Reaction tank

Abstract

The present invention provides a technique that enables easy recovery of a chemical solution containing a metal eluted from waste in a reaction tank. A reaction tank (1) has a storage container (11) and an uneven distribution mechanism (2). The storage container (11) can store a pulverized product (9E) of waste and a chemical solution (9L). The uneven distribution mechanism (2) can unevenly distribute the pulverized product (9E) in the chemical solution 9L downward in the storage container (11).

Description

Reactor

[0001] The subject matter disclosed herein relates to a reactor.

[0002] In recent years, metals such as rare metals and precious metals have been recovered from waste such as crushed E-waste (electronic waste). Technologies for recovering such metals are broadly classified into pyrometallurgy and hydrometallurgy. Pyrometallurgy is a method of recovering metals by melting waste in a high-temperature furnace, while hydrometallurgy is a method of recovering metals by dissolving them in a chemical solution such as an acid or alkali. In general, hydrometallurgy is more energy-efficient and environmentally friendly than pyrometallurgy. Hydrometallurgy methods are disclosed, for example, in Patent Document 1.

[0003] Special Publication No. 2021-501259

[0004] However, in the cited document 1, no consideration is given to the point of separating and recovering the chemical solution from the waste after the waste is reacted with the chemical solution.

[0005] An object of the present invention is to provide a technology that can easily recover chemical solutions containing metals dissolved from waste from a reaction tank.

[0006] In order to solve the above problem, a first aspect is a reaction tank for extracting target metals from waste, comprising a storage container capable of storing the waste and a chemical solution, and a distribution mechanism capable of distributing the waste in the storage container in one direction along a first direction.

[0007] A second aspect is the reaction tank of the first aspect, wherein the uneven distribution mechanism further includes a plate-like member extending in a second direction intersecting the first direction, and a moving member that moves the plate-like member back and forth in the first direction relative to the storage container.

[0008] A third aspect is the reaction tank of the first or second aspect, further comprising an agitation mechanism that agitates the chemical solution stored in the storage container.

[0009] A fourth aspect is the reaction vessel of the third aspect, wherein the stirring mechanism has a spacer stand, a stirrer disposed inside the spacer stand, and a rotation drive unit that rotates the stirrer.

[0010] A fifth aspect is the reaction vessel of the fourth aspect, wherein the stirring mechanism further includes a mesh member that covers the outside of the spacer stand.

[0011] A sixth aspect is the reaction vessel according to any one of the first to fifth aspects, wherein the storage vessel is made of glass.

[0012] A seventh aspect is the reaction tank according to any one of the first to sixth aspects, further comprising a lid that closes the opening of the storage container.

[0013] An eighth aspect is the reaction tank of any one of the first and seventh aspects, wherein the storage container is formed with a pouring spout.

[0014] According to the reaction tanks of the first to sixth aspects, the waste is unevenly distributed in the storage container, which makes it easier to recover the metal dissolved in the chemical solution.

[0015] According to the reaction tank of the second aspect, the waste can be unevenly distributed by the plate-like member.

[0016] According to the reaction vessel of the third aspect, the extraction of the target metal can be promoted by stirring the chemical solution.

[0017] According to the reaction vessel of the fourth aspect, a space for accommodating the stirring bar can be provided by the spacer stand.

[0018] According to the reaction vessel of the fifth aspect, the mesh member can prevent the waste from moving inside the spacer stand, thereby preventing the waste from interfering with the rotation of the stirrer.

[0019] According to the reaction tank of the seventh aspect, leakage of the chemical solution in the reaction tank to the outside can be reduced.

[0020] According to the reaction vessel of the eighth aspect, the chemical solution inside can be easily poured out through the spout.

[0021] 1 is a diagram showing the configuration of a reaction tank according to one embodiment. FIG. 2 is a perspective view showing a storage container of the reaction tank shown in FIG. 1. FIG. 3 is a diagram showing the reaction tank during stirring. FIG. 4 is a diagram showing the reaction tank during solid-liquid separation.

