Recovery treatment method, and, recovery treatment system

Abstract

To provide a recovery treatment method and so on capable of readily realizing to efficiently recover recovery target components.SOLUTION: In a solution preparation step, a solution is prepared by dissolving a first solute in a solvent. In the auxiliary salt dissolving step, an auxiliary salt dissolution process is performed in which a second solute is added as an auxiliary salt to the solution prepared in the solution preparation step and dissolved. In the electrolysis process, an electrolysis process is performed on the recovery treatment target while the recovery treatment target is immersed in the solution in which the auxiliary salt dissolution process was performed in the auxiliary salt dissolution step, thereby dissolving the recovery treatment target components from the recovery treatment target into the solution. The solubility of the second solute in the solvent is more temperature-dependent than the solubility of the first solute in the solvent, and in the auxiliary salt dissolution step, the proton activity in the solution is adjusted by performing the auxiliary salt dissolution process.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a recovery and treatment method and a recovery and treatment system. [Background technology]

[0002] Electrochemical devices have electrochemical cells configured such that a hydrogen electrode and an oxygen electrode sandwich an electrolyte membrane. In electrochemical devices, the electrochemical cell is, for example, a membrane electrode assembly (MEA) including an electrolyte membrane formed of a solid polymer membrane, and functions as a fuel cell for converting hydrogen energy into electric energy and an electrolysis device. For this reason, electrochemical devices are attracting attention as we move toward a carbon-neutral society.

[0003] In electrochemical cells, expensive and rare metals are used as electrode catalysts for the hydrogen and oxygen electrodes. Specifically, when an electrochemical cell functions as a polymer electrolyte fuel cell (PEFC), metal components such as platinum and ruthenium are used as electrode catalysts. Also, when an electrochemical cell functions as a polymer electrolyte membrane (PEM) water electrolysis device, metal components such as iridium and platinum are used as electrode catalysts.

[0004] Various techniques have been proposed for recovering target components such as the above-mentioned metal components from electrochemical cells. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 1626036 [Patent Document 2] Patent No. 6652518 [Patent Document 3] Patent No. 6652454 [Patent Document 4] Patent No. 6109769 [Patent Document 5] Patent Publication No. 63-270421 Summary of the Invention [Problem to be solved by the invention]

[0006] Conventionally, there has been a demand for efficient recovery of target components such as metals from electrochemical cells. Similarly, there has been a demand for efficient recovery from devices other than electrochemical cells.

[0007] Therefore, an object of the present invention is to provide a recovery method and recovery system that can easily and efficiently recover target components. [Means for solving the problem]

[0008] The recovery treatment method of the embodiment includes a dissolving step and a recovery step. In the dissolving step, the recovery target component is dissolved in a solution from a recovery treatment target containing the recovery target component. In the recovery step, the recovery target component is recovered from the solution in which the recovery target component has been dissolved. The dissolving step includes a solution preparation step, an auxiliary salt dissolving step, and an electrolysis treatment step. In the solution preparation step, a solution is prepared by dissolving a first solute in a solvent. In the auxiliary salt dissolving step, an auxiliary salt dissolving step is performed to add and dissolve a second solute as an auxiliary salt to the solution prepared in the solution preparation step. In the electrolysis treatment step, the recovery treatment target is immersed in the solution in which the auxiliary salt dissolving step was performed, and an electrolysis treatment is performed on the recovery treatment target, thereby dissolving the recovery target component from the recovery treatment target into the solution. The solubility of the second solute in the solvent is more temperature-dependent than the solubility of the first solute in the solvent, and in the auxiliary salt dissolving step, the proton activity in the solution is adjusted by performing the auxiliary salt dissolving step. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a recovery method and recovery system that can easily and efficiently recover target components. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a flow chart showing the recovery processing method of the first embodiment. [Figure 2] FIG. 2 is a functional block diagram that schematically shows the recovery and processing system 1 according to the first embodiment. [Figure 3A] FIG. 3A is a diagram schematically showing the dissolving device section 10 in the recovery and processing system 1 according to the first embodiment. [Figure 3B] FIG. 3B is a diagram showing a state in which electrolysis is performed in the recovery treatment method of the first embodiment. [Figure 3C] FIG. 3C is a diagram schematically showing the recovery device section 20 in the recovery processing system 1 according to the first embodiment. [Figure 3D] FIG. 3D is a diagram showing a state in which electrolysis is carried out in a modified example of the first embodiment when the recovery target component SK15 is an "indium" component. [Figure 4] FIG. 4 is a functional block diagram that schematically shows the recovery and processing system 1 according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment

[0012] [A] Collection and disposal method FIG. 1 is a flow chart showing the recovery processing method of the first embodiment.

