Electrorefining apparatus and electrorefining method

Abstract

To provide an electrorefining apparatus capable of efficiently electrorefining a refining target substance even with a low-grade refining raw material having a low content of the refining target substance, and an electrorefining method using the same.SOLUTION: The electrorefining apparatus comprises a hollow cylindrical container body, an inlet formed on one opening end side of the container body and introducing an electrolytic solution into the container body, an outlet formed on the other opening end side of the container body and discharging the electrolytic solution from the interior of the container body, a cathode electrode formed on an inner peripheral surface of the container body, and an anode electrode disposed at a center of the container body, spaced apart from the cathode electrode, and capable of coming into contact with the electrolytic solution.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrolytic refining apparatus and an electrolytic refining method using the same. [Background technology]

[0002] When electrolytically refining low-grade blister copper (refined raw material) with a copper content of approximately 70 to 80% by mass, which is obtained from copper ore or recycled raw materials containing copper, for example, such blister copper can be formed into a plate-like anode electrode, and electrolytic refining can be performed between the anode and a cathode electrode made of stainless steel or the like, thereby depositing high-purity copper (electrolytic copper) with a purity of 99% by mass or more on the cathode electrode.

[0003] However, in this type of copper electrorefining, the blister copper anode electrode contains many impurities, and therefore anode slime and other substances form on the surface, easily passivating the electrode, and the progress of electrorefining tends to be limited to the surface layer of the cathode electrode. As a result, there has been a problem of low electrorefining efficiency, such as the need to periodically remove the anode slime that forms on the surface of the blister copper anode electrode.

[0004] For this reason, for example, Patent Document 1 discloses a mineral recovery device that improves refining efficiency by circulating an electrolyte in a cylindrical cell and placing an anode electrode that is insoluble in the electrolyte at the center of the cylindrical cell. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 5,529,672 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the invention disclosed in Patent Document 1 uses a material insoluble in the electrolyte as the anode electrode, and the metal ions to be refined that are dissolved in the electrolyte are precipitated by electrolysis. Therefore, not only is it necessary to dissolve the material to be refined in the electrolyte, but the required amount of electricity is large, resulting in high refinement costs.

[0007] The present invention has been proposed in view of the above-mentioned problems, and aims to provide an electrolytic refining apparatus that can efficiently electrolytically refine a material to be refined, even if the material is a low-grade raw material with a low content of the material to be refined, and an electrolytic refining method using the same. [Means for solving the problem]

[0008] In order to solve the above problems, the electrolytic refining apparatus and the electrolytic refining method using the same according to one embodiment of the present invention propose the following means. (1) The electrolytic refining apparatus of the first aspect of the present invention comprises a hollow cylindrical vessel body, an inlet formed at one open end of the vessel body for introducing an electrolytic solution into the vessel body, an outlet formed at the other open end of the vessel body for discharging the electrolytic solution from the vessel body, a cathode electrode formed on the inner peripheral surface of the vessel body, and an anode electrode disposed at the center of the vessel body, spaced apart from the cathode electrode, and capable of coming into contact with the electrolytic solution.

[0009] (2) A second aspect of the present invention is an electrolytic refining apparatus according to the first aspect, further comprising a liquid transport means for circulating the electrolytic solution discharged from the outlet toward the inlet.

[0010] (3) A third aspect of the present invention is an electrolytic refining apparatus according to the first or second aspect, further comprising a rotating means for rotating the anode electrode around the cylindrical central axis of the vessel body in a direction opposite to the swirling flow direction of the electrolyte.

[0011] (4) A fourth aspect of the present invention is the electrolytic refining apparatus of the second aspect, wherein the liquid transport means further comprises a solid phase separation means for filtering out solids contained in the circulating electrolytic solution.

[0012] (5) A fifth aspect of the present invention is the electrolytic refining apparatus according to any one of the first to fourth aspects, wherein the anode electrode is an electrode terminal that applies a voltage to the object to be refined.

[0013] (6) A sixth aspect of the present invention is the electrolytic refining apparatus of the fifth aspect, wherein the electrode terminal is made of a cylindrical conductor that accommodates the material to be refined therein.

