Systems and methods for a vanadium (II) generating electrolyzer

Abstract

System and method for a vanadium (II) generating electrolyzer that can include an electrolyzer system, the electrolyzer system comprising of at least one cell comprising: a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membrane separator.

Description

SYSTEMS AND METHODS FOR A VANADIUM (II) GENERATING ELECTROLYZERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This Application claims the benefit of U.S. Provisional Application No. 63 / 635,235, filed on 17-APR-2024, titled “SYSTEMS AND METHODS FOR A VANADIUM (II) GENERATING ELECTROLYZER”, which is incorporated in its entirety by this reference.TECHNICAL FIELD

[0002] This invention relates generally to the field of vanadium electrochemical systems and more specifically to a new and useful system and method for a vanadium (II) generating electrolyzer.BACKGROUND OF THE INVENTION

[0003] Mineral resources are imperative for modern civilization, providing essential materials for infrastructure, electronics, and countless other applications. However, minerals rarely occur in pure form, typically being dispersed within rock formations as mixtures with other minerals and waste materials. Extracting these valuable minerals from their host rock, a process known as mineral concentration, is crucial for their economic and sustainable utilization.

[0004] Traditionally, mineral concentration relies on a variety of physical and chemical separation techniques. Physical methods, such as flotation and gravity separation, exploit differences in the physical properties of minerals, such as density and surface chemistry, to selectively separate them from gangue materials. While these methods are widely used, they often suffer from low selectivity, high energy consumption, and the inability to process certain minerals effectively.

[0005] Chemical methods, such as hydrometallurgy, offer alternative routes for mineral concentration. These methods employ various chemical reagents to dissolve or modify the targeted minerals, enabling their separation from the surrounding rock. While hydrometallurgy can be highly selective and effective for specific minerals, it often faces limitations due to the high cost of reagents, potential environmental impact, and the need for complex processing steps.

[0006] Thus, there is a need in the vanadium electrochemical system field to create a new and useful system and method for a vanadium (II) generating electrolyzer. This invention provides such a new and useful system and method.BRIEF DESCRIPTION OF DRAWINGS

[0007] FIG. 1 is a schematic representation of an electrolyzer variation.

[0008] FIG. 2 is a schematic representation of an electrolyzer variation used with a reduction reactor.

[0009] FIG. 3 is a detailed schematic representation of an electrolyzer variation.

[0010] FIG. 4 is a detailed schematic representation of the electrolyzer used in connection with a metal processing system.

[0011] FIG. 5 and FIG. 6 are schematic representations of variations of metal processing systems used with the electrolyzer.

[0012] FIG. 7 is a schematic representation of an exemplary electrolyzer.

[0013] FIG. 8 is an exploded view of a schematic of an exemplary electrolyzer.

[0014] FIG. 10 and FIG. 11 are flowchart representations of a method variations.

[0015] FIG. 12 is a schematic representation of processes of an electrolyzer used in combination with a metal processing system.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The following description of the embodiments of the invention is not intended to limit the invention to these embodiments but rather to enable a person skilled in the art to make and use this invention.1. Overview

[0017] Herein are described systems and methods for a Vanadium (II) generating electrolyzer. In particular, the systems and methods may facilitate electrochemical processing of vanadium for use in material processing. In particular, the systems and methods may be used to generate V(II) ions for the recovery of valuable metals through a metal processing system. Furthermore, the systems and methods described herein may also be used in reduction of Vanadium in other oxidation states including V(V) and V(IV). Herein Vanadium (II), which is V2+, will be referred to as V(H); Vanadium (III), which is V3+, will be referred to as V(HI); Vanadium (IV), which is V4+, will be referred to as V(IV); and Vanadium (V), which is Vr>+, will be referred to as V(V).

[0018] The systems and methods preferably involve the operation of a specialized electrolyzer that has a catholyte and anolyte flowed into the cathode half-cell and anode half-cell, respectively, where the cathode half-cell sees the electrochemical reduction of V(HI) to V(H). The electrolyzer can include an anode half-cell that oxidizes H20 to 02. Different electrolyzer configurations may be used, for example, a single cell electrolyzer variation or multi-cell electrolyzer variation maybe used When used within applications for metal processing, the Vanadium-based catholyte can include presence of ferrous sulfate. In some variations, this may include ferrous sulfate in concentrations from zero up to or at its saturation limit. In some variations, the ferrous sulfate accumulates in the electrolyte due to metal processing.

[0019] The catholyte can be cycled out of the cathode half-cell to be a solution with the V(H) ions. This solution maybe used as a reducing agent within some connected system like a reduction reactor. If such a reducing agent is oxidized, the V(H) ions yield V(HI) ions. This oxidized reducing agent may then be cycled back into the cathode half-cell for processing by the electrolyzer to regenerate V(H) ions. In this way, the Vanadium material can be recycled repeatedly using the electrolyzer.

[0020] The systems and methods are preferably used in the reproduction of V(II) ions that may be used in processing and / or extraction of metals. The systems and methods maybe used in metal extraction processes for extraction of copper, gold, silver, platinum, palladium, molybdenum, rhenium, nickel, cobalt, arsenic, lead, bismuth, tellurium and / or gallium.

[0021] The system and method may provide a number of potential benefits. The system and method are not limited to always providing such benefits and are presented only as exemplary representations for how the system and method may be put to use. The list of benefits is not intended to be exhaustive, and other benefits may additionally or alternatively exist.

[0022] As one potential benefit, the systems and methods enable the cost-effective use of V(II) ions in chemical processes. Vanadium can have relatively high monetary cost compared to many other metals. However, the systems and methods may enable the recycled use of a Vanadium-based reductant. After oxidation of the Vanadium-based reductant, the reductant may be regenerated by recycling the material through the electrolyzer.

[0023] As related potential benefit, the systems and methods may similarly provide economical efficiencies when applied or used to particular applications such as copper extraction or other forms of metal processing. For example, the system and method when used for copper extraction may be economical despite poor electrochemical efficiencies in the context of other applications. One variation of an electrolyzer of the systems and methods maybe designed for a voltaic efficiency of 55% and a faradaic efficiency of 90%. These lower efficiencies may be tolerable due to the value of copper processing. Typical electrolyzer systems experience a trade-off in current density and voltage efficiency whereas increases in current density may lead to decreases in voltage efficiency. The electrolyzer of the systems and methods when used for copper extraction may favor high current densities with low voltage efficiencies for the most economic processing. This may inform use of serial multicell stacks of the electrolyzer.

[0024] As one potential benefit, the systems and methods may provide an efficient material source used in a chemical process. In particular, the systems and methods may be used to supply a vanadium-based reducing agent within a metal extraction process. V(II) can oxidize to V(III) and then the recycling of Vanadium after its oxidation to V(III) so that it can be reused in the chemical process.

[0025] As another potential benefit within the context of metal extraction, the systems and methods may enable metal to be extracted while avoiding the release of hazardous and environmentally unfriendly by products. The use of an electrolyzer for metalextraction may also enable the use of renewable energy to power the metals production system.

[0026] As another potential benefit, the systems and methods may enable modularization of metal extraction processes. Smelters are typically large scale. The system and methods maybe used in alternative metal extraction processes such that the extraction process can be scaled down. This may be used such that small amounts of metals maybe extracted at the site of metal concentrate production.2. System

[0027] As shown in FIG. 1, a system for producing Vanadium (II) can include an electrolyzer system 100, the electrolyzer system comprising at least one cell comprising: a cathodic half-cell no with a catholyte source 112 containing Vanadium (III) and a catholyte output 114 containing Vanadium (II); an anodic half-cell 120; and a membrane separator 130. The anodic half-cell 120 can include an anolyte source 122 containing water and an anolyte output 124 containing 02and H+. The system may be connected to an electrical power source 150. The cathodic half-cell 11, in response to a current driven by the electrical power source 150 (through the cathodic half-cell and anodic half-cell) results in a cathode reaction characterized by:and an anode reaction characterized by:2H2O - 02+ 4H+ + 4c.

[0028] Herein the system is primarily described in its use for reduction of V(III) to V(II), but the system may additionally be used in sequential reduction of Vanadium from other oxidation states including V(IV) and optionally V(IV) or other oxidation states. In one variation, this may include two stages of sequential reduction of V(IV) to V(III) and then reduction of V(III) to V(II). In another variation, this may also include three stages of sequential reduction of V(V) to V(IV), then V(IV) to V(III), and then reduction of V(III) to V(II).