[0013] In the recovery treatment method of this embodiment, as shown in FIG. 1, a dissolving step ST10 and a recovery step ST20 are carried out in sequence to recover a recovery target component SK15 from a recovery treatment target SB.

[0014] In the dissolving step ST10, as shown in Fig. 1, a solution preparation step ST11, an auxiliary salt dissolving step ST13, and an electrolytic treatment step ST15 are sequentially performed. As will be described in detail later, in the dissolving step ST10, a recovery target component dissolving process is performed in which the recovery target component is dissolved in a solution from the recovery target.

[0015] In the recovery step ST20, an auxiliary salt precipitation step ST23 and a recovery treatment step ST25 are sequentially carried out. As will be described in detail later, in the recovery step ST20, a recovery target component recovery treatment is carried out to recover the recovery target component from the solution in which the recovery target component has been dissolved in the dissolution step ST10.

[0016] [B] Configuration of Collection and Processing System 1 An example of a recovery and treatment system 1 used when carrying out the above recovery and treatment method will now be described.

[0017] FIG. 2 is a functional block diagram that schematically shows the recovery and processing system 1 according to the first embodiment.

[0018] 2, the recovery and processing system 1 of this embodiment includes a dissolving device section 10 and a recovery device section 20. Each section constituting the recovery and processing system 1 will be explained in order.

[0019] [B-1] Configuration of the melting device section 10 FIG. 3A is a diagram schematically showing the dissolving device section 10 in the recovery and processing system 1 according to the first embodiment.

[0020] 3A, the dissolving device 10 includes a solution preparing section 11, an auxiliary salt dissolving section 13, an electrolytic processing section 15, and a recovery processing solution buffer section 17, and is configured to perform a dissolving step ST10. That is, the dissolving device 10 is provided to perform a recovery target component dissolving process in which a recovery target component SK15 is dissolved in a solution from the recovery target SB.

[0021] In this embodiment, the recovery treatment target SB is, for example, an electrochemical cell (MEA) of an electrochemical device that functions as at least one of a fuel cell device and an electrolysis device, and includes the recovery target component SK15 and components other than the recovery target component SK15. The recovery target component SK15 is, for example, a "platinum" component used as an electrode catalyst in the hydrogen electrode and oxygen electrode of the electrochemical cell that constitutes the electrochemical device. The components other than the recovery target component SK15 are, for example, a "carbon" component that constitutes the diffusion layer in the hydrogen electrode and oxygen electrode of the electrochemical cell.

[0022] [B-1-1] Solution preparation section 11 The solution preparation unit 11 is provided to perform a solution preparation step ST11 (see FIG. 1).

[0023] The solution preparation unit 11 includes a tank and is configured so that a solvent SS11 and a first solute SB11 are introduced into the tank. A solution preparation step ST11 (see FIG. 1) is performed in the solution preparation unit 11, whereby the first solute SB11 is dissolved in the solvent SS11 to prepare a solution S11. The first solute SB11 may be any of an acid salt, a basic salt, and a normal salt, and is selected depending on the component SK15 to be recovered.

[0024] In this embodiment, the solvent SS11 is, for example, water. The first solute SB11 is, for example, hydrogen chloride (HCl), and dissolves (ionizes) in the solvent SS11. Therefore, the solution S11 is, for example, acidic. Specifically, when dissolving a "platinum" component as the recovery target component SK15 in the dissolution step ST10, the proton activity (a H+ =f·[H + ]; f is the activity coefficient) 10 [a H+ ]) and the like are set to the following conditions, so that the solution S11 is prepared. (conditions) pH (equivalent to proton activity): 1 or more, 5 or less

[0025] [B-1-2] Auxiliary salt dissolving unit 13 The auxiliary salt dissolving unit 13 is provided to perform the auxiliary salt dissolving step ST13 (see FIG. 1).

[0026] The auxiliary salt dissolver 13 includes a tank, and is configured so that the solution S11 prepared in the solution preparer 11 is introduced into the tank via a pipe L11 to which a pump P11 is installed. The auxiliary salt dissolver 13 is also configured so that a second solute SS13 is introduced into the tank.