[0014] (7) Aspect 6 of the present invention is an electrolytic refining method using the electrolytic refining apparatus of any one of aspects 1 to 6, comprising: a preparation step of positioning the electrolytic refining apparatus so that the inlet is on the lower side in the vertical direction and the outlet is on the upper side in the vertical direction; an electrolyte flow step of supplying the electrolytic solution from the inlet, causing it to flow from the lower side to the upper side inside the container body, and discharging it from the outlet; and an electrolysis step of applying a voltage between the anode electrode and the cathode electrode, causing a refined product obtained by electrolytically refining a material to be refined to be deposited on the cathode electrode.

[0015] (8) In an eighth aspect of the present invention, in the electrolytic refining method of the seventh aspect, the electrolytic solution is caused to flow in a spiral swirl inside the vessel body.

[0016] (9) A ninth aspect of the present invention is the electrolytic refining method of the seventh or eighth aspect, wherein the object to be refined is formed into a rectangular parallelepiped shape.

[0017] (10) Aspect 10 of the present invention is an electrolytic refining method according to any one of aspects 7 to 9, wherein the object to be refined is arranged so as to surround an insoluble dummy material arranged at the center inside the anode electrode containing the object to be refined.

[0018] (11) In an eleventh aspect of the present invention, in the electrolytic refining method of any one of the seventh to tenth aspects, the object to be refined is blister copper.

[0019] (12) A twelfth aspect of the present invention is the electrolytic refining method of the eleventh aspect, wherein the electrolytic solution contains a water-soluble chloride. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide an electrolytic refining apparatus capable of efficiently electrolytically refining a material to be refined, even if the material is a low-grade raw material with a low content of the material to be refined, and an electrolytic refining method using the same. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram illustrating an electrolytic refining apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is an external perspective view showing an example of an anode electrode. [Figure 3] FIG. 2 is a schematic diagram showing a state in which blister copper, which is an object to be refined, is contained in an anode electrode. [Figure 4] 3 is a schematic diagram showing the flow state of the electrolyte inside the container body. FIG. [Figure 5] This is a schematic diagram showing the state in which blister copper and dummy material are accommodated in the anode electrode. [Figure 6] FIG. 1 is a schematic diagram showing the configuration of an electrolytic refining apparatus used in the examples. [Figure 7] 1 is a graph showing the change in anode potential during electrolytic refining of a pure copper sample and a blister copper sample. [Figure 8] 1 is a graph showing the dissolution rates of a pure copper sample and a blister copper sample after electrolytic refining. DETAILED DESCRIPTION OF THE INVENTION

[0022] An electrolytic refining apparatus according to one embodiment of the present invention and an electrolytic refining method using the same will be described below with reference to the drawings. The following embodiment is specifically described to provide a better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified. Furthermore, the drawings used in the following description may show essential parts enlarged for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional proportions of the components may not necessarily be the same as those in reality.

[0023] (Electrolytic refining equipment) In the embodiment described below, copper electrorefining in which blister copper having a copper purity of about 70 to 80 mass % is electrorefined to precipitate high-purity copper will be described as an example of electrorefining using the electrorefining apparatus 10. Note that the electrorefining apparatus of the present invention is not limited to the electrorefining of copper, and can be applied to the electrorefining of various metals.

[0024] FIG. 1 is a schematic diagram showing the configuration of an electrolytic refining apparatus according to one embodiment of the present invention. The electrolytic refining apparatus 10 of this embodiment comprises a hollow cylindrical container body 11, an upper cover body 12 attached to one opening end 11a of the container body 11, a lower cover body 13 attached to the other opening end 11b of the container body 11, an outlet 15 provided in the upper cover body 12, an inlet 16 provided in the lower cover body 13, a liquid transfer pipe 17 connecting the outlet 15 and the inlet 16, and a circulation device (liquid transfer means) 18 formed midway along the liquid transfer pipe 17.

[0025] The container also includes a cathode electrode 21 formed on the inner peripheral surface of the container body 11, an anode electrode 22 arranged at a distance from the cathode electrode 21 in the center of the container body 11, and a power supply unit 23 that applies a voltage between the cathode electrode 21 and the anode electrode 22.