[0029] Accordingly, the cathode reaction may alternatively be characterized by sequential reactions of:and an anode reaction seeing evolution of oxygen characterized by:2H2O -> O2+ 4H++ 4e\

[0030] The system is described as including an electrolyzer system 100 (i.e., the electrolyzer) with at least one cell comprised of a cathodic half-cell 110 and an anodic halfcell 120. In some variations, the electrolyzer more specifically includes a plurality of cells. Accordingly, a system for producing Vanadium (II) can include an electrolyzer system 100, the electrolyzer system comprising a plurality of cells, wherein each cell comprises a cathodic half-cell no and an anodic half-cell 120. In some variations, the electrolyzer may include a single cell.

[0031] The system may be used where the vanadium-based catholyte (i.e., catholyte containing vanadium in some oxidation state such as +3 and / or +2) can be cycled through the electrolyzer system 100 and then used in one or more chemical processes that results in oxidation of V(II) to one or more higher oxidation states (e.g., V(III), V(IV), and / or V(V)).

[0032] As shown in FIG. 2, one system variation may interface the electrolyzer 100 with a reduction reactor 200. This functions to establish a redox cycle of Vanadium transitioning within the electrolyzer system 100 and reduction reactor between V(III) and V(II) such that the catholyte may be repeatedly used as a reductant in the reduction reactor 200. In some variations, the reduction reactor may be used in processing and extraction of metals from a feedstock as shown in FIG. 4. The system may include system components to integrate or fluidically interface the catholyte source 112 and / or catholyte output 114 with the reduction reactor 200 and / or some other external chemical process. Alternatively, the system may include the reduction reactor 200 and / or components used in such a chemical process.

[0033] Within the reduction reactor 200 the V(II) catholyte source 112 is provided as a chemical reducing agent to the reduction reactor 200. As such the V(II) catholyte source 112 may alternatively be referred to as a reducing agent within the context of its use within the reduction reactor 200 and other chemical processing systems. Within the reductionreactor 200, the reducing agent is used within a chemical process that yields V(III) ions. The V(III) maybe produced as an oxidized reducing agent as an output from the reducing reactor 200.

[0034] In some variations, the reduction reactor 200 may involve chemical processes that result in concentrations of FeSO4in the catholyte. The system may be used with concentrations of FeSO4in the catholyte as shown in FIG. 2. In some variations, the FeSO4concentrations may be at concentrations at or near saturation though any non-zero concentration of FeSO4. For example, FeSO4may be present in the amounts 0.1M to 2M in the catholyte. In some variations, the reduction reactor 200 may involve chemical processes that result in concentrations of impurities such as calcium zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), aluminum (Al3+), chromium (Cr3+), chloride (Ch), and fluoride (F-), amongst other potential impurities and mixtures thereof.

[0035] The system will generally include additional components in facilitating operation and implementation of the electrolyzer when the electrolyzer 100 interfaces with the reduction reaction 200 or any other suitable chemical processing components. As shown in FIG. 3, a variation of a system for an electrolyzer used for a reduction reaction may more specifically include: a cathodic half-cell no with a catholyte source 112 containing Vanadium (III), a catholyte output 114 containing Vanadium (II), and a cathode electrode 116; an anodic half-cell 120 with an anolyte source 122 containing water, an anolyte output 124 containing 02and H+, and an anode electrode 126; a membrane separator 130; a pump system 140; and a reduction reactor 200 connected with the catholyte output 114 and the catholyte source 112. The pump system 140 can include a catholyte pump system 141 configured to fluidically cycle the catholyte output 114 to the reduction reactor 200 and to the catholyte source 112 from the reduction reactor 200.

[0036] In some variations, the system may be used with a metal extraction process, wherein a Vanadium (II) reductant from the catholyte output 116 is used as a reducing agent in the reduction reactor 200 as part of processing a metal ore. The reduction reactor 200 results in the oxidation of V(II) to V(III). As shown FIG. 4, the reduction reactor 200 may include a metal ore input 210 and a metal output 220.

[0037] The system configured for metal extraction and processing may include additional components to facilitate processing of metal ore and reuse of the Vanadium- based reductant. As shown in FIG. 5 and FIG. 6, the system may additionally include processing components like an impurity removal system 230 and / or a phase separator system 240. Configuration of the impurity processing system(s) 230 and / or phase separator system(s) 240 maybe integrated within a metal processing system in different ways.

[0038] The electrolyzer 100 functions as a system that uses an electrochemical process to generate V(II) ions within some solution. The V(II) ions may be used as a reducing agent within a reduction reactor 200. As described, this may be used in the processing and / or extraction of metals.

[0039] The electrolyzer 100 will include at least one cell, where a cell comprises a cathodic half-cell no and an anodic half-cell 120. The cathodic half-cell 110 and anodic half-cell 120 preferably include liquid electrolytes that maybe flowed through the cathode half-cell or the anode half-cell.

[0040] The electrolyzer 100 may also include a cathode electrode 116 and an anode electrode 126. The electrolyzer 100 may include or conductively connect to an electrical power source 150 that supplies voltage / current to the cathode electrode 116 and the anode electrode 126.

[0041] As mentioned in some variations, the electrolyzer 100 includes a plurality of cells. Accordingly, a system for producing Vanadium (II) can include an electrolyzer system 100, the electrolyzer system comprising a plurality of cells, wherein each cell comprises a cathodic half-cell 110 and an anodic half-cell 120. The plurality of cells, as above, may include: a cathodic half-cell no with a catholyte source 112 containing Vanadium (III) and a catholyte output 114 containing Vanadium (II); an anodic half-cell 120; and a membrane separator 130. Any of the variations described herein for the cathodic half-cell no and anodic half-cells 120 maybe used in a multi-cell variation of the electrolyzer system 100. In some variations, configuration of cells maybe varied.

[0042] In some variations, the number of cells may comprise a plurality of cells ranging from 5-500 cells. In many applications there will 10 cells or more, and as a typical upper range there may be 400 or fewer cells. For example, in some industrial applications, a system may include 200-300 cells. In particular, the plurality of cells maybe greater than50 and may be adjusted to suit the particular application. For example, many implementations may include 50-250 cells. Different applications may call for different volumes or flowrates of V(II) for use as a reducing agent in a coupled reduction reactor 200.

[0043] The different cells may be substantially homogenous where each cell comprises substantially similar cathodic half-cells no and anodic half-cells 120. In some variations however, differently configured cathodic half-cells and / or anodic half-cells 120 may be used.

[0044] In some variations, the plurality of cells may be arranged and connected in series. An electrolyzer with a plurality of cells connected in series may function to maintain the same current density through all the cells. In a series configuration, the end cells would include unipolar plates. A variation used for sequential reduction could be similarly configured. The cells may additionally or alternatively include parallel connections.

[0045] As mentioned in other variations, the electrolyzer 100 may include a single cell. In such a variation, a system with at least one cell will include only a single cell.

[0046] The cathodic half-cell no is preferably specialized to operate with the catholyte (i.e., electrolyte for the cathode) that facilitates the production of V(II) ions. Current driven through the cathode electrode 116 and the anode electrode 126 facilitates the reduction of V(III) ions to V(II) within the catholyte and an oxidation of water within the anolyte.

[0047] The cathodic half-cell no functions to facilitate the reduction of V(III) ions to V(II) ions within the catholyte. The cathode 100 preferably includes a catholyte product input referred to as a catholyte source 112 and a catholyte output 114. As such the electrochemical reaction of the catholyte in the cathode of the electrolyzer results in: V3+

[0048] In one variation, the cathode half-cell no may include interdigitated flow fields. The interdigitated flow fields may function to provide increased surface area and facilitate better reduction of V(III) ions to V(II) ions. In some variations, the flow fields may use titanium (Grade 2), titanium (grade 1), titanium (grade 7), titanium (grade 12), platinum coated, or other suitable materials.

[0049] The catholyte source 112 functions as a supply of electrolyte to the cathodic halfcell. The catholyte source 112 preferably arrives as an electrolyte solution with a concentration of V(III) ions. In some cases, V(II) ions and / or other ions may additionally be present which may or may not be subject to reactions within the cathode. For example, V(II) ions that did not get oxidized when processed by the reduction reactor 200 maybe present still. As discussed, additional oxidation states of vanadium may also be present including V(V) and V(IV). These different oxidation states may be sequentially reduced to V(II) by the electrolyzer 100. In some variations, an initial source of vanadium used in the electrolyte solution may be V(V). In this variation, the initial state of vanadium may need to be reduced to V(II) within the electrolyzer. During normal operations additional vanadium may be added to make up for lost vanadium during operation. In this way, after initial reduction of V(V) to V(II), a source of V(V) maybe added to make up for vanadium that is lost from using the V(II) in other reactions. For example, when used for metal extraction, 1 gram of vanadium may be lost for every kilogram of copper produced, and so 1 gram of vanadium maybe added to the electrolyte in the form of V(V).

