Metal recovery device

Abstract

The present invention provides a technology capable of automatically recovering a target metal from waste. A metal recovery device (1) is provided with a reactor (20), an extraction liquid supply unit (30), a microorganism supply unit (40), and a microorganism recovery unit (60). The reactor (20) can accommodate waste (9E). The extraction liquid supply unit (30) supplies, to the reactor (20), an extraction liquid for dissolving metals contained in the waste (9E). The microorganism supply unit (40) supplies a microorganism that assimilates the target metal to the extraction liquid in which the target metal has been dissolved. The microorganism recovery unit (60) recovers, from the extraction liquid, the microorganism that has assimilated the target metal.

Description

Metal Recovery Equipment

[0001] The subject matter disclosed herein relates to metal recovery devices.

[0002] Recovering rare and precious metals from waste materials such as electronic equipment (E-waste) has been attracting attention in recent years because it is far more efficient than extracting new metal resources from mines and places less of a burden on the environment.

[0003] For example, Patent Document 1 discloses a method for recovering a target metal from a noble aqueous solution containing the target metal. Specifically, the method includes a dissolution step, which includes dissolving the target metal from a solid source material with a leachate to form a noble aqueous solution containing target metal ions, a biosorption step, which includes contacting microorganisms with the noble aqueous solution so that at least a portion of the target metal is biosorbed by the microorganisms, the microorganisms containing the metal, and the noble aqueous solution becomes a barren solution, a separation step, which includes substantially separating the metal-containing microorganisms from the barren solution, and a recovery step, which includes recovering the target metal from the metal-containing microorganisms.

[0004] Special table 2019-535910 publication

[0005] However, Patent Document 1 does not take into consideration the automation of the recovery of target metals from waste.

[0006] An object of the present invention is to provide a technology that can automatically recover target metals from waste.

[0007] In order to solve the above problem, a first aspect is a metal recovery device that recovers target metals from waste, and includes a reactor that can accommodate waste, an extract liquid supply unit that supplies an extract liquid to the reactor that dissolves metals contained in the waste, a microorganism supply unit that supplies microorganisms or components derived from microorganisms that absorb the target metal to the extract liquid in which the target metal has been dissolved, and a microorganism recovery unit that recovers the microorganisms or components derived from the microorganisms that have absorbed the target metal from the extract liquid.

[0008] The second aspect is a metal recovery device of the first aspect, wherein the extraction liquid supply unit has a first tank for storing a liquid used in a primary extraction liquid that dissolves unwanted metals, a second tank for storing a liquid used in a secondary extraction liquid that dissolves the target metal, and a liquid delivery unit for delivering the liquid from the first tank and the second tank to the reactor.

[0009] A third aspect is the metal recovery device according to the first or second aspect, wherein the extract liquid supply unit has a spray nozzle that sprays the extract liquid.

[0010] A fourth aspect is the metal recovery device according to any one of the first to third aspects, further comprising a stirring mechanism that stirs the extract in the reactor.

[0011] A fifth aspect is the metal recovery device of any one of the first to fourth aspects, further comprising an ultrasonic vibrator disposed within the reactor.

[0012] A sixth aspect is the metal recovery device according to any one of the first to fifth aspects, further comprising a leaching degree detection unit that detects the degree of leaching of metal into the extraction liquid.

[0013] A seventh aspect is a metal recovery device according to any one of the first to sixth aspects, wherein the microorganism recovery section further includes a filter transport mechanism that transports a portion of a long strip filter that adsorbs the microorganisms or components derived from the microorganisms into and out of the reactor.

[0014] An eighth aspect is the metal recovery device according to the seventh aspect, wherein the filter transport mechanism hangs a portion of the filter inside the reactor and immerses the filter in the extraction liquid.

[0015] A ninth aspect is the metal recovery device according to any one of the first to eighth aspects, further comprising a waste recovery unit that recovers waste within the reactor.

[0016] A tenth aspect is the metal recovery device of the ninth aspect, wherein the waste recovery unit further includes a mesh container capable of containing the waste and having a plurality of holes formed therein for allowing liquid to pass through, a container moving unit that moves the mesh container between a position within the reactor and a position outside the reactor, and a waste storage unit that stores the waste discharged from the mesh container outside the reactor.

[0017] An eleventh aspect is the metal recovery device according to any one of the first to tenth aspects, further comprising an apparatus housing capable of accommodating the reactor, the extract supply unit, the microorganism supply unit, and the microorganism recovery unit.