[0026] A cylindrical space S is formed inside the container body 11. When in use (during electrolytic refining), the container body 11 is placed upright with the central axis of the hollow portion aligned vertically, and the space S is filled with an electrolyte for electrolytic refining.

[0027] The container body 11 is made of an insulating material, such as resin, that is resistant to corrosion by the electrolyte solution. In this embodiment, the container body 11 is made of a pipe made of ABS resin.

[0028] The upper lid 12 is formed so as to close one open end 11a which is the upper vertical side of the container body 11. The upper lid 12 may be fastened to the open end 11a of the container body 11 by a bolt, for example, via a packing (not shown) that maintains watertightness.

[0029] The upper lid 12 is made of an insulating material, such as resin, that is resistant to corrosion by the electrolyte. In this embodiment, the upper lid 12 is made of ABS resin, similar to the container body 11.

[0030] Outlet 15, which is formed integrally with top cover 12, is a hollow conduit, one end of which communicates with space S on the side of one open end 11a of container body 11, and the other end of which opens to the outside of top cover 12. The other end of outlet 15 is connected to one end of liquid transport pipe 17, in which circulating device (liquid transport means) 18, which will be described later, is formed. The electrolyte filling space S of container body 11 is discharged from outlet 15 toward circulating device (liquid transport means) 18.

[0031] The lower lid 13 is formed so as to close the other open end 11b, which is on the vertically lower side of the container body 11. The lower lid 13 may be attached to the open end 11b of the container body 11 by a bolt, for example, via a packing (not shown) that maintains watertightness.

[0032] The lower lid 13 is made of an insulating material, such as resin, that is resistant to corrosion by the electrolyte. In this embodiment, the lower lid 13 is made of ABS resin, similar to the container body 11.

[0033] Inlet 16, which is formed integrally with lower cover 13, is a hollow conduit, one end of which communicates with space S on the side of the other open end 11b of container body 11, and the other end of which opens outside lower cover 13. The other end of inlet 16 is connected to the other end of liquid transport pipe 17, in which a circulating device (liquid transport means) described below is formed. The electrolyte circulated via circulating device (liquid transport means) 18 described below is introduced into space S of container body 11 from inlet 16.

[0034] The liquid transfer pipe 17 is a pipe that transfers the electrolyte solution flowing out from the outlet 15 toward the inlet 16, and is made of an insulating material, such as resin, that is resistant to corrosion by the electrolyte solution. In this embodiment, the liquid transfer pipe 17 is made of a soft polyvinyl chloride tube.

[0035] The circulation device (liquid transfer means) 18 is composed of a device, such as a pump, that transfers the electrolyte from the outlet 15 of the container body 11 toward the inlet 16 via the liquid transfer pipe 17. Various pumps can be used as the pump, such as a turbine pump, an axial flow pump, a piston pump, a screw pump, and a tube pump. These pumps are preferably made of a material that is resistant to corrosion by the electrolyte, and are preferably coated with a corrosion-resistant material.

[0036] A filtration device (solid phase separation means) 19, which is a solid phase separation means, is preferably provided upstream (inlet side) of the circulation device (liquid transfer means) 18. The filtration device 19 may be composed of various solid-liquid separation filters, such as a nonwoven fabric filter, a metal filter, or a membrane filter, and a removal means for removing cake (solid content) accumulated on the solid-liquid separation filter. In this embodiment, the filtration device 19 captures insoluble anode slime (solid content) generated during electrolytic refining and contained in the electrolyte flowing out from the outlet 15 of the vessel body 11.

[0037] The cathode electrode 21 is made of a conductive metal that will not be ionized and eluted by the electrolyte during electrolytic refining, and is formed on the cylindrical inner circumferential surface of the container body 11. In this embodiment, a thin-film electrode made of stainless steel is used as the cathode electrode 21.

[0038] In this embodiment, the anode electrode 22 is a cylindrical mesh electrode terminal made of a mesh material made of a conductive metal that will not be ionized and eluted by the electrolyte during electrolytic refining and is formed into a cylindrical shape with a closed bottom end. As shown in Fig. 2, in this embodiment, a titanium mesh formed into a cylindrical mesh shape is used as the anode electrode 22.

