Metal recovery system, metal recovery support system, and metal recovery support method

Abstract

To provide a metal recovery system highly efficiently carrying out the extraction and recovery of a plurality of kinds of metals included in a recovery object, with a low environmental load.SOLUTION: The metal recovery system comprising an extraction unit dissolving a plurality of kinds of object metals included in a recovery object into one kind of solvent, a recovery unit allowing a reference electrode and a plurality of recovery electrodes to contact the solvent and an electric control device controlling the electric potential of the plurality of recovery electrodes, recovers a first object metal by setting the electric potential of a first recovery electrode in a manner of allowing the first object metal among the plurality of kinds of object metals to precipitate on the first recovery electrode among the plurality of recovery electrodes and recovers a second object metal by setting the electric potential of a second recovery electrode in a manner of allowing the second object metal other than the first object metal among the plurality of kind of object metals to precipitate on the second recovery electrode other than the first recovery electrode among the plurality of recovery electrodes.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a metal recovery system, a metal recovery support system, and a metal recovery support method. [Background technology]

[0002] In order to address environmental issues and secure resources, efforts are being made on product remanufacturing, part remanufacturing, direct reuse, and raw material recovery. In particular, direct reuse and raw material recovery are being promoted for metal products.

[0003] For raw material recovery, there are methods that utilize metal refining technology, dissolve the product in acid or organic solvent, and recover it electrically, or dissolve it at high temperature and separate it based on specific gravity, etc.

[0004] Patent Document 1 discloses a method for producing a specific metal by electrolysis from an ore containing two or more types of metal elements, in which an anode is used that is obtained by crushing the ore into a powder and filling the pores of a three-dimensional mesh-like metal porous body with the powdered ore, and by controlling the potential at the anode to a predetermined value, metal elements from the ore that correspond to the controlled potential are selectively dissolved in an electrolyte, and predetermined ones of the metal elements dissolved in the electrolyte are selectively precipitated on the cathode by electrolysis at a predetermined potential.

[0005] Patent Document 2 discloses a method for separating and recovering rare elements in spent nuclear fuel with high efficiency, in which a hydrochloric acid solution of fission products containing two or more rare elements is subjected to constant current electrolysis in stages, and the rare elements are separated from other elements by being precipitated on a cathode electrode by electrolytic reduction, and then recovered. Patent Document 2 also discloses that the recovery rate is further improved by gradually increasing the electrode current density in the electrolytic reduction, thereby gradually increasing the electrode potential, and that this is because an appropriate amount of Rh is precipitated on the electrode in the initial stage of the electrolytic operation, thereby allowing Re and Tc to be efficiently guided to the electrode. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-117062 A [Patent Document 2] JP 2009-58370 A Summary of the Invention [Problem to be solved by the invention]

[0007] When recovering multiple types of metals from waste or other used products (materials to be recovered), it is usually necessary to separate the metals using a solution suitable for dissolving (extracting) them, set multiple potentials, raise the temperature multiple times, etc., and this requires a multi-stage process, which may result in a decrease in recovery efficiency and an increase in consumption of solutions and energy, which may increase the environmental burden in areas other than the original purpose of resource recovery.

[0008] The method described in Patent Document 1 involves selectively dissolving a specific metal element from an ore in an electrolyte and then precipitating it, and the object of processing is the ore, not used products, etc. In addition, since it requires a step of crushing the ore into powder, the processing requires a large amount of energy.

[0009] The method described in Patent Document 2 targets rare elements in spent nuclear fuel and involves gradually increasing the electrode potential in electrolytic reduction, so there is thought to be room for improvement in terms of separating the target metals.