[0050] The catholyte source 112 is preferably fluidically connected to a source of catholyte with a concentration of V(III) ions. As discussed, this maybe recycled catholyte that has been used as a reducing agent in some other chemical process such as within a reduction reactor 200 used for metal extraction and / or processing. In some cases, the catholyte source 112 may additionally or alternatively be connected to any suitable source of catholyte with a concentration of V(III) ions.

[0051] In such variations, there may be one or more other impurities in the catholyte. In particular, as part of a system used in connection with a reduction reactor used for metal recovery.

[0052] In some variations, the catholyte source 112 includes a non-zero concentration of iron (II) sulfate (FeSO4or ferrous sulfate). Accordingly, the catholyte source 112 may include ferrous sulfate in concentrations greater than zero. In particular, the ferrous sulfate concentration may be at or close to saturation levels. In some examples, the ferrous sulfate concentration maybe within the range of 0.1M to 2M.

[0053] There may be other elemental impurities which could include elements such as sodium (Na), magnesium (Mg), manganese (Mn), potassium (K), zinc (Zn), cobalt (Co), nickel (Ni), iron (Fe), chromium (Cr), aluminum (Al), titanium (Ti), chloride (Cl), fluoride(F), silver (Ag), calcium (Ca), copper (Cu), molybdenum (Mo), lead (Pb), mercury (Hg), barium (Ba), uranium (U), and / or lithium (Li).

[0054] In particular variations, the catholyte comprises impurities such as zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), aluminum (A13+), chromium (Cr3+), chloride (CL), and fluoride (F-), amongst other potential impurities and mixtures thereof.

[0055] Such element impurities may include concentrations of one or more impurities ranging from trace amounts (e.g., less than or equal to 0.001M) up to 7.5 M Na, 2.0 M Mg, 1.9 M Mn, 1.8 M K, 1.7 M Zn, 1.1 M Co, 1.1 M Ni, 1.0 M Fe, 1.0 M Cr, 0.5 M Al, 0.1 M Ti, 0.1 M Cl, 0.1 M F, 0.06 M Ag, 0.02 M Ca, 0.01 M Cu, 0.008 M Mo, 0.002 M Pb, 0.002 M Hg, 0.06 M Ba, 1.0 M U, and / or 7.5 M Li. Different applications may include one of such impurities or any suitable combination of impurities.

[0056] Different impurities may be present depending on the mine site or feedstock source. In one example, a copper concentrate from one source processed by the system may result in a catholyte with the following elemental impurities: zinc (Zn) at a concentration of 1.7 M, iron (Fe) at 0.8 M, sodium (Na) at 0.5 M, magnesium (Mg) at 0.4 M, titanium (Ti) at 0.1 M, aluminum (Al) at 0.05 M, calcium (Ca) at 0.03 M, nickel (Ni) at 0.01 M, potassium (K) at 0.009 M, chromium (Cr) at 0.0007 M, molybdenum (Mo) at 0.0004 M, and lead (Pb) at 0.00005 M. In another example, a copper concentrate from another source processed by the system may result in a catholyte with the following elemental impurities: iron (Fe) at a concentration of 0.8 M, sodium (Na) at 0.2 M, magnesium (Mg) at 2.0 M, titanium (Ti) at 0.06 M, aluminum (Al) at 0.4 M, chromium (Cr) at 0.05 M, and molybdenum (Mo) at 0.007 M.

[0057] The catholyte output 114 functions as a chemical product output from the electrolyzer 100. The catholyte output 114 is preferably the electrolyte from the cathode that has a concentration of V(II) ions resulting from an electrochemical induced conversion of V(III) or other oxidation states of vanadium ions in the catholyte.

[0058] The catholyte output 114 may be fluidically connected and used as a supply of chemical product to be used in one or more other chemical processes. In particular, the catholyte output 114 with its concentration of V(II) ions maybe used as a reducing agent. This reducing agent can be used in a fluidically connected reduction reactor 200, whichmay be used for metal extraction and / or other processing. In some variations, the produced catholyte output 114, or more specifically the reducing agent used in the reduction reactor 200, may be an acidic aqueous solution that has a concentration of about 0.0 IM to about 10 M as the V(II) reducing agent.

[0059] The cathode electrode 116 functions as the conductive element connected to and in conductive contact with the catholyte within the cathodic half-cell. The cathode electrode facilitates transfer of electrons to the electrochemically active ions in the cathode electrolyte solution.

[0060] In some variations, the cathode electrode 116 (and electrodes in general) may be oxidized using some treatment. For example, the cathode electrode 116 maybe made of or include treated carbon paper or be subject to some other oxidizing treatment. Treatment may be oxidative and include thermal or acid oxidation. This may function to enhance conductivity, mechanical properties, and / or chemical stability.

[0061] In some variations, the cathode electrode 116 may additionally include or be made of carbon felt. Carbon felt may be advantageous for its increased compressibility that leads to improve sealing.

[0062] The anodic half-cell 120 functions as a complimentary oxidizing reaction to facilitate ion exchange within the electrolyzer 100. In particular, the anodic half-cell 120 may include a water-based electrolyte that during the electrochemical reaction H20 is oxidized to 02, protons, and electrons. More specifically, the reaction maybe represented as 2H2O -> 02+ 4H++ 4e\ The resulting electrodes can be transferred through an external circuit to the cathodic half-cell.

[0063] The anodic half-cell 120 preferably includes an anolyte (i.e., an electrolyte within the anode half-cell). The anolyte can be a liquid solution that can be flowed in and out. In some variations, the anolyte may be cycled in and cycled out. Accordingly, the anodic half-cell 120 may include an anolyte source 122 and an anolyte output 124.

[0064] In one variation, the anodic half-cell 120 may include interdigitated flow-fields similar to the cathodic half-cell no. In some variations, anodic half-cell 120 may include parallel flow fields, which serve to lower the pressure drop through a membrane-electrode assembly that integrates the membrane 130 and the anode electrode 126.

[0065] The anolyte source 122 functions as a supply of anolyte that can be oxidized during operation of the electrolyzer 100. The anolyte source 122 preferably includes water, sulfuric acid, or mixtures thereof. Other anolytes may alternatively be used.

[0066] In some variations, the anolyte may comprise Fe(II), V(II), or V(III), H2SO4, and / or impurities from crossover across the membrane. The anode, particularly its catalyst, may preferably remain stable despite the presence of H2SO4, impurities, and side reactions. Impurity management, H2SO4management, and materials selection may be adjusted to enhance operability of the V-electrolyzer. In some variations, presence of such anolyte components may result in anodic side reactions, which may include:Fe2+ — Fe3++ e-V2+V3+ + e-H20 + V3+ V02++ 2H+ + e-H2O + VO2+VO2++ 2H++ e-These side reactions may occur due to crossover. In some variations, the anolyte may be adjusted through impurity removal and / or by using a bleed stream of anolyte to keep impurity or other material concentrations within or in compliance with some threshold (e.g., to keep impurity levels below a maximum threshold).

[0067] The anolyte output 124 functions as a chemical product output from the anodic half-cell. The anolyte output will be recombined with electrolyte supplied as the anolyte source 122. Any water consumed by anodic half-cell maybe replaced. In some variations, the anolyte output 124 may be augmented with an anolyte bleed stream. This may function to adjust concentrations of material components present in the anolyte. In particular, introduction of an anolyte bleed stream may be used to adjust or otherwise manage concentration levels of impurities, oxygen, and / other components before use of the anolyte for the anolyte source 122. This maybe used to adjust levels of Fe(II), V(II), or V(III), H2SO4, and / or other impurities to keep them below a concentration threshold. In some variations, sensing or monitoring of pH or other conditions may be used. Alternatively, a bleed stream may be calibrated such that it may be continuously or periodically used to keep the catholyte and / or anolyte sources within some operational condition to enhance performance.

[0068] The anode electrode 126 functions as the conductive element connected to and in conductive contact with the anolyte within the anodic half-cell 120. In some variations, the anode electrode 126 may be integrated with the membrane 130 on the anode side to form a membrane-electrode assembly. In a membrane-electrode assembly variation, a catalyst is embedded in the membrane and metal component (e.g., a titanium component) may function as a structural support and serve as a gas diffusion layer to allow gases formed to exit the system. In one variation, a carbon material anode variation may be used, particularly when aiming for Iron or Vanadium oxidation.

[0069] Different variations of integrating an anode electrode 126 within the anodic half-cell 120 may be used. In one variation, the electrolyzer stack may include: a cathode flow field and a cathode electrode 116 (within the cathodic half-cell no), a membrane 130, a catalyst coated on the anode side of the membrane 130, a gas diffusion layer, and then an anode flow field. In another variation, the electrolyzer stack may include: a cathode flowfield and a cathode electrode 116 (within the cathodic half-cell no), a membrane 130, a porous metal (such as Titanium DSA mesh) that is both electrode and gas diffusion layer, and then an anode flow field. In another variation, the electrolyzer stack may include: a cathode flow field, a cathode electrode 116, a membrane 130, a catalyst coated on the anode side of the membrane 130, a gas diffusion layer, and then an anode flow field.