[0039] The anode electrode 22 is detachably attached to the inside of the upper lid 12 in the container body 11 so as to be spaced apart from the cathode electrode 21. The cylindrical mesh-shaped anode electrode 22 contains an object to be refined. In this embodiment, a plurality of blister copper pieces formed into a cubic shape are contained inside the anode electrode 22 and electrolytic refining is performed.

[0040] In this embodiment, blister copper molded into a cube shape is used as the object to be refined, but the object to be refined housed in the cylindrical mesh anode electrode 22 is not limited to a cube shape. For example, objects molded into various shapes that can increase the surface area of ​​the object to be refined, such as a sphere, a rod, or an irregular shape, can be used.

[0041] A power supply 23 is connected to lead-out conductive wires 21a, 22a that are respectively led out from the cathode electrode 21 and the anode electrode 22 to the outside of the container body 11. A DC stabilized power supply, for example, can be used as the power supply 23. When a predetermined DC voltage is applied between the cathode electrode 21 and the anode electrode 22 by the power supply 23, the material to be refined, such as blister copper, contained in the anode electrode 22 is ionized, dissolved in the electrolyte, and deposited on the cathode electrode 21.

[0042] (Electrolytic refining method) The operation of the electrolytic refining apparatus 10 described above and the electrolytic refining method of this embodiment using the electrolytic refining apparatus 10 will be described. When using the above-described electrolytic refining apparatus 10 to perform electrolytic refining of, for example, crude copper, the electrolytic refining apparatus 10 is positioned so that the inlet 16 of the electrolytic refining apparatus 10 is on the lower side in the vertical direction and the outlet 15 is on the upper side in the vertical direction.

[0043] Then, the upper lid 12 is opened to remove the anode electrode 22, and the blister copper C to be refined is placed inside the anode electrode 22 (preparation step). For example, as shown in Fig. 3, the blister copper C may be formed into a cube shape (rectangular parallelepiped) of about 4 mm square. In this embodiment, about 160 cube-shaped blister copper C are stacked and filled inside the anode electrode 22.

[0044] Next, the top cover 12 is closed so that the anode electrode 22 is positioned at the center of the container body 11, and the inside of the container body 11 is sealed.

[0045] Next, the circulation device (liquid transfer means) 18 is operated to introduce the electrolyte into the vessel body 11 via the liquid transfer pipe 17. The electrolyte may be, for example, a solution of copper (II) sulfate (CuSO4) dissolved in dilute sulfuric acid. At this time, in the electrolytic refining apparatus 10 of this embodiment, the electrolyte flows from the inlet 16 at the lower end of the vessel body 11 along the cathode electrode 21 formed on the inner wall of the vessel body 11, and is discharged from the outlet 15 at the upper end of the vessel body 11 (electrolyte flowing step). As a result, as shown in FIG. 4, the electrolyte W forms a spiral upward swirling flow inside the vessel body 11, and the electrolyte W in the vessel body 11 is constantly agitated by the swirling flow.

[0046] In this manner, while the electrolytic solution W is caused to flow within the container body 11 and circulated by the circulation device 18, the power supply device 23 is operated to apply a predetermined DC voltage between the anode electrode 22 and the cathode electrode 21.

[0047] As a result, copper and impurity metals with a higher ionization tendency than copper, among the cube-shaped crude copper C contained in the cylindrical mesh electrode constituting the anode electrode 22, emit electrons and become ionized, and are eluted into the electrolyte W. The ionized metals then move toward the cathode electrode 21.

[0048] Then, at the cathode electrode 21, the ionized copper is deposited as refined copper on the surface of the cathode electrode 21 (electrolysis process). On the other hand, non-ionized metal is deposited as anode slime on the surface of the cubic blister copper.

[0049] In this electrolysis process, in the electrolytic refining apparatus 10 of this embodiment, an upward swirling flow is formed in the electrolyte W within the container body 11, so that the anode slime precipitated on the surface of the crude copper is peeled off from the surface of the crude copper by the upward swirling flow of the electrolyte W and discharged together with the electrolyte from the outlet 15 at the upper end.