[0018] According to the metal recovery devices of the first to eleventh aspects, recovery of the target metal can be automated.

[0019] According to the metal recovery device of the third aspect, the extraction liquid can be sprayed from the spray nozzle, thereby supplying the extraction liquid to the entire waste within the reactor, thereby improving the efficiency of metal extraction.

[0020] According to the metal recovery device of the fourth aspect, the efficiency of metal extraction can be improved.

[0021] According to the metal recovery device of the fifth aspect, the permeability of the extracting liquid into the waste can be improved.

[0022] According to the metal recovery device of the sixth aspect, the degree of metal leaching can be detected, thereby making it possible to properly grasp the state of metal extraction.

[0023] FIG. 1 is a perspective view showing the appearance of a metal recovery device according to an embodiment. FIG. 2 is a perspective view showing the internal configuration of the metal recovery device shown in FIG. 1. FIG. 3 is a perspective view showing the internal configuration of the metal recovery device shown in FIG. 2 with some of the internal configuration omitted. FIG. 4 is a diagram showing an example of the configuration of an extract liquid supply unit. FIG. 5 is a flowchart showing the flow of metal recovery processing in the metal recovery device. FIG. 6 is a diagram showing the flow of introducing waste into the metal recovery device. FIG. 7 is a diagram showing the state in which the reactor is closed. FIG. 8 is a diagram showing the flow of discharging waste from the reactor. FIG. 9 is a diagram showing the flow of recovering microorganisms.

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the components described in this embodiment are merely examples and are not intended to limit the scope of the present invention to those components. In the drawings, the dimensions and numbers of each part may be exaggerated or simplified as necessary to facilitate understanding. Furthermore, in the drawings, elements may be shown transparent or simplified to facilitate understanding of the description.

[0025] 1. Embodiment Fig. 1 is a perspective view showing the appearance of a metal recovery device 1 according to an embodiment. Fig. 2 is a perspective view showing the internal configuration of the metal recovery device 1 shown in Fig. 1. Fig. 3 is a perspective view showing the internal configuration of the metal recovery device 1 shown in Fig. 2 with some of the internal configuration omitted.

[0026] The metal recovery device 1 is an apparatus for extracting target metals from electronic waste (E-waste) 9E (hereinafter simply referred to as "waste") using an extraction solution that dissolves metals. The materials to be processed by the metal recovery device 1 are not limited to E-waste. For example, hydrogen fuel cell systems and their component electrodes (such as hydrogen generation electrodes or fuel ionization electrodes), as well as electrode materials (catalytic materials) used in the electrodes, may also be processed. Furthermore, electrode ink waste, precious metal functional materials, and semiconductor effluent may also be processed. The materials to be processed may take a wide variety of forms, including solid materials such as plate materials, particulate matter, liquids (including effluents), and metallic materials. Specifically, the target metal is a rare metal or a precious metal. Rare metals include indium, gallium, chromium, germanium, cobalt, zirconium, strontium, cesium, cerium, tungsten, tantalum, titanium, niobium, nickel, vanadium, palladium, platinum, manganese, rhodium, ruthenium, and osmium. Precious metals include gold, silver, platinum, and iridium. In the following explanation, we will mainly focus on recovering gold, a precious metal, as the target metal.

[0027] The metal recovery device 1 includes a device housing 2, a waste input unit 10, a reactor 20, an extract supply unit 30, a microorganism supply unit 40, a waste recovery unit 50, a microorganism recovery unit 60, and a control unit 70. The waste input unit 10, the reactor 20, the extract supply unit 30, the microorganism supply unit 40, the waste recovery unit 50, and the microorganism recovery unit 60 are housed within the device housing 2. The device housing 2 includes an opening 2a through which a user inputs waste 9E and a shutter 2b that opens and closes the opening 2a. The opening 2a is provided so that a user U can input waste 9E into the device housing 2. It is preferable that the waste 9E input into the metal recovery device 1 be crushed to a predetermined size (e.g., a diameter of approximately 5 mm) in advance.

[0028] The waste input unit 10 has a detection unit that detects the amount of waste 9E input through the opening 2a. The detection unit has, for example, a weight sensor that measures the weight of the waste 9E. The detection unit transmits the detected amount of waste 9E to the control unit 70. The waste input unit 10 also has a carry-in unit that carries the waste 9E into the reactor 20. The carry-in unit is controlled by the control unit 70.