[0070] As mentioned, a catalyst may be used in the anodic half-cell 120. The catalyst maybe coated on either on the anode side of the membrane 130, on a gas diffusion layer, or both. The catalyst maybe an iridium (e.g., iridium oxide), ruthenium (e.g., ruthenium oxide), or combined ruthenium-iridium oxide catalyst, which may function to facilitate enhanced oxygen evolution. In one variation, the catalyst may be directly deposited on a membrane 130 on the anode side and / or integrated within the anode electrode 126 formed as a membrane-electrode assembly. Using a ruthenium-iridium (Ru-Ir) catalyst on the anodic half-cell of electrolyzer 100 may enhance the efficiency and kinetics of the oxygen evolution reaction (OER).

[0071] The electrolyzer 100 preferably includes a membrane separator / membranei30. The membrane separator 130 may function to allow protons to pass between the cathode and anode while isolating the two electrolytes - the catholyte and the anolyte. The membrane separator 130 may force electrons to be conducted throughan external circuit that electrically couples the cathodic half-cell and the anodic half-cell. In some variations, the membrane or membrane separator 130 used in membraneelectrode assembly maybe a cation exchange membrane.

[0072] The membrane separator 130 may be a solid or semi-solid polymer. In one variation, the membrane separator 130 can be or include a proton-exchange membrane (PEM). In one variation, the membrane separator 130 may be a perfluorosulfonic acid (PFSA)-based PEM. This PFSA-based PEM may include a sulfonated tetrafluoroethylenebased fluoropolymer-copolymer such as Nafion (TM). In some alternative variations, a perfluoroalkyl phosphonic acid (PFAP) anionic membrane may be used. In some variations, the catalyst maybe deposited directly onto the membrane.

[0073] A gas-diffusion layer may be used in a membrane-electrode assembly to facilitate the transfer of oxygen generated out of the system. In one variation, the gas diffusion layer used in membrane-electrode assembly is a titanium mesh. In another variation, the gas diffusion layer is a titanium felt.

[0074] The system may additionally include an electrical power source used to power and drive electrical operation of the electrolyzer 100. The electrical source supplies voltage / current to the cathodic half-cell and anodic half-cell. In some variations, amperage may be proportional to throughput of a reduction reactor 200. The driving voltage may be variable (e.g., dependent on proportion of V(III) / V(II) and exact cell design / components). Alternatively, the electrolyzer may connect within a suitable power source.

[0075] A multi-cell electrolyzer system 100 may include components to facilitate distribution of the electrolyte. In particular, as the catholyte may be cyclically used, then components may be integrated to facilitate distribution of the catholyte. Similar or alternative design approaches maybe used for the anolyte. In one variation, the catholyte source 112 may be delivered to one or more inlets, where the catholyte is flowed or otherwise directed to a plurality of cathodic half-cells no. The catholyte maybe flowed to the different cells in parallel or in series.

[0076] In one variation, the system may include a manifolded parallel flow configuration, in which a catholyte inlet manifold is configured to distribute the catholyte simultaneously to each of the cells in the stack of the electrolyzer system 100. In this variation, the catholyte may flow through fluid paths in parallel, such that each cathodichalf-cell no or sub-grouping of cells (e.g., pair of cells) receives a substantially equal and fresh supply of catholyte directly from an inlet manifold. The catholyte may then exit each cell into an outlet manifold for collection and distribution of the catholyte output 114. Although the fluid flow is parallel, the electrochemical cells maybe electrically connected in series, such that the same current flows through each cell while the voltage across the stack accumulates. The use of inlet and outlet manifolds in this configuration may function to improve uniformity of electrolyte exposure, enhance performance consistency across the cells, and simplify thermal and pressure management. Variations may include individual flow channels or ports for each cell, integrated flow fields, or multi-port manifold blocks.

[0077] In another variation, the catholyte may be delivered using a serpentine or cascading flow configuration. In this setup, the catholyte enters a first cell or section of the cell stack and is directed sequentially from one cell to the next in a series of interconnected fluid channels. Each cell receives catholyte that has already passed through one or more upstream cells. This series-type flow path may be simpler to implement in smaller systems or prototypes but can introduce concentration gradients or temperature differences between upstream and downstream cells. Cascading flow may result in uneven electrochemical performance, as downstream cells may receive catholyte with altered composition or reduced reactivity. Variations of the cascading configuration may include integrated flow paths within a shared housing or inter-cell plumbing designed to minimize flow resistance and manage pressure drop.

[0078] The electrolyzer preferably has a supply of catholyte and / or anolyte cycled through the cathodic half-cell and anodic half-cell. The system may include a pump system 140 to facilitate the fluidic transport of catholyte and / or anolyte into and out of the electrolyzer 100 and optionally through other connected material processing systems.

[0079] The pump system 140 may include a catholyte pump system 141, which functions to facilitate the pumping of the catholyte. The catholyte pump system 141 may include one or more fluidic pumps fluidically coupled to the catholyte source 112 and / or the catholyte output 114.

[0080] In some variations, the pump system 140 may additionally include or connect to a catholyte reservoir 142. The catholyte reservoir 142 may be a stored reserve of a volume of catholyte. In some variations, the system may include a catholyte reservoir 142for the catholyte source 112 (containing V(III) ions) and / or a catholyte reservoir 142 for the catholyte output 114 (containing V(II) ions). The reservoirs may assist in managing catholyte usage and processing speeds of the electrolyzer and / or the reduction reactor 200.

[0081] In some variations, there may also be an alternative or additional reservoir for storing of catholyte from the output of the electrolyzer system 100. The post electrolyzer reservoir can store catholyte with V(II) ions.

[0082] In a similar manner, the pump system may include an anolyte pump system 143, which functions to facilitate the pumping of the anolyte. The anolyte pump system 143 may include one or more fluidic pumps fluidically coupled to the anolyte source 122 and / or anolyte output 124.

[0083] In some variations, the pump system 140 may additionally include or connect to an anolyte reservoir 144. In some variations, the system may include an anolyte reservoir 144 for the anolyte source 122 and / or an anolyte reservoir 144 for the anolyte output 124.

[0084] In some variations, the catholyte and / or anolyte flow stream used to supply the catholyte source and anolyte source may include a subsystem for removal of impurities and / or for augmenting catholyte and / or anolyte compositions to rebalance components. As shown in FIG. 9, in one variation, the system can include a catholyte impurity removal system 231 and / or an anolyte impurity removal system 232. In some variations, the impurity removal system 230 may more generally function by introducing a bleed stream of a catholyte or anolyte. Accordingly, the catholyte impurity processing system may include a catholyte bleed stream for management of the catholyte source, and the anolyte impurity processing system may include an anolyte bleed stream for management of the anolyte source. In such variations, the impurity removal system 230 may be or be called a catholyte or anolyte bleed stream system. The impurity removal systems 230 may in some instances remove catholyte or anolyte and replace with new catholyte or anolyte. However, in some applications, the system may be configured to operate with tolerance of impurities. When the electrolyzer is used to produce V(II) for use in metal processing, the electrolyzer 100 can be used with economic benefits to such a unique application despite any potential inefficiencies of the electrolyzer from impurities. Impurity removal systems 230 or other subsystems to introduce bleed streams.

[0085] In one such variation, a catholyte impurity removal subsystem may be configured such that a portion of the catholyte may be deliberately removed from the system to provide an outlet for impurities and prevent their continued accumulation. This portion of the catholyte may undergo pH neutralization for vanadium recovery in the form of a solid precipitate and liquid waste removal. Vanadium make-up and acid makeup maybe provided to the catholyte to ensure acceptable concentrations for the vanadium electrolyzer 100. Similarly, a portion of the anolyte maybe deliberately removed from the system to provide an outlet for impurities and prevent their continued accumulation. The portion of the anolyte may also be fed to a reduction reactor 200 or may undergo pH neutralization. Other forms of impurity removal may include their precipitation or electro-deposition prior to their introduction to the V-electrolyzer.

