SYSTEM AND PROCESS FOR ELECTROWINNING

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. Provisional Application No. 63/733,895, filed on Dec. 13, 2024, which is hereby incorporated by reference in its entirety.

FIELD

This application relates generally to systems and processes for electrowinning, and more particularly to closed loop precious metal recovery.

BACKGROUND

75% of global gold demand is met with mined virgin gold. The remaining amount is sourced from recycled gold, typically coming from recycled jewelry. Approximately 2.5% of yearly gold demand currently comes from gold recycled from electronics. However, of the 260,875 tons of gold believed to exist on the planet, approximately 208,875 tons have already been mined. 20%, or 52,000 tons, remain in the ground. ⅔ of all gold, or 137,858 tons, have been mined in the last 75 years.

Alternative methods, such as bio-mechanical deposition, solvometallurgy, and liquid-liquid extraction have been explored to introduce circularity to the gold economy. However, these systems are costly, large, and require complex infrastructure to operate and maintain.

The LBMA forecasts that existing gold stocks are sufficient to maintain production for the next 11 years. However, this assumption allows concessions for the rate and quality of exploration, as well as for the funding of this exploration backed by sustained gold price levels.

Global production has continued to rise year over year and trend upwards due to increased gold prices and demand. However, because it is a finite resource, the increase in production only accelerates the movement towards the inflection point where the business case for mining virgin gold is no longer sufficient either to meet demand or to maintain unit costs. The all-in sustaining costs of gold mining (non-inclusive of CAPEX) have recently reached all-time highs and are growing at a pace that is outpacing the average year-over-year gold price.

Alternative methods, such as bio-mechanical deposition, solvometallurgy, and liquid-liquid extraction have been explored to introduce circularity to the gold economy. However, these systems are costly, large, and require complex infrastructure to operate and maintain.

SUMMARY

This approach to value-added metal recovery intensifies the typically multi-stage, intermittent process into a single, continuous, closed-loop process, achieving highly efficient recoveries and yielding over 99.95% purity precious metals. Within the span of a single day, crude ore can be processed to produce bullion grade precious metals near the entropic limit of energy efficiency. Closed-loop operation entails that all process chemicals are used and reused dually negating the need for chemical consumption and waste stream processing. Process intensification is a major driver of the process speed and efficiency, where the leach, purification, and recovery stages are combined. The leach and recovery stages are combined to utilize the oxidizing environment of the leach reactor in order to drive selective capture and purification of the target molecule. Similarly, the electrochemical reactions of each stage (leaching, purification, and recovery) are networked together for the first time, yielding an electrochemical cell network that 1) minimizes side reactions, 2) improves energy efficiency and system performance, and 3) simplifies the overall process. The process of this work is the industrial materialization of cutting-edge academic work, moving beyond an idea, to a refined, stand-alone system process.

Methods, systems, and apparatus, including providing an electrowinning cell that includes a first interior chamber portion with a first anode, a central interior chamber portion with a cathode and a third interior chamber portion with a second anode. An electropotential is applied to the first anode and the cathode which results in competing metals being captured from a solution in the first chamber portion. Another electropotential is applied to the second anode and the cathode which results in target metals being captured from a solution in the second chamber portion.

In some embodiments an electrowinning cell an electrowinning cell includes a chamber body with a filter and a membraned positioned in the chamber body. A first interior chamber portion is fluidly coupled to a crude loop inlet and a competing metal outlet, the first interior chamber portion comprising a first cathode. A second interior chamber portion is fluidly coupled to a pure loop outlet, a pure loop inlet and a target metal outlet, the second interior chamber portion comprising a second cathode. A central interior chamber portion is disposed between the filter and the membrane. The central interior chamber portion is fluidly coupled to a crude loop outlet, the central interior chamber portion comprising an anode.

In some embodiments a process to capture target metals includes applying a first electropotential via the second cathode and the anode to capture target metals via the second cathode. The capture target metals are transferred from the second interior chamber portion via the metal outlet. The process further includes applying a second electropotential via the second cathode and the anode to capture competing metals via the first anode. The captured competing metals are transferred from the first interior chamber portion via the competing metal outlet.

