Metal elution apparatus and metal elution method

Abstract

This technology provides a method for reducing the amount of processing solution used to dissolve target metals. [Solution] The metal elution device 1 is a device that elutes a target metal from a workpiece 9. The metal elution device 1 comprises a treatment tank 10, a nozzle 20, a nozzle moving unit 23, and a circulation piping system 60. The treatment tank 10 houses the workpiece 9. The nozzle 20 discharges a treatment liquid toward the workpiece 9 stored in the treatment tank 10. The nozzle moving unit 23 moves the nozzle 20 relative to the workpiece 9 stored in the treatment tank 10. The circulation piping system 60 returns the treatment liquid discharged from the treatment tank 10 to the nozzle 20.

Description

Technical Field

[0001] The subject matter disclosed in this specification relates to a metal elution device and a metal elution method.

Background Art

[0002] Recovering rare metals and precious metals from waste such as electronic and electrical equipment waste called e-waste has attracted attention in recent years because it is much more efficient and has less environmental impact than mining newly produced metal resources from mines.

[0003] For example, Patent Document 1 discloses a method for recovering a target metal from an aqueous precious solution containing the target metal. Specifically, a dissolution step including dissolving the target metal from a solid raw material with a leaching solution to form an aqueous precious solution containing target metal ions, and a biosorption step including contacting the microorganism with the aqueous precious solution so that at least a part of the target metal is biosorbed by the microorganism, wherein the microorganism contains a metal and the aqueous precious solution becomes a lean solution, a separation step including substantially separating the microorganism containing the metal from the lean solution, and a recovery step including recovering the target metal from the microorganism containing the metal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When eluting a metal from a treatment object using a treatment liquid, from the viewpoint of suppressing cost increase and environmental load, it is required to reduce the usage amount of the treatment liquid. However, in the above Patent Document 1, no consideration is given to reducing the usage amount of the treatment liquid.

[0006] The object of the present invention is to provide a technology that can reduce the amount of processing solution used for dissolving target metals. [Means for solving the problem]

[0007] To solve the above problems, the first embodiment is a metal elution apparatus for eluting a target metal from a workpiece, comprising: a treatment tank for storing the workpiece; a nozzle for discharging a treatment liquid toward the workpiece stored in the treatment tank; a relative movement unit for moving the nozzle relative to the workpiece stored in the treatment tank; and a circulation piping system for returning the treatment liquid discharged from the treatment tank to the nozzle.

[0008] A second embodiment is a metal elution apparatus according to the first embodiment, further comprising at least one mesh basket capable of containing the object to be processed and stored in the processing tank.

[0009] A third embodiment is a metal elution apparatus according to the second embodiment, further comprising a basket moving unit for moving the basket in and out of the processing tank.

[0010] A fourth embodiment is a metal elution apparatus according to the second embodiment, wherein the basket has an annular bottom and an inner portion rising from the bottom, and the nozzle discharges the processing liquid from inside the inner portion of the basket to the inner portion.

[0011] A fifth aspect is a metal elution apparatus according to the second or third aspect, wherein the at least one basket includes a first basket and a second basket, and the nozzle is positioned between the first basket and the second basket and discharges a processing liquid toward the first basket and the second basket.

[0012] The sixth embodiment is a metal elution apparatus according to the first or second embodiment, further comprising a heating unit for heating the processing liquid.

[0013] A seventh embodiment is a metal elution apparatus according to the first or second embodiment, further comprising a processing liquid supply unit capable of selectively supplying a plurality of types of processing liquids to the nozzle.

[0014] The eighth aspect is a metal elution apparatus according to the seventh aspect, wherein the plurality of processing liquids include a chemical solution and washing water.

[0015] The ninth aspect is a metal elution apparatus according to the seventh aspect, wherein the plurality of processing solutions include chemical solutions of different types.

[0016] The tenth embodiment is a metal elution apparatus according to the first or second embodiment, further comprising a recovery unit for recovering the treatment liquid from which the metal has been eluted.

[0017] The eleventh aspect is a metal elution method, comprising the steps of: a) storing an object to be treated in a treatment tank; b) discharging a treatment liquid from a nozzle toward the object to be treated stored in the treatment tank; c) moving the nozzle relative to the object to be treated stored in the treatment tank; and d) returning the treatment liquid discharged from the treatment tank to the nozzle. [Effects of the Invention]

[0018] According to the first to eleventh embodiments, the elution efficiency of the target metal can be improved, thereby reducing the amount of chemical solution consumed.

[0019] According to the second embodiment, by storing the object to be processed in a basket, it is possible to easily load and unload the object to be processed into the processing tank. Furthermore, by discharging the processing liquid into the basket while the object to be processed is still contained in the basket, the processing liquid can be supplied to the object to be processed. Therefore, the target metal can be eluted efficiently.

[0020] According to the third embodiment, the use of the basket movement unit can reduce the physical burden on the worker. In addition, safety can be improved by reducing the risk of the basket falling or other incidents.

[0021] According to the fourth aspect, since the object to be processed in the basket can efficiently contact the processing liquid, the elution efficiency can be increased.