[0027] In the auxiliary salt dissolver 13, an auxiliary salt dissolution process is performed in which a second solute SS13 is added as an auxiliary salt to the solution S11 prepared in the solution preparation unit 11 and dissolved. The second solute SS13 is an ionically bonded substance whose solubility in the solvent SS11 is more temperature-dependent than that of the first solute SB11. By performing the auxiliary salt dissolution process, the auxiliary salt dissolver 13 obtains a solution S13 in which the second solute SS13 is further dissolved, and the proton activity is adjusted.

[0028] The second solute SS13 is preferably at least one of an alkali metal salt and an alkaline earth metal salt. The second solute SS13 may be any of an acid salt, a basic salt, and a normal salt, and is selected depending on the component SK15 to be recovered.

[0029] In this embodiment, the second solute SS13 is, for example, potassium chloride (KCl), and is dissolved (ionized) in the solvent SS11. As a result, the proton activity is adjusted so that the acidity of the solution S13 after the second solute SS13 is dissolved is higher than the acidity of the solution S11 before the second solute SS13 is dissolved. Specifically, when a "platinum" component is dissolved as the recovery target component SK15 in the dissolution step ST10, the proton activity (a H+ =f·[H + ]; f is the activity coefficient) 10 [a H+ ]) and the like are set to the following conditions, so that the solution S11 is prepared. (conditions) pH (equivalent to proton activity): -2 or more, 1 or less Concentration of the second solute SS13: 10 wt% or more, 40 wt% or less

[0030] [B-1-3] Electrolytic processing unit 15 The electrolysis processing unit 15 is provided to perform the electrolysis processing step ST15 (see FIG. 1).

[0031] The electrolytic treatment unit 15 includes a tank, and is configured so that the solution S13 prepared in the auxiliary salt dissolver 13 is introduced into the tank via a pipe L13 in which a pump P13 is installed. The electrolytic treatment unit 15 also includes, for example, an AC power supply 150, and is configured to perform electrolysis on the recovery treatment target SB using the AC power supply 150. The recovery treatment target SB is electrically connected to one terminal of the AC power supply 150, and a counter electrode 152 is connected to the other terminal.

[0032] Specifically, in the electrolysis treatment unit 15, the SB to be recovered is immersed in the solution S13 in which the auxiliary salt dissolving treatment has been performed in the auxiliary salt dissolver 13. Then, while the SB to be recovered is immersed in the solution S13, a voltage is applied between the SB to be recovered and the counter electrode 152 using the AC power supply 150, thereby performing an electrolysis treatment on the SB to be recovered. The electrolysis treatment is performed, for example, by applying a voltage to the hydrogen electrode and the oxygen electrode constituting the electrochemical cell (MEA) that is the SB to be recovered. The electrolysis treatment may be performed by disassembling the electrochemical device and removing the electrochemical cell (MEA) from the electrochemical device, or may be performed with the electrochemical cell (MEA) attached to the electrochemical device without disassembling the electrochemical device. The counter electrode 152 may also be another electrochemical cell (MEA). By performing the electrolysis treatment, in the electrolysis treatment unit 15, a solution S15 in which the recovery target component SK15 is dissolved from the SB to be recovered is obtained in the solution S13 prepared in the auxiliary salt dissolver 13.

[0033] In the electrolysis treatment unit 15, an AC power supply 150 is used to alternately and repeatedly perform a reduction treatment in which a reduction potential is applied to the recovery treatment target SB and an oxidation treatment in which an oxidation potential is applied to the recovery treatment target SB as electrolysis treatment.

[0034] In this embodiment, for example, the "platinum" component, which is the recovery target component SK15, dissolves. Then, as a component other than the recovery target component SK15, for example, the "carbon" component peels off from the recovery treatment target SB and settles.

[0035] FIG. 3B is a diagram showing a state in which electrolysis is performed in the recovery treatment method of the first embodiment.

[0036] As shown in FIG. 3B, by performing a reduction process in which a reduction potential is applied to the recovery process target SB, platinum oxide 301 (=PtO2) formed on the surface of platinum metal 300 (=Pt) is reduced to platinum metal 300 (=Pt) (see the reaction formula below).