The appended claims may serve as a summary of this application.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an exemplary general closed-loop selective purification process.

FIG. 2 is a diagram illustrating an exemplary networked electrochemical cell configuration.

FIG. 3 is a diagram illustrating an exemplary networked electrochemical cell configuration.

FIG. 4 is a diagram illustrating an exemplary electro chemical cell.

FIG. 5 is an example piping and instrumentation diagram of the closed-loop refinement process.

FIG. 6 is a diagram illustrating an exemplary solvent extraction column of the closed-loop refinement process.

FIG. 7 is a diagram illustrating equations that are referenced in the specification.

FIG. 8 process flow chart illustrating an exemplary method 800 that may be performed in some embodiments.

FIG. 9 process flow chart illustrating an exemplary method 900 that may be performed in some embodiments.

DETAILED DESCRIPTION OF THE DRAWINGS

In this specification, reference is made in detail to specific embodiments of the invention. Some of the embodiments or their aspects are illustrated in the drawings.

For clarity in explanation, the invention has been described with reference to specific embodiments, however it should be understood that the invention is not limited to the described embodiments. On the contrary, the invention covers alternatives, modifications, and their equivalents as may be included within its scope as defined by any patent claims. The following embodiments of the invention are set forth without any loss of generality to, and without imposing limitations on, the claimed invention. In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In addition, well-known features may not have been described in detail to avoid unnecessarily obscuring the invention.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

The present disclosure encompasses a process by which value-add minerals which are confined by a non-homogeneous feedstock are liberated from the feedstock.

The disclosed process involves the recovery of valuable metals, particularly copper, gold, and platinum group metals from non-homogeneous feedstock through an integrated system of leaching, phase separation, and electrochemical deposition.

Briefly described, the feedstock is subjected to a leaching stage, where targeted metals are dissolved into a solution using chemical agents. This leachate, now containing dissolved metal ions, undergoes subsequent treatment to separate the metal-laden organic phase from the aqueous phase.

Phase separation is achieved through a mixer-settler configuration, where the metal ions are selectively transferred into an organic phase. Copper, gold, and platinum group metals are extracted into separate organic streams, each containing a high concentration of the desired metal ions. Once isolated in their respective phases, the metal ions undergo electrochemical reduction in specialized cells. Copper, gold, and platinum group ions are subsequently reduced and deposited as pure solid metals.

The disclosed process is designed to operate continuously, utilizing pumps and flow controls to ensure consistent throughput and steady-state conditions. The process integrates multiple stages—leaching, extraction, and deposition—into a streamlined process, optimizing metal recovery efficiency while minimizing energy consumption and material losses. This scalable approach allows for the effective processing of various grades of feedstock, from high-quality electronic components to more degraded materials, ensuring that value-add minerals are efficiently recovered from all non-homogeneous waste streams.

FIG. 1 is a diagram illustrating an exemplary general closed-loop selective purification process. FIG. 1 depicts a generic service metal capture diagram. The electrochemical cells labeled HC 1-4 represent the pertinent half-cell reactions to aid in visualizing the process.

The general closed-loop selective purification process, shown in FIG. 1, inputs a solid-phase, target-rich ore with high excess of competing species (for example, 0.1% target, 60% competing metal, and the remainder inert solids), and the process outputs a pure target metal, a crude competing metal, and inert solids. The process consumes minimal electrical energy and operates with closed-loop chemistry that requires minimal make-up or replacement. It should be noted that “Closed loop” means the process operates by continuously regenerating all necessary chemical components and does not regularly consume chemicals nor produce chemical waste to operate. The process operates solely on electrical energy supplied to electrochemical cells. The process does not operate on a temperature gradient and can be operated at any temperature within reason (100C<T<0C). The process does not fundamentally operate using pressure gradients, however pumping, with <0.5 bar pressure drop, is required to move fluid loops.