[0029] The reactor 20 is capable of accommodating the waste 9E and storing various extracts. The reactor 20 has a main container 21 and a lid 23. The main container 21 is cylindrical with a bottom and has an opening at the top. The lid 23 is attached to the top of the main container 21 to close the opening of the main container 21. The lid 23 is movable by a movement mechanism (not shown) between a closed position where the opening of the main container 21 is closed and an open position where the opening at the top of the main container 21 is open.

[0030] The reactor 20 further includes an ultrasonic vibrator 25. The ultrasonic vibrator 25 generates ultrasonic waves within the main container 21. By generating ultrasonic waves, it is possible to increase the permeability of the extractant into the waste 9E. The ultrasonic vibrator 25 can be placed anywhere, such as on the inner bottom or inner side of the main container 21. The ultrasonic vibrator 25 is controlled by the control unit 70.

[0031] An agitation mechanism is provided within the reactor 20. The agitation mechanism is a mechanism for agitating the extract within the reactor 20. The agitation mechanism is, for example, a mechanism equipped with blade-like agitation blades attached to a rotating shaft. The agitation mechanism may be a mechanism for shaking, rotating, or vibrating the reactor 20 itself. The agitation mechanism may also be a magnetic stirrer that uses magnetic force to rotate a stir bar disposed within the reactor 20. The agitation mechanism is controlled by the control unit 70.

[0032] A heater for heating the extract stored inside and a detection sensor (such as a level sensor) for detecting the amount of extract stored inside are also appropriately arranged inside the reactor 20. The heater and the detection sensor are connected to the control unit 70.

[0033] The extracting liquid supplying unit 30 supplies an extracting liquid that dissolves metals contained in the waste 9E to the reactor 20. The extracting liquid supplying unit 30 has a plurality of first tanks 31, a plurality of second tanks 32, a waste liquid tank 33, and a liquid sending unit 34.

[0034] The first tank 31 is a container for storing the primary extraction liquid to be supplied to the reactor 20. The primary extraction liquid is a chemical liquid capable of dissolving unwanted metals (e.g., base metals) different from the target metal. Examples of the primary extraction liquid include dilute nitric acid and a ferric chloride aqueous solution. The second tank 32 is a container for storing the secondary extraction liquid to be supplied to the reactor 20. The secondary extraction liquid is a chemical liquid capable of dissolving the target metal. Examples of the secondary extraction liquid include 50% to 100% aqua regia, an ammonium thiosulfate aqueous solution (pH 9 to 11), and an iodine aqueous solution. Note that the primary tank or the secondary tank may store a liquid that is the source of the primary extraction liquid or the secondary extraction liquid, and the liquids may be mixed to produce the final primary extraction liquid or the secondary extraction liquid supplied to the reactor 20.

[0035] The waste liquid tank 33 is a container for storing waste liquid that is no longer needed after being used in the reactor 20. The liquid delivery unit 34 delivers the extract from the plurality of first tanks 31 and the plurality of second tanks 32 to the reactor 20. The liquid delivery unit 34 also delivers the extract used in the reactor 20 to the waste liquid tank 33.

[0036] Fig. 4 is a diagram showing an example of the configuration of the extract liquid supply unit 30. In the example shown in Fig. 4, the extract liquid supply unit 30 has a first tank 31a storing pure water and a first tank 31b storing an aqueous solution of ferric chloride. The extract liquid supply unit 30 also has a first tank 31c storing an unused aqueous solution of ferric chloride. The extract liquid supply unit 30 further has a second tank 32a storing hydrochloric acid and a second tank 32b storing nitric acid. The liquid delivery unit 34 has multiple pipes, pumps that deliver the liquid in each pipe in a predetermined direction, and on-off valves. Each pump and each on-off valve is controlled by the control unit 70.

[0037] A flow meter for measuring the flow rate and a pressure gauge for detecting abnormalities may be installed in-line in each pipe of the liquid delivery section 34. In addition, each pipe may be provided with an in-line heater such as an in-line rubber heater to prevent a temperature drop during delivery.

[0038] The extract supply unit 30 has a circulation pipe 341 for circulating the liquid in the reactor 20. A circulation pump 351 is provided in the circulation pipe 341. By driving the circulation pump 351, the liquid in the reactor 20 passes through the circulation pipe 341 and is returned to the reactor 20. A filtration filter 361 that filters the liquid passing through the circulation pipe 341 is provided in the circulation pipe 341. Note that by having the circulation pump 351 send the liquid in the reverse direction, it is also possible to remove foreign matter adhering to the filtration filter 361 from the filtration filter 361.