[0022] According to the fifth aspect, since the object to be processed can be divided into a plurality of baskets, the storage and removal of the baskets with respect to the processing tank are easier than in the case of using one basket. In addition, by dispersing the object to be processed among a plurality of baskets, the object to be processed can easily contact the processing liquid, and the elution efficiency of the metal can be increased.

[0023] According to the sixth aspect, the elution efficiency of the metal can be increased.

[0024] According to the seventh aspect, since a plurality of processing liquids are handled by one nozzle, the device can be miniaturized and simplified. In addition, by reducing the number of nozzles, the manufacturing cost and maintenance cost of the device can be reduced.

[0025] According to the eighth aspect, the metal of the object to be processed can be eluted with a chemical solution, and the object to be processed can be washed with washing water.

[0026] According to the ninth aspect, according to the target metal, an optimal chemical solution can be selected or combined and used. Thereby, the target metal can be appropriately eluted.

[0027] According to the tenth aspect, the eluted metal can be recovered.

Brief Description of Drawings

[0028] [Figure 1] It is a diagram showing the configuration of a metal elution device according to the first embodiment. [Figure 2] It is a perspective view showing a basket. [Figure 3] It is a schematic perspective view showing the positional relationship when a lid portion is attached to the processing tank main body portion. [Figure 4] It is a flowchart showing the procedure of an elution process executed by the metal elution device shown in FIG. 1. [Figure 5] This is a schematic perspective view showing a part of the metal elution apparatus according to the second embodiment. [Figure 6] This is a schematic perspective view showing a part of the metal elution apparatus according to the third embodiment. [Figure 7] This graph shows the measurement results of copper concentration obtained by eluting using different methods. [Modes for carrying out the invention]

[0029] Embodiments of the present invention will be described below with reference to the attached drawings. Note that in the drawings, the dimensions and number of parts may be exaggerated or simplified for ease of understanding.

[0030] <1. First Embodiment> Figure 1 shows the configuration of a metal elution device 1 according to the first embodiment. This metal elution device 1 is a device that elutes a target metal from a material to be treated 9. The material to be treated 9 is, for example, electrical and electronic equipment waste called e-waste, which is used or discarded electronic equipment and electrical products. Note that the material to be treated 9 is not limited to electrical and electronic equipment waste, but may be other objects. To increase the elution efficiency, the material to be treated 9 is preferably crushed to a predetermined size (for example, a maximum dimension of 5 mm or less). The target metal is a precious metal (such as gold (Au), silver (Ag), platinum (Pt), palladium (Pd)) or a rare metal (such as lithium (Li), cobalt (Co), neodymium (Nd), indium (In)).

[0031] The metal elution apparatus 1 comprises a processing tank 10, a nozzle 20, a basket 30, a processing liquid supply unit 40, a processing liquid discharge unit 50, a circulation piping system 60, and a control unit 80.

[0032] The processing tank 10 is a container for storing the object to be processed 9. The processing tank 10 has a processing tank body 11 and a lid 13. The processing tank body 11 is a bottomed cylindrical shape. The processing tank body 11 has a circular opening at the top, and the object to be processed 9 is inserted and removed when the top is open. The inner surface of the processing tank body 11 is resistant to processing liquid. The lid 13 is removably attached to the upper end of the processing tank body 11. The lid 13 opens and closes the opening of the processing tank body 11. The processing tank body 11 is sealed when the lid 13 is fixed to the processing tank body 11.

[0033] The nozzle 20 is a component that discharges the processing liquid into the processing tank 10. The tip of the nozzle 20 is cylindrical, extending in the height direction (vertical axis z direction), and multiple discharge ports are provided on the nozzle surface 21, which is the outer surface of the cylindrical portion. The nozzle 20 is a shower nozzle that sprays the processing liquid radially from the multiple discharge ports. The nozzle 20 is attached to the lid 13 and is movable together with the lid 13. The nozzle 20 is positioned in the center of the lid 13. When the lid 13 is attached to the processing tank body 11, the tip of the nozzle 20 is positioned inside the processing tank 10.

[0034] The metal elution apparatus 1 further comprises a nozzle moving unit 23. The nozzle moving unit 23 is a device that moves the nozzle 20 relative to the object to be processed 9. The nozzle moving unit 23 is fixed to the upper part of the lid 13 and is integrated with the lid 13. The nozzle moving unit 23 has, for example, an electric motor (for example, an electric servo motor) and a mechanism (ball screw mechanism, cam mechanism, etc.) that converts the driving force of the electric motor into linear motion. The nozzle moving unit 23 is electrically connected to the control unit 80 and moves the nozzle 20 up and down (in the z direction) relative to the lid 13 in response to a command from the control unit 80. The nozzle moving unit 23 is an example of a "relative moving unit".

