ti, Ru, Re, Cd, W, Nb, Tc, and Mo. In some embodiment, a metal of the metal-rich clay or the metal ore is lithium.

[0058] In some embodiments, the metal-rich clay comprises a lithium-rich clay. In some embodiments, the lithium-rich clay is a clay from a group hectorite, swinefordite, tainiolite, smectite, laterite, bauxite, antigorite, kaolinite, illite, montmorillonite, chlorite, vermiculite, biotite, muscovite, phlogopite, lepidolite, margarite, glauconite, spodumene, nambulite, augite, pezzottaite, sugilite, tourmaline, petalite, willemite, tephroite, staurolite, clinohumite, jadarite, and mixtures thereof.

[0059] In some embodiments, the carbon is carbon selected from a group carbon powder, activated carbon powder, carbon black, graphite, carbon nanotubes, graphite nanotubes, graphene, and mixtures thereof. In some embodiments, the carbon is electrically conductive. In some embodiments, the carbon further includes alpha phase hematite iron nanoparticles mixed therein. In some embodiments, the carbon is ferromagnetic.

[0060] In some embodiments, the metal-rich clay and the carbon or the metal ore and the carbon are ball milled (as described above with respect to block 105 of the method 100 shown in Figure 1 A) prior to incorporating them into the cell. In some embodiments, after the ball milling, a binder solution is added to the powder mixture to form a slurry. In some embodiments, the slurry is ball milled. In some embodiments, the slurry is cast onto a metal foil or a metal mesh to form the cathode. [0061] In some embodiments, the binder solution comprises a solvent and a polymer that is soluble in the solvent, hi some embodiments, the binder solution comprises a solvent and a thermoplastic fluoropolymer that is soluble in the solvent. In some embodiments, the binder solution comprises N-methylpyrrolidone (NMP) and polyvinylidene fluoride (PVDF).

[0062] Returning to the method 160 shown in Figure 1C, at block 170 a potential is applied between (or to) the anode and the cathode. Applying a potential between the anode and the cathode drives a metal in the metal-rich clay or the metal ore from the metal-rich clay or the metal ore into the electrolyte.

[0063] After block 170, the cell can be disassembled and the metal can be separated from the electrolyte.

[0064] The following examples are intended to be examples of the embodiments disclosed herein, and are not intended to be limiting. The examples show that anodic polarization hectorite-carbon black composite electrodes (HCCE) achieve ion removal from real hectorite clay via a multi-step mechanism implicating both electrochemical (E) and chemical (C) events. An initial oxidation of electrolyte (E) facilitates proton abstraction by surface oxides (C), via proton-coupled electron transfer, resulting in an altered lattice structure. Thereafter, the oxidation of iron (E) results in an oxidative deintercalation, which further alters and weakens the lattice. The weakened lattice structure is then attacked by reactive byproducts generated from electrolyte oxidation (C) leading to structural collapse of the original hectorite lattice, and substantial alkaline ion release into the electrolyte.

EXAMPLE - Preparation of HCCE electrodes

[0065] Hectorite is classified as a smectite, composed of a sheet of octahedrally coordinated Mg²⁺, Fe²⁺, or Li⁺ ions with oxygen or fluoride as corner- sharing atoms, sandwiched between two identical layers of linked Si CL tetrahedrons. Sheets of this type are superimposed and linked by a plane of cations (Na⁺ K⁺, and Ca²⁺) and water molecules, forming a turbostratic layered material. ICP-MS analysis of the hectorite clays used in this study confirmed this composition. [0066] Hectorite, being a phyllosilicate, is a poor conductor in its pristine form making it difficult for electrochemical activation. To alleviate this and improve electron percolation into the material, a hectorite-carbon black composite electrode (HCCE) was prepared to enable electrochemical activation and assess its electrochemical behavior. [0067] Hectorite-carbon composites were prepared by ball milling hectorite and carbon black (1:1) for 30 min, and then adding to a 2 weight % poly vinylidene fluoride (PVdF) N- methyl-2-pyrrolidone (NMP) solution to create a viscous slurry. The composite slurry was then doctor-bladed onto an aluminum foil current collector and dried in a vacuum oven at 120 °C for 48 h affording a thin film hectorite-carbon composite electrode (HCCE) with a 10 pm thickness and an active material loading of 7 mg cm^-2. Electrodes were then cut from the thin film sheets using a hole punch and then used as electrodes in T-cells for polarization experiments. EXAMPLE