The ore here can be electronic waste, dirt from the earth, or waste streams—it is composed of 1) a metals species to target, i.e. the target species, 2) other metals that compete in the process, i.e. the competing species, and 3) solids/liquids that are inert to the leaching process, i.e. the inert solids. The composition range of target-rich ore can vary, for example scrap jewelry may contain 80% target, 19% competing, and 1% inert. Electronic waste may contain 0.1% target, 60% competing, and the remainder inert. Dirt ore may contain 0.01% target, 10% competing, and the remainder inert. The target species can be any metal that forms an anionic complex in water and typical target species include Au, Ag, Pt, Pd, Ir, Ru, Rh, or Os. The target is usually a single element but can be more than one element. The competing species can be any water-soluble molecule, typically Cu, Ni, Fe, Zn, Pb, Cr.

The closed-loop process consists of three closed liquid loops of different composition and function: 1) The aqueous crude loop (red), aqueous pure loop (yellow), and organic selective transfer loop (blue). The process consists of a leach reactor unit, two liquid extraction units (shown in FIG. 1 as two sets of mixer-settler extraction units), and 1 to 4electrochemical cells. FIG. 1 shows each electrochemical reaction as an individual half-cell for illustration purposes; the half-cells can be combined to improve efficiency and compactness (Shown in FIG. 2, and FIG. 3). More information on individual process components will be in a separate paragraph.

Process description. The process starts with target rich ore entering the leaching reactor, where target and competing metals are leached into the aqueous crude stream (red). The leaching reactor has two flow streams, the solid stream in black, and the liquid crude loop stream, which are mixed and separated easily with gravity. The leaching reactor utilizes aqueous oxidizer and ligand species to oxidize and dissolve the target metal species, thereby transferring metal from the solid ore inlet into the liquid loop known as the “crude loop” shown in red; For gold, EQN 1 and EQN 2 exemplify the chemical reaction. (FIG. 7 describes the equations referenced in this application). There are many other competing metal species that also leach and dissolve into the crude loop, hence the name crude loop.

Following the leach reactor, solids that are inert to the leaching process are removed and the target-containing crude stream enters the first mixer/settler unit. The mixer mixes the aqueous crude stream (red) with the immiscible organic selective transfer loop stream (blue). Mixing can be done naturally or assisted with a mechanical impeller. When the crude loop and transfer loop interact in the mixer, multiple chemical reactions occur that 1) activate the extractant species and 2) transfer the target species from the crude loop to the organic transfer loop. First, the oxidizer in the crude loop interacts with the extractant species by oxidizing it EQN 3, then the oxidized extractant species (denoted RFc in EQN 3) binds to the target metal species in the aqueous crude loop (EQN 4), selectively transferring the target out of the crude loop and into the transfer loop. The two immiscible aqueous and organic phases are allowed to settle in the settler.

Following settler 1, the target-devoid crude loop is regenerated by electrodeposition of the competing species in HC-2 of FIG. 1, generally following EQN 5. The reaction removes competing metal from accumulating in the crude loop and simultaneously liberates stabilizing ligand species for reuse in the leach reactor. HC-2 is a cathodic half-cell, and the pairing reaction for all half-cells will be discussed in a later paragraph. The competing metal species is removed from the process by phase separation - the electrochemical reaction converts the soluble salt into insoluble metal that accumulates onto the electrode surface, which is recovered over time. Following HC-2, the crude loop enters HC-1 to regenerate the oxidant species at the anode (EQN 6). The regenerated crude loop stream then flows back into the leach reactor in a closed loop.

Returning to Settler 1, the target-laden immiscible transfer loop stream exits settler 1 and enters mixer 2, alongside the aqueous pure loop stream (yellow). Mixer/settler 2 allow the momentary contact of the mutually immiscible transfer and pure loops to 1) electrochemically deactivate the extractant in the transfer phase causing 2) release of the target species from transfer loop to the aqueous pure loop. EQN 7 shows the reaction that occurs in mixer/settler 2, where Rd refers to the aqueous reducing agent species in the pure loop.