[0039] The first tank 31a is connected to the reactor 20 via a pipe 311. The pure water in the first tank 31a is supplied to the reactor 20 through the pipe 311. The first tank 31b is connected to the reactor 20 via a pipe 312. The aqueous ferric chloride solution in the first tank 31b is supplied to the reactor 20 through the pipe 312. The first tank 31c is connected to the first tank 31b via a pipe 313. The aqueous ferric chloride solution in the first tank 31c is supplied to the first tank 31b through the pipe 313.

[0040] The second tank 32a is connected to the reactor 20 via a pipe 321. The hydrochloric acid in the second tank 32b is supplied to the reactor 20 through the pipe 321. The second tank 32b is connected to the reactor 20 via a pipe 322. The nitric acid in the second tank 32b is supplied to the reactor 20 through the pipe 322.

[0041] The ends of the pipes 311, 312, 321, and 322 on the reactor 20 side are connected to a spray nozzle 363. The spray nozzle 363 sprays the extraction liquid in multiple directions (for example, in directions with a diffusion angle of 120° to 160°). By spraying the extraction liquid into the reactor 20 using the spray nozzle 363, the extraction liquid is supplied to all of the waste 9E in the reactor 20, thereby improving the efficiency of metal extraction. Note that multiple pipes may be connected to one spray nozzle 363, or a different spray nozzle 363 may be connected to each pipe. Note that instead of the spray nozzle 363, a nozzle that discharges in only one direction may be used.

[0042] The waste liquid tank 33 is connected to a circulation pipe 341 via a pipe 331. The used extract in the reactor 20 passes through the circulation pipe 341 and the pipe 331 and is discharged into the waste liquid tank 33.

[0043] The first tank 31b is connected to the circulation pipe 341 via pipe 314. In the metal recovery apparatus 1, the ferric chloride aqueous solution can be reused multiple times. For this reason, the ferric chloride aqueous solution used in the reactor 20 passes through the circulation pipe 341 and pipe 314 and is returned to the first tank 31b. The first tank 31b is also connected to the waste liquid tank 33 via pipe 315. The ferric chloride aqueous solution that is no longer needed in the first tank 31b is discharged into the waste liquid tank 33 via pipe 315. After the ferric chloride aqueous solution that is no longer needed in the first tank 31b is discharged, unused ferric chloride aqueous solution is supplied to the first tank 31b from the first tank 31c.

[0044] The extract supply unit 30 includes a leaching degree detection unit 37 for simulating the leaching degree of the target metal. The leaching degree detection unit 37 includes a measurement container 371 for storing the extract containing the dissolved metal, and a transmittance measurement device 372 for measuring the light transmittance of the extract in the measurement container 371. The measurement container 371 is connected to a pipe 373 for sending the extract from the circulation pipe 341 to the measurement container 371, and a pipe 374 for returning the extract from the measurement container 371 to the circulation pipe 341.

[0045] As the dissolution of metals by the extractant progresses in the reactor 20, the light transmittance of the extractant changes. Therefore, by measuring the transmittance using the transmittance meter 372, the degree of metal leaching (metal concentration) can be simulated. In this way, by simulatedly detecting the degree of leaching using the leaching degree detection unit 37, the state of metal extraction in the reactor 20 can be properly grasped. The measured values ​​measured by the transmittance meter 372 are transmitted to the control unit 70 as appropriate.

[0046] The microorganism supply unit 40 introduces microorganisms capable of absorbing target metals into the reactor 20. The microorganism supply unit 40 introduces dry microorganism powder into the extract solution in the reactor 20. For example, microorganisms such as yeast, Torula yeast, Cupriavidus metallidurans, Chromobacterium, and Chromobacterium violaceum can be used to adsorb gold. By changing the type of microorganism, it is possible to recover metals other than gold. The microorganisms introduced by the microorganism supply unit 40 may be live or dead. Alternatively, components derived from microorganisms may be introduced instead of the microorganisms themselves. Specifically, powders or extracts obtained by purifying components such as polysaccharides on the surface of microorganisms (e.g., cell walls) can be used. Although microbial components do not function as living microorganisms, they can be effective in adsorbing metals. Alternatively, the microorganism supply unit 40 may introduce microorganisms or liquids containing components derived from microorganisms.