[0068] Figure 2A shows cyclic voltammetry (CV) scans of the composite HCCE cycled three times between 2.5 and 3.75 V (vs Li/Li⁺) at a scan rate of 0.5 mV s^-1. Cycle one shows negligible anodic and cathodic current, with only a slight increase in anodic current between 3.5 and 3.75 V. Voltammograms from cycles two and three are similar but show a reduction in the anodic current intensity at 3.75 V. Extending the anodic sweep limit to 4.3 V yields a different set of voltammograms (Figure 2B). Cycle one shows an irreversible anodic event with a peak potential at 4.3 V, due to electrolyte oxidation, and no cathodic events. Cycle two results in a large irreversible cathodic event with a peak potential of 3.25 V. This species is then observed as a reversible event in cycle three with an anodic peak potential at 3.4 V and cathodic peak potential at 3.2 V. The lack of a cathodic event at 3.25 V in cycle one suggests that both electrolyte oxidation at 4.3 V and subsequent reduction of those reaction products at cathodic potentials below 3 V in cycle one is necessary to condition the structure and enable the electrochemical activity observed in the following cycles. The redox couple seen in cycle three corresponds to the deintercalation of lithium in hectorite and is consistent with the oxidation potential range observed in lithium iron phosphate (LFP) cathodes, suggesting that Fe²⁺ oxidation is implicated in the deintercalation event.

[0069] Note that there is a possibility of magnesium deintercalation. However, prior work suggests that the insertion/extraction potentials of magnesium from magnesium iron oxide cathode materials are significantly lower than those observed in this work. CVs were performed using a 100% carbon-based electrode and showed a voltammogram typical of a capacitive system, confirming that the reversible redox character is attributed to hectorite. Cycles four and five are nearly identical to cycle three, suggesting that the conditioning of the electrode is complete after three cycles. The observed order of electrochemical events would suggest that the oxidation state of iron in hectorite is Fe³⁺. However, the anodic charge consumed in cycle three, 36.93 mC, is higher than in the preceding cathodic process in cycle two, -26.2 mC. This suggests that there is a mixed valence state of iron in hectorite, with an apparent ratio of Fe²⁺ to Fe³⁺ of 0.41-1. In fact, iron valency in smectite clays has been reported to be either solely Fe³⁺ or Fe²⁺, or a mixture of the Fe^2+/3+.

[0070] The apparent conditioning of the structure by electrolyte oxidation and subsequent reduction of these reaction products at cathodic potentials below 3 V may be related to two possible mechanisms; (i) proton generation from residual water in the electrolyte (<10 ppm) and surface etching of MgO in hectorite, or (ii) the generation of protons and other reactive moieties from organic carbonate solvents oxidation. Organic carbonate-based electrolyte degradation mechanisms have been extensively evaluated previously and suggest a two-step reaction mechanism, proton abstraction from ethylene carbonate (EC) and transfer to the surface oxygen sites, followed by a ring opening of the proton abstracted EC to generate reactive oxalates and or other chelating moieties. It appears that the electrolyte oxidation at 4.3 V is needed for the electrochemical activation of hectorite and the emergence of the reversible Fe^2+/3+ redox couple. Protons generated by electrolyte oxidation can react with edge MgO surface sites in hectorite, a process that is known to be highly exergonic, resulting alteration of Mg²⁺ ion in the octahedral sites adjacent to the surface. Such processes would alter the lattice at the surface to open the appropriate channels for subsequent lithium-ion deintercalation.

