Gold electrolysis device

Abstract

To provide a gold electrolytic gold extraction apparatus that can extract gold with high efficiency without using an ion exchange membrane. [Solution] The electrolytic cell 20 is provided for electrolyzing an aqueous solution containing gold ions obtained by dissolving gold with triiodide ions. The electrolytic cell 20 has a partition wall 25 that separates an anode tank 23 and a cathode tank 24. The partition wall 25 is configured to separate most of the anode tank 23 and the cathode tank 24, while allowing the remaining parts to communicate.

Description

[Technical Field]

[0001] This invention relates to an electrolytic gold extraction apparatus utilizing an aqueous solution of iodine and iodide. [Background technology]

[0002] In recent years, while the reserve life of gold (Au) produced from mines has shortened, the demand for gold as a safe-haven asset continues to rise, and efforts are being made to recover and reuse Au from urban mines. Although there are various commercial methods for Au smelting, the toxicity of the cyanide and aqua regia solutions used in smelting, as well as the difficulty in handling wastewater treatment, results in a significant environmental burden. Furthermore, stricter regulations on wastewater from factories have created a need for the development of new smelting technologies both domestically and internationally.

[0003] Halogens are highly reactive and are known to dissolve gold (Au). Iodine (I2), in particular, is a solid at room temperature and is easy to handle. Although I2 is sparingly soluble in water, iodide ions (I2) are available. - ) If present, triiodide ions (I3 - ) is produced and dissolved. Also, this I3 - It is known to act as an oxidizing agent that dissolves Au, and until now, iodine and iodide (I2,I - The use of aqueous solutions in the smelting of Au has been considered, but a large amount of reagent is required to promote the dissolution of Au, and from an economic and environmental standpoint, I3 is used as an oxidizing agent. - The revitalization of this will be crucial.

[0004] I3 - As a regeneration method, Patent Document 1 describes recovering Au from an iodine etching solution containing Au discharged during semiconductor component manufacturing by electrolysis (electrolysis) using an ion exchange membrane, and the process associated with the recovery of Au. - Regeneration of the iodine etching solution that has been reduced to (i.e., I3) -A method for stably performing (the playback) is described. Specifically, in Patent Document 1, an electrolytic cell is partitioned into an anode cell and a cathode cell by a cation exchange membrane. An iodine etching solution containing Au is supplied to the cathode cell, and an iodine etching solution reduced to I - is supplied to the anode cell respectively as the iodine etching solution is reduced to I during Au recovery in the cathode cell. By appropriately adjusting the current densities of the anode and the cathode, Au recovery and I3 - regeneration can be stably performed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in Patent Document 1, by appropriately adjusting the current densities of the anode and the cathode, electrolysis of water and precipitation of I2 can be suppressed, and Au recovery and I3 - regeneration can be stably performed. However, in order to prevent the movement of the regenerated I3 - in the anode cell to the cathode cell, the use of an expensive cation exchange membrane is assumed. This not only increases the manufacturing cost of the device, but also causes an increase in electrical resistance and a decrease in ion separation performance when solute adhesion to the surface of the ion exchange membrane progresses during electrolysis. Therefore, maintenance such as membrane replacement and membrane cleaning is required, resulting in an increase in running costs. Thus, there is a problem that operation is difficult from the perspective of economy.

[0007] The present invention has been made by focusing on such problems, and an object thereof is to provide a gold electrolytic collection device that can collect gold with high efficiency without using an ion exchange membrane.

Means for Solving the Problems

[0008] In order to solve the above problems, the gold electrolytic extraction apparatus of the present invention comprises an electrolytic cell for electrolyzing an aqueous solution containing gold ions in which gold is dissolved by triiodide ions, the electrolytic cell has a partition wall separating an anode cell and a cathode cell, the partition wall is configured to partition most of the anode cell and the cathode cell and communicate the remaining parts, and is characterized in this regard. According to this feature, the anode cell and the cathode cell are connected by a so-called thin liquid layer formed by the partition wall, and by utilizing the precipitation of triiodide ions regenerated in the anode cell, the movement of triiodide ions to the cathode cell can be suppressed and the redissolution of gold in the cathode cell can be prevented, so that gold can be extracted with high efficiency without using an ion exchange membrane.