[0047] The microorganism supply unit 40 supplies microorganisms to the reactor 20 in an amount corresponding to (preferably, an amount proportional to) the amount of waste 9E measured by the waste input unit 10. For this reason, the microorganism supply unit 40 may have a sensor (such as a weight sensor) for measuring the amount of microorganisms added. The microorganism supply unit 40 may also have a pouch-type storage unit for storing multiple types of microorganisms without contamination. The storage unit may also have a temperature control unit that maintains the temperature at, for example, 10°C to 30°C to prevent deterioration of the microorganisms.

[0048] The waste recovery unit 50 has a mesh container 51 arranged in the reactor 20, a container transfer unit 53, and a waste storage unit 55. The mesh container 51 has a plurality of holes that allow liquid to pass through. The mesh container 51 is cylindrical with a bottom and has an opening at the top. The waste 9E introduced into the reactor 20 is introduced into the mesh container 51 by the waste introduction unit 10. The holes in the mesh container 51 are smaller than the size of the pulverized waste 9E. With the waste 9E contained in the mesh container 51, the primary extract or secondary extract is introduced into the reactor 20.

[0049] The container moving unit 53 moves the mesh container 51 between a processing position inside the reactor 20 and a discharge position outside the reactor 20. The mesh container 51 is supported in an obliquely tilted position at the discharge position (see FIG. 9(b)). As a result, the waste 9E inside the mesh container 51 is discharged to the outside from the side of the mesh container 51.

[0050] The waste storage unit 55 stores the waste discharged from the mesh container 51. The waste storage unit 55 has an input unit 551. The input unit 551 is arranged adjacent to the rear side of the reactor 20. The input unit 551 has an input port 551a into which the waste 9E discharged from the mesh container 51 is input. Alternatively, the input unit 551 moves up and down between a position above the main container 21 of the reactor 20 and a position below the main container 21. The waste storage unit 55 transports the input waste 9E to the outside, for example, by conveyor transport.

[0051] The microorganism recovery unit 60 is a mechanism for recovering the microorganisms that have absorbed the target metal from the extract. The microorganism recovery unit 60 is disposed at the rear of the reactor 20, opposite the waste input unit 10. The microorganism recovery unit 60 has a supply roller 61, a recovery roller 62, support rollers 63 and 64, and a roller moving unit 65.

[0052] The supply roller 61 supplies a filter 9F capable of adsorbing microorganisms (or components derived from microorganisms). The filter 9F is in the form of a long strip. The filter 9F is, for example, porous, and specifically, is a filter paper or a membrane filter. The supply roller 61 supports and continuously pays out the rolled filter 9F. The recovery roller 62 winds and recovers the filter 9F paid out from the supply roller 61. The recovery roller 62 is located below the supply roller 61. The support rollers 63 and 64 are rollers that support and transport the filter 9F paid out from the supply roller 61. In the transport path of the filter 9F from the supply roller 61 to the recovery roller 62, the support roller 64 is located downstream of the support roller 63.

[0053] The support rollers 63 and 64 are located closer to the reactor 20 than the supply roller 61 and the recovery roller 62. The support roller 63 is disposed closer to the reactor 20 than the support roller 64. The filter 9F unwound from the supply roller 61 is first hung on the support roller 63, then passed between the support rollers 63 and 64 and hung on the support roller 64, and then taken up by the recovery roller 62.

[0054] The roller moving unit 65 includes a support plate that supports the rotation axes of the support rollers 63 and 64, and a rotation drive unit that rotates the support plate integrally around the rotation axis A1. The rotation axis A1 is located between the supply roller 61 and the recovery roller 62 in the vertical direction. The roller moving unit 65 rotates the support rollers 63 and 64 between a retracted position and an adsorption position (see FIGS. 10( a) and 10(b)). The retracted position is the position when the filter 9F is retracted to the outside of the reactor 20. The adsorption position is the position when the filter 9F is supplied into the main vessel 21 of the reactor 20 and adsorbs microorganisms.

[0055] The control unit 70 is a device that controls each part of the metal recovery device 1. As shown in Figure 1, the control unit 70 is configured by a computer having a processor such as a CPU, a memory such as a RAM, and a storage unit such as a hard disk drive. A computer program for executing the printing process is installed in the storage unit.