[0035] Figure 2 is a perspective view showing the basket 30. The basket 30 is a mesh container for holding the objects to be processed 9. The size of the mesh holes in the basket 30 is smaller than the size of each individual object to be processed 9. The basket 30 has an annular (donut-shaped) bottom 31 with a hole in the center, and an inner part 33 and an outer part 35 that rise vertically upward from the inner and outer edges of the bottom 31, respectively. The basket 30 has an annular opening at the top (the upper ends of the inner part 33 and the outer part 35), and the objects to be processed 9 are placed in it with the top open. The basket 30 can be used to stack a large number of objects to be processed 9 thinly in the height direction (z direction).

[0036] As shown in Figure 1, the metal elution device 1 further includes a basket moving unit 37. The basket moving unit 37 moves the basket 30 between a position inside the processing tank body 11 and a position outside the processing tank body 11. The basket moving unit 37 has, for example, an arm that grips the basket 30 and a drive unit such as a hydraulic cylinder that drives the arm. The basket moving unit 37 is electrically connected to the control unit 80 and operates in response to commands from the control unit 80.

[0037] The metal elution device 1 further includes a lid opening / closing unit 15. The lid opening / closing unit 15 moves the lid 13 between a position that closes the opening of the processing tank body 11 and a position that opens the opening of the processing tank body 11. The lid opening / closing unit 15 includes, for example, an arm attached to the lid 13 and a drive unit such as a hydraulic cylinder that drives the arm. The lid opening / closing unit 15 is electrically connected to a control unit 80 and operates in response to commands from the control unit 80.

[0038] Figure 3 is a schematic perspective view showing the positional relationship when the lid 13 is attached to the processing tank body 11. As shown in Figure 3, the lid opening / closing mechanism 15 moves the lid 13 linearly downward from a position above the processing tank body 11. As a result, the nozzle 20 and the nozzle moving mechanism 23 (not shown) are also moved downward along with the lid 13. When the lid 13 is attached, the nozzle 20 is inserted into a circular hole provided inside the basket 30, which is stored in the processing tank body 11 beforehand. Then, as shown in Figure 1, when the lid 13 is attached to the processing tank body 11, the nozzle 20 is positioned in the through hole inside the basket 30. The nozzle 20 extends parallel to the direction in which the hole in the basket 30 extends (the direction in which the inner part 33 extends).

[0039] As shown in Figure 1, the metal elution device 1 further includes an oscillating unit 17. The oscillating unit 17 is electrically connected to the control unit 80 and, in response to commands from the control unit 80, oscillates the basket 30 housed in the processing tank 10. The oscillating unit 17 may vibrate the basket 30 horizontally or vertically, or rotate it around a vertical axis z extending in the vertical direction. The oscillating unit 17 may also cause the basket 30 to perform a combined motion of vibration and rotation. By moving the basket 30 with the oscillating unit 17, the object to be processed 9 can be moved relative to the nozzle 20. The oscillating unit 17 is an example of a "relative movement unit".

[0040] Furthermore, the oscillating unit 17 is not limited to oscillating the basket 30, but may be configured, for example, to oscillate the processing tank 10 itself.

[0041] As shown in Figure 1, the processing liquid supply unit 40 is a device that supplies processing liquid to the nozzle 20. The processing liquid supply unit 40 can selectively supply multiple types of processing liquid to the nozzle 20. The processing liquid supply unit 40 includes a processing liquid adjustment unit 41, a supply pipe 43, a supply pump 45, and a supply valve 47.

[0042] The processing liquid adjustment unit 41 is a unit that adjusts the processing liquid supplied to the nozzle 20. The processing liquid adjustment unit 41 has a cleaning water tank 411 that stores cleaning water, and a plurality of chemical solution tanks 413 that each store different types of chemical solutions. The processing liquid adjustment unit 41 has an electric valve and a pump controlled by the control unit 80, and selectively supplies the cleaning water or multiple types of chemical solutions stored in the cleaning water tank 411 and the plurality of chemical solution tanks 413 to the supply pipe 43. Alternatively, the processing liquid adjustment unit 41 may mix the cleaning water or multiple chemical solutions to adjust the concentration or ratio and supply the mixture to the supply pipe 43.

[0043] When the target metal is gold, for example, a 50-100% aqua regia, an aqueous solution of ammonium thiosulfate (pH 9-11), or an aqueous solution of iodine can be used as a treatment solution to dissolve the gold. In addition, a primary treatment solution may be supplied to the treatment tank 10 to dissolve unwanted metals (e.g., base metals) before dissolving the target metal. The primary treatment solution may be, for example, dilute nitric acid or an aqueous solution of ferric chloride. By removing unwanted metals from the object to be treated 9 with the primary elution solution, the recovery rate of the target metal can be increased.

[0044] The washing water is a liquid used to remove foreign matter and chemicals adhering to the object to be treated 9. For example, pure water or tap water can be used as the washing water. It is also possible to use chemicals such as hydrochloric acid or sulfuric acid as the washing water.

[0045] The supply pipe 43 is connected to the nozzle 20 to transport the processing liquid between the processing liquid adjustment unit 41 and the nozzle 20. The supply pump 45 and supply valve 47 are installed in the supply pipe 43 and are electrically connected to the control unit 80. The supply pump 45 pumps the processing liquid supplied from the processing liquid adjustment unit 41 to the nozzle 20 in response to a command from the control unit 80. The supply valve 47 opens and closes the supply pipe 43 in response to a command from the control unit 80, starting or stopping the flow of processing liquid from the processing liquid adjustment unit 41 to the nozzle 20. The supply valve 47 is, for example, an electromagnetic valve.