[0086] As shown in FIG. 7 and FIG. 8, an exemplary implementation of an electrolyzer system 100 may include a variety of internal components configured to enable electrochemical oxidation of vanadium to V(II) in a flowing catholyte. Components of some implementations of an electrolyzer system may include electrical isolators, busplates, flowfields, cathode and anode structures (including transfer layers and catalysts), membranes, fluid manifolds, sealing elements, and fasteners. The following sections describe variations in materials and production methods that may be used for each of these components. As shown in the exploded view of FIG. 8, an electrolyzer system 100 may include a stack of components compression plate 801, a compression bladder 802, o-ring 811, busplates 812, flowfields 813, anode transfer layer 814, membrane 815 (e.g., a catalyst membrane), cathode transfer layer and catalyst 816, o-ring 817, flowfields 818, busplates 819, fluid manifold 821, compression piston 822, o-ring 823, and a compression plate 824. In a multi-cell electrolyzer system 100, the components o-ring 811, busplates 812, flowfields 813, anode transfer layer 814, membrane 815 (e.g., a catalyst membrane), cathode transfer layer and catalyst 816, o-ring 817, flowfields 818, and / or busplates 819 could be repeated in the stack of components shown in FIG. 8 to add additional cells.

[0087] Electrical isolators may function to prevent undesired electrical conduction between structural or conductive elements within the electrolyzer system 100. In one variation, the isolators may be formed from polypropylene (homopolymer) material. In some variations, the isolators may additionally or alternatively include high-densitypolyethylene (HDPE), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), or chlorinated polyvinyl chloride (CPVC). These materials may be processed using CNC machining or formed using injection molding techniques.

[0088] Busplates may serve to distribute electrical current evenly across each electrochemical cell within the stack. In one variation, the busplates may be constructed from gold-plated copper, using copper, or other suitable materials. Fabrication may include laser cutting followed by plating, depending on the material used. Gold-plated copper may be formed by laser cutting then electroless nickel immersion gold plating or alternatively electrochemically plated gold.

[0089] Flowfields may be used to direct and distribute electrolyte flow uniformly across the surface of the electrodes in each cell. Flowfields maybe formed from titanium, such as Grade 2 titanium. In alternative or additional variations, other grades of titanium maybe used, including Grade 1, Grade 7, or Grade 12. Flowfields may also be formed with a platinum-coated surface. These components may be produced using stamping, photoetching, CNC machining techniques, or other suitable production methods.

[0090] The cathode transfer layer may function to facilitate electronic and ionic conduction between the electrode and the catholyte. In one variation the cathode transfer layer may include carbon paper. In other variations, the transfer layer may alternatively or additionally include carbon felt or graphite felt.

[0091] A cathodic half-cell 110 or the cathode more generally may include a cathode catalyst, which may function to enable or enhance electrochemical reactions occurring in the cathodic half-cells no. In some variations, no catalyst may be used. In alternative variations, the cathode may include a catalyst such as cobalt oxides. Catalyst layers may be applied via methods such as spray-casting or spin-coating.

[0092] In some variations, the anode may include titanium mesh as a base structure. In variations, the anode may additionally or alternatively include titanium felt, sintered titanium, or titanium mesh coated with platinum.

[0093] An anodic half-cell or the anode more generally may include an anode catalyst, which may function to enhance the electrochemical reactions occurring at the anodic halfcells 120. The anode catalyst may include iridium oxide. In other variations, the anode catalyst may include ruthenium oxide or iridium-ruthenium oxide combinations. Deposition methods may include spin-coating or spray-casting.

[0094] The membrane may function as a separator between the anode and cathode compartments, allowing ion transfer while preventing crossover of electrolyte or reactive species. The membrane may include a perfluorosulfonic acid (PFSA) cationic membrane. In variations, a perfluoroalkyl phosphonic acid (PFAP) anionic membrane may be used. These membranes may be sourced in rolls and cut to fit the device geometry.

[0095] The fluid manifold may distribute electrolyte to and from each cell uniformly and without leakage. The manifold may be constructed from polypropylene homopolymer. Variations may include HDPE, PTFE, PVC, or CPVC materials. Production methods may include injection molding, CNC machining, or other suitable production methods. The fluid manifolding may connect to inlets for the catholyte source 112 and the catholyte output 114, and / or inlets for the anolyte source 122 and the anolyte output 124.

[0096] O-rings may function to seal fluid interfaces and prevent leakage under pressurized operation. In one variation, O-rings or other seals may be made from fluoroelastomer. In other variations, the O-rings may include FEP-encapsulated silicone or PTFE. These sealing elements may be purchased in standard sizes or formed through vulcanization.

[0097] Fasteners such as bolts, washers, and nuts may secure the electrolyzer stack and ensure proper compression of internal seals and gaskets. These components may be constructed from 316 stainless steel. In variations, alternative materials may include 18- 8 stainless steel or 8.8 grade steel. Fasteners maybe commercially available in standard mechanical sizes.

[0098] As discussed, the electrolyzer system 100 may be used as a system for generating a V(II) source. The V(II) ions may then be used in a secondary reaction as a reducing agent, which may result in production of V(III) or higher oxidation states of vanadium such as V(IV) or V(V). In particular, in some variations, the electrolyzer 100 maybe integrated with a reduction reactor 200.

[0099] In some variations, the catholyte output 114 may be fluidically coupled or otherwise interfaced with such a reduction reactor 200. In some variations, the system may include a reduction reactor 200.

[0100] The reduction reactor 200 functions to use the catholyte output 114 as a reducing agent such that the catholyte output 114 with V(II) ions is oxidized to produce V(III) ions. One chemical product output from the reduction rector 200 can be a fluidsolution with the V(III) ions. The fluid solution may additionally or alternatively include higher vanadium of higher oxidation states like V(IV) or V(V). The reaction may additionally include or involve the introduction of ferrous sulfate. This maybe introduced such that ferrous sulfate is present in the catholyte at concentrations greater than zero.

[0101] The reduction reactor 200 may include a reactor input 201 coupled to the catholyte output 114 of the electrolyzer system 100 and a reactor output 202 coupled to the catholyte source 112 of the electrolyzer system 100. The reactor output 202 may be directly coupled to an inlet for the catholyte source 112. However, there may be various intermediary subsystems through which a material with an elevated oxidized state of vanadium (e.g., V(III)) may pass.

[0102] In some preferred applications, the reduction reactor 200 maybe used in metal extraction and / or processing. In such variations, the reduction reactor 200 may include a metal ore input 210 (or some other input feedstock). The reduction reactor 200 may perform a reduction process which may be applied to metal ore input 210 that include various metal sulfides, metal sulfide ores, and / or metal sulfide concentrates to extract metals.

[0103] The metal ore input 210 functions as a source of metal ore or metal concentrate. This metal ore input 210 maybe from a mined metal product that is in a non-refmed state, in other words the desired metal materials have not been extracted. Processing in the reduction reactor 200 can facilitate metal extraction and purification. The reduction reactor 200 may be used for recovery of valuable metals including but not limited to copper (Cu), gold (Au), silver (Ag), platinum (Pt), palladium (Pd), molybdenum (Mo), rhenium (Re), nickel (Ni), cobalt (Co), bismuth (Bi), tellurium (Te), and gallium (Ga), iron (Fe), lead (Pb), zinc (Zn), and / or antimony sulfides. In such variations, the reduction reactor 200 may include a metal output 220 extracted from reduction of the metal ore input 210 (e.g., the metal sulfide) with the Vanadium (II) in the catholyte output. In particular, the metal output 220 may include copper, but may additionally or alternatively include other minerals such as gold (Au), silver (Ag), platinum (Pt), palladium (Pd), molybdenum (Mo), rhenium (Re), nickel (Ni), cobalt (Co), bismuth (Bi), tellurium (Te), and gallium (Ga), iron (Fe), lead (Pb), zinc (Zn), and / or antimony sulfides. As discussed herein, a phase separator system or other system maybe used to separate the vanadium- based catholyte from a material product containing metal component.

[0104] The reduction reactor 200 may introduce impurities into the catholyte source 112 as a result of processing feedstock for metal recovery / extraction (or for other suitable chemical processes using the V(II). The impurities may include those discussed herein.

[0105] In some variations, the reduction reactor 200 may be part of a metal processing system that may include additional processing stages such as impurity processing systems 230 and / or phase separator systems 240. The catholyte may be captured as the liquid phase product outlet of the metal processing system. These may be used in refining the different output material products and separating them for additional processing. In the case of the catholyte, the catholyte source 112 may be a liquid output of the metal processing system that has been treated to include a majority if not all the Vanadium material within the system. Efficient isolation of the Vanadium may enhance the efficiency of the electrolyzer recycling of Vanadium.

[0106] As discussed above, the impurity processing system 230 functions to remove or rebalance concentrations of various impurities prior to deliver as the catholyte source 112. In system variations used with a reduction reactor 200, the system may include the impurity processing system which can be integrated into a fluidic output path from the reactor output 202 to the catholyte source 112. In one variation, the impurity processing system 230 may be integrated within a metal processing system as shown in FIG. 5. In another variation, the impurity processing system 230 may be integrated as a preprocessing system between the metal processing system (e.g., the reduction reactor 200 and accompanying metal processing subsystems) and the electrolyzer system 100 as shown in FIG. 6.