[0037] PtO2+4H + +4e - =Pt+2H2O

[0038] Then, by performing an oxidation treatment by applying an oxidation potential to the recovery treatment target SB, the platinum metal 300 (Pt) dissolves in the solution S13 as a dissolved component 302 (=PtCl6 2- ) (see the reaction formula below). As a result, in the electrolytic treatment unit 15, the "platinum" component, which is the recovery target component SK15, is dissolved, and a solution S15 is obtained.

[0039] Pt+6Cl - =PtCl6 2- +4e -

[0040] In this way, by alternately repeating a reduction process in which a reduction potential is applied to the SB to be recovered as an electrolytic process, and an oxidation process in which an oxidation potential is applied to the SB to be recovered as an electrolytic process, the recovery target component SK15 can be efficiently dissolved from the SB to be recovered as an electrolytic process.

[0041] [B-1-4] Recovered treated liquid buffer unit 17 The recovered treated liquid buffer unit 17 includes a tank, and is configured so that the solution S15 obtained in the electrolytic treatment unit 15 is introduced into the tank via a pipe L15 in which a pump P15 is installed.

[0042] The recovered treated solution buffer unit 17 is provided to temporarily store the solution S15 obtained in the electrolytic treatment unit 15 as a recovered solution S16.

[0043] [B-2] Configuration of the recovery device section 20 FIG. 3C is a diagram schematically showing the recovery device section 20 in the recovery processing system 1 according to the first embodiment.

[0044] In the recovery processing system 1 of this embodiment, the recovery device section 20 has a recovery processing liquid storage section 21, an auxiliary salt precipitation section 23, a recovery processing section 25, and a slurry buffer section 27, as shown in Figure 3C, and is provided to perform a recovery process for the recovery target component SK15 in order to recover the recovery target component SK15 from a solution (recovery solution S16) in which the recovery target component SK15 is dissolved in the dissolution device section 10 shown in Figure 3A.

[0045] [B-2-1] Recovered treated liquid storage unit 21 The recovery processing liquid storage unit 21 includes a tank and is configured so that the recovery solution S16 stored in the recovery processing liquid buffer unit 17 shown in Fig. 3A is introduced into the tank. The recovery processing liquid storage unit 21 stores the recovery solution S16 as the recovery processing solution S21 for performing the recovery process of the recovery target component in the recovery device unit 20.

[0046] In the recovered processing liquid storage unit 21, as in the case of the solution preparation unit 11 shown in FIG. 3A, the solvent SS11 and the first solute SB11 may be charged into a tank to prepare a recovered processing liquid S21, if necessary.

[0047] [B-2-2] Auxiliary salt precipitation section 23 The auxiliary salt precipitation unit 23 is provided to perform the auxiliary salt precipitation step ST23 (see FIG. 1).

[0048] The auxiliary salt precipitator 23 includes a tank 230, and is configured so that the recovered and treated solution S21 stored in the recovered and treated solution storage unit 21 is introduced into the tank 230 via a pipe L21 to which a pump P21 is installed.

[0049] The auxiliary salt precipitation unit 23 further includes, for example, a cooling device 231 to perform an auxiliary salt precipitation process for precipitating at least a portion of the second solute SS13 dissolved as an auxiliary salt in the recovery treatment solution S21. The cooling device 231 is installed, for example, to surround the periphery of the tank 230, and cools the recovery treatment solution S21.

[0050] In the auxiliary salt precipitation section 23, the solubility of the second solute SS13 decreases due to cooling of the recovered treatment solution S21, and a precipitate SK23 of the second solute SS13 is generated. As a result, in the auxiliary salt precipitation section 23, the recovered treatment solution S21 is separated into a slurry S23b containing the precipitate SK23 of the second solute SS13 and a supernatant liquid S23a in which the amount of dissolved ions of the second solute SS13 has been reduced.

[0051] In this embodiment, the precipitate SK23 of the second solute SS13 is potassium chloride (KCl).

[0052] [B-2-3] Collection and Processing Unit 25 The recovery processing unit 25 is provided to perform a recovery processing step ST25 (see FIG. 1).

[0053] The recovery processing unit 25 includes a tank, and is configured so that the supernatant S23a is introduced into the tank from the auxiliary salt precipitator 23 via a pipe L23 equipped with a pump P23. The recovery processing unit 25 is also configured to perform a recovery process for a component to be recovered, which recovers the component to be recovered SK15 dissolved in the supernatant S23a.