[0009] It is characterized in that the aqueous solution containing gold ions is allowed to flow into the cathode cell, and the aqueous solution in the anode cell is allowed to flow out for electrolysis. According to this feature, the movement of triiodide ions to the cathode cell is suppressed, and the decrease in the gold ion concentration in the cathode cell is suppressed, thereby enhancing the reactivity, so that the recovery amount of gold can be increased.

[0010] It is characterized in that an outlet for flowing out the aqueous solution is provided below the anode cell. According to this feature, by flowing out the aqueous solution containing triiodide ions precipitated in the anode cell from the outlet provided below, the movement of triiodide ions to the cathode cell is suppressed, so that gold can be extracted with high efficiency.

[0011] It is characterized in that an opening for communicating the anode cell and the cathode cell is provided in the partition wall. This feature allows for the stabilization of the flow of the aqueous solution from the cathode tank to the anode tank by moving the aqueous solution through an opening in the partition wall, thereby reducing the resistance between the electrodes and increasing the amount of gold recovered. Furthermore, it eliminates the need to adjust the water levels in the anode and cathode tanks, simplifying operation.

[0012] The aforementioned opening is characterized by being a horizontally elongated slit. This characteristic makes it easier to further stabilize the flow of the aqueous solution from the cathode tank to the anode tank.

[0013] The aforementioned slit is characterized by being a single slit. This feature allows for highly efficient gold extraction because only the aqueous solution moves from the cathode tank to the anode tank through the slit, while the movement of triiodide ions to the cathode tank is suppressed.

[0014] The slit is characterized by having a width that is approximately the same as the electrode width. This feature allows the aqueous solution to flow between the electrodes and the partition wall in the anode and cathode tanks, respectively, and to move smoothly from the cathode tank to the anode tank through the slits.

[0015] The aforementioned opening is characterized by being located above the liquid level of the electrolytic cell. This feature more reliably suppresses the movement of triiodide ions settling in the anode tank through the opening to the cathode tank, allowing for highly efficient gold extraction.

[0016] The gold electrolysis apparatus of the present invention is A smelting tank for dissolving gold using triiodide ions, A liquid transfer means for transferring a gold ion-containing aqueous solution containing gold refined in the aforementioned smelting tank to one of the electrolytic cells described above, The system is characterized by comprising a return liquid means for returning the gold ion-containing aqueous solution, which has been electrolyzed by the electrolytic cell, to the smelting tank. This feature allows the aqueous solution containing triiodide ions, regenerated by electrolysis in the electrolytic cell, to be reused in the gold smelting tank, thereby reducing the cost of iodine raw materials used in gold smelting. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram showing the configuration of a gold electrolytic extraction apparatus in an embodiment of the present invention. [Figure 2] This is a schematic diagram showing the configuration of the electrolytic cell in the embodiment. [Figure 3] This is a cross-sectional view showing an example of the configuration of the partition wall of the electrolytic cell in the embodiment. [Figure 4] This diagram shows the reaction system of a gold ion-containing aqueous solution in an electrolytic cell. [Figure 5] This graph shows the effect of space time in the aqueous solution on the current value when using the gold electrolytic extraction apparatus described in the example in Experiment 1. [Figure 6] This graph shows the effect of space time in an aqueous solution on the current value when using an electrolytic gold extraction device with an ion exchange membrane in Experiment 1. [Figure 7] Experiment 2 shows examples of partition wall configurations with modified opening shapes, sizes, and numbers. (a) is a cross-sectional view showing a partition wall configuration with two 2mm slits as openings, and (b) is a cross-sectional view showing a partition wall configuration with a 5mm diameter through-hole. [Figure 8] This graph shows the effect of different connection conditions between the anode and cathode tanks, resulting from changing the shape, size, and number of openings in Experiment 2, on the current value. [Figure 9] This is a schematic diagram showing a modified example of the partition wall of an electrolytic cell. [Modes for carrying out the invention]

[0018] Embodiments for implementing the gold electrolytic extraction apparatus according to the present invention will be described below based on examples. [Examples]

[0019] The electrolytic gold extraction apparatus according to the embodiment will be described with reference to Figures 1 to 8.