Following settler 2, the immiscible transfer loop stream is recycled to mixer 1 to form a closed loop. Additionally, the pure loop stream exits settler 2 and enters HC-4 of FIG. 1, where the target species is electrodeposited out (following EQN 8 and EQN 9 for example) as a pure >90% solid. Lastly, the reducing agent used in mixer/settler 2 is regenerated in HC-3 of FIG. 1, where the aqueous pure stream is electrochemically reduced at the cathode following EQN 10. The regenerated pure loop stream is finally recycled back to mixer 2 to form a closed loop.

Composition of closed loops. There are also many chemicals present in the three liquid loops that catalyze the process and are continuously reused. The following only describes the key chemical components that are used and regenerated, but not consumed.

The crude loop (red) is composed of a ligand species, a leach oxidizer, and an extractant oxidizer in water; each could be a unique species or could all be the same species. The ligand and leach oxidizer are used in the leaching reactor and regenerated in HC-2 and HC-1 respectively. The ligand species may be any metal stabilizing species, CN⁻, I^-, Br⁻, or Cl⁻for example. The leach oxidizer is typically O₂, I₂, I₃⁻, Br₂, Cl₂, H₂O₂, NO⁺, TEMPO, W(CN)₈³⁻, Mo(CN)₈³⁻, or any other oxidizing species capable of increasing the oxidation state of the target metal above zero. The extractant oxidizer is typically O₂, I₂, I₃⁻, Br₂, Cl₂, H₂O₂, NO⁺, TEMPO, or any other oxidizing species capable of increasing the oxidation state of the extractant species to the activated form. There could also exist supporting electrolyte that enhances the electrical conductivity and act as charge carriers such as Na⁺, K⁺, Ca²⁺, ClO₄⁻, SO₄²⁻, NO₃⁻, BF₄⁻, PF₆⁻, and/or PO₄³⁻. Lastly, the crude loop may be acidic or basic, depending on the leaching reaction. For cyanide leaching, pH must be >9.5, for Iodine/bromine pH˜7, for chlorine, pH<7.

The transfer loop (blue) is composed of a redox-active extractant species in a water-immiscible solvent. The redox-active extractant species may be of two species:

• • metallocene or viologen, with functionalization to improve solubility/miscibility in the solvent phase (increase water insolubility/immiscibility). Typically, the extractant functionalization is acyl, alkyl, or allyl group with >4 carbon atoms. A typical metallocene would be 1,1′-dioctanonyl ferrocene, 1,1′-didecanonyl ferrocene, 1,1′-dioctyl ferrocene, or 1,1′-decyl ferrocene. A typical viologen would be 1,1′-dibutyl viologen, 1,1′-dihexyl viologen, 1,1′-dioctyl viologen, 1,1′-didecyl viologen, 1,1′-dibutanoyl viologen, 1,1′-dihexanoyl viologen, 1,1′-dioctanoyl viologen, or 1,1′-didecanoyl viologen. The transfer loop solvent can be any solvent that is immiscible with water, does not react to chemicals in the crude or pure loops, and possesses a wide electrochemical potential window. Typically, esters, ethers, halogenated solvents, or ionic liquids are used - for example amyl acetate, methylene chloride, perchloro ethylene, or hexyl-3-methylimidazolium hexafluorophosphate.

The pure loop (yellow) is composed of a reducing agent, ligand species (of the same composition as in the crude loop), and a resting concentration of target metal salt. The reducing agent can be any reversible redox-active species with a reduction potential below that of the extractant species in the transfer loop. The purpose of the reducing agent is to reduce the extractant species and be capable of continuous regeneration. Some example reducing agents are Fe(CN)₆⁴⁻, ascorbic acid, or paraquat. It is important that the pH of the pure loop is maintained to keep the reducing agent and target species stable; typically, the pH required is between 7 and 10. The resting concentration of target species is >1 mM, typically 15 mM.