[0010] An object of the present disclosure is to provide a metal recovery system that extracts and recovers multiple types of metals contained in materials to be recovered with high efficiency and with a low environmental impact. [Means for solving the problem]

[0011] In order to solve the above problems, the metal recovery system of the present disclosure comprises an extraction unit that dissolves multiple types of target metals contained in a material to be recovered into one type of solution, a recovery unit that brings a reference electrode and multiple recovery electrodes into contact with the solution, and an electric control device that controls the potentials of the multiple recovery electrodes, and recovers a first target metal by setting the potential of a first recovery electrode among the multiple recovery electrodes so as to precipitate a first target metal among the multiple types of target metals on a first recovery electrode, and recovers a second target metal by setting the potential of a second recovery electrode among the multiple recovery electrodes other than the first recovery electrode so as to precipitate a second target metal among the multiple types of target metals, other than the first target metal. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a metal recovery system that extracts and recovers multiple types of metals contained in recovery objects with high efficiency and low environmental impact. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing a metal recovery system according to a first embodiment. FIG. [Diagram 2] FIG. 2 is a flow chart showing a method for determining an extraction and recovery process in the metal recovery system of the first embodiment. [Diagram 3] FIG. 2 is a flow chart showing a method for determining an extraction process in the metal recovery system of the first embodiment. [Figure 4] FIG. 2 is a flow chart showing a method for determining a recovery process in the metal recovery system of the first embodiment. [Diagram 5] FIG. 1 is a schematic diagram showing a metal recovery system according to a second embodiment. [Figure 6] 1 is a graph showing the relationship between the potential and current of a recovery electrode in a solution. [Figure 7] 1 is a graph showing the change in current value over time in a state in which the potential of the recovery electrode in a solution is maintained. [Figure 8]1 is a graph showing the change in current value over time in a state in which the potential of the recovery electrode in a solution is maintained and metal deposits accumulate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present disclosure relates to a metal recycling system, and more particularly to a system for recovering multiple types of metals individually.

[0015] Until now, the use of natural resources has been essential for the production of metal products, but in the future, it may become impossible to continue production due to the depletion of natural resources and rising costs. For this reason, it will be necessary to recover usable parts from products and reuse them as products or regenerate them as raw materials. There are several processes for recovering raw materials from metal products, including a process to chemically or thermally extract metal components, a process to electrically separate and recover chemically dissolved metal components, and a process to separate and recover metals melted by heat by controlling specific gravity or temperature.

[0016] On the other hand, when promoting the use of metals as raw materials in the future, even if the alloys contain the same metal elements as their main components, if the alloy types are different or the impurity concentrations are different, and we try to extract and recover them as we have done in the past, the quality may decrease, making it impossible to reuse them as raw materials, or the rare metals contained therein may be wasted.

[0017] For this reason, it is necessary to recover multiple metals from multiple states with high accuracy. For this, the conditions for recovering metals differ depending on the surface state and the deterioration state of the metal, and it is necessary to specify these conditions. These conditions are implemented using a treatment time according to the standard electrode potential and content of the metal. However, since the electrode potential and the energy dependence of electrical dissolution differ depending on the oxidation state of the metal and surface treatment such as plating, tuning of the conditions is necessary. In this case, when multiple metals are contained in the recovery solution, it is possible that multiple metals exist near the recovery potential, in which case they may not be recovered electrically. For this reason, methods other than electrical recovery may be required.

[0018] In addition, these processes may involve high-concentration chemicals and high-temperature processes, and are likely to have a high environmental impact on water and soil in terms of energy consumption and waste disposal. If the environmental impact is high, it may be rejected due to the expected expansion of requirements for disclosure of environmental impact and data management, so it is necessary to minimize it as much as possible. This requires streamlining the extraction and recovery process and minimizing the environmental impact of the process conditions. On the other hand, minimizing the environmental impact may result in a decrease in process efficiency, so a balance must be struck.

[0019] In view of the above, this disclosure proposes a metal recovery system that extracts and recovers raw materials from waste (materials to be recovered) in a single environment as a raw material recovery process that reduces the environmental impact.

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0021] First Embodiment 1 is a schematic diagram showing a metal recovery system according to a first embodiment. In the following description, the term "raw material" is synonymous with the metal to be recovered, and is also referred to as the "target metal."