[0054] In this embodiment, the recovery processing unit 25 includes a DC power supply 250, a cathode member 251, and an anode member 252. In the recovery processing unit 25, the cathode member 251 is electrically connected to the cathode of the DC power supply 250, and the anode member 252 is electrically connected to the anode of the DC power supply 250. The cathode member 251 and the anode member 252 are immersed in the supernatant liquid S23a introduced into the recovery processing unit 25. The recovery processing unit 25 performs a recovery target component recovery process by having the DC power supply 250 apply a voltage between the cathode member 251 and the anode member 252. This executes a plating process in which the recovery target component SK15 dissolved in the supernatant liquid S23a is precipitated as a deposit SK25 on the surface of the cathode member 251 (the member to be plated). As a result, in the recovery processing unit 25, a recovery processed liquid S25 in which the ions of the recovery target component SK15 have been reduced is obtained by performing the recovery target component recovery process.

[0055] In this embodiment, the precipitate SK25 is, for example, "platinum" metal.

[0056] [B-2-4] Slurry buffer section 27 The slurry buffer unit 27 includes a tank, and is configured so that slurry S23b is introduced into the tank from the auxiliary salt settling unit 23 via a pipe L23b on which a pump P23b is installed. At the same time, the slurry buffer unit 27 is configured so that recovered liquid S25 is introduced into the tank from the recovery processing unit 25 via a pipe L25 on which a pump P25 is installed.

[0057] The slurry buffer section 27 is provided to temporarily store the slurry S23b and the recovered liquid S25 as a slurry buffer liquid S27.

[0058] [C] Summary As described above, in this embodiment, the solubility of the second solute SS13 in the solvent SS11 is more temperature-dependent than the solubility of the first solute SB11 in the solvent SS11, and the proton activity in the solution S11 is adjusted by performing an auxiliary salt dissolution process in the auxiliary salt dissolution step ST13. The proton activity is adjusted so that the solubility of the recovery target component SK15 in the electrolysis process is higher after the addition of the second solute SS13 than before the addition of the second solute SS13. Furthermore, by selecting a second solute SS13 whose solubility is strongly temperature-dependent, the concentration of the second solute SS13 can be adjusted by temperature.

[0059] In this embodiment, when recovering the "platinum" component as the recovery target component SK15 from the recovery treatment target SB, the proton activity is adjusted (i.e., the pH is adjusted to be lower) so that the acidity of the solution S13 after the second solute SS13 is dissolved is higher than the acidity of the solution S11 before the second solute SS13 is dissolved. The solubility (maximum concentration) of the "platinum" component in the electrolytic treatment increases as the acidity of the solution S13 increases.

[0060] Therefore, when electrolysis is carried out in the electrolysis treatment step ST15 after the auxiliary salt dissolving step ST13, the "platinum" component, which is the recovery target component SK15, can be efficiently dissolved from the recovery treatment target SB.

[0061] Therefore, in this embodiment, it is possible to efficiently recover the recovery target component SK15 from the recovery treatment target SB.

[0062] In this embodiment, in addition to the above, an auxiliary salt precipitation process is performed in an auxiliary salt precipitation step ST23. In the auxiliary salt precipitation process, at least a portion of the second solute SS13 dissolved as an auxiliary salt in the solution that has been subjected to electrolysis is precipitated by adjusting the temperature. Then, in a recovery process step ST25, the recovery treatment target SB is recovered from the solution S25 in which the concentration of the second solute SS13 has been reduced by performing the auxiliary salt precipitation process. Therefore, in this embodiment, it is possible to more efficiently recover the recovery target component SK15 from the recovery treatment target SB.

[0063] [D] Variation In the above embodiment, the recovery target component SK15 is a "platinum" component, but this is not limiting. The recovery target component SK15 may be, for example, an "indium" component.

[0064] FIG. 3D is a diagram showing a state in which electrolysis is carried out in a modified example of the first embodiment when the recovery target component SK15 is an "indium" component.

[0065] 3D, by performing a reduction treatment in which a reducing potential is applied to the recovery treatment target SB, the surface of indium oxide 401 is reduced to indium metal 400. Then, by performing an oxidation treatment in which an oxidizing potential is applied to the recovery treatment target SB, indium metal 400 is oxidized to dissolved components 402 that dissolve in solution S13.

[0066] As in the case of the platinum component, when recovering an indium component as the recovery treatment target SB, the proton activity is adjusted so that the acidity of the solution S13 after the second solute SS13 is dissolved is higher than the acidity of the solution S11 before the second solute SS13 is dissolved, thereby increasing the solubility (maximum concentration) of the indium component in the electrolysis treatment. Therefore, as in the case of the above embodiment, efficient recovery can be easily achieved.