Electrochemical half-cell organizations. FIG. 1 shows 4 separate essential half-reactions in the process for illustrative purposes; however, every electrochemical reaction must be composed of a cathodic and anodic reaction. Half-cells can be combined, or networked, to minimize wasted energy from side reactions (analogous to a heat exchanger network), and the following figures exemplifies two possible electrochemical cell networks for the closed-loop refinement process.

FIG. 2 is a diagram illustrating an exemplary networked electrochemical cell configuration. FIG. 2 depicts a networked electrochemical cell configuration that reduces the number of electrochemical cells to two. An advantage is reduced energy consumption and process simplification.

By combining HC-3 and HC-4 to the same cathodic half cell and adding HC-1 as the balancing anodic cell with an ion exchange membrane division, FC-1 is formed in FIG. 2. The advantage of FC-1 over three individual cells is the minimization of wasteful side reactions, and allowing the crude loop and pure loop to interact via a dividing membrane allows equilibration of pH and mitigates accumulation of ligand species. The dividing membrane can be an ion exchange membrane or nano-filtration membrane. In addition, combination of HC-1 as the anode reaction with HC-2 as the cathode reaction with a dividing micro-filtration membrane yields FC-2 of FIG. 2. The design of FC-2 utilizes a simple filter (such as a filter paper comprising a cellulose fiber paper) to divide the cell by slowing transport, improving cell efficiency while minimizing cost and complexity. The overall schematic of FIG. 2 results in a simple, balanced two-cell design.

The electrochemical cells, FC-1 and FC-2 can be made of any inert material such as polypropylene, acrylic, PET, Teflon, epoxy, silicone, viton rubber, or UV cured resin for example. The anode can be made of graphite, stainless steel, platinum, or MMO (mixed metal oxide) coated titanium. The cathode can be made of gold, copper, stainless steel, or graphite. The cell can be operated at a constant current or potential with or without a reference electrode.

FIG. 3 is a diagram illustrating an exemplary networked electrochemical cell configuration. FIG. 3 depicts a networked electrochemical cell configuration that reduces a number of electrochemical cells a single divided bi-potential cell. Advantages include reduced energy consumption, improved system control and more significant process simplification.

By combining the anodes of FC-1 and FC-2 of FIG. 2 to a single anode, the process can be simplified to a single bipotential cell, shown in schematic FIG. 3 and in more detail on FIG. 4. The singular cell design improves control of the anodic regeneration of oxidizer by simplifying the control scheme to one single anode. In addition, the common anode anchors the bipotential cell. The cell is operated by applying two individual potentials, one between the crude-side cathode and anode, and another between the pure-side cathode and anode. On the crude loop side, the stream enters the anode first and exits the anode chamber for two reasons 1) this ensures that the leaving stream is fully oxidized/regenerated, and 2) this allows any gaseous oxidizer or ligand species (EQN 11 and EQN 12) to naturally recycle to the leach reactor. The system can be operated with a filter (such as a filter paper) between the crude-side cathode and anode to stabilize the flow and minimize parasitic back reactions.

FIG. 4 is a diagram illustrating an exemplary electro chemical cell. FIG. 5 illustrates a detailed schematic of a divided bi-potential flow cell. The cell combines all half-cell reactions into a single unit. There are two separate flow paths with a membrane dividing the left (red) crude stream from the yellow (right) pure stream.

FIG. 5 is an example piping and instrumentation diagram of the closed-loop refinement process. FIG. 5 is an example piping and instrumentation diagram (P&ID) of the closed-loop refinement process.