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the components described in the embodiment are merely examples and are not intended to limit the scope of the present invention. In the drawings, the dimensions and numbers of each part may be exaggerated or simplified as necessary to facilitate understanding.

[0023] 1 is a diagram showing the configuration of a reaction vessel 1 according to one embodiment. The reaction vessel 1 is a container for extracting target metals contained in waste such as e-waste (electronic waste) using a chemical solution that dissolves the target metals.

[0024] The target metal is specifically a rare metal or a noble metal. Rare metals include indium, gallium, chromium, germanium, cobalt, zirconium, strontium, cesium, cerium, tungsten, tantalum, titanium, niobium, nickel, vanadium, palladium, platinum, manganese, and rhodium. Noble metals include gold, silver, platinum, and iridium.

[0025] The chemical is a liquid capable of dissolving the target metal contained in the waste. When the target metal is gold, platinum, or palladium, aqua regia can be used as the chemical. When the target metal is silver, nitric acid can be used as the chemical.

[0026] The reaction tank 1 includes a storage container 11 and a distribution mechanism 2. The storage container 11 is capable of storing therein a chemical solution that dissolves target metals contained in the waste. The storage container 11 is cylindrical with a bottom, and specifically has a plate-shaped bottom and a cylindrical (here, cylindrical) wall extending in a first direction from the top surface of the bottom.

[0027] The inner surface of the storage container 11 is resistant to chemicals. The storage container 11 can be made of, for example, a chemical-resistant resin (e.g., a fluororesin such as perfluoroalkoxyalkane (PFA), polychlorotrifluoroethylene (PCTFE), or polytetrafluoroethylene (PTFE)) or glass.

[0028] In the following description, the reaction tank 1 is installed so that the bottom of the storage container 11 is approximately horizontal, and the first direction is parallel to the vertical direction. However, the first direction does not necessarily have to be parallel to the vertical direction, and may be parallel to a direction intersecting the vertical direction (for example, the horizontal direction).

[0029] The uneven distribution mechanism 2 is a mechanism that can unevenly distribute the waste in the storage container 11 vertically downward (one of the first directions). The uneven distribution mechanism 2 has a plate-shaped member 21 and a moving member 23. The plate-shaped member 21 is a member that extends in the horizontal direction (second direction). The plate-shaped member 21 has, for example, a flat, disk-like shape. The outer diameter of the plate-shaped member 21 is approximately the same as the inner diameter of the storage container 10.

[0030] The moving member 23 is a member for moving the plate-shaped member 21 back and forth in the vertical direction. The moving member 23 is rod-shaped and extends in the vertical direction, and the lower end of the moving member 23 is connected to the upper part of the plate-shaped member 21. The outer diameter of the moving member 23 is smaller than the outer diameter of the plate-shaped member 21. The plate-shaped member 21 and the moving member 23 are movable up and down relative to the storage container 11.

[0031] Furthermore, one or more through holes are formed in the plate-like member 21. By providing such through holes, the chemical solution 9L passes through the through holes, allowing the plate-like member 21 to move smoothly up and down in the chemical solution 9L.

[0032] The uneven distribution mechanism 2 further includes a mesh sheet 25. The mesh sheet 25 is a mesh-like member that covers the outside of the plate-like member 21. The mesh sheet 25 is formed of a chemical-resistant resin material. The mesh sheet 25 has a large number of holes that allow liquid to pass through while preventing the pulverized material 9 from passing through. By covering the plate-like member 21 with the mesh sheet 25, damage to the plate-like member 21 caused by the pulverized material 9 when the pulverized material 9 is crushed by the plate-like member 21 can be reduced.

[0033] The reaction tank 1 further has a lid 13. The lid 13 is a member that closes an opening provided at the top of the storage container 11. The lid 13 is positioned higher than the storage container 11. Annular flanges 111, 131 that protrude outward are provided at the top of the storage container 11 and the bottom of the lid 13. When the reaction tank 1 is in use, the flanges 111, 131 are fixed together with clips or the like, thereby fixing the lid 13 to the storage container 11.