[0071] After five CV cycles of the electrode, galvanostatic cycling of HCCE was performed between the open circuit potential (2.9 V) and 4.5 V at i = 0.72 mA g^-1. The anodic polarization curve yields a potential profile that shows a distinct plateau at 3.4 V (Figure 2C), consistent with the anodic peak observed in the CV of the HCCE. A second plateau is observed at 4.3 V corresponding to the electrolyte oxidation event observed at 4.3 V in the CVs of HCCE. Note that the anodic polarization curve resembles those observed for LiFcPCU lithium-ion positive electrodes. In comparison to the HCCE polarization curve, a pure carbon electrode control, shows capacitive behavior with no plateaus, confirming iron oxidation and ion deintercalation as the primary anodic reaction in the HCCE. The following cathodic discharge polarization profile of HCCE, shown in Figure 2C, shows markedly different features in both shape and duration. There is a rapid voltage decrease that resembles a pseudocapacitive or capacitive discharge behavior. This illustrates that the anodic charging process irreversibly alters hectorites structural ordering, preventing the possibility of ion re-intercalation. Reversible Li intercalation and dcintcrcalation into analogous layered iron phyllosilicates have been previously reported. This reversibility is attributed to the charge-neutral sheets in the layered iron phyllosilicate. The irreversible behavior observed here is consistent with this as hectorite does possess interplanar cations. Note that irreversible chemical redox behavior and structural degradation of similar smectite clays have been previously observed.

[0072] To interpret the Faradaic efficiency (FE) of the process chronoamperometry was performed. FE is a factor to evaluate the effectiveness of an electrochemical reaction and evaluates the usage of electrons passed through a cell. It is defined as the amount of electrons used for the intended product formation relative to the theoretical amount of product that can be produced from the total charge passed. To deconvolute the charge obtained from the oxidation of the active material (HCCE) from the charge obtained from the oxidation of the electrolyte, a potential of 4.5 V vs Li⁺/Li was applied with HCCE as the positive electrode (after CV cycling five times) and then again at the same potential using a pure carbon black electrode. Chronoamperometry experiments were left to run until the current reached zero. The results show that the FE of the process is 54.8%, suggesting that electrolyte oxidation is an active participant in the reaction.

[0073] During the anodic polarization, there is a phase change event and irreversible alteration to the structural order of the hectorite lattice. As mentioned previously, it is hypothesized that this may be due to the consumption of protons from EC oxidation and alteration of magnesium surface sites in hectorite, followed by electrochemically coupled iron oxidation and lithium-ion deintercalation. Additionally, given that there appears to be some meaningful level of electrolyte oxidation at 4.3 V, oxidized electrolyte byproducts may also be reacting chemically with hectorite, further exasperating structural enervation. Such induced structural defects and lattice perturbations could promote fast ion diffusion as well as trigger an irreversible structural transformation of the clay lattice structure. Indeed, the capacitive and rapid cathodic discharge behavior of HCCE, shown in Figure 2C, supports this hypothesis.

EXAMPLE

[0074] High-resolution XPS reveals a change in the lithium and iron environments of hectorite after polarization. The polarized HCCEs show no Lils peak at 56.6 eV in comparison of pristine HCCE, shown in Figure 3 A, which does exhibit the Lils core level peak. This is consistent with lithium-ion presence as one of the predominant octahedral cations in trioctahedral type smectites.

[0075] Depth-penetrating Li IS XPS provided additional information about the bulk lithium environment. Probing below the surface of the electrode reveals a gradual increase in the Lils core level at 56.6 eV, suggesting that there is still considerable lithium remaining in the HCCE after polarization. Other alkaline ion spectra were examined but revealed little change when comparing pristine to polarized samples.

[0076] XPS analysis of the transition metals present in hectorite was also performed to learn more about the nature of electron transfer during polarization. There are salient differences between Fe2p high-resolution XPS spectra of pristine and polarized HCCEs (Figure 3B). The pristine spectrum shows two distinct peaks with binding energies of -711 and 708 eV corresponding to oxidation states of Fe³⁺ and Fe²⁺. After polarization of HCCE, only the peak at a binding energy of -711 eV is present, suggesting that all Fe²⁺ has been oxidized to Fe³⁺. Depthpenetrating XPS and electron energy-loss spectroscopy (EELS) further confirmed that the oxidation state changes are a bulk phenomenon rather than a surface artifact. EELS Fe L edge spectra of the pristine material show energy losses in the Fe L-3 regions with two peaks related to Fe²⁺ and Fe³⁺ while the polarized samples exhibit an L edge region with only one peak, consistent with Fe³⁺. The EELS and XPS results corroborate the earlier hypothesis of a mixed iron valency in pristine hectorite and confirm that iron oxidation is implicated in the release of ions after polarization. Other notable changes to the HCCE are seen in high-resolution Cis spectra, showing a high degree of carbon oxidation in the composite material after anodic polarization. Collection of additional high-resolution Mn2p, and Ti2p, minority components of hectorite observed in our ICP-MS measurements, scans show no signal changes upon electrochemical polarization, suggesting that iron is the only transition metal implicated in the redox activity of the HCCEs.