[0107] The phase separator system 240 functions to separate material products that are an output from the reduction reactor 200. The phase separator system 240 can preferably produce a metal output 220 that is separate from liquid material that can be used as the catholyte source 112. The phase separator system 240 can be used in combination with an impurity processing system 230, wherein the system may include an impurity processing system 230 coupled to the reactor output 202 of the reduction reactor 200, and a phase separator system 240 coupled to an impurity processing output of the impurity processing system 230, wherein the phase separator system 240 comprises a first output of an enriched product phase and a second output coupled to the catholyte source of the electrolyzer. The enriched product phase may include theextracted metals such as copper or other minerals. The second output may additionally be fluidically coupled to other subsystems used to manage cycling of the catholyte such as reservoirs and / or pump systems.

[0108] As shown in FIG. 6, the system may additionally include a catholyte pump system configured to fluidically convey the catholyte output to the reduction reactor and / or convey the catholyte source from the reduction reactor. Similarly, the system may include a catholyte reservoir and optionally an anolyte reservoir. The system may also include subsystems to replenish or refresh an electrolyte source. Replenishment may be performed to address concentration levels of impurities and / or vanadium. The anolyte in some variations may be used in a non-cyclical manner, where an anolyte input may be drawn from a source and then the anolyte output can be directed elsewhere.3. Method

[0109] As shown in FIG. 10, a method for generating a Vanadium (II) reducing agent may include supplying a catholyte source to a cathode of an electrolyzer, the catholyte source containing Vanadium (III) ions S110; applying power to the electrolyzer S120 thereby, at the cathode, electrolyzing V(III) ions to V(II) ions S121; and outputting a catholyte output from the cathode as a reducing agent solution with V(II) ions S130.

[0110] As a complimentary process to supplying the catholyte source, the method may also include supplying an anolyte source to an anode of the electrolyzer and outputting an anolyte output from the anode. The method is preferably used with a system such as described above. In such a system, the method produces V(II) ions within a liquid material (usable as a reducing agent product) through a cathode electrochemical reaction that maybe characterized asand an anode electrochemical reaction of:2H2O -» 02+ 4H+ + 4e-.

[0111] Accordingly, as shown in FIG. 11, the method may more specifically include: supplying a catholyte source to a cathode of an electrolyzer, the catholyte source containing Vanadium (III) ions Sno; supplying an anolyte source (e.g., a water anolyte source) to an anode of the electrolyzer S112; applying power to electrolyzer S120 thereby,at the cathode, electrolyzing V(III) ions to V(II) ions S121 and, at an anode of the electrolyzer, oxidizing water S122; and outputting the catholyte as a reducing agent solution with V(II) ions S130 and outputting an anolyte output from the anode S132.

[0112] As discussed herein, other oxidation states of vanadium may also be sequentially reduced by the electrolyzer, and so V(IV) and V(V) may also be reduced sequentially to V(II). Block S110, which includes supplying a catholyte source to a cathode of an electrolyzer, the catholyte source containing Vanadium (III) ions may additionally include Vanadium (V) and / or Vanadium (IV). In some variations, the initial source and / or any additional sources of vanadium maybe V(V) and / or V(IV). In this way block S120 may also include sequentially electrolyzing of an initial oxidation state down to a V(II) oxidation state. In other words, the electrolyzer maybe used for vanadium reduction no matter oxidation state and / or mixture of oxidation state of the cathode source.

[0113] In some variations, the V(II) containing reducing agent from the electrolyzer may be supplied to a reduction reactor where it may be used as a reducing agent. The oxidized reducing agent (e.g., the V(III) ions) maybe collected as output product that can be recycled back into the cathode of the electrolyzer.

[0114] In some variations, the method may include recycling oxidized reducing agent back into the cathode of the electrolyzer. This maybe performed when the reducing agent is oxidized resulting in the reaction of V(II) to V(III). This V(III) solution maybe recycled back into the cathode for regeneration of V(II) ions.

[0115] Accordingly, the method may additionally include, as shown in FIG. 12, directing the catholyte output to a reduction reactor S210, using the catholyte output within the reduction reactor to result in oxidation of the catholyte output S220; and directing a reactor output with Vanadium (III) from the reduction reactor to the cathode S230. This process may specifically be used with a reduction reactor that takes in metal ore or concentrate and outputs other metal products.

[0116] As discussed, the method may be performed using a system or one of the disclosed variations discussed herein. Accordingly, in some variations, the method may include providing system or subsystem configured as described. In the case of the electrolyzer, the system may include providing an electrolyzer with at least one cell that includes a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membraneseparator S105. Providing the electrolyzer functions to configure an electrolyzer for production and / or use of a generated V(II) reducing agent.

[0117] As in the system discussed herein, the electrolyzer may be single-cell or a multicell electrolyzer. When the at least one cell includes a plurality of cells, then the method maybe modified for implementation across multiple cells. For example, S110 may include supplying the catholyte source to the cathode of the electrolyzer comprises supplying the catholyte source through multiple cells of the electrolyzer. In the case of a single cell, then supplying the catholyte source to the cathode of the electrolyzer comprises supplying the catholyte source through a single cell of the electrolyzer. The anolyte can similarly be supplied through multiple cells or a single cell depending on the type of electrolyzer used.

[0118] Block S110, which includes supplying a catholyte source to a cathode of an electrolyzer, the catholyte source containing Vanadium (III) ions functions to receive a catholyte that includes a concentration of vanadium ions at oxidation state greater than V(II). In some variations, the catholyte source may additionally or alternatively include vanadium (IV) and / or vanadium (V) ions.

[0119] The method may also generally include the anodic complimentary step of supplying an anolyte source to an anode of the electrolyzer. The anolyte may include water, sulfuric acid, mixtures thereof, and / or other anolyte materials.

[0120] As above, the catholyte source may include ferrous sulfate, possibly as a byproduct of the catholyte being source, at least in part from a reduction reactor / metal processing system. In some variations, the ferrous sulfate may be at concentration levels in the range 0.1M to 2M. The catholyte may also include additional or alternative impurities. In some variations, the impurities may include concentrations of zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), aluminum (A13+), chromium (Cr3+), chloride (Ch), and fluoride (F-)., and / or other impurities discussed herein. These impurities may be byproducts of the reduction reactor / metal processing, in which the V(II) reducing agent is used.

[0121] Block S120, which includes applying power to the electrolyzer functions to drive an electric current through the electrolyzer. The electrical power maybe driven using any suitable source. The current is preferably driven through each cell of the electrolyzer.

[0122] Applying the electrical power to the electrolyzer will in response drive electrochemical reactions within the cathodic and anodic half cells. At the cathode, applying electrical power to the electrolyzer will result in electrolyzing V(III) ions (or vanadium of other elevated oxidation states) to V(II) ions S121. At the anode, applying electrical power to the electrolyzer will result in oxidizing water (or another suitable anolyte) S122.

[0123] In particular, applying electrical power to the electrolyzer results in triggering a cathode reaction characterized by V3+ + e_-> V2+, and at the anode, triggering the anode reaction characterized by 2H20 -> 02 + qH++ qe-.

[0124] In the case where vanadium of other oxidation states is included in a catholyte source, then applying electrical power to the electrolyzer may result in sequentially electrolyzing of an initial oxidation state down to a V(II) oxidation state.

[0125] Accordingly, the cathode reaction may alternatively be characterized by triggering a sequence of reactions characterized by cathode reactions:and an anode reaction characterized by:2H2O - 02+ 4H+ + 4e-.

[0126] Block S130, which includes outputting a catholyte output from the cathode as a reducing agent solution with V(II) ions functions to produce a material with presence of V(II) ions. The reducing agents is preferably the catholyte output from the cathode portion of the electrolyzer system. The method will generally also include outputting an anolyte output from the anode.

[0127] The reducing agent is preferably used within another chemical process that results in the oxidation of the reducing agent. Accordingly, the method may include flowing or otherwise directing the reducing agent to another connected system such as a reduction reactor. When oxidized, the vanadium ions will be oxidized to a higher oxidation state, and so the material resulting from the chemical process maybe reused as a catholyte in the electrolyzer. Accordingly, the method may include recycling oxidized reducing agent back into the cathode of the electrolyzer.

[0128] As discussed, the method may have particular applications in use in combination with a reduction reactor. The method may additionally include directing the catholyte output to a reduction reactor S210. Block S210 functions to fluidically couple the cathodic output from the electrolyzer with a reduction reactor. The reduction reactor may use the catholyte output as a reducing agent. Directing the catholyte output can include flowing or otherwise conveying the catholyte output from the electrolyzer. A conduit may be used to connect an output from the cathode of the electrolyzer to the reduction reactor. In some variations, a pump or other system may be used to promote fluid motion.