[0034] A through-hole through which the moving member 23 is inserted is formed in the center of the ceiling of the lid 13. An annular sealing member 133 is disposed in the through-hole. The sealing member 133 blocks the gap between the lid 13 and the moving member 23, thereby preventing the chemical solution in the storage container 11 from leaking from the through-hole in the lid 13. The sealing member 133 is formed, for example, from a chemical-resistant resin.

[0035] The moving member 23 protrudes outward from the lid portion 13. A user can move the moving member 23 up and down from outside the storage container 11 to move the plate-like member 21 up and down. The moving member 23 may also be moved up and down by a linear motion mechanism (not shown).

[0036] The reaction tank 1 has an agitation mechanism 3. The agitation mechanism 3 agitates the chemical solution in the storage container 11. The agitation mechanism 3 has a stirrer 31 and a rotation drive unit 33. The stirrer 31 is disposed on the bottom surface inside the storage container 11. The rotation drive unit 33 is disposed outside the storage container 11.

[0037] The stirring bar 31 is a rod-shaped member made of a magnet or a magnetically sensitive material. The rotation drive unit 33 generates a magnetic force that rotates the stirring bar 31. The rotation drive unit 33 has a magnet and a motor that rotates the magnet. The rotation drive unit 33 may also have an electromagnet. The rotation drive unit 33 has an exterior part with a horizontal upper surface, and the storage container 11 is placed on the upper surface of the exterior part.

[0038] The stirring mechanism 3 has a spacer stand 35 and a mesh sheet 37. The spacer stand 35 forms a space inside for accommodating the stirring bar 31. The spacer stand 35 has a ceiling portion 351 and legs 353 extending downward from the ceiling portion 351. The top plate-like member 351 of the spacer stand 35 is, for example, a ring-shaped member with an opening in the center. The legs 353 extend downward from the ceiling portion 351 and contact the inner bottom surface of the storage container 11.

[0039] The mesh sheet 37 is a mesh-like member attached to the outside of the spacer base 35. The mesh sheet 37 has a large number of holes that are large enough to allow the chemical solution to pass through but prevent the pulverized waste from passing through. The mesh sheet 37 prevents the pulverized waste from moving inside the spacer base 35. The mesh sheet 37 is made of a chemical-resistant resin material.

[0040] Figure 2 is a perspective view showing the storage container 11 of the reaction tank 1 shown in Figure 1. A spout 113 is formed at the top of the storage container 11. In this example, the spout 113 is formed at the opening at the top of the storage container 11. More specifically, the spout 113 is configured as a groove-like portion of the flange 111 that extends outward and is recessed downward. By providing such a spout 113, the solution in the storage container 11 can be easily discharged to the outside.

[0041] FIG. 3 is a diagram showing the reaction tank 1 during stirring. As shown in FIG. 3, when extracting a target metal from waste, a chemical solution 9L and pulverized material 9E obtained by pulverizing the waste are introduced into a storage container 11. When the target metal is gold, for example, aqua regia heated to 90°C is used as the chemical solution 9L. As shown in FIG. 3, the plate-like member 21 of the uneven distribution mechanism 2 is positioned at a position (first position) above and spaced apart from the spacer stand 35. This provides a space between the spacer stand 35 and the plate-like member 21. In this state, the stirring mechanism 3 rotates the stirrer 31, thereby stirring the chemical solution 9L.

[0042] The extraction of the target metal can be promoted by stirring the chemical solution 9L with the stirring mechanism 3. Furthermore, because the ceiling portion 351 of the spacer stand 35 has an opening, a vortex can be generated above the spacer stand 35 when the stirrer 31 is rotated. This allows the pulverized material 9E to be stirred above the spacer stand 35. Furthermore, because the stirrer 31 is disposed inside the spacer stand 35 covered with the mesh sheet 37, the rotation of the stirrer 31 can be prevented from being hindered by the settled waste.