[0022] The metal recovery system 100 shown in the figure is composed of an extraction and recovery tank 10 that extracts and recovers raw materials from waste 1, a temperature control device 30 that adjusts the temperature of the solution 20 in the extraction and recovery tank 10, a recovery electrode 40 that precipitates and recovers metal components dissolved in the solution 20, a reference electrode 41 that serves as a potential standard, and an electric control device 50 that controls the potential and current of the recovery electrode 40, etc. In addition, the metal recovery system 100 desirably includes an input device (not shown) that accepts input from a user, a target metal selection device (not shown) that determines the metal to be recovered, an environment selection device (not shown) that selects the solution and determines the temperature conditions, and a condition selection device (not shown) that determines the output conditions of the electric control device 50.

[0023] The target metal selection device, the environment selection device, and the condition selection device constitute a metal recovery support system. The metal recovery support system supports a user in selecting the content of operations to be performed by the metal recovery system 100.

[0024] The extraction and recovery tank 10 is desirably made of a material that has sufficient chemical resistance to the solution 20 that dissolves the target metal contained in the waste 1 and can be used for a long period of time. The solution 20 is an acid or an organic solvent for dissolving the target metal. Suitable acids for dissolving the target metal include nitric acid, sulfuric acid, hydrochloric acid, and hydrofluoric acid of specific concentrations. Suitable organic solvents include choline chloride.

[0025] The recovery electrode 40 is also preferably a metal material, carbon electrode, or plated electrode that has sufficient chemical resistance to the solution 20 and has catalytic performance as necessary. Specific examples of the recovery electrode 40 include metal materials such as platinum, iridium oxide, and titanium, carbon electrodes such as glassy carbon, and electrodes made of resin or the like with a precious metal plated on the surface.

[0026] The reference electrode 41 may be a commonly used standard electrode such as a silver-silver-chloride saturated potassium chloride electrode, or a metal that is stable in the solution 20, such as a platinum, gold, or iridium oxide electrode.

[0027] The electric control device 50 is a device capable of applying and adjusting voltage and current, such as a DC power supply. In order to perform more precise control, it is preferable that the electric control device be an electrochemical control device.

[0028] In the extraction process, first, an environment selection device selects a solution 20 that dissolves the metal to be extracted and recovered (target metal). Then, the waste 1 is placed in the extraction and recovery tank 10.

[0029] In the dissolution process (extraction treatment), in order to increase the dissolution rate of the target metal, the temperature of the solution 20 is increased by the temperature control device 30. The temperature conditions of the solution 20 and the settings of the temperature control device 30 are selected by the environment selection device.

[0030] After the target metal has been sufficiently dissolved, the recovery electrode 40 and the reference electrode 41 are immersed in the solution 20, and the potential for reducing and depositing the target metal on the recovery electrode 40 is controlled by the electric control device 50. At this time, the output conditions such as the potential control of the electric control device 50 are determined by the condition selection device.

[0031] After a predetermined amount of the target metal has been deposited, it is desirable to remove the recovery electrode 40 from the solution 20 to avoid re-dissolution of the target metal.

[0032] By carrying out the extraction and recovery processes as described above, a metal recovery system that achieves both low environmental impact and high recovery rates can be realized.

[0033] Regarding the conditions set in the environment selection device, the higher the temperature, the faster the dissolution rate. However, while the higher the temperature, the more energy is consumed, there are cases where the dissolution rate does not increase significantly even if the energy consumption is increased, in which case the energy efficiency decreases. For this reason, the temperature is determined by balancing the energy consumption and the dissolution rate or dissolution time. Data showing these correlations is stored in the database of the environment selection device. The user is supported in making decisions by specifying the target metal and displaying recommended conditions.

[0034] In summary, the metal recovery system of this embodiment determines whether it is possible to separate and recover the metals contained in the waste to be recovered, and if so, determines a treatment process.Then, using a database or the like, the extraction process and recovery process that make up the treatment process are determined to be the most desirable process in terms of the load on the external environment (hereinafter referred to as "environmental load"), that is, the process that reduces the environmental load as much as possible.

[0035] Also, both the extraction and recovery processes can be carried out sequentially using a single extraction and recovery vessel 10.

[0036] Next, the metal recovery support method will be described.

[0037] FIG. 2 is a flow diagram showing a method for determining the extraction and recovery process in the metal recovery system of this embodiment.