[0046] The processing liquid supply unit 40 may also supply the processing liquid to the nozzle 20 by gravity drain (natural fall). In this case, for example, the washing water tank 411 and the multiple chemical tanks 413 are placed at a higher position than the processing tank 10. In this configuration, the supply pump 45 may not be necessary.

[0047] When the processing liquid supply unit 40 supplies processing liquid to the nozzle 20, the multiple discharge ports of the nozzle 20 eject the processing liquid radially. As a result, the processing liquid is sprayed onto the numerous objects 9 contained in the basket 30.

[0048] The processing liquid discharge unit 50 discharges the processing liquid from the processing tank body 11. The processing liquid discharge unit 50 includes a discharge pipe 51, a discharge pump 53, a recovery unit 55, and a recovery valve 57. The discharge pipe 51 is connected to the discharge port provided in the processing tank body 11 and the recovery unit 55 via a flow path. The discharge pump 53 is provided in the discharge pipe 51. The discharge pump 53 is electrically connected to the control unit 80 and, in response to a command from the control unit 80, sucks the processing liquid from the processing tank body 11 and pumps it through the recovery pipe 51.

[0049] The recovery unit 55 is a device for recovering the treatment liquid discharged from the treatment tank 10, and includes, for example, a tank for storing the treatment liquid. The recovery valve 57 is installed in the discharge pipe 51. The recovery valve 57 is located between the discharge pump 53 and the recovery unit 55. The recovery valve 57 is electrically connected to the control unit 80 and opens and closes the discharge pipe 51 in response to commands from the control unit 80, thereby starting or stopping the flow of treatment liquid from the treatment tank 10 to the recovery unit 55. The recovery valve 57 is, for example, an electromagnetic valve.

[0050] The circulation piping system 60 includes a circulation pipe 61, a circulation valve 63, and a circulation pump 64. The circulation pipe 61 connects the intermediate section of the supply pipe 43 to the intermediate section of the discharge pipe 51. More specifically, one end of the circulation pipe 61 is flow-connected to the section of the discharge pipe 51 between the discharge pump 53 and the recovery valve 57. The other end of the circulation pipe 61 is flow-connected to the section of the supply pipe 43 between the supply valve 47 and the nozzle 20. The circulation pipe 61 forms a circulation path for circulating the treatment liquid in the treatment tank 10. The circulation valve 63 is provided on the circulation pipe 61 and is electrically connected to the control unit 80. The circulation valve 63 opens and closes the circulation pipe 61 in response to commands from the control unit 80, and starts or stops the flow of treatment liquid in the circulation pipe 61. The circulation valve 63 is, for example, a solenoid valve. The circulation pump 64 is provided on the circulation pipe 61 and is electrically connected to the control unit 80. The circulation pump 64, in response to a command from the control unit 80, pumps the processed liquid discharged from the processing tank 10 to the discharge pipe 51 through the circulation pipe 61 to the nozzle 20.

[0051] The metal elution apparatus 1 further comprises a heating unit 65. The heating unit 65 is provided in the circulation pipe 61. The heating unit 65 is electrically connected to the control unit 80. The heating unit 65 comprises a temperature sensor and a heater (heat source). Based on the signal from the temperature sensor, the control unit 80 adjusts the output of the heater to heat the temperature of the processing liquid flowing through the circulation pipe 61 to a target temperature. The heating unit 65 may also be provided to heat the processing liquid at a location other than the circulation pipe 61 (for example, the processing liquid in the processing tank 10, the supply pipe 43, or the discharge pipe 51).

[0052] The control unit 80 is composed of a computer, for example, a processor 81 and a memory 83. The processor 81 includes a CPU (Central Processing Unit), etc. The memory 83 is specifically a semiconductor memory such as RAM (Random-Access Memory) or flash memory, or an auxiliary storage device such as a hard disk drive. The memory 83 stores a computer program P. The processor 81 reads and executes the computer program P stored in the memory 83. Through this execution, the control unit 80 controls each component of the metal elution device 1, thereby executing the elution process in the metal elution device 1 according to a predetermined procedure.

[0053] <Elution Treatment Method> Figure 4 is a flowchart showing the procedure for the elution process performed in the metal elution apparatus 1 shown in Figure 1. Unless otherwise specified, the procedure described below is performed under the control of the control unit 80. First, the material to be treated 9 is placed in a basket 30 located outside the treatment tank 10 (step S1; see Figure 2). The material to be treated 9 may be placed in by a person or by a device not shown. Next, the basket 30 is stored inside the treatment tank body 11 by the basket moving unit 37 (step S2).

[0054] After the basket 30 is stored in the processing tank body 11, the processing tank 10 is closed (step S3). More specifically, as shown in Figure 3, the lid 13 is attached to the processing tank body 11 and the nozzle 20 is set. The nozzle 20 is inserted into the hole in the inner part 33 of the basket 30 stored in the processing tank body 11 and positioned inside the inner part 33 (see Figure 1). That is, the nozzle 20 is surrounded by the inner part 33.