[0077] XRD, FTIR, and FIB -S EM provide additional bulk characterization information that confirms the structural deterioration of hectorite during anodic polarization. X-ray diffraction patterns of pristine HCCE show 001 reflection at 7° 20, Figure 3C, arising from the interplanar spacing of 12.61 A between hectorite’s silicon layers, in addition to a -111 reflection at 20° 20. In large part, however, the XRD pattern is dominated by CaCCL (calcite) and SiCL (quartz), both of which commonly co-occur as admixtures amongst hectorite. Diffraction patterns collected after galvanostatic polarization of the hectorite HCCEs show noticeable divergence as these are amorphous, confirming the deterioration and structural collapse of the clay lattice as well as the other mineral phases. High-resolution transmission electron microscopy (HR-TEM) was also performed to confirm the amorphous nature of the leached electrode. This is consistent with electrochemical data which implicates all three octahedral metal ions in the mechanism. These lattice perturbations ostensibly serve as the impetus for structural reformation.

[0078] Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) of the HCCE before and after galvanostatic polarization further supports the observed structural collapse and provides additional insight into the chemical deterioration of the clays resulting from reactions with reactive oxidized electrolyte intermediates (Figure 3D). Pristine HCCE features three prominent bands. All of the bands, 870, 1010, and 1400 cm^-1, have been previously assigned as the vibration of metal-0 octahedral, Si-0 symmetric stretching, and CO .^2- vibration of calcium carbonate, respectively. After anodic polarization, there are stark changes in the IR spectrum. The metal-0 octahedral stretching band at 870 cm^-1 is removed, implying that the octahedrally coordinated ions are considerably altered. Interestingly, there is the emergence of two new vibrational modes at 1090 and 1160 cm^-1. The band at 1090 has been observed in the literature previously, assigned to the asymmetric Si-0 stretches that result from structural lattice alteration after treatment of hectorite with 1.5 M acids. This assignment suggests that similar chemical and structural degradation occurs when subjecting hectorite to anodic polarization. SEM images of polarized HCCE further support this. After anodic polarization, there is substantial morphological alteration and an overall reduction in the size of hectorite particles, transforming into smaller, porous particles. The band at 1160 cm^-1 can be attributed to possible C-0 stretching associated with organic electrolyte decomposition products on the surface of hectorite.

[0079] The EC -rich solvent used herein suggests that the oxidized electrolyte byproduct identities could include oxalates, di-carbonyls, and carbonates. First-principles calculations have indicated that carbonate ester solvents are oxidized at high potentials via direct electron transfer to produce protons, independent of the electrode surface. Moreover, protons and these oxidized electrolyte byproducts have a high propensity to chemically react with metal oxide in the electrode to induce further structural deterioration and promote additional ion removal beyond transition metal coupled oxidation and deintercalation. To confirm this, the MgO and FcoO : environments were probed in both pristine and polarized HCCE using FTIR between the range of 460 to 640 cm^-1. There arc changes in the vibrational modes of the polarized spectrum between 460 and 520 cm^-1, consistent with the removal of MgO. Pristine samples show characteristic stretching vibrations of Fe^CL between 580 and 620 cm^-1. After polarization, the bands are slightly shifted in addition to the emergence of a new band at 590 cm^-1. Collectively, the results suggest that chemical reactions between protons or oxidized electrolyte byproducts and both magnesium and iron oxides are implicated in the leaching mechanism.