[0056] The control unit 70 is communicatively connected to each of the driving units such as motors and various sensors possessed by the waste input unit 10, reactor 20, extract supply unit 30, microorganism supply unit 40, waste recovery unit 50, and microorganism recovery unit 60.

[0057] The control unit 70 temporarily reads the computer programs and data stored in the storage unit into memory, and the processor performs arithmetic processing based on the computer programs, thereby operating each unit of the metal recovery device 1. In this way, the metal recovery process in the metal recovery device 1 progresses.

[0058] <Metal Recovery Process> Fig. 5 is a flowchart showing the flow of the metal recovery process in the metal recovery device 1. In the following description, the operation of the metal recovery device 1 is assumed to be performed under the control of the control unit 70 unless otherwise specified.

[0059] First, the user U puts waste 9E into the metal recovery device 1 (step S1). Figures 6 and 7 are diagrams showing the flow of putting waste 9E into the metal recovery device 1. First, as shown in Figure 6(a), the shutter 2b rises to open the opening 2a. Then, as shown in Figure 6(b), the user U puts the pre-crushed waste 9E into the waste input section 10. Once the waste 9E has been put in, the shutter 2b descends to close the opening 2a.

[0060] The shutter 2b is preferably opened and closed while the reactor 20 is closed, thereby reducing the risk of the extract or the like in the reactor 20 being released to the outside through the opening 2a.

[0061] Next, the metal recovery device 1 performs a loading process to load the waste 9E into the reactor 20 (step S2). Specifically, the waste input unit 10 automatically identifies the amount of loaded waste 9E. Specifically, the weight of the waste 9E measured by a weight sensor in the detection unit provided in the waste input unit 10 is acquired as the amount of waste 9E. Thereafter, as shown in FIG. 7( a), the lid 23 of the reactor 20 moves to the open position, thereby opening the reactor 20. Then, the loading unit of the waste input unit 10 moves the platform on which the waste 9E is placed toward the reactor 20, thereby loading the waste 9E into the main container 21. As a result, the waste 9E is contained inside the mesh container 51 arranged in the reactor 20. Thereafter, the lid 23 of the reactor 20 moves to the closed position, thereby closing the reactor 20.

[0062] Returning to Fig. 5, once the loading process of the waste 9E is completed, the primary extraction liquid is supplied to the reactor 20 (step S3). That is, as shown in Fig. 8, with the reactor 20 closed, the liquid delivery unit 34 of the extraction liquid supply unit 30 supplies the primary extraction liquid (or the liquid that is the source of the primary extraction liquid) from the first tank 31 to the reactor 20. At this time, the primary extraction liquid supplied to the reactor 20 is sprayed by the spray nozzle 363, so that the primary extraction liquid is supplied uniformly to the entire waste 9E. This can increase the extraction efficiency of unnecessary metals.

[0063] In step S3, the primary extraction liquid is stored in the reactor 20. This allows the extraction process (primary extraction) of unnecessary metals from the waste 9E using the primary extraction liquid to proceed (step S4).

[0064] In the primary extraction in step S4, the heater, stirring mechanism, etc. are controlled so that the process proceeds under preset conditions (temperature, stirring speed, etc.). Furthermore, while the primary extraction is proceeding, it is determined whether the primary extraction is complete (step S5). Specifically, the primary extraction is determined to be complete when the infusion degree detected by the infusion degree detection unit 37 exceeds a preset value. Alternatively, the primary extraction may be determined to be complete when the processing time for the primary extraction exceeds a preset value.

[0065] If it is determined in step S5 that the primary extraction is complete (YES in step S5), the primary extract liquid is discharged from the reactor 20 (step S6). If the primary extract liquid is reusable, it is sent to the first tank 31 by the liquid sending unit 34 of the extract liquid supply unit 30. On the other hand, if the primary extract liquid is to be discarded, it is sent to the waste liquid tank 33 by the liquid sending unit 34.

[0066] After the primary extraction liquid is discharged, the secondary extraction liquid is supplied to the reactor 20 (step S7). That is, as shown in Fig. 8, with the reactor 20 closed, the liquid delivery unit 34 of the extraction liquid supply unit 30 supplies the secondary extraction liquid (or the liquid that is the source of the secondary extraction liquid) from the second tank 32 to the reactor 20. At this time, the secondary extraction liquid supplied to the reactor 20 is sprayed by the spray nozzle 363, so that the secondary extraction liquid is supplied uniformly to the entire waste 9E. This can increase the extraction efficiency of the target metal.