[0020] As shown in Figure 1, the gold electrolytic extraction apparatus 1 of this embodiment (hereinafter sometimes referred to as "this electrolytic extraction apparatus 1") uses an iodine-iodide aqueous solution containing iodine (I2) and potassium iodide (KI), i.e., iodide ions (I2). - Due to the presence of ), I2 becomes a triiodide ion (I3 - Gold (Au) is dissolved in aqueous solution S1, and the Au is collected (recovered) at cathode 22 by electrolysis (electrolysis) of the gold ion-containing aqueous solution S2 in which the Au has been dissolved. At the same time, the I that is reduced mainly in conjunction with the Au recovery at cathode 22 is also collected. - From aqueous solution S3 containing I3 at anode 21 - Play back the I3 - The aqueous solution S1 containing the above-mentioned Au is reused for dissolving the Au.

[0021] For details, see I3. This electrolytic collection device 1 is used when used semiconductor substrates etc. are fed into it. - A smelting tank 10 dissolves Au in an aqueous solution S1 containing the following: an electrolytic cell 20 electrolyzes the gold ion-containing aqueous solution S2 obtained in the smelting tank 10; a liquid transfer pump 30 as a liquid transfer means for transferring the gold ion-containing aqueous solution S2 from the smelting tank 10 to the electrolytic cell 20; and I3 regenerated by electrolysis in the electrolytic cell 20. - The system includes a return pump 40 as a return means for returning an aqueous solution S1 containing to the smelting tank 10.

[0022] In Figure 1, the smelting tank 10 consists of a main tank for dissolving Au and I3 returned by the return pump 40. - The smelting tank 10 is composed of a storage tank for temporarily storing an aqueous solution S1 containing the gold ions, and a storage tank for temporarily storing the gold ion-containing aqueous solution S2 obtained in the main tank before it is delivered by the liquid transfer pump 30. However, the smelting tank 10 is not limited to this configuration, and the smelting tank 10 may be configured as a multi-tank system in which these main tank and storage tanks are integrated, or the storage tanks may be omitted.

[0023] The electrolytic cell 20 in this embodiment has a partition wall 25 that separates the anode tank 23 and the cathode tank 24. The partition wall 25 is configured to separate most of the anode tank 23 and the cathode tank 24 with a linearly extending, horizontally elongated slit 25a (see Figure 3) as an opening, while allowing the remaining portion to communicate. In other words, the electrolytic cell 20 is connected to the anode 21 and the cathode 22 by a thin liquid layer formed by the slit 25a provided in the partition wall 25. This eliminates the need to adjust the liquid level L1 (see Figure 2) in the anode tank 23 and the cathode tank 24. The partition wall 25 is sealed and fixed to the electrolytic cell 20, separating the anode tank 23 and the cathode tank 24.

[0024] In this embodiment, the thin liquid layer refers to the portion where the aqueous solutions in the anode tank 23 and the cathode tank 24 are connected in a way that allows for fluid flow between them.

[0025] Furthermore, in this embodiment, a slit refers to a horizontally elongated through-hole with an aspect ratio of 2 or more, and the shape of the slit is not limited to a rectangle; for example, it may be a trapezoid or an ellipse.

[0026] Furthermore, in this embodiment, the slit 25a provided in the partition wall 25 is positioned above the liquid level L1 of the electrolytic cell 20. Note that "above the liquid level L1" means above the vertical center of the liquid level L1 (L2 ≥ 0.5 × L1).

[0027] As shown in Figures 2 and 3, in this embodiment, the liquid height L1 = 37 mm and the height L2 to the lower end of the slit 25a provided in the partition wall 25 are configured to be 28 mm. The height L2 to the lower end of the slit 25a is preferably configured to be 70-90% of the liquid height L1, more preferably 75-85% of the liquid height L1, thereby allowing the regenerated I3 in the anode tank 23 to be recovered. - The movement of the aqueous solution S1 containing the substance to the cathode tank 24 through the slit 25a is suppressed.

[0028] In this embodiment, the slit 25a is configured with a vertical width L3 = 2 mm. The vertical width L3 of the slit 25a is preferably configured to be 5 to 20% of the liquid height L1, and more preferably 10 to 15% of the liquid height L1.

[0029] Furthermore, as shown in Figure 3, in this embodiment, the slit 25a is configured with a width L4 = 110 mm. That is, the slit 25a is formed horizontally across the inner walls of the electrolytic cell 20. This makes it possible to suppress the generation of vortices near the inner walls of the electrolytic cell 20 by the flow of aqueous solution S1 moving from the cathode tank 24 to the anode tank 23 through the slit 25a (see arrow in Figure 1).