EXAMPLE

[0080] FIB-SEM analysis shows the formation of a surface film on HCCE after anodic polarization, supporting the hypothesis of oxidized electrolyte byproduct film formation. SEM images show hectorite in pristine HCCEs to be 1-2 m in diameter with smooth surfaces (Figure 4A). This contrasts with HCCEs held at 4.5 V for 24 h, shown in Figure 4B, and 144 h, shown in Figure 4C, that both show particle surfaces covered with spherical nodules <1 m in size and non-uniformly distributed across the surface, yet becoming noticeably more heterogeneous after longer polarization time of 144 h. FIB analysis shows the formation of surface films on the polarized electrodes, as demonstrated by the deposits and gaps (dotted circles) under the sputtered coating. Conversely, the pristine HCCE samples show a uniform coating with no apparent inconsistencies (Figures 4D^-F). Nanopore formation is also confirmed by FIB analysis showing clear nanopore morphology in the polarized samples, contrasting with images of the pristine sample.

[0081] To probe the ion release from HCCE and to quantify the effectiveness of ion removal, ICP-MS analysis of the pristine and polarized HCCEs was performed. The analysis conclusively shows that calcium, magnesium, lithium, sodium, and iron are all released from the HCCEs after polarization. This confirms that the anodic polarization of HCCE results in a complete dissolution of the hectorite lattice. Along with the removal of lithium, 50.7 ± 4.4%, substantial levels of calcium, sodium, and magnesium are released from the electrodes, 79.6 ± 4.5%, 73.6 ± 2.6%, and 70.9 ± 2.5%, respectively. The high level of release of these ions is not surprising given that they constitute the main intraplanar ions in hectorite. These results support the stark structural changes observed in XRD, ATR-FTIR, EELS, and XPS data and suggest that anodic charging is an effective method for the mineral dissolution of ores.

EXAMPLE [0082] The prospect of eliminating the use of a kiln during lithium extraction from sedimentary clays, which necessitates the use of vast amounts of chemical reagents and temperatures of 1000 °C, is intriguing. To provide context for how such electrochemical dissolution technologies could be competitive with incumbent industrial methodologies, a CO2 and energy intensity estimate of the LGR process to ascertain energy and CO2 intensity baselines was performed. Mining operations employing the LGR process for lithium removal from clays report that the extraction facility, which encompasses the kiln and other reagents required for leaching, represents 72% of process plant Capital costs. Additionally, the extraction facility accounts for 72% of the total energy consumed, or 12.1 MWh per t of lithium carbonate equivalent (LCE). From a carbon intensity perspective, the extraction facility accounts for between 4.4 and 14.1 1 of CO2 per t of LCE, dependent on the electricity source. Considering the use of natural gas, it is 6.831 of CO2 per t LCE, the majority of this, 5.47 t of CO2, is attributed to power consumption while the remaining 1.36 t of CO2 per t of LCE is attributed to reagent use. Note that these numbers consider only the extraction step and not the additional minority energyconsuming processing steps that afford battery-grade Li2CO3 or LiOH-lLO. These estimates provide a suitable context for what would be competitive with incumbent technologies in terms of both energy and CO2 intensity.

CONCLUSION

[0083] Further details regarding the embodiments described herein can be found in Haddad, A.Z., et al. “Electrochemical lithium extraction from hectorite ore,” Commun. Chem. 7, 285 (2024), which is hereby incorporated by reference.

[0084] In the foregoing specification, the invention has been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention.

Claims

CLAIMS What is claimed is:

1. A method comprising: ball milling a metal-rich clay and carbon or a metal ore and the carbon to form a powder mixture; mixing the powder mixture and water to form an aqueous mixture; inserting a first electrode and a second electrode in the aqueous mixture; and applying a bias between the first electrode and the second electrode to drive metal ions out of the metal-rich clay or the metal ore and into the aqueous mixture.

2. The method of claim 1, wherein a weight % of the carbon in the powder mixture is about 0.1 weight % to 50 weight percent.

3. The method of claim 1, wherein particle sizes of the metal-rich clay and the carbon or the metal ore and the carbon are about 50 nanometers to 10 microns after the ball milling.

4. The method of claim 1, wherein during the ball milling, acoustic frequencies are applied to the powder mixture.

5. The method of claim 1, wherein a metal of the metal-rich clay or the metal ore is a metal from a group an alkali metal, an alkaline metal, a transition metal, and a rare earth element.

6. The method of claim 1, wherein a metal of the metal-rich clay or the metal ore is a metal from a group Li, Na, Mg, Mn, Ni, Fe, Zn, Al, Co, In, Ga, Ir, Pt, Au, Ag, Cr, V, Ti, Ru, Re, Cd, W, Nb, Tc, and Mo.