Solvent extraction. The process calls for two continuous solvent extraction units, labelled M-101 and M-102 in FIG. 5. The operation of each solvent extraction unit is the same: 1) to increase the interfacial area between two immiscible liquids via mixing and 2) to allow each phase to separate back out or settle upon exit. The purpose of M-101 (or mixer/settler 1 in FIG. 1) is to selectively transfer the target metal into the organic-phase transfer loop, and the purpose of M-102 (mixer/settler 2 in FIG. 1) is to transfer the target metal into a new aqueous stream called the pure loop. For FIGS. 1, 2, 3, 4 and 5, the solvent extraction unit is represented as a mixer/settler unit, where mixing is carried out with a motor and impeller, and the thoroughly mixed stream then goes to a reservoir to settle out. The mixer/settler can be designed in a way to utilize the mixing impeller as a pump, providing dual use.

FIG. 8 is a diagram illustrating an exemplary solvent extraction column of the closed-loop refinement process. FIG. 8 illustrates a solvent extraction column for the closed loop metal recovery process.

Another design for continuous solvent extraction that can be used in this process as a direct replacement for the mixer/settler unit is a solvent extraction column or tower (example shown in FIG. 6). The solvent extraction column is essentially a vertical column that pumps the heavy liquid phase in from the top, where it exits the bottom and pumps the light liquid phase into the bottom of the column, where it exits from the top. To increase the interface area of the two liquid phases, trays or packing can be added into the column. The advantage of a solvent extraction column over a mixer/settler is that multiple equilibrium stages can be present in a single column, whereas a mixer/settler unit will only be considered one equilibrium stage. However, the single stage efficiency of a solvent extraction column is considerably lower than that of a mixer/settler. A cascade of mixer/settlers can be used to achieve multiple high efficiency equilibrium stages, but at a higher land area footprint and increased utility cost as each mixer/settler in series will require a motorized impeller. The consideration on which solvent extraction technology to utilize in the process depends on many factors, but both technologies have shown to work in the process.

System operation. The closed loop metal recovery process can be operated at many different scales, measured in target metal output over time, from 0.5 grams of target metal produced per day to over 1000 grams/day and beyond.

For 1000 gram/day recovery of gold from electronic waste as example basis, the following plant sizing and process flows will be utilized. A mass flow of 1000 kg/day electronic scrap will be processed, and the flowrate of the crude stream, pure stream, and organic transfer stream is 1430 L/day, 1430 L/day, and 760 L/day respectively. The leach reactor, R-101, is 480 L in volume, the mixer/settlers, M-101 and M-102, are each 50 L in volume. FC-101 of FIG. 5 has an electrode area of 600cm2 , and FC-102 has an electrode area of 1200 cm2 . Both FC-101 and FC-102 operate with a current density of roughly 100A/m2 , and typical overall cell potential is 3 volts for both. The typical power consumption of the overall process is 10 kW, roughly equivalent to the power of 7 household space heaters (1500W each). The 1000 gram/day plant takes up 130 SQFT of floorspace, not accounting for the space of E-Waste inventory. All values stated in this paragraph are for example.

FIG. 8 a process flow chart illustrating an exemplary method 800 that may be performed in some embodiments.

In step 810, an electrowinning cell is provided includes a chamber body with a filter and a membraned positioned in the chamber body. A first interior chamber portion is fluidly coupled to a crude loop inlet and a competing metal outlet, the first interior chamber portion comprising a first cathode. A second interior chamber portion is fluidly coupled to a pure loop outlet, a pure loop inlet and a target metal outlet, the second interior chamber portion comprising a second cathode. A central interior chamber portion is disposed between the filter and the membrane. The central interior chamber portion is fluidly coupled to a crude loop outlet, the central interior chamber portion comprising an anode.

In step 820, the electrowinning cell receives into the first interior chamber a concentrated metal salt solution comprising the competing metal.

In step 830, a first electropotential is applied to the first anode the cathode resulting in competing metal being released from the concentrated metal salt solution including the competing metal.

In step 840, competing metals are captured via the first anode and the captured competing metals are transferred from the first interior chamber portion via the competing metal outlet.

In step 850, the electrowinning cell receives into the second interior chamber a concentrated metal salt solution comprising the target metal.

In step 860, a second electropotential is applied to the second anode the cathode resulting in target metal being released from the concentrated metal salt solution including the target metal.