[0043] FIG. 4 is a diagram showing the reaction tank 1 during solid-liquid separation. After the chemical solution 9L and the pulverized material 9E are sufficiently reacted in the storage container 11, the plate-like member 21 is brought close to the spacer stand 35, as shown in FIG. 4. This causes the pulverized material 9E in the chemical solution 9L to move toward the spacer stand 35. In other words, the uneven distribution mechanism 2 allows the pulverized material 9E to be unevenly distributed below the storage container 11. In this state, the lid 13 is removed from the storage container 11, and the opening of the storage container 11 is released. This allows the chemical solution 9L to be discharged from the storage container 11 while leaving the pulverized material 9 in the storage container 11.

[0044] By unevenly distributing the pulverized material 9E using the uneven distribution mechanism 2, the chemical solution can be quickly discharged after the reaction. In particular, in the case of the reaction tank 1 of this embodiment, the pulverized material 9E can be settled faster than the natural settling rate. Therefore, the chemical solution 9L can be quickly discharged.

[0045] The outer diameter of the plate-shaped member 21 is approximately the same as the inner diameter of the storage container 10. Therefore, when the pulverized material 9E is pressed by the plate-shaped member 21, it is possible to reduce the pulverized material 9E passing by the side of the plate-shaped member 21 and escaping upward.

[0046] 2. Modifications Although the embodiments have been described above, the present invention is not limited to the above and various modifications are possible.

[0047] For example, the stirring mechanism 3 is not limited to one that rotates the stirrer 31. As an example, a stirring blade may be attached to the underside of the plate-like member 21. Then, the moving member 23 may be rotated to rotate the stirring blade together with the plate-like member 21, thereby stirring the chemical solution 9L and the pulverized material 9E.

[0048] The spout 113 does not necessarily have to be provided on the flange 111. For example, the spout may be formed in a tubular shape extending obliquely from the side surface of the storage container 11.

[0049] Alternatively, the pulverized material 9 may be placed on the top of the plate-like member 21. In this case, the plate-like member 21 can be pulled upward to cause the pulverized material 9 to be unevenly distributed upward.

[0050] 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.

[0051] REFERENCE SIGNS LIST 1: Reaction tank 2: Uneven distribution mechanism 3: Stirring mechanism 11: Storage container 13: Lid 21: Plate-like member 22: Moving member 31: Stirring bar 33: Rotation drive unit 35: Spacer base 37: Mesh sheet (mesh member) 113: Spout

Claims

1. A reaction tank for extracting a target metal from waste with a chemical solution, comprising: a storage container capable of storing the waste and the chemical solution; and a non-uniform distribution mechanism for non-uniformly distributing the waste in the chemical solution to one side in a first direction in the storage container.

2. The reaction tank according to claim 1, wherein the non-uniform distribution mechanism further comprises: a plate-like member extending in a second direction intersecting the first direction; and a moving member for reciprocally moving the plate-like member in the first direction with respect to the storage container.

3. The reaction tank according to claim 1 or 2, further comprising a stirring mechanism for stirring the chemical solution stored in the storage container.

4. The reaction tank according to claim 3, wherein the stirring mechanism comprises: a spacer base; a stirrer disposed inside the spacer base; and a rotational drive unit for rotating the stirrer.

5. The reaction tank according to claim 4, wherein the stirring mechanism further comprises a mesh member covering the outside of the spacer base.

6. The reaction tank according to any one of claims 1 to 5, wherein the storage container is made of glass.

7. The reaction tank according to any one of claims 1 to 6, further comprising a lid for closing the opening of the storage container.

8. The reaction tank according to any one of claims 1 to 7, wherein a pouring port is formed in the storage container.

9. A metal extraction method for extracting a target metal from waste with a chemical solution, comprising: a) a step of charging waste and a chemical solution into a storage container; b) a step of stirring the chemical solution in the storage container; c) a step of non-uniformly distributing the waste in the chemical solution to one side in a first direction of the storage container by a non-uniform distribution mechanism; and d) a step of discharging the chemical solution from the storage container after the step c).

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