[0067] In step S7, the secondary extraction liquid is stored in the reactor 20. This allows the extraction process (secondary extraction) of the target metal from the waste 9E using the secondary extraction liquid to proceed (step S8).

[0068] In the secondary extraction of step S8, the heater for heating the secondary extraction liquid and the stirring mechanism are appropriately controlled so that the process proceeds under preset conditions (temperature, stirring speed, etc.). Furthermore, while the secondary extraction is in progress, it is determined whether the secondary extraction is complete (step S9). Specifically, the secondary extraction is determined to be complete when the leaching degree of the target metal detected by the leaching degree detection unit 37 exceeds a preset value. Alternatively, the secondary extraction may be determined to be complete when the processing time for the secondary extraction exceeds a preset value.

[0069] When it is determined in step S9 that the secondary extraction is completed (YES in step S9), the waste 9E is discharged from the reactor 20 (step S10). Figures 9(a) and (b) are diagrams showing the flow of discharging the waste 9E from the reactor 20.

[0070] As shown in FIG. 9( a), first, the lid 23 moves to the upper position, thereby opening the reactor 20. Then, the input section 551 of the waste storage section 55 in the waste collection section 50 rises above the main container 21. Next, as shown in FIG. 9( b), the mesh container 51 in the reactor 20 is raised to the discharge position, and the waste 9E is discharged from the side of the mesh container 51 to the input port 551a of the input section 551. The waste storage section 55 transports the input waste 9E to the rear end of the metal recovery device 1 and discharges it as appropriate. Furthermore, the mesh container 51 of the waste collection section 50 is returned from the discharge position shown in FIG. 9( b) to the processing position shown in FIG. 9( a).

[0071] Returning to FIG. 5 , after the waste 9E is discharged from the reactor 20, the microorganism supply unit 40 adds microorganisms to the extract solution in which the target metal has been dissolved within the reactor 20 (step S11). The microorganism supply unit 40 adds microorganisms in an amount corresponding to the amount of waste 9E measured in the waste 9E loading process (step S2). After the microorganisms are added, the extract solution is stirred by the stirring mechanism of the reactor 20 (step S12). Step S12 uniformly disperses the added microorganisms. Note that the reactor 20 may be closed by moving the lid 23 of the reactor 20 to the closed position before step S12.

[0072] After step S12, it is determined whether the adsorption process using the microorganisms is complete (step S13). Specifically, it is determined that the adsorption process is complete when the elapsed time since the microorganisms were added (or since the stirring in step S12 was started) exceeds a predetermined value.

[0073] If it is determined in step S13 that the adsorption process is complete (YES in step S13), the microorganisms are collected by the microorganism collection unit 60 (step S14). Figures 10(a), (b), and (c) are diagrams showing the flow of microorganism collection. First, as shown in Figure 10(a), the input section 551 of the waste storage section 55 in the waste collection unit 50 is lowered. Next, as shown in Figure 10(b), the roller movement section 65 of the microorganism collection unit 60 rotates and moves the support rollers 63, 64 from the retracted position shown in Figure 10(a) to the adsorption position shown in Figure 10(b). As shown in Figure 10(b), when the support rollers 63, 64 are positioned at the adsorption position, the support rollers 63, 64 are positioned above the main container 21 and below the lid 23. Furthermore, the support rollers 63, 64 are positioned above the downwardly-depressed input section 551.

[0074] Next, as shown in FIG. 10( c), the microorganism collection unit 60 hangs a portion of the filter 9F into the reactor 20, immersing the filter 9F. Specifically, the collection roller 62 does not rotate and does not wind up the filter 9F, and the supply roller 61 rotates to unwind the filter 9F by a predetermined length. As a result, a portion of the filter 9F downstream of the support roller 63 hangs down by a certain length, and a portion of the filter 9F is immersed in the extract in the reactor 20. Over time in this state, microorganisms are adsorbed to a portion of the filter 9F. Alternatively, with a portion of the filter 9F hanging down in the reactor 20, both the supply roller 61 and the collection roller 62 may be rotated to adsorb microorganisms onto a new portion of the filter 9F. Once the adsorption of microorganisms is complete, the supply roller 61 is stopped and the collection roller 62 rotates, thereby winding up the portion of the filter 9F with the adsorbed microorganisms onto the collection roller 62. In this way, the microorganisms that have selectively adsorbed the target metal are recovered, and the metal recovery process in the metal recovery device 1 is completed.