[0055] After step S3, unwanted metals are eluted using the primary treatment solution (step S4). Specifically, the primary treatment solution is sprayed onto the object to be treated 9. That is, the primary treatment solution is supplied from the treatment solution supply unit 40 to the nozzle 20, and the nozzle 20 discharges the primary treatment solution into the inner part 33 of the basket 30. In other words, the nozzle 20 discharges the primary treatment solution toward the object to be treated 9.

[0056] In step S4, the nozzle movement unit 23 causes the nozzle 20 to move up and down. As a result, the nozzle 20, which moves vertically relative to the object to be treated 9, sprays the primary treatment liquid towards the object to be treated 9.

[0057] In step S4, the primary treatment liquid is circulated. That is, after a predetermined amount of primary treatment liquid is supplied from the treatment liquid supply unit 40 to the treatment tank 10, the supply valve 47 is closed and the circulation valve 63 is opened. Then, driven by the discharge pump 53, the primary treatment liquid in the treatment tank 10 is pumped through the discharge pipe 51 and the circulation pipe 61 to the nozzle 20 and sprayed again from the nozzle 20. In step S4, the heating unit 65 may heat the primary treatment liquid to a predetermined temperature in order to increase the efficiency of dissolution of unwanted metals.

[0058] After the primary treatment liquid is sprayed for a predetermined time according to step S4, the primary treatment liquid is discharged from the treatment tank 10 (step S5). Specifically, the circulation valve 63 is closed and the recovery valve 57 is opened. Then, the discharge pump 53 sends the primary treatment liquid in the treatment tank 10 to the recovery unit 55 via the discharge pipe 51. The primary treatment liquid sent to the recovery unit 55 is disposed of after being appropriately treated, for example. Unwanted metals can be removed by pre-dissolving them from the object to be treated 9 using the primary treatment liquid.

[0059] Once the primary treatment liquid has been discharged, the object to be treated 9 is washed using the washing water (step S6). Specifically, the treatment liquid supply unit 40 supplies washing water to the nozzle 20, and the nozzle 20 discharges the washing water toward the object to be treated 9. In step S6, the nozzle 20 may move up and down, as in step S4. The washing water may also be circulated. After washing is performed for a predetermined time, the washing water is discharged from the treatment tank 10. Specifically, as in step S5, the recovery valve 57 is opened, and the washing water in the treatment tank 10 is sent to the recovery unit 55 via the discharge pipe 51 by the discharge pump 53. The washing water sent to the recovery unit 55 is disposed of after being appropriately treated, for example.

[0060] Once the washing water has been drained, the target metal is eluted using a secondary treatment solution (step S7). Specifically, the secondary treatment solution is sprayed onto the object to be treated 9. That is, the secondary treatment solution is supplied from the treatment solution supply unit 40 to the nozzle 20, and the nozzle 20 discharges the secondary treatment solution into the inner part 33 of the basket 30. In other words, the nozzle 20 discharges the secondary treatment solution toward the object to be treated 9.

[0061] In step S7, the nozzle movement unit 23 causes the nozzle 20 to move up and down. As a result, the secondary treatment liquid is sprayed from the nozzle 20, which is moving up and down, toward the object to be treated 9.

[0062] In step S7, the secondary treatment liquid is circulated. That is, after a predetermined amount of secondary treatment liquid is supplied from the treatment liquid supply unit 40 to the treatment tank 10, the supply valve 47 is closed and the circulation valve 63 is opened. Then, driven by the discharge pump 53, the secondary treatment liquid in the treatment tank 10 is pumped to the nozzle 20 via the discharge pipe 51 and the circulation pipe 61, and is sprayed again from the nozzle 20. In step S7, the heating unit 65 may heat the secondary treatment liquid to a predetermined temperature in order to increase the elution efficiency of the target metal.

[0063] After the secondary treatment liquid is sprayed in step S7 for a predetermined time, the secondary treatment liquid is recovered from the treatment tank 10 (step S8). Specifically, the circulation valve 63 is closed and the recovery valve 57 is opened. Then, the discharge pump 53 sends the secondary treatment liquid in the treatment tank 10 to the recovery unit 55 via the discharge pipe 51. The secondary treatment liquid sent to the recovery unit 55 is processed, for example, to recover the target metal.

[0064] Once the secondary treatment liquid has been discharged, the object to be treated 9 is washed with washing water (step S9). Step S9 is the same as step S6, so its explanation is omitted. This washing removes the secondary treatment liquid that had adhered to the basket 30 and the object to be treated 9, making it possible to handle the basket 30 and the object to be treated 9 safely.

[0065] After the washing water is discharged, the lid 13 is removed from the main body 11 of the treatment tank, and the treatment tank 10 is opened (step S10). With the removal of the lid 13, the nozzle 20 is released from the treatment tank 10. Then, the basket 30 is removed from the treatment tank 10 by the basket moving unit 37. With this, the target metal elution process in the metal elution device 1 is completed.