[0129] The method may additionally include using the catholyte output within the reduction reactor to result in oxidation of the catholyte output S220. The catholyte output is thereby used as a reducing agent and this step may alternatively be described as using the reducing agent within the reduction reactor to result in oxidation of the reducing agent. Using the catholyte output may include contacting the reducing agent within the reduction reactor with other materials. The other materials may include metal ore input.

[0130] The reduction reactor as discussed may be used in extraction or processing of metals. Accordingly, the method may include receiving a metal ore input with metal sulfides and reacting the metal ore input with the catholyte output thereby yielding a reactor output with Vanadium (III). Reacting the metal ore input with the catholyte output results in oxidization of V(II) to a higher oxidation state such as V(III) but may additionally or alternatively include V(IV) or V(V). The reactor output will generally include the oxidized reducing agent and as such may contain V(III) and / or vanadium ions with higher oxidation states.

[0131] This reactor output with V(III) may then be reused within the electrolyzer. Accordingly, the method may include directing reactor output with Vanadium (III) from the reduction reactor to the cathode S230. This functions to reuse vanadium containing material as a catholyte within the electrolyzer. In some cases, the reactor output may be directed through additional pre-processing. The pre-processing maybe used for removing impurities and extracting other material outputs (e.g., extracted metals). Additionally, the method may include depositing any material from the reactor output into a catholyte source reservoir. In some cases, the method may include refreshing the catholyte source. Refreshing may include adding vanadium ions for adjusting concentrations. Refreshingmay also mean partially or fully replenishing the catholyte source. This refreshing maybe performed if and / or when the catholyte source is determined to be in a condition outside of configured operating parameters. For example, the catholyte source maybe refreshed after some number of cycles, when the impurities reach some sensed or predicted concentration levels or other conditions.

[0132] The method may include processing of the reactor output prior to directing a portion containing the V(III) to the cathode.

[0133] In one variation, the method may include processing impurities in the reactor output prior to conveying at least a portion of the reactor output with V(III) to the electrolyzer as the cathodic source.

[0134] In another variation, the method may additionally include separating a metal product phase from the reactor output. This may include performing phase separation, which may yield at least two material outputs, one material output includes an output containing V(III) and the other being a metal-containing product. The other material output, in the case of metal extraction or refinement, may include a metal product phase which can include concentrations of copper and / or other metals depending on the metal ore input and configuration of the reduction reactor.

[0135] When used in combination as shown in FIG. 11, the method may additionally include: directing the catholyte output to a reduction reactor S210, using the catholyte output within the reduction reactor to result in oxidation of the catholyte output S220; and ; directing a reactor output with Vanadium (III) from the reduction reactor to the cathode S230 comprising processing impurities in the reactor output prior to conveying S232, and separating a metal product phase from the reactor output S234.4. Examples

[0136] Hereafter are described different examples of system and / or method variations. These examples are not intended to limit the systems and / or methods and their variations, and these examples do not include every variation and combination of variations of the systems and methods described herein.

[0137] Example 1.1: A system comprising: an electrolyzer system, the electrolyzer system comprising of at least one cell comprising: a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membrane separator.

[0138] Example 2.1: A system comprising: an electrolyzer system, the electrolyzer system comprising of at least one cell comprising: a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membrane separator; and a reduction reactor. The reduction reactor may include an input fluidically coupled to the catholyte output and an output that is fluidically coupled to supply at least in part the catholyte source.

[0139] Example 1.2: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein, wherein the anodic half-cell comprises an anolyte source containing water and an anolyte output containing 02and H+.

[0140] Example 1.3: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein further comprising an electrical power source wherein the cathodic half-cell in response to a current driven by the electrical power source results in a cathode reaction characterized by V3+ + e~ -> V2+, and an anode reaction characterized by 2H2O -> 02+ 4H++ 4e\

[0141] Example 1.4: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein wherein the catholyte comprises a ferrous sulfate.

[0142] Example 1.5: A variation of example 1.1, 2.1, 1.4, and / or any of the other system examples and variations herein wherein in a catholyte with ferrous sulfate, the ferrous sulfate is in concentration levels in the range of 0.1M to 2M.

[0143] Example 1.6: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein wherein the catholyte source may include concentrations of V(III), V(IV), and / or V(V).

[0144] Example 1.7: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein wherein the catholyte comprises at least one impurity selected from the set of impurities including concentrations of zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), aluminum (A13+), chromium (Cr3+), chloride (Ch), and fluoride (F-). In particular, the catholyte may include concentration ofiron impurities. In some variations, the anolyte may also include iron impurities resulting potentially from crossover across the membrane.

[0145] Example 1.8: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein comprising a reduction reactor with a reactor input coupled to the catholyte output of the electrolyzer system and a reactor output coupled to the catholyte source of the electrolyzer system.

[0146] Example 1.9: A variation of example 1.1, 2.1, 1.8 and / or any of the other system examples and variations herein wherein the reduction reactor introduces impurities into the catholyte source.

[0147] Example 1.10: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein wherein the at least one cell of the electrolyzer comprises or is a plurality of cells greater than 10 cells. In such an example, the electrolyzer system comprises a plurality of cells wherein each cell comprises: a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membrane separator.

[0148] Example 1.11: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein wherein the at least one cell of the electrolyzer is a single cell. In such an example, the electrolyzer system comprises a single cell which comprises: a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membrane separator.

[0149] Example 1.12: A variation of example 1.1, 2.1, 1.8, and / or any of the other system examples and variations herein wherein the reduction reactor comprises a metal ore and / or metal concentrate input with metal sulfides.

[0150] Example 1.13: A variation of example 1.1, 2.1, 1.8 and / or any of the other system examples and variations herein wherein the reduction reactor comprises a metal output extracted from reduction of the metal sulfide with the Vanadium (II) in the catholyte output.

[0151] Example 1.6: A variation of example 1.1, 2.1, 1.8, 1.13, and / or any of the other system examples and variations herein wherein the metal output comprises copper.

[0152] Example 1.15: A variation of example 1.1, 2.1, 1.8 and / or any of the other system examples and variations herein comprising a pump system with at least a catholyte pump system configured to fluidically convey the catholyte output to a reduction reactor andconvey the catholyte source from the reduction reactor. The example may additionally variations comprising a catholyte reservoir and optionally an anolyte reservoir. The anolyte may be a noncyclical system where an anolyte input is drawn from a source, and the anolyte output is directed elsewhere.

[0153] Example 1.16: A variation of example 1.1, 2.1, 1.8, and / or any of the other system examples and variations herein comprising an impurity processing system that is integrated into a fluidic output path from the reactor output to the catholyte source.

[0154] Example 1.17: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein wherein the anolyte may include water, sulfuric acid, and / or mixtures thereof.

[0155] Example 1.18: A variation of example 1.1, 2.1, 1.8, and / or any of the other system examples and variations herein further comprising an impurity processing system coupled to a reactor output of a reduction reactor, and a phase separator system coupled to an impurity processing output of the impurity processing system, wherein the phase separator system comprises a first output of an enriched product phase and a second output coupled to the catholyte source of the electrolyzer. The first output may contain extracted metals such as copper and / or other metals.

[0156] Example 1.19: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein comprising an electrical power source wherein the cathodic half-cell in response to a current driven by the electrical power source results in a cathode reaction characterized by sequential reactions of Vs+ + e- -> V4+, V4+ + e- -> V3+, V3+ + e- - V2+, and an anode reaction characterized by 2H2O -> 02+ 4H+ + 4e_.

[0157] Example 1.20: A variation of example 1.1, 2.1, and / or any of the other system examples and variations herein comprising a catholyte impurity processing system and an anolyte impurity processing system, wherein the catholyte impurity processing system includes a catholyte bleed stream for management of the catholyte source, and wherein the anolyte impurity processing system includes an anolyte bleed stream for management of the anolyte source.

[0158] Example 3.1: A method for generating Vanadium (II) reducing agent comprising: supplying a catholyte source to a cathode of an electrolyzer, the catholyte source containing Vanadium (III) ions; applying power to the electrolyzer thereby, at the cathode, electrolyzing V(III) ions to V(II) ions; and outputting a catholyte output fromthe cathode as a reducing agent solution with V(II) ions. Example 3.1 and its variations maybe implemented in connection with any of the system examples described above.

[0159] Example 3.2: A variation of example 3.1, and / or any of the other method examples and variations further comprising supplying an anolyte source to an anode of the electrolyzer and outputting an anolyte output from the anode.