[0050] This prevents the surface of the crude copper from being covered with passive anode slime, which would otherwise reduce the efficiency of electrolysis, and keeps the surface of the crude copper constantly exposed to the electrolytic solution W. In addition, the anode slime generated by electrolysis is quickly discharged from the vessel body 11 by the electrolytic solution W, which forms an upward swirling flow.

[0051] The electrolyte W, in which the anode slime is dispersed, discharged from the container body 11 flows into a filtration device (solid phase separation means) 19 formed in the circulation device 18 via a liquid transfer pipe 17, where the anode slime dispersed in the electrolyte W is filtered out and removed. Then, the electrolyte W from which the anode slime has been removed is returned to the vessel body 11 from the inlet 16 by a pump constituting the circulation device (liquid transfer means) .

[0052] The anode slime obtained by solid-liquid separation in the filtration device (solid-phase separation means) 19 can be used as a raw material for regenerating metals that have a lower ionization tendency than the copper contained in the blister copper, such as precious metals such as gold and silver.

[0053] The refined copper deposited on the cathode electrode 21 by the electrolytic refining method of this embodiment forms an upward swirling flow of the electrolytic solution W within the vessel body 11, and therefore tends to have a higher concentration of impurity metals other than copper (e.g., nickel, tin, lead, etc.) from the bottom to the top in the vertical direction of the cylindrical cathode electrode 21. This is thought to be because the closer the electrolytic solution W is to the outlet 15, the greater the amount of anode slime that is entrained.

[0054] As described above, according to the electrolytic refining method using the electrolytic refining apparatus 10 of this embodiment, the object to be refined, for example, blister copper C, is accommodated inside the cylindrical mesh-shaped anode electrode 22 disposed inside the container body 11, and the electrolytic solution W is caused to swirl from the bottom to the top of the container body 11. Even if copper sulfate or anode slime adheres to the surface of the blister copper, it is always peeled off from the surface of the blister copper and flows out of the container body 11. As a result, the electrolytic solution W is supplied evenly to the blister copper C accommodated in the anode electrode 22 and the cathode electrode 21 without stagnation, preventing a decrease in reaction sites due to coatings, and enabling efficient electrolytic refining of the object to be refined even when a high current density is applied.

[0055] As a modification of the electrolytic refining apparatus 10 of this embodiment, it is also preferable to further include a rotation means for rotating the anode electrode 22 around the cylindrical central axis of the vessel body 11. For example, if the cylindrical mesh-shaped anode electrode 22 is rotated by a motor (rotation means) formed outside the vessel body 11, the material to be refined contained in the anode electrode 22 will come into stronger contact with the swirling flow of the electrolyte solution W, thereby further enhancing the peeling effect of the generated anode slime. In this case, it is preferable that the rotation direction of the anode electrode 22 is opposite to the swirling flow direction of the electrolyte solution W.

[0056] Furthermore, as shown in FIG. 5, when the object to be refined, for example, cubic blister copper C, is accommodated inside the cylindrical mesh anode electrode 22, a dummy material 35 that is insoluble in the electrolytic solution is placed in the center of the anode electrode 22, and the cubic blister copper C is arranged so as to surround the dummy material 35. This prevents the blister copper C from being placed in the center where it is difficult to electrolyze, and therefore the efficiency of electrolysis of the blister copper C can be further improved.

[0057] Furthermore, when electrolytic refining of crude copper C as the object to be refined is performed, it is also preferable to dissolve a water-soluble chloride in the copper (II) sulfate (CuSO4) aqueous solution that is the electrolyte. By including such a water-soluble chloride in the electrolyte, more impurities are precipitated during electrolytic refining, and by removing these impurities with a filtration device (solid-phase separation means) 19, the purity of the refined copper precipitated on the cathode electrode 21 can be further increased.

[0058] In the above-described embodiment, the cylindrical mesh container serves as the anode electrode (electrode terminal) 22, and the blister copper C, which is the object to be refined, is contained therein. However, the present invention also includes a configuration in which the object to be refined itself is used as the anode electrode material. In this case, in order to use the object to be refined, for example, the blister copper, as the anode electrode material, it is sufficient that the end of the voltage wire (lead wire) extending from the output terminal of the power supply device is provided with an electrode terminal that contacts the blister copper. In this case, a member (which may be either a conductor or a dielectric) that supports the blister copper in a predetermined position in the container body may also be provided.