[0066] In steps S4, S6, S7, and S9, the oscillating unit 17 may oscillate the basket 30. This allows the object to be processed 9 to oscillate, thereby increasing the elution efficiency. However, oscillation may cause fragments to be generated from the object to be processed 9. From the viewpoint of preventing this, for example, in step S7 where the target metal is eluted, it may be preferable not to oscillate the object to be processed 9.

[0067] As described above, the metal elution apparatus 1 of this embodiment is an apparatus for eluting a target metal from a workpiece 9, and comprises a processing tank 10, a nozzle 20, a nozzle moving unit 23 (relative moving unit), and a circulation piping system 60. The processing tank 10 houses the workpiece 9. The nozzle 20 discharges processing liquid toward the workpiece 9 stored in the processing tank 10. The nozzle moving unit 23 moves the nozzle 20 relative to the workpiece 9 stored in the processing tank 10. The circulation piping system 60 returns the processing liquid discharged from the processing tank 10 to the nozzle 20.

[0068] Furthermore, the metal elution method for eluting a target metal from the object to be treated 9 in this embodiment includes the steps of: placing the object to be treated 9 in the treatment tank 10 (steps S1, S2); discharging a treatment liquid from the nozzle 20 toward the object to be treated 9 stored in the treatment tank 10 (step S7); moving the nozzle 20 relative to the object to be treated 9 stored in the treatment tank 10 (step S7); and returning the treatment liquid discharged from the treatment tank 10 to the nozzle 20 (step S7).

[0069] According to the above configuration, by discharging the processing liquid from the nozzle 20 and moving the nozzle 20 relative to the object to be processed 9, the object to be processed 9 can efficiently come into contact with the processing liquid. This increases the efficiency of metal dissolution and reduces the amount of processing liquid used. Furthermore, by circulating the processing liquid, the amount of processing liquid used can be reduced even further. By reducing the amount of processing liquid used, the cost and environmental impact associated with the dissolution of the target metal can be reduced.

[0070] The metal elution apparatus 1 has at least one mesh basket 30 that can accommodate the object to be treated 9 and is stored in the treatment tank 10. With this configuration, by storing the object to be treated 9 in the basket 30, the object to be treated 9 can be easily put in and taken out of the treatment tank 10. In addition, by discharging the treatment liquid into the basket 30 containing the object to be treated 9, the object to be treated 9 can be brought into contact with the treatment liquid. Therefore, the target metal can be eluted efficiently. Furthermore, after the target metal has been eluted, the treatment liquid and the object to be treated 9 can be easily separated.

[0071] The metal elution device 1 further includes a basket moving unit 37 for moving the basket 30 in and out of the processing tank 10. With this configuration, the use of the basket moving unit 37 can reduce the physical burden on the worker. In addition, it can reduce the risk of the basket 30 falling, thereby improving safety.

[0072] The basket 30 has an annular bottom portion 31 and an inner portion 33 that rises from the bottom portion 31. The nozzle 20 discharges the processing liquid into the inner portion 33 from inside the inner portion 33 of the basket 30. With this configuration, the object to be processed 9 inside the basket 30 can efficiently come into contact with the processing liquid, thereby increasing the elution efficiency.

[0073] The metal elution device 1 further includes a heating unit 65 for heating the processing solution. This configuration makes it possible to increase the efficiency of metal elution.

[0074] The metal elution apparatus 1 further includes a processing liquid supply unit 40 capable of selectively supplying multiple types of processing liquids to the nozzle 20. This configuration allows for the miniaturization and simplification of the apparatus because multiple processing liquids are handled by a single nozzle 20. Furthermore, reducing the number of nozzles lowers the manufacturing and maintenance costs of the apparatus.

[0075] The multiple types of treatment solutions include chemical solutions and washing water. With this configuration, the chemical solution can dissolve the metal from the object to be treated 9, and the washing water can wash the object to be treated 9.

[0076] Multiple types of treatment solutions contain different types of chemicals. This configuration allows for the selection or combination of the most suitable chemicals depending on the target metal, thereby enabling proper elution of the target metal.

[0077] The metal elution apparatus 1 further includes a recovery unit 55 for recovering the treatment liquid from which the metal has been eluted. With this configuration, the eluted metal can be recovered. <2. Second Embodiment> Next, a second embodiment will be described. In the following description, elements having the same function as those already described will be given the same reference numeral or a reference numeral with an additional alphabetic character, and detailed descriptions may be omitted.

[0078] Figure 5 is a schematic perspective view showing a part of the metal elution apparatus 1a according to the second embodiment. As shown in Figure 5, the processing tank 10a of the metal elution apparatus 1a has a rectangular parallelepiped processing tank body 11a. The processing tank body 11a is a bottomed rectangular tube with a rectangular opening at the top.

[0079] Furthermore, the metal elution device 1a has a pair of mesh baskets 30a and 30b. The baskets 30a and 30b are the same size and shape. Specifically, the baskets 30a and 30b are bottomed rectangular tubes with a rectangular opening at the top. The pair of baskets 30a and 30b are arranged apart from each other within the processing tank body 11a. Also, in a top view, the long sides of the openings of the pair of baskets 30a and 30b are arranged to face each other.