[0075] As shown in Figure 10 (c), the supply roller 61, the recovery roller 62, and the support rollers 63 and 64 function as a filter transport mechanism that transports the long strip filter 9F that adsorbs microorganisms into the reactor 20 and out of the reactor.

[0076] When isolating the target metal from the microorganisms adsorbed to the filter 9F, it is advisable to calcinate the filter 9F. By calcining, the filter 9F is eliminated, and it is possible to easily isolate only the target metal.

[0077] As described above, the metal recovery device 1 according to the embodiment is provided with a configuration for recovering the target metal, and therefore the recovery of the target metal can be automated.

[0078] 2. Modifications Although the embodiments of the present invention have been described above, the present invention is not limited to the above and various modifications are possible.

[0079] For example, in the above embodiment, the primary extraction and the secondary extraction are performed in one reactor 20. However, by providing two or more reactors 20, the primary extraction and the secondary extraction may be performed in different reactors 20.

[0080] Although the present invention has been described in detail, the above description is merely illustrative in all respects and does not limit the present invention. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present invention. The configurations described in the above embodiments and variations can be combined or omitted as appropriate as long as they are not mutually inconsistent.

[0081] REFERENCE SIGNS LIST 1 Metal recovery device 2 Device housing 9E Waste 9F Filter 20 Reactor 21 Main container 23 Lid 25 Ultrasonic vibrator 30 Extraction liquid supply section 31 First tank 32 Second tank 33 Waste liquid tank 34 Liquid delivery section 37 Leaching degree detection section 40 Microorganism supply section 50 Waste recovery section 51 Mesh container 53 Container movement section 55 Waste storage section 60 Microorganism recovery section 61 Supply roller (filter transport mechanism) 62 Recovery roller (filter transport mechanism) 63, 64 Support roller (filter transport mechanism) 65 Roller movement section (filter transport mechanism) 70 Control section 363 Spray nozzle

Claims

1. A metal recovery device for recovering target metals from waste, comprising: a reactor capable of accommodating waste; an extract solution supply unit for supplying an extract solution for dissolving metals contained in the waste to the reactor; a microorganism supply unit for supplying microorganisms or components derived from microorganisms that absorb the target metal to the extract solution in which the target metal has been dissolved; and a microorganism recovery unit for recovering the microorganisms or components derived from the microorganisms that have absorbed the target metal from the extract solution.

2. A metal recovery apparatus as described in claim 1, wherein the extraction liquid supply unit has: a first tank for storing a liquid used in a primary extraction liquid that dissolves unwanted metals; a second tank for storing a liquid used in a secondary extraction liquid that dissolves the target metals; and a liquid delivery unit for delivering the liquids in the first tank and the second tank to the reactor.

3. A metal recovery apparatus according to claim 1 or 2, wherein the extract supply unit has a spray nozzle for spraying the extract.

4. A metal recovery apparatus according to any one of claims 1 to 3, further comprising a stirring mechanism for stirring the extract in the reactor.

5. The metal recovery apparatus according to any one of claims 1 to 4, further comprising an ultrasonic vibrator disposed within the reactor.

6. A metal recovery device according to any one of claims 1 to 5, further comprising a leaching level detection unit that detects the level of metal leaching into the extraction liquid.

7. A metal recovery device according to any one of claims 1 to 6, wherein the microorganism recovery section further comprises a filter transport mechanism that transports a portion of a long strip filter that adsorbs the microorganisms or components derived from the microorganisms into and out of the reactor.

8. A metal recovery apparatus according to claim 7, wherein the filter transport mechanism hangs a portion of the filter inside the reactor, immersing the filter in the extraction liquid.

9. The metal recovery apparatus according to any one of claims 1 to 8, further comprising a waste recovery section that recovers waste from within the reactor.

10. A metal recovery apparatus according to claim 9, wherein the waste recovery unit further comprises: a mesh container capable of containing the waste and having a plurality of holes formed therein for allowing liquid to pass through; a container moving unit that moves the mesh container between a position within the reactor and a position outside the reactor; and a waste storage unit that stores the waste discharged from the mesh container outside the reactor.

11. A metal recovery device according to any one of claims 1 to 10, further comprising an apparatus housing capable of accommodating the reactor, the extract supply unit, the microorganism supply unit, and the microorganism recovery unit.

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