[0030] The slit 25a is not limited to being formed across the inner walls of the electrolytic cell 20 as in this embodiment, but it is preferable that the width L4 of the slit 25a is approximately the same as the electrode width of the anode 21 and cathode 22. Furthermore, by setting the width L4 of the slit 25a to 95-115% of the electrode width, and more preferably 100-110% of the electrode width, the aqueous solution can be allowed to flow between the anode 21 and cathode 22 and the partition wall 25, respectively, and move smoothly from the cathode tank 24 to the anode tank 23 through the slit 25a.

[0031] Furthermore, this electrolytic collection device 1 introduces a gold ion-containing aqueous solution S2 into the cathode tank 24 of the electrolytic cell 20, and also collects the regenerated I3 in the anode tank 23. - Electrolysis is performed while draining an aqueous solution S1 containing the above. In this embodiment, the amount of gold ion-containing aqueous solution S2 flowing into the cathode tank 24 and the amount of I3 from the anode tank 23 are controlled so that the liquid level L1 of the electrolytic cell 20 does not change. -The outflow rate of aqueous solution S1 containing is controlled. That is, in this electrolytic extraction apparatus 1, the aqueous solution is circulated between the smelting tank 10 and the electrolytic cell 20, so that a flow from the cathode tank 24 to the anode tank 23 (see arrow in Figure 1) is formed in the electrolytic cell 20 through the slit 25a. In addition, the flow from the cathode tank 24 to the anode tank 23 is mainly due to the reduction of I accompanying the electrolytic extraction (Au recovery) of Au in the cathode 22. - This is due to aqueous solution S3 containing [the substance].

[0032] Furthermore, the piping 41 connecting the electrolytic cell 20 and the return pump 40 is connected to an outlet 20a (see Figure 2) located below the anode tank 23. In addition, because the piping 41 extends below and near the center of the anode tank 23, the I3 regenerated in the anode 21 is connected to the outlet 20a (see Figure 2). - I3 utilizes the physical property that its high specific gravity causes it to settle. - The system is designed to efficiently draw in the aqueous solution S1 containing the substance and return it to the smelting tank 10.

[0033] Furthermore, the piping 31 connecting the liquid transfer pump 30 and the electrolytic cell 20 is connected to an inlet 20b (see Figure 2) located below the cathode tank 24. The piping 31 also transfers the gold ion-containing aqueous solution S2 obtained in the smelting tank 10 from below and near the center of the cathode tank 24, thereby mainly reducing the I that is recovered in the cathode 22. - The aqueous solution S3 containing the substance flows upward towards the cathode tank 24, making it easier for it to move to the anode tank 23 through the slit 25a. The piping 31 may be connected to the top or center of the cathode tank 24.

[0034] When electrolysis is performed in the electrolytic cell 20, the reaction of the gold ion-containing aqueous solution S2 shown in Figure 4 proceeds, Au precipitates at the cathode 22, and I3 precipitates at the anode 21. - It will be regenerated. Also, I3 - It takes electrons from Au to form [AuI2] - [AuI4] - It dissolves as a complex ion, but in the gold ion-containing aqueous solution S2 in this embodiment, [AuI2]- Since the Au species is considered dominant, [AuI2] - This shows only the reactions that form complex ions.

[0035] (Experiment 1) Next, using the gold electrolysis apparatus 1 described above, Au is electrolyzed and I3 - The regeneration process was carried out. First, Au was added to a smelting tank 10 to which an I2 / KI aqueous solution prepared so that I2 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was 0.05 M and KI (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was 0.6 M. The mixture was then shaken for 16 hours in a constant temperature shaker while maintaining the temperature at 40°C to dissolve the Au until it was saturated, thereby obtaining a gold ion-containing aqueous solution S2.