[0038] As shown in this figure, first, the user inputs contained metals (metals contained in waste 1) into an input device (step S210). In response to this input, the target metal selection device determines the metals to be recovered (step S220). Next, the environment selection device determines the treatment solution and the treatment conditions (step S230). Next, the environment selection device judges whether it is possible to separate and recover only the target metals (step S240). If it is possible (Yes), the environment selection device confirms the treatment process and outputs the results to an output device such as a user's terminal (step S250). If it is not possible (No), the process returns to step S230.

[0039] FIG. 3 is a flow diagram showing a method for determining an extraction process in the metal recovery system of this embodiment.

[0040] In this diagram, the input device receives contained metals (metals contained in waste 1) input by the user (step S310). In this case, it is desirable to input the amount of contained metals, the alloy standard number if known, and whether or not surface treatment has been performed. The user may also specify the metal to be recovered. The target metal selection device may also determine the type of metal to be recovered based on the input data (step S320).

[0041] Next, the environment selection device performs a judgment (collation) based on the metal recovery database (step S330). At this time, the judgment result as to the conditions under which the metals can be separated and recovered is output. The metal recovery database records data on metal extraction such as the solubility of various metals in acids and organic solvents and the temperature dependence of the dissolution rate, the electrode potential of metals and alloy species in solution, and the current characteristics when dissolving or precipitating by applying electrical energy.

[0042] Then, the environment selection device determines the type and concentration of the solution (step S340). Next, the environment selection device determines the temperature and additives of the solution (step S350). Setting the temperature of the solution high usually promotes the dissolution of the target metal. In this case, the addition of a compound that promotes the dissolution of the target metal or the blowing of a gas may be determined. In addition, in order to accelerate the dissolution of the target metal, positive electrical energy may be applied to the waste to electrochemically dissolve the metal. Next, the environment selection device determines the extraction time (step S360) and, if necessary, the addition of a precipitation additive (step S370). The extraction time is determined based on the amount of waste, but if the content of the target metal in the waste is input, the extraction time calculated from the content and dissolution rate is adopted. In addition, the addition of a precipitation additive may be performed to coagulate and precipitate metals that are not the target of recovery when the target metal cannot be separated by simple dissolution alone, or when the metal cannot be separated and recovered independently in the subsequent recovery process.

[0043] Then, the environment selection device judges whether the environmental load of the recovery process is the smallest (step S380). If Yes, the environment selection device determines the extraction process and moves to the selection of the recovery process (step S390). At this time, the result may be output to an output device such as a user terminal. If No, the process returns to step S330.

[0044] The above extraction process is determined based on a balance between energy consumption and the expected dissolution rate of the target metal, and the process that has been internally adjusted to minimize the environmental impact is output as the final extraction process proposal.

[0045] FIG. 4 is a flow diagram showing a method for determining a recovery process in the metal recovery system of this embodiment.

[0046] In this figure, the condition selection device selects the recovery electrode and the reference electrode (step S410). Here, the condition selection device sets the recovery potential based on the potential at which a single metal can be recovered, using the polarization characteristics of the target metal in the solution as one of the criteria. When multiple metals are dissolved in the solution, a potential that provides high recovery efficiency and high separation efficiency is selected.

[0047] In response to the selection result in step S410, the user installs the recovery electrode and the reference electrode (step S420). This step may be automatically performed by a predetermined device that is a component of the metal recovery system instead of the user. When recovering multiple types of metals, multiple recovery electrodes are immersed in the solution, and different potentials are set for each of the multiple recovery electrodes, and different types of metals are deposited on each recovery electrode and recovered.

[0048] Next, the condition selection device sets the solution temperature (step S430). Furthermore, the condition selection device sets the additives (step S440) and the recovery time (step S450). Then, the condition selection device determines whether the environmental impact of the recovery process is minimal (step S460). If Yes, the condition selection device determines the recovery process (step S470). At this time, the result may be output to an output device such as a user terminal. If No, the process returns to step S430.