[0160] Example 3.3: A variation of example 3.1, and / or any of the other method examples and variations wherein applying power to the electrolyzer further results in triggering a cathode reaction characterized by V3+ + e- - V2+, and at the anode, triggering the anode reaction characterized by 2H2O -> O2+ 4H++ 4e\

[0161] Example 3.4: A variation of example 3.1, and / or any of the other method examples and variations wherein the catholyte source comprises a ferrous sulfate.

[0162] Example 3.5: A variation of example 3.1, and / or any of the other method examples and variations wherein in a catholyte with ferrous sulfate, the ferrous sulfate is in concentration levels in the range of 0.1M to 2M.

[0163] Example 3.6: A variation of example 3.1, and / or any of the other method examples and variations wherein the catholyte material may include concentrations of V(III), V(IV), and / or V(V).

[0164] Example 3.7: A variation of example 3.1, and / or any of the other method examples and variations wherein the catholyte comprises impurities including concentrations of zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), aluminum (A13+), chromium (Cr3+), chloride (Cl-), and fluoride (F ).

[0165] Example 3.8: A variation of example 3.1, and / or any of the other method examples and variations further comprising providing an electrolyzer comprising of at least at least one cell comprising: a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membrane separator. The method may additionally include providing a reduction reactor and / or any of the system components described herein.

[0166] Example 3.9: A variation of example 3.1, 3.8, and / or any of the other method examples and variations wherein supplying the catholyte source to the cathode of the electrolyzer comprises supplying the catholyte source through multiple cells of the electrolyzer.

[0167] Example 3.10: A variation of example 3.1, 3.8, and / or any of the other method examples and variations wherein supplying the catholyte source to the cathode of the electrolyzer comprises supplying the catholyte source through a single cell of the electrolyzer.

[0168] Example 3.11: A variation of example 3.1, and / or any of the other method examples and variations directing the catholyte output to a reduction reactor. The example may additionally include using the catholyte output within the reduction reactor to result in oxidation of the catholyte output; and directing a reactor output with Vanadium (III) from the reduction reactor to the cathode.

[0169] Example 3.12: A variation of example 3.1, 3.11, and / or any of the other method examples and variations, at a reduction reactor, receiving a metal ore or metal concentrate input with metal sulfides and reacting the metal ore input with the catholyte output thereby yielding a reactor output with Vanadium (III).

[0170] Example 3.13: A variation of example 3.1, 3.11, 3.12, and / or any of the other method examples and variations comprising processing impurities in the reactor output prior to conveying to the electrolyzer as the cathodic source.

[0171] Example 3.14: A variation of example 3.1, 3.11, 3.12, 3.13, and / or any of the other method examples and variations comprising separating a metal product phase from the reactor output. The metal produce phase may be a metal or other suitable enriched product phase.

[0172] Example 3.15 A variation of example 3.1, 3.11, 3.12, 3.13, 3.14, and / or any of the other method examples and variations wherein a metal product phase comprises concentrations of copper.

[0173] As used herein, first, second, third, etc. are used to characterize and distinguish various elements, components, regions, layers and / or sections. These elements, components, regions, layers and / or sections should not be limited by these terms. Use of numerical terms may be used to distinguish one element, component, region, layer and / or section from another element, component, region, layer and / or section. Use of such numerical terms does not imply a sequence or order unless clearly indicated by the context. Such numerical references maybe used interchangeable without departing from the teaching of the embodiments and variations herein.

[0174] As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the embodiments of the invention without departing from the scope of this invention as defined in the following claims.

Claims

CLAIMSWe Claim:

1. A system comprising: an electrolyzer system, the electrolyzer system comprising of at least one cell comprising: a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membrane separator.

2. The system of claim 1, wherein the anodic half-cell comprises an anolyte source containing water and an anolyte output containing 02and H+.

3. The system of claim 2, comprising an electrical power source wherein the cathodic half-cell in response to a current driven by the electrical power source results in a cathode reaction characterized by V3+ + e- - V2+, and an anode reaction characterized by 2H2O -> 02+ 4H+ + 4e\4. The system of claim 1, wherein the catholyte comprises a ferrous sulfate.

5. The system of claim 4, wherein the ferrous sulfate is in concentration levels in the range of 0.1M to 2M.

6. The system of claim 1, wherein the catholyte source may include concentrations of V(III), V(IV), and / or V(V).

7. The system of claim 1, wherein the catholyte comprises at least one impurity selected from a set of impurities including concentrations of zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), aluminum (A13+), chromium (Cr3+), chloride (Ch), and fluoride (F-).

8. The system of claim 1, further comprising a reduction reactor comprising a reactor input coupled to the catholyte output of the electrolyzer system and a reactor output coupled to the catholyte source of the electrolyzer system.

9. The system of claim 8, wherein the reduction reactor introduces impurities into the catholyte source.

10. The system of claim i, wherein the at least one cell of the electrolyzer comprises a plurality of cells greater than 10 cells.

11. The system of claim 1, wherein the at least one cell of the electrolyzer is a single cell.

12. The system of claim 8, wherein the reduction reactor comprises a metal ore or metal concentrate input with metal sulfides.

13. The system of claim 12, wherein the reduction reactor comprises a metal output extracted from reduction of the metal sulfide with the Vanadium (II) in the catholyte output.

14. The system of claim 13, wherein the metal output comprises copper.

15. The system of claim 8, further comprising a pump system comprising a catholyte pump system configured to fluidically convey the catholyte output to the reduction reactor and convey the catholyte source from the reduction reactor.

16. The system of claim 8, further comprising an impurity processing system that is integrated into a fluidic output path from the reactor output to the catholyte source.

17. The system of claim 1, wherein the anolyte input may include water, sulfuric acid, and / or mixtures thereof.

18. The system of claim 8, further comprising an impurity processing system coupled to the reactor output of the reduction reactor, and a phase separator system coupled to an impurity processing output of the impurity processing system, wherein the phase separator system comprises a first output of an enriched product phase and a second output coupled to the catholyte source of the electrolyzer.

19. The system of claim 2, comprising an electrical power source wherein the cathodic half-cell in response to a current driven by the electrical power source results in a cathode reaction characterized by sequential reactions of Vr>+ + e— > V4+, V4+ + e— > V3> V3+ + e- -> V2+, and an anode reaction characterized by 2H2O -> 02+ 4H+ + 4e\20.The system of claim 1, further comprising a catholyte impurity processing system and an anolyte impurity processing system, wherein the catholyte impurity processing system comprises a catholyte bleed stream for management of the catholyte source, and wherein the anolyte impurity processing system comprises an anolyte bleed stream for management of the anolyte source.

21. A method for generating Vanadium (II) reducing agent comprising:supplying a catholyte source to a cathode of an electrolyzer, the catholyte source containing Vanadium (III) ions; applying power to the electrolyzer thereby, at the cathode, electrolyzing V(III) ions to V(II) ions; and outputting a catholyte output from the cathode as a reducing agent solution with V(II) ions.

22. The method of claim 20, further comprising supplying an anolyte source to an anode of the electrolyzer and outputting an anolyte output from the anode.

23. The method of claim 21, wherein applying power to the electrolyzer further results in triggering a cathode reaction characterized by V3+ + e- -> V2+, and at the anode, triggering the anode reaction characterized by 2H2O -> o2+ 4H+ + 4c.

24. The method of claim 20, wherein the catholyte source comprises a ferrous sulfate.

25. The method of claim 24, wherein the ferrous sulfate is in concentration levels in the range of 0.1M to 2M.

26. The system of claim 1, wherein the catholyte source may include concentrations of V(III), V(IV), and / or V(V).

27. The method of claim 24, wherein the catholyte source comprises at least one impurity selected from the set of impurities including concentrations of zinc (Zn2+), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), aluminum (A13+), chromium (Cr3+), chloride (Ch), and fluoride (F ).28.The method of claim 1, further comprising providing an electrolyzer comprising of at least at least one cell comprising: a cathodic half-cell with a catholyte source containing Vanadium (III) and a catholyte output containing Vanadium (II), an anodic half-cell, and a membrane separator.

29. The method of claim 28, wherein supplying the catholyte source to the cathode of the electrolyzer comprises supplying the catholyte source through multiple cells of the electrolyzer.30.The method of claim 28, wherein supplying the catholyte source to the cathode of the electrolyzer comprises supplying the catholyte source through a single cell of the electrolyzer.

31. The method of claim 1, further comprising directing the catholyte output to a reduction reactor.

32. The method of claim 31, at the reduction reactor receiving a metal ore input with metal sulfides and reacting the metal ore or metal concentrate input with the catholyte output thereby yielding a reactor output with Vanadium (III).

33. The method of claim 32, further comprising processing impurities in the reactor output prior to conveying to the electrolyzer as the cathodic source.

34. The method of claim 32, further comprising separating a metal product phase from the reactor output.

35. The method of claim 34, wherein the metal product phase comprises concentrations of copper.

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