In step 870, target metals are captured via the second anode and the captured target metals are transferred from the second interior chamber portion via the target metal outlet.

FIG. 9 a process flow chart illustrating an exemplary method 900 that may be performed in some embodiments. An example electrowinning process is described using a crude loop process, an aqueous pure loop process and an organic selective process.

In step 910, a crude loop process is performed as described herein.

In step 920, an aqueous pure loop process is performed as described herein.

In step 930, an organic selective process is performed as described herein.

In step 940, target metals are extracted via the pure loop process in a manner a described herein.

In some embodiments, the organic selective process uses a first mixer-settler extraction unit and a second mixer settler extraction unit. The crude loop processes uses the first mixer-settler extraction unit. The aqueous pure loop process uses the second mixer-settler extraction unit.

In some embodiments, the crude loop processes uses a first cathodic half cell and a first anodic half cell to perform a first electrochemical reaction causing a competing metal to be extracted. The pure loop process uses a second cathodic half cell and a second anodic half cell to perform a second electrochemical reaction causing the target metal to be extracted.

In some embodiments, the crude loop processes uses a first combined cell comprising a cathodic cell portion and an anodic cell portion to perform a first electrochemical reaction causing a competing metal to be extracted. The pure loop process uses a second combined cell comprising a cathodic cell portion and an anodic cell portion to perform a second electrochemical reaction causing the target metal to be extracted. The first combined cell is fluidly coupled to the second combined cell.

In some embodiments, the crude loop processes uses a divided flow cell and the pure loop process uses the divided flow cell. A first portion of the divided flow cell performs a first chemical reaction to extract a competing metal and a second portion of the divided flow cell performs a second chemical reaction to extract a target metal.

In some embodiments, an electrowinning system is used which includes a leaching unit, a first mixer-settler extraction unit fluidly coupled with the leaching unit, a second mixer settler extraction unit that is fluidly coupled with the first mixer-settler extraction unit, a first half-cell, a second half-cell, a third half-cell, and a fourth half-cell. The first half-cell is fluidly coupled with a settler portion of the first mixer-settler extraction unit, and is fluidly coupled with the second half-cell. The third half-cell is fluidly coupled with a settler portion of the second mixer-settler extraction unit, and the third half-cell is fluidly coupled with the fourth half-cell. The fourth half-cell is fluidly coupled with a mixer portion of the second mixer-settler extraction unit.

In some embodiments, an electrowinning system is used which includes a leaching unit, a leaching unit, a first mixer-settler extraction unit fluidly coupled with the leaching unit, and a second mixer settler extraction unit fluidly coupled with the first mixer-settler extraction unit, a first combined cell comprising a cathodic cell portion and an anodic cell portion, and a second combined cell comprising a cathodic cell portion and an anodic cell portion. The first combined cell is fluidly coupled the leaching unit, is fluidly coupled with a settler portion of the first mixer-settler unit, and is fluidly coupled with the second combined cell. The second combined cell is fluidly coupled to a mixer portion of the second mixer-settler and a settler portion of the second mixer settler.

In some embodiments, an electrowinning system is used which includes a leaching unit, a first mixer-settler extraction unit fluidly coupled with the leaching unit, a second mixer settler extraction unit fluidly coupled with the first mixer-settler extraction unit, and a divided flow cell. The divided flow cell is fluidly coupled to the leaching unit, is fluidly coupled with a settler portion of the first mixer-settler unit, is fluidly coupled with a mixer portion of the second mixer-settler unit, and is fluidly coupled with a settler portion of the second mixer-settler unit.

It will be appreciated that the present disclosure may include any one and up to all of the following examples.