[0049] A recovery electrode 40 that is insoluble in the solution 20 is placed in the extraction and recovery tank 10 after the extraction process has been completed. Next, a voltage is applied between the reference electrode 41 and the recovery electrode 40, and the recovery electrode 40 is scanned to a negative potential to recover the metal. The potential of the recovery electrode 40 is set to the electrode potential of each metal in the solution 20. It is desirable to carry out the process at the lowest possible temperature, since the re-dissolution rate of the metal, which is a natural reaction, increases at high temperatures. In addition, a corrosion inhibitor such as sodium nitrate may be added to suppress re-dissolution. The potential retention time is determined by the amount of the target metal contained in the waste 1, the amount of electricity calculated from the amount of current flowing while the electrode potential is held at the set potential, and the amount of metal recovered or the weight change of the recovery electrode 40 calculated from Coulomb's law. As with the extraction process, these process configurations are determined from the balance between the energy consumption and the expected precipitation rate of the target metal, and a process adjusted to minimize the environmental load is output internally.

[0050] An existing process for recovering silver and copper from solar panels will be described in detail below as an example.

[0051] The process for recovering metals from solar panels involves first precipitating and separating silver in an organic solvent containing chloride ions such as choline chloride, then dissolving the waste again in sulfuric acid to extract copper, and then precipitating the copper on a stainless steel electrode that serves as the recovery electrode 40 using an ion exchange membrane. For this reason, an organic solvent is selected in determining the solution components in Figure 3, and a chloride ion-containing substance such as choline chloride is set as an additive for precipitation. The precipitation time is determined by the reaction rate of silver with chloride ions, which are stored in the metal recovery database, and the amount of silver contained in the waste 1.

[0052] In this case, a different solution is used, but the solution is replaced or sulfuric acid is added as solution 20 in another extraction and recovery tank 10, and the potential is set from the metal recovery database to recover copper. Stainless steel is selected for the recovery electrode 40, and copper can be deposited on the stainless steel electrode by applying a potential. At this time, the balance between energy consumption and deposition rate is calculated from the relationship between the solution concentration, temperature, and deposition rate, achieving a metal recovery process with the smallest environmental impact.

[0053] Second Embodiment A method for determining an extraction and recovery process in a metal recovery system when the metal content and state are unknown will be described with reference to Figures 5 to 8. Basically, this is the same as in Example 1, so only the differences will be described.

[0054] FIG. 5 is a schematic configuration diagram showing a metal recovery system according to the second embodiment.

[0055] The metal recovery system 500 shown in this figure differs from the first embodiment (FIG. 1) in that an impurity removing electrode 42 is additionally provided. The rest of the configuration is the same as that of the first embodiment.

[0056] The metal recovery database stores the representative compositions of products contained in waste 1, and outputs the approximate amount of target metals from the constituent weights of waste 1. Using the results, the extraction process determination method shown in Figure 3 is applied to determine the temperature, type and concentration of the solution, additives, extraction time, etc. in the extraction process.

[0057] In the recovery process, since the state of the metal is unknown, it is unclear whether a sufficient amount of metal can be recovered even when a specific electrode potential is maintained, and there is a possibility that metals other than the target metal will be precipitated on the recovery electrode 40. For this reason, it is desirable to provide an impurity removal electrode 42 in addition to the recovery electrode 40.

[0058] The impurity removal electrode 42 is an electrode that is insoluble in the solution 20 , similar to the recovery electrode 40 .

[0059] In this embodiment, a potential is first applied to the impurity removal electrode 42. However, a constant potential is not applied, but the potential is scanned at a constant rate in the negative direction from the natural immersion potential of the electrode. It is considered that a sufficient reaction occurs at a scanning rate of 1 mV / s or 20 mV / min, which is called a pseudo-equilibrium state.

[0060] As a result, the reduction current of the impurity recovery electrode gradually increases, but the current value rises significantly as a specific reduction reaction occurs. If the potential at this time differs from the immersion potential of the target metal by 50 mV or more, it is assumed that a reduction reaction of a different metal is occurring. When the current value increases by 10 times or more, or the change in current value falls to 10% or less, the potential scanning is stopped and the potential is held at that potential. After holding, the current value decreases as the metal ions in the solution are depleted as the reduction reaction of the metal progresses, but when the current value falls below the re-dissolution rate, further recovery is not expected, so the potential holding at the constant potential is stopped.