[0080] The tip of the nozzle 20a of the metal elution device 1a is formed in a thin, flat shape. The tip of the nozzle 20a has a pair of nozzle surfaces 21a, each having multiple discharge ports for discharging the processing liquid. The pair of nozzle surfaces 21a are planar. When the lid (not shown) is attached to the processing tank body 11a, the tip of the nozzle 20a is inserted between the baskets 30a and 30b inside the processing tank body 11a. Once the lid is attached, the tip of the nozzle 20a is sandwiched between the pair of baskets 30a and 30b. That is, one of the pair of nozzle surfaces 21a faces the side of basket 30a, and the other faces the side of basket 30b. In the metal elution device 1a, the processing liquid is discharged from the pair of nozzle surfaces 21a of the nozzle 20a towards the baskets 30a and 30b, respectively. As a result, the processing liquid is discharged towards the objects to be processed 9 contained in each of the baskets 30a and 30b.

[0081] In other words, at least one basket includes basket 30a (first basket) and basket 30b (second basket), and nozzle 20a is positioned between basket 30a and basket 30b and discharges the processing liquid toward basket 30a and basket 30b.

[0082] According to the metal elution apparatus 1a of this embodiment, by making the processing tank 10a rectangular parallelepiped, the dead space in the space where the processing tank 10a is arranged can be reduced. Furthermore, by making the basket 30a rectangular parallelepiped, the dead space within the processing tank 10a can be reduced. In addition, by making the nozzle 20a a thin flat plate, the dead space within the processing tank 10a can be reduced.

[0083] Furthermore, the material to be processed 9 is divided into multiple baskets 30a and 30b, each stored in the processing tank 10a. This reduces the amount of material to be processed 9 that can be contained in baskets 30a and 30b, making it easier to store and remove baskets 30a and 30b from the processing tank 10a compared to using only one basket. In addition, dispersing the material to be processed 9 in baskets 30a and 30b makes it easier for the material to come into contact with the processing liquid, thereby increasing the efficiency of metal elution.

[0084] <3. Third Embodiment> Figure 6 is a schematic perspective view showing a part of the metal elution apparatus 1b according to the third embodiment. In the metal elution apparatus 1b, the axis of the processing tank 10 is tilted horizontally. In addition, a basket lid 39 is attached to the opening of the basket 30 to prevent the object to be processed 9 stored in the basket 30 from falling out.

[0085] In the metal elution apparatus 1b, for example, a rocking part 17 (not shown) that rotates the basket 30 around a horizontal axis x within the processing tank 10 may be provided. In this case, the processing liquid can be efficiently stirred, thereby improving the elution efficiency.

[0086] <5. Variant> Although embodiments have been described above, the present invention is not limited to those described above, and various modifications are possible.

[0087] For example, the metal dissolution device 1 includes a nozzle moving part 23 and a swinging part 17 as relative moving parts, but one of them may be omitted.

[0088] The metal elution device may have three or more baskets. However, baskets are not mandatory and may be omitted.

[0089] The metal elution device may have multiple nozzles. For example, the processing liquid may be discharged from multiple nozzles to a single basket. Alternatively, nozzles may be provided in a one-to-one correspondence between multiple baskets.

[0090] It is not essential that the nozzle be integrated with the lid; it may be provided separately from the lid.

[0091] The relative movement of the nozzle to the object being processed, the opening and closing of the lid, or the movement of the basket may be performed manually rather than automatically.

[0092] The metal elution apparatus may be equipped with multiple treatment tanks. In this case, the treatment solution may be supplied to multiple treatment tanks simultaneously, and the elution process may be performed in each treatment tank.

[0093] The objects to be processed are not limited to e-waste, but may be other objects. For example, the objects to be processed may be fuel cell stacks, catalysts for purifying exhaust gases in automobiles, jewelry, etc. For example, the catalyst-coated membrane (CCM) that makes up a fuel cell may contain platinum (Pt) or iridium (Ir) as a catalyst.

[0094] In the above embodiment, the nozzles 20 and 20a discharge the processing liquid laterally, spraying it laterally toward the basket 20. However, the nozzles may be configured to supply the cleaning liquid from diagonally above. In this case, the nozzles may be positioned higher than the basket. In this configuration, a shower nozzle may be used as the nozzle, which sprays the processing liquid so that it spreads radially from the center outwards at a predetermined angle (for example, within the range of 30 to 90 degrees).

[0095] Alternatively, a rotating spray ball may be used as the nozzle. The rotating spray ball has multiple nozzle holes arranged in the head, and the head rotates automatically due to the reaction force of the liquid spray. Furthermore, a ring-shaped nozzle may be used as the nozzle, having a fixed pipe arranged in a ring and multiple holes arranged at predetermined intervals in the fixed pipe.