Example 1. An electrowinning process comprising, the operations of:

Example 1. An electrowinning process comprising, the operations of: providing an electrowinning cell comprising: a chamber body; a filter positioned in the chamber body; a membrane positioned in the chamber body; a first interior chamber portion fluidly coupled to a crude loop inlet and a competing metal outlet, the first interior chamber portion comprising a first cathode; a second interior chamber portion fluidly coupled to a pure loop outlet, a pure loop inlet and a target metal outlet, the second interior chamber portion comprising a second cathode; and a central interior chamber portion disposed between the filter and the membrane, the central interior chamber portion fluidly coupled to a crude loop outlet, the central interior chamber portion comprising an anode; applying a first electropotential via the second cathode and the anode; capturing target metals via the second cathode; and transferring the captured target metals from the second interior chamber portion via the target metal outlet.

Example 2. The method of claim 1, further comprising: applying a second electropotential via the second cathode and the anode; capturing competing metals via the first anode; and transferring the captured competing metals from the first interior chamber portion via the competing metal outlet.

Example 3. The method of claim 2, further comprising: receiving into the first interior chamber a concentrated metal salt solution comprising the competing metal and the target metal.

Example 4. The method of claim 2, wherein the first electropotential and the second electropotential are different voltages.

Example 5. The method of claim 2, wherein the first electropotential and the second electropotential are applied individually and not concurrently.

Example 6. The method of claim 2, wherein the filter is a cellulose paper that divides the first interior chamber portion and the central interior chamber portion.

Example 7. The method of claim 2, wherein the membrane is an ion exchange membrane or a nano-filtration membrane that the central interior chamber portion and second interior chamber portion.

Example 8. The method of claim 1, wherein the filter reduces and/or stops turbulence of the received concentrated metal salt solution in the first interior chamber portion flowing into the central chamber portion, and precludes solids produced at the first cathode from entering into the central chamber and contacting the anode.

Example 9. The method of claim 1, further comprising: transferring from the central interior chamber, through the membrane, into the second interior chamber at least a portion of the target metal.

Example 10. The method of claim 11, wherein: the electrowinning cell is fluidly coupled to a leaching unit; the electrowinning cell is fluidly coupled to a first settler unit; the electrowinning cell is fluidly coupled to a second settler unit; and the electrowinning cell is fluidly coupled to a second mixer unit.

Example 11. The method of claim 10, wherein: the second mixer unit is fluidly coupled to the first settler unit; a first mixer unit is fluidly coupled to the first settler unit; a leaching unit is fluidly coupled to the first mixer unit; and the first settler unit is fluidly coupled to the second mixer unit.

Example 12. An electrowinning system comprising: an electrowinning cell comprising: a chamber body; a filter positioned in the chamber body; a membrane positioned in the chamber body; a first interior chamber portion fluidly coupled to a crude loop inlet and a competing metal outlet, the first interior chamber portion comprising a first cathode; a second interior chamber portion fluidly coupled to a pure loop outlet, a pure loop inlet and a target metal outlet, the second interior chamber portion comprising a second cathode; and a central interior chamber portion disposed between the filter and the membrane, the central interior chamber portion fluidly coupled to a crude loop outlet, the central interior chamber portion comprising an anode.

Example 13. The system of claim 12, wherein the filter is a cellulose paper that divides the first interior chamber portion and the central interior chamber portion.

Example 14. The system of claim 12, wherein the membrane is an ion exchange membrane or a nano-filtration membrane that the central interior chamber portion and second interior chamber portion.

Example 15. The system of claim 12, further comprising: a leaching unit; a first mixer unit; a first settler unit; a second mixer unit; a second settler unit; wherein: the electrowinning cell is fluidly coupled to the leaching unit; the electrowinning cell is fluidly coupled to the first settler unit; the electrowinning cell is fluidly coupled to second settler unit; and the electrowinning cell is fluidly coupled to the second mixer unit.

Example 16. The system of claim 15, wherein: the leaching unit is fluidly coupled to the first mixer unit; the first mixer unit is fluidly coupled to the first settler unit; the first settler unit is fluidly coupled to the second mixer unit; and the second mixer unit is fluidly coupled to the first settler unit.

In the foregoing disclosure, implementations of the disclosure have been described with reference to specific example implementations thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of implementations of the disclosure as set forth in the following claims. The disclosure and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.