7. The method of claim 1, wherein the metal-rich clay comprises a lithium-rich clay.

8. The method of claim 1, wherein the metal-rich clay comprises a lithium-rich clay, and wherein the lithium-rich clay is a clay from a group hectorite, swinefordite, tainiolite, smectite, laterite, bauxite, antigorite, kaolinite, illite, montmorillonite, chlorite, vermiculite, biotite, muscovite, phlogopite, lepidolite, margarite, glauconite, spodumene, nambulite, augite, pezzottaite, sugilite, tourmaline, petalite, willemite, tephroite, staurolite, clinohumite, jadaritc, and mixtures thereof.

9. The method of claim 1, wherein the carbon is carbon is a carbon from a group carbon powder, activated carbon powder, carbon black, graphite, carbon nanotubes, graphite nanotubes, graphene, and mixtures thereof.

10. The method of claim 1, wherein the carbon is electrically conductive.

11. The method of claim 1, wherein during the ball milling, the metal-rich clay and the carbon or the metal ore and the carbon further include a liquid.

12. The method of claim 11, wherein the liquid comprises an alcohol or water.

13. The method of claim 1, wherein a loading of powder mixture to water is about 25 grams per liter of water to 500 grams per liter of water.

14. The method of claim 1, further comprising: after the mixing the powder mixture and the water, homogenizing the powder mixture and the water.

15. The method of claim 1, wherein the water includes an acid.

16. The method of claim 15, wherein a molarity of a solution of the acid and water is about 0.05 molar to 0.3 molar.

17. The method of claim 15, wherein the acid is an acid from a group sulfuric acid, hydrochloric acid, and combinations thereof.

18. The method of claim 1, wherein the bias applied between the first electrode and the second electrode is about 0.3 V to 2.5 V.

19. The method of claim 1, wherein the bias is applied between the first electrode and the second electrode for about 6 hours to 36 hours.

20. The method of claim 1, further comprising: processing the water to remove the metal ions from the aqueous mixture.

21. A method comprising: providing two horizontal subsurface wells, a horizontal portion of each of the horizontal subsurface wells being substantially parallel; injecting a fluid in at least one of the horizontal subsurface wells to fracture the material between the two horizontal subsurface wells, the material including a metal-rich clay or a metal ore, and the fluid including water and carbon; inserting an electrode in each of the two horizontal subsurface wells; applying a bias between the electrodes, the bias driving metal ions out of the metal-rich clay or the metal ore and into the fluid; and pumping the fluid out of the two horizontal subsurface wells.

22. The method of claim 21, wherein a metal of the metal-rich clay or the metal ore is a metal from a group an alkali metal, an alkaline metal, a transition metal, and a rare earth element.

23. The method of claim 21, wherein a metal of the metal-rich clay or the metal ore is a metal from a group Li, Na, Mg, Mn, Ni, Fe, Zn, Al, Co, In, Ga, Ir, Pt, Au, Ag, Cr, V, Ti, Ru, Re, Cd, W, Nb, Tc, and Mo.

24. The method of claim 21, wherein the metal-rich clay comprises a lithium-rich clay.

25. The method of claim 21, wherein the metal-rich clay comprises a lithium-rich clay, and wherein the lithium-rich clay is a clay from a group hectorite, swinefordite, tainiolite, smectite, laterite, bauxite, antigorite, kaolinite, illite, montmorillonite, chlorite, vermiculite, biotite, muscovite, phlogopite, lepidolite, margarite, glauconite, spodumene, nambulite, augite, pezzottaite, sugilite, tourmaline, petalite, willemite, tephroite, staurolite, clinohumite, jadarite, and mixtures thereof.

26. The method of claim 21, wherein the carbon is a carbon from a group carbon powder, carbon powder, activated carbon black, graphite, carbon nanotubes, graphite nanotubes, graphene, and mixtures thereof.

27. The method of claim 21, wherein the carbon is electrically conductive.

28. The method of claim 21, further comprising: processing the fluid to remove the metal ions from the water.

29. The method of claim 21, further comprising: injecting water into at least one of the two horizontal subsurface wells after inserting the electrodes or while applying a bias between the electrodes.