[0061] At this time, the impurity removal electrode 42 is covered with metals other than the target metal, and is not suitable for recovering the target metal. For this reason, the control target of the potential is changed to the recovery electrode 40, and the potential is scanned again in the negative direction at a constant speed from the potential at which the impurity removal electrode 42 was held, until it approaches the electrode potential of the target metal. When the potential is reached and the current value becomes 10 times larger or the change in the current value becomes 10% or less, as in the case of the reduction of impurities, the potential scanning is stopped, and the target metal is recovered from the solution 20 by maintaining the potential.

[0062] The above process will be specifically explained using the values ​​in FIG.

[0063] 6 is a graph showing the relationship between the potential of the recovery electrode in solution and the current, with the horizontal axis representing the potential of the recovery electrode relative to the reference electrode and the vertical axis representing the current.

[0064] In this figure, when the potential is scanned in the negative direction, the current value tends to increase overall, but regions where the current change is small and regions where it is large alternately occur.

[0065] First, the potential is scanned in the negative direction from +0.55 V vs. Ag / AgCl sat.KCl in the natural immersion state, for example at a rate of 20 mV / min. When the potential falls below 0.4 V vs. Ag / AgCl sat.KCl, the current value increases, and the reaction becomes stationary at around 0.2 V vs. Ag / AgCl sat.KCl, and the mode switches to potential holding mode.

[0066] 7 is a graph showing the change in current value over time when the potential of the recovery electrode in the solution was maintained, with the horizontal axis representing time and the vertical axis representing current value.

[0067] As shown in the figure, when the potential is held, the current value decreases and approaches a constant value.

[0068] The impurities are consumed from the solution 20, and the potential falls below −0.5 mA in about 40 seconds, which is below the re-dissolution rate, and the potential is then stopped being maintained.

[0069] Next, as shown in Figure 6, the controlled electrode is switched and the potential is scanned in the negative direction from 0.2 V vs. Ag / AgCl sat.KCl. As the potential decreases, the current increases when it falls below 0.1 V vs. Ag / AgCl sat.KCl, indicating that another reaction has begun. When this approaches -0.1 V vs. Ag / AgCl sat.KCl, it approaches the electrode potential of the target metal and switches to potential holding mode.

[0070] When the potential is maintained, not only may the absolute value of the current decrease as shown in FIG. 7, but the current may also increase due to an increase in the surface area caused by the deposited metal.

[0071] 8 is a graph showing the change in current value over time when the potential of the recovery electrode in the solution is maintained and metal deposits accumulate, with the horizontal axis representing time and the vertical axis representing current value.

[0072] As shown in this figure, when the potential is maintained, the current value (absolute value) may increase due to an increase in the surface area caused by the deposited metal.

[0073] In addition, as shown in this figure, the current value may be constant at a value corresponding to the deposition rate of the target metal, indicating a balance (equilibrium state) between deposition and re-dissolution.

[0074] Thereafter, the current value may decrease. In this case, it is considered that the re-dissolution rate of the deposited metal is lower than the deposition rate. In such a case, the potential is stopped.

[0075] Then, by quickly pulling the recovery electrode 40 out of the solution 20, the target metal can be recovered before the precipitated target metal is reduced by re-dissolution. In this case, the environmental load is not necessarily minimized, but since there is no need to carry out additional processes such as removing impurities or to highly purify the metal by re-dissolution, the overall environmental load can be reduced.

[0076] In the above embodiment, the target metal is recovered by immersing the recovery electrode 40 in the solution 20 stored in the extraction recovery tank 10, but the metal recovery system of the present disclosure is not limited to this. The recovery electrode may be installed in a pipe in which the solution in which the target metal is dissolved circulates, and the target metal may be precipitated by setting the recovery electrode to a predetermined potential. In this case, after a predetermined amount of the target metal is precipitated on the recovery electrode, the valve of the pipe may be closed to block the solution flowing in the pipe, and the solution may be circulated in a pipe in which another recovery electrode is installed to continue the recovery of the target metal. In addition, it is preferable to discharge the solution from a drain connected to the pipe so that the solution does not remain in the pipe and the solution does not continue to contact the recovery electrode. This is to prevent the target metal precipitated on the recovery electrode from re-dissolving in the solution.