[0096] <Example of experiment> Figure 7 is a graph showing the results of copper concentration measurements in the treatment solution under different elution conditions. In Figure 7, the horizontal axis represents elution time (h), and the vertical axis represents the copper concentration in the treatment solution (ppm). The material used for treatment was crushed electrical and electronic equipment waste (DDR substrate) into 5 mm squares. The material was treated with a primary eluate (ferric chloride (III) and hydrochloric acid 6M (volume ratio 0.92:0.08), 60°C) for 24 hours, and the copper concentration in the eluate was measured at predetermined elution intervals. The pulp concentration was 1:3, specifically 150 mL of eluate was used per 50 g of substrate.

[0097] In Figure 7, curve C1 shows the measurement results for liquid injection method A, where the eluate is supplied from a fixed nozzle 20. Curve C2 shows the measurement results for liquid injection method B, where the eluate is supplied from a fixed shower nozzle instead of the nozzle 20. Curve C3 shows the measurement results for the upper stirring method, where the eluate is supplied from a nozzle 20 that moves up and down relative to the object to be treated. Curve C4 shows the measurement results for the bubbling method, where the treatment liquid is immersed in the eluate and stirred by supplying bubbles from below. Curve C5 shows the measurement results for the static method, where the object to be treated is left immersed in the eluate.

[0098] As shown in Figure 7, the top-stirring method (curve C3) results in a high concentration and steep slope of eluted copper. However, this method makes it easy for particles to be released from the substrate due to physical contact, which can cause clogging of the piping. In contrast to the top-stirring method, the valve ring method (curve C4) and the static method (curve C5) involve less physical contact, resulting in less particle release. However, the magnitude and slope of the eluted copper concentration are relatively small. Compared to these methods, the liquid injection methods A and B (curves C1 and C2) show a higher concentration and steeper slope of eluted copper compared to the bubbling method (curve C4) and the static method (curve C5). This indicates that using an injection nozzle allows for high elution efficiency and enables less liquid than other methods. By sufficiently eluting base metal copper in the primary elution using liquid injection methods A and B, the recovery efficiency of precious metals such as gold (Au) in the secondary elution can be increased.

[0099] Although this invention has been described in detail, the above description is illustrative in all respects, and the invention is not limited thereto. It is understood that countless variations not illustrated can be conceived without falling outside the scope of this invention. The components described in each of the above embodiments and variations can be combined or omitted as appropriate, as long as they do not contradict each other. [Explanation of symbols]

[0100] 1,1a,1b: Metal elution device 9: Items to be processed 10,10a: Processing tank 17: Oscillating part (relative movement part) 20,20a: Nozzle 23: Nozzle movement section (relative movement section) 30: Basketball 30a: 1st Basket 30b: Second Basket 31: Bottom 33: Inner part 37: Basket movement unit 40: Processing liquid supply unit 55: Recovery Department 60: Circulation piping system 65: Heating part

Claims

1. A metal elution device that elutes a target metal from a material to be processed, A processing tank for storing the material to be processed, A nozzle that discharges a processing liquid toward the object to be processed, which is stored in the processing tank, A relative movement unit that moves the nozzle relative to the object to be processed stored in the processing tank, A circulation piping system that returns the treated liquid discharged from the treatment tank to the nozzle, A metal elution device equipped with the following features.

2. A metal elution apparatus according to claim 1, At least one mesh basket capable of containing the object to be processed and stored inside the processing tank, A metal elution device that also includes additional features.

3. A metal elution apparatus according to claim 2, A basket moving unit for inserting and removing the basket into the processing tank, A metal elution device that also includes additional features.

4. A metal elution apparatus according to claim 2, The basket has an annular bottom and an inner part that rises from the bottom, The nozzle is a metal dissolution device that discharges the processing liquid from the inside of the basket into the inside of the basket.

5. A metal elution apparatus according to claim 2 or claim 3, The aforementioned at least one basket includes a first basket and a second basket, The nozzle is positioned between the first basket and the second basket and discharges a processing liquid toward the first basket and the second basket in the metal elution device.

6. A metal elution apparatus according to claim 1 or claim 2, A heating unit for heating the aforementioned processing liquid, A metal elution device that also includes additional features.

7. A metal elution apparatus according to claim 1 or claim 2, A processing liquid supply unit capable of selectively supplying multiple types of processing liquids to the nozzle, A metal elution device that also includes additional features.

8. A metal elution apparatus according to claim 7, The aforementioned multiple types of processing solutions include chemical solutions and washing water, and the device is a metal elution apparatus.

9. A metal elution apparatus according to claim 7, The aforementioned multiple types of processing solutions include different types of chemical solutions in the metal elution apparatus.

10. A metal elution apparatus according to claim 1 or claim 2, A recovery unit for recovering the treatment liquid from which the metal has been leached, A metal elution device that also includes additional features.

11. A method for eluting metals, a) A step of storing the material to be processed in a processing tank, b) A step of discharging a processing liquid from a nozzle toward the object to be processed stored in the processing tank, c) A step of moving the nozzle relative to the object to be processed stored in the processing tank, d) A step of returning the processing liquid discharged from the processing tank to the nozzle, A method for eluting metals, including the method described above.

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