[0067] In the above embodiment, the solvent SS11 is water, but a polar solvent other than water may be used. Furthermore, the second solute SS13, which is an auxiliary salt, may be calcium chloride (CaCl2) or the like in addition to potassium chloride (KCl). When the second solute SS13 is calcium chloride (CaCl2), for example, carbon dioxide (CO2) is used as a precipitant in the auxiliary salt precipitation step ST23 to precipitate calcium ions (Ca 2+ ) and carbon dioxide (CO2) to produce calcium carbonate as a precipitate.

[0068] Furthermore, depending on the type of component SK15 to be recovered, the first solute SB11 may be a substance that makes the solution S11 alkaline. For example, when the component SK15 to be recovered is an aluminum (Al) component, it is preferable that the solution S11 be alkaline. Furthermore, when the component SK15 to be recovered is an aluminum (Al) component, it is preferable that the proton activity is adjusted so that the basicity of the solution S13 after the second solute SS13, which is an auxiliary salt, is dissolved is higher than the basicity of the solution S11 before the second solute SS13 is dissolved (i.e., it is preferable that the pH is adjusted to be higher).

[0069] In the recovery step ST20 of the above embodiment, the recovery target component SK15 is recovered by performing a plating process to precipitate the recovery target component SK15 on the surface of the negative electrode member 251 (member to be plated). However, this is not limiting. In the recovery step ST20, the recovery target component SK15 may be recovered by performing an ion exchange process to adsorb ions of the recovery target component SK15 onto an ion exchange material (e.g., an ion exchange resin). In addition, in the recovery step ST20, the recovery target component SK15 may be recovered by performing a precipitation process to precipitate the recovery target component SK15 in the supernatant liquid S23a (solution). The precipitation process is performed, for example, by adding a precipitant to the supernatant liquid S23a (solution). In addition, the precipitation process is performed, for example, by lowering the temperature of the supernatant liquid S23a (solution) to reduce the solubility of the recovery target component SK15.

[0070] Second Embodiment [A] Configuration of collection and processing system 1 FIG. 4 is a functional block diagram that schematically shows the recovery and processing system 1 according to the second embodiment.

[0071] As shown in FIG. 4, the recovery and processing system 1 of this embodiment differs from the first embodiment (see FIG. 3A) in that the dissolving device section 10 does not have a recovery and processing liquid buffer section 17. In contrast, as shown in FIG. 4, the recovery and processing system 1 of this embodiment differs from the first embodiment (see FIG. 3A) in that a pipe L27 in which a pump P27 is installed is provided. Except for this point and related points, this embodiment is similar to the above-mentioned embodiment. Therefore, explanations of overlapping points will be omitted as appropriate.

[0072] In this embodiment, the recovered and treated liquid storage unit 21 is configured so that the solution S15 obtained in the electrolytic treatment unit 15 is introduced into the tank via a pipe L15 in which a pump P15 is installed, as shown in FIG.

[0073] In addition, in this embodiment, the solution preparation unit 11 is configured so that the slurry buffer liquid S27 temporarily stored in the slurry buffer unit 27 is introduced into the tank via a pipe L27 on which a pump P27 is installed.

[0074] [B] Summary As described above, in this embodiment, the slurry buffer solution S27 containing the precipitate SK23 of the second solute SS13 precipitated in the auxiliary salt precipitation unit 23 is introduced into the solution preparation unit 11. In other words, the second solute SS13 precipitated in the auxiliary salt precipitation step ST23 can be reused in the dissolving step ST10.

[0075] Therefore, in this embodiment, the dissolving step ST10 for dissolving the recovery target component SK15 from the recovery treatment target SB can be efficiently performed.