[0059] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Example]

[0060] The electrolytic refining apparatus shown in Figure 6 was assembled, and electrolytic refining was actually performed to examine its effects. [Electrolytic refining equipment] A cylindrical refining vessel (height 50 mm, inner diameter 3.5 mm, inlet and outlet diameters 30 mm) for the electrolytic refining equipment, designed using CAD, was molded using a 3D printer. ABS resin was used as the material for the vessel. The vessel was then positioned so that the inlet was on the lower vertical side and the outlet was on the upper vertical side. This allowed the electrolyte flowing in from the inlet to form an upward swirling flow (cyclone-like) within the vessel, ensuring sufficient stirring force for the electrolyte.

[0061] A cylindrical titanium basket with an opening at the top was formed using a 0.8 mm thick titanium plate and titanium punched metal as the anode electrode placed in the center of the refining vessel (basket diameter: 20 mm, height: 50 mm), as shown in Figure 2. The inside of this titanium basket was filled with the refinement target: pure copper cut wire (pure copper sample) and blister copper formed into a cube shape (3.7 mm on each side) (blister copper sample).

[0062] This titanium basket was positioned in the center of the refining vessel, and the vessel was then sealed. Because there was concern that the pure copper cut wire (pure copper sample) might fall through the gaps in the titanium basket, a titanium mesh (100 mesh, manufactured by Nilaco Corporation) was placed inside the titanium basket and the pure copper sample was packed inside this. The titanium basket contained 12 cubes of blister copper (blister copper sample), for a total of 160 pieces, with 13 layers plus 4 cubes.

[0063] To prevent the material to be refined from swaying in the titanium basket, which serves as the anode electrode, due to the flow of the electrolyte during electrolytic refinement, a silicone sheet is further packed on top of the filled material to be refined and held down with a flange.

[0064] A 0.05 mm thick rectangular piece of stainless steel foil (50 mm long, 145 mm wide) was cut as the cathode electrode and placed in close contact with the cylindrical inner surface of the purification vessel. The anode potential was measured using an Ag-AgCl electrode immersed in a potassium chloride solution (3.33 M concentration) via a salt bridge from a plastic tank as the reference electrode. A DC stabilized power supply (PWR400L, manufactured by Kikusui Electronics Co., Ltd.) was used to control the current, and an insulated multi-channel handheld logger (Midi LOGGER GL200, manufactured by Graphtec Corporation) was used to measure the cathode potential during current flow.

[0065] The electrolyte was a solution of copper (II) sulfate (CuSO4) dissolved in dilute sulfuric acid. The electrolyte was heated to 60°C using a heater installed in a polyethylene tank, and circulated between the purification vessel and the polyethylene tank using a magnetic pump (Iwaki Pump, manufactured by Iwaki Corporation).

[0066] Using the electrolytic refining apparatus of the above example, the current value of the DC stabilized power supply was set to 2.64 A, and the anode current density was 200 mA / m 2 , cathode current density is 500mA / m 2 The pure copper sample and the blister copper sample were each subjected to electrolytic refining under the conditions given below.

[0067] The change in anode potential during the above-mentioned electrolytic refining for the pure copper sample and blister copper sample is shown in a graph in Figure 7. Furthermore, the dissolution rates after electrolytic refining for the pure copper sample and blister copper sample are shown in Figure 8. The dissolution rate (%) is expressed by the following formula (1). ((Sample mass before electrorefining - Sample mass after electrorefining) / Sample mass before electrorefining) × 100 (1)

[0068] According to the results shown in Fig. 7, although noise-like fluctuations in potential were observed throughout the electrolytic refining process for both the pure copper sample and the blister copper sample, it was confirmed that electrolytic refining proceeded stably until the potential suddenly rose 8.9 hours after the start of electrolysis.

[0069] 8, the dissolution rate of the pure copper sample reached 72.2%, confirming that it is possible to dissolve the target material at a high dissolution rate and perform efficient electrolytic refining. On the other hand, the dissolution rate of the blister copper sample was 51.5%, which is lower than the dissolution rate of the pure copper sample due to the presence of impurities, but it also confirmed that it is possible to dissolve the target material and perform efficient electrolytic refining.