[0077] In addition, when recovering multiple types of target metals, multiple pipes through which a solution containing multiple types of dissolved target metals circulate, with recovery electrodes installed in each pipe, may be connected in parallel or series to the extraction and recovery tank 10, and each recovery electrode may be set to a predetermined potential corresponding to each of the multiple types of target metals, thereby depositing each of the target metals on each recovery electrode.

[0078] In the above specific examples, the target metals are described as silver and copper, but the target metals according to the present disclosure are not limited to these, and may be any metal that can be extracted, precipitated, and recovered by using a specific solution and setting the recovery electrode to a specific potential, such as iron, cobalt, nickel, zinc, aluminum, etc. In this case, a part of the target metal may be separated and recovered by precipitating it by mixing an additive. [Explanation of symbols]

[0079] 1: waste, 10: extraction recovery tank, 20: solution, 30: temperature control device, 40: recovery electrode, 41: reference electrode, 42: impurity removal electrode, 50: electrical control device, 100, 500: metal recovery system.

Claims

1. An extraction unit that dissolves multiple types of target metals contained in the material to be recovered into one type of solution; a recovery section that brings a reference electrode and a plurality of recovery electrodes into contact with the solution; an electric control device for controlling the potentials of the plurality of recovery electrodes; recovering the first target metal by setting a potential of the first recovery electrode among the plurality of recovery electrodes so as to deposit the first target metal among the plurality of target metals on the first recovery electrode; A metal recovery system which recovers a second target metal by setting the potential of a second recovery electrode which is one of the plurality of recovery electrodes other than the first recovery electrode so as to deposit a second target metal which is one of the plurality of target metals other than the first target metal.

2. When the number of the plurality of target metals is three or more, the nth recovery electrode (n is an integer of 3 or more; the same applies below) among the plurality of recovery electrodes is used.

2. The metal recovery system according to claim 1, wherein the nth target metal is recovered by setting the potential of the nth recovery electrode so as to deposit the nth target metal among the plurality of target metals on the recovery electrode.

3. 2. The metal recovery system of claim 1, wherein the potential of at least one of the plurality of recovery electrodes is scanned to change the current, and when the rate of change of the current reaches a certain level or more, the potential is set to a constant value and the metal precipitated at that potential is recovered.

4. 4. The metal recovery system according to claim 3, wherein when a change occurs in the rate of change of the current while the potential is at the constant value, the plurality of target metals are recovered by another recovery electrode.

5. 4. The metal recovery system of claim 3, wherein said scanning of said potential varies said potential in a negative direction.

6. The metal recovery system of claim 4, wherein when the change in the rate of change of the current when the potential is at the constant value indicates a state in which the change is lower than the re-dissolution rate at the potential, the multiple types of target metals are recovered by the other recovery electrode.

7. 2. The metal recovery system of claim 1, wherein the solution is mixed with an additive.

8. An extraction unit that dissolves multiple types of target metals contained in the material to be recovered into one type of solution; a recovery section that brings a reference electrode and a plurality of recovery electrodes into contact with the solution; and an electric control device for controlling the potentials of the plurality of recovery electrodes, A target metal selection device for determining the target metal; An environment selection device that selects the solution and determines the temperature conditions; A condition selection device that determines the output conditions of the electric control device.

9. An extraction unit that dissolves multiple types of target metals contained in the material to be recovered into one type of solution; a recovery section that brings a reference electrode and a plurality of recovery electrodes into contact with the solution; and an electric control device for controlling the potentials of the plurality of recovery electrodes. a target metal selection device for determining the target metal; An environment selection device selects the solution and determines the temperature conditions; A metal recovery support method, comprising: a condition selection device that determines an output condition of the electric control device.

Images