[0076] <Other> Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0077] 1: recovery treatment system, 10: dissolving device section, 11: solution preparation section, 13: auxiliary salt dissolving section, 15: electrolytic treatment section, 17: recovered treatment liquid buffer section, 20: recovery device section, 21: recovered treatment liquid storage section, 23: auxiliary salt precipitation section, 25: recovery treatment section, 27: slurry buffer section, 150: AC power supply, 152: counter electrode, 230: tank, 231: cooling device, 250: DC power supply, 251: cathode member, 252: anode member, 300: platinum metal, 301: platinum oxide, 302: dissolved component, 400: indium metal, 401: indium oxide, 402: dissolved component, L11: piping, L13: piping, L15: piping, L21: piping, L23: piping, L23b: piping, L25: piping, L27: piping, P11: pump, P13: pump, P15: pump, P21: pump, P23: pump, P23b: pump, P25: pump, P27: pump, ST10: dissolving step, ST11: solution preparation step, ST13: auxiliary salt dissolving step, ST15: electrolytic treatment step, ST20: recovery step, ST23: auxiliary salt precipitation step, ST25: recovery treatment step

Claims

1. a dissolving step of dissolving the recovery target component from a recovery treatment target containing the recovery target component into a solution; a recovery step of recovering the target component from the solution in which the target component is dissolved; A recovery and treatment method comprising: The dissolving step comprises: a solution preparation step of preparing a solution by dissolving a first solute in a solvent; an auxiliary salt dissolving step of performing an auxiliary salt dissolving process in which a second solute is added as an auxiliary salt to the solution prepared in the solution preparing step and dissolved therein; an electrolysis treatment step in which the recovery treatment target is immersed in the solution in which the auxiliary salt dissolution treatment has been performed in the auxiliary salt dissolution step, and an electrolysis treatment is performed on the recovery treatment target, thereby dissolving the recovery treatment target components from the recovery treatment target into the solution; and the solubility of the second solute in the solvent is more temperature-dependent than the solubility of the first solute in the solvent, and in the auxiliary salt dissolving step, the proton activity in the solution is adjusted by performing the auxiliary salt dissolving treatment. Recovery processing method.

2. The recovery step includes: an auxiliary salt precipitation step of performing an auxiliary salt precipitation process to precipitate at least a portion of the second solute dissolved as an auxiliary salt in the solution after the electrolysis process; Including, recovering the recovery treatment target from the solution on which the auxiliary salt precipitation treatment has been performed in the auxiliary salt precipitation step; The recovery and treatment method according to claim 1.

3. In the electrolytic treatment step, The electrolytic treatment alternately and repeatedly includes a reduction treatment in which a reduction potential is applied to the target to be recovered so as to reduce oxides of the target components to the target components, and an oxidation treatment in which an oxidizing potential is applied to the target to be recovered so as to oxidize the target components to be recovered and dissolve them in the solution. The recovery and treatment method according to claim 1.

4. the second solute is at least one of an alkali metal salt and an alkaline earth metal salt; The recovery and treatment method according to claim 1.

5. In the recovery step, The recovery target component is recovered by performing a plating process to deposit the recovery target component on the surface of a plated member. The recovery and treatment method according to claim 1.

6. In the recovery step, The target component is recovered by performing an ion exchange treatment in which ions of the target component are adsorbed onto an ion exchange material. The recovery and treatment method according to claim 1.

7. In the recovery step, recovering the target component by performing a precipitation process to precipitate the target component in the solution; The recovery and treatment method according to claim 1.

8. The precipitation treatment is carried out by adding a precipitating agent to the solution. The recovery and treatment method according to claim 7.

9. The precipitation treatment is carried out by lowering the temperature of the solution to reduce the solubility of the component to be recovered. The recovery and treatment method according to claim 7.

10. The object of the recovery process is an electrochemical device that functions as at least one of a fuel cell device and an electrolysis device. The recovery and treatment method according to claim 1.

11. a dissolving device unit that dissolves the recovery target component from a recovery treatment target containing the recovery target component into a solution; a recovery device unit that recovers the recovery target component from the solution in which the recovery target component is dissolved; A recovery and processing system comprising: The dissolving device section includes: a solution preparation unit that prepares a solution by dissolving a first solute in a solvent; an auxiliary salt dissolving unit that performs an auxiliary salt dissolving process of adding a second solute as an auxiliary salt to the solution prepared in the solution preparing unit and dissolving the second solute; an electrolysis treatment unit that performs electrolysis treatment on the recovery treatment target while the recovery treatment target is immersed in the solution in which the auxiliary salt dissolution treatment has been performed in the auxiliary salt dissolving unit, thereby dissolving the recovery treatment target components from the recovery treatment target into the solution; and the solubility of the second solute in the solvent is more temperature-dependent than the solubility of the first solute in the solvent, and the proton activity in the solution is adjusted by performing the auxiliary salt dissolving process in the auxiliary salt dissolving unit. Collection and processing system.

Images