[0070] Next, the concentrations of impurities (Ni, Sn, Pb, Sb, Ag) contained in the electrolytic copper deposited on the cathode electrode, obtained by electrolytic refining using the above-mentioned crude copper sample, were measured at the downstream (upper side of the refining vessel), midstream (center of the refining vessel), and upstream (lower side of the refining vessel) of the cathode electrode. The measurements were performed using ICP atomic emission spectroscopy. The results are shown in Table 1.

[0071] [Table 1]

[0072] According to Table 1, there is a tendency for the impurity concentration to increase the further upstream of the cathode electrode (the lower the refining vessel). This is thought to be due to the entrainment of anode slime that falls to the bottom of the refining vessel. For this reason, it is thought that the impurity concentration can be further reduced by installing an additional nonwoven fabric filter on the inlet side of the magnet pump of the electrolytic refining device to filter out anode slime and other substances contained in the circulating electrolyte. [Industrial Applicability]

[0073] The electrolytic refining apparatus and the electrolytic refining method using the same of the present invention enable efficient electrolytic refining of the target material even when the target material is a low-grade raw material containing only a small amount of the target material, thereby contributing to promoting the effective use of mineral resources and thus having industrial applicability. [Explanation of symbols]

[0074] 10…Electrolytic refining equipment 11...Container body 12...Top lid body 13…Lower lid body 15... Outlet 16…Inlet 17…Liquid feed pipe 18…Circulation device (liquid delivery means) 19...filtration device (solid phase separation means) 21...Cathode electrode 22...Anode electrode 23…Power supply device

Claims

1. A hollow cylindrical container body; an inlet formed on one open end side of the container body for introducing an electrolyte into the container body; an outlet formed on the other open end side of the container body for discharging the electrolyte from inside the container body; a cathode electrode formed on the inner circumferential surface of the container body; an anode electrode that is disposed at the center of the container body and spaced apart from the cathode electrode and that can come into contact with the electrolyte; An electrolytic refining apparatus having the above structure.

2. The electrolytic refining apparatus according to claim 1 , further comprising a liquid transport means for circulating the electrolytic solution discharged from the outlet toward the inlet.

3. 3. The electrolytic refining apparatus according to claim 1, further comprising a rotating means for rotating the anode electrode around the cylindrical central axis of the vessel body in a direction opposite to the swirling flow direction of the electrolyte.

4. 3. The electrolytic refining apparatus according to claim 2, wherein the liquid transport means further comprises solid phase separation means for filtering out solids contained in the circulating electrolytic solution.

5. 3. The electrolytic refining apparatus according to claim 1, wherein the anode electrode is an electrode terminal that applies a voltage to the object to be refined.

6. 6. The electrolytic refining apparatus according to claim 5, wherein the electrode terminal is formed of a cylindrical conductor that accommodates the material to be refined therein.

7. An electrolytic refining method using the electrolytic refining apparatus according to claim 1 or 2, a preparation step of disposing the electrolytic refining apparatus so that the inlet is located on a lower side in a vertical direction and the outlet is located on an upper side in the vertical direction; an electrolyte flowing step of supplying the electrolyte from the inlet, causing it to flow from the bottom to the top inside the container body, and discharging it from the outlet; an electrolysis step of applying a voltage between the anode electrode and the cathode electrode to deposit a refined product obtained by electrolytically refining a refinement target on the cathode electrode.

8. The electrolytic refining method according to claim 7 , wherein the electrolytic solution is caused to flow in a spiral swirl inside the vessel body.

9. The electrolytic refining method according to claim 7 , wherein the object to be refined is shaped like a rectangular parallelepiped.

10. 8. The electrolytic refining method according to claim 7, wherein the object to be refined is arranged so as to surround an insoluble dummy material arranged at the center inside the anode electrode containing the object to be refined.

11. 8. The electrolytic refining method according to claim 7, wherein the object to be refined is blister copper.

12. The electrolytic refining method according to claim 11 , wherein the electrolyte contains a water-soluble chloride.

Images