[0036] Next, 77 mL of gold ion-containing aqueous solution S2 was initially added to the cathode tank 24 and 77 mL of 0.6 M KI aqueous solution was initially added to the anode tank 23 of the electrolytic cell 20. Electrolysis was performed for 2 hours by applying a voltage of 1.2 V while circulating the aqueous solutions using the liquid transfer pump 30 and the liquid return pump 40, and the current value was read using a DC voltage / current source (GS200, Yokogawa Electric Corporation). The amount of Au recovered was defined as the weight difference of the cathode 22 before and after electrolysis, and the precipitate was confirmed to be high-purity Au using SEM-EDS (JSM-6510A, JEOL). In this embodiment, the anode 21 in the electrolytic cell 20 is made of a 96 × 100 mm Pt mesh. The cathode 22 is made of a 100 × 100 mm stainless steel plate, and the effective electrode area of ​​the cathode 22 is 37 cm². 2 That is the case.

[0037] Table 1 shows the circulation rate of the aqueous solution in the electrolytic cell 20. In Table 1, the space time is the value obtained by dividing the amount of KI aqueous solution and gold ion-containing aqueous solution S2 (77 mL) initially introduced into the anode tank 23 and cathode tank 24 of the electrolytic cell 20 by the solution volume flow rate (flow rate).

[0038] [Table 1]

[0039] Figure 5 shows the effect of spatial time T on the current value in an aqueous solution. Table 2 shows the effect of spatial time T on the amount of Au recovered. Note that the current value in the graph in Figure 5 is approximately proportional to the amount of Au recovered. Also, the amount of Au recovered in Table 2 is shown as the amount of Au recovered in a single time period.

[0040] [Table 2]

[0041] As shown in Table 2, it was confirmed that the amount of Au recovered was maximum at 3.25 mmol when the spatial time T=26 min and T=64 min. Furthermore, as shown in Figure 5, the current value in the graph for spatial time T=64 min is always higher than the current value in the graph for spatial time T=26 min, confirming that the spatial time T=64 min is the best condition for connection using the slit 25a provided in the partition wall 25.

[0042] Furthermore, by adjusting the space time T of the aqueous solution to preferably 20 to 110 min, more preferably 50 to 80 min, Au can be collected with high efficiency.

[0043] Here, as a comparative example, Figure 6 shows the effect of the spatial time T of the aqueous solution on the current value when the anode tank 23 and cathode tank 24 of the electrolytic cell 20 are separated by a cation exchange membrane (DuPont, Nafion 424). Table 3 shows the effect of the spatial time T of the aqueous solution on the amount of Au recovered.

[0044] [Table 3]

[0045] As shown in Figure 6 and Table 3, the amount of Au recovered in the electrolytic cell 20 of the electrolytic collection apparatus 1 described above is about the same as when using an ion exchange membrane, confirming that Au can be collected with high efficiency.

[0046] Furthermore, the inventors have confirmed that the current efficiency in the electrolytic cell 20 of this electrolytic collection apparatus 1 is comparable to that when an ion exchange membrane is used, regardless of the space-time. The current efficiency is calculated as the ratio of the amount of electricity used for Au deposition (C) to the amount of electricity supplied (C).

[0047] Thus, it was confirmed that Au can be collected with high efficiency using the electrolytic cell 20 of this electrolytic collection device 1 without using an ion exchange membrane.

[0048] (Experiment 2) Next, experiments were conducted to investigate the effect of differences in connection conditions between the anode tank 23 and the cathode tank 24, achieved by changing the shape, size, and number of openings in the partition wall 25 of the electrolytic cell 20, on the amount of Au recovered. The circulation of the aqueous solution under each connection condition was performed by operating the liquid transfer pump 30 and the return liquid pump 40 under the same spatial time T=64min conditions that were favorable in Experiment 1.

[0049] In Experiment 2, in addition to the 2mm x 1 slit, which has the same connection conditions as the slit 25a in Experiment 1, connection conditions were prepared for a 5mm x 1 slit, which has a larger vertical width L3 than the slit 25a; connection conditions for a 2mm x 2 slit (see Figure 7(a)); and connection conditions for a 5mm diameter through-hole and a 2mm diameter through-hole, which have the shape of the opening changed to a circular through-hole 25c (see Figure 7(b)).

[0050] As shown in Figure 7(a), for the connection conditions of the 2mm x 2 slits, the upper slit 25a is the same shape and position as the slit 25a in Experiment 1, and the lower slit 25b is the same shape as slit 25a, but is positioned below the liquid level L1 of the electrolytic cell 20, that is, below the vertical center of the liquid level L1. Also, as shown in Figure 7(b), for the connection conditions of the 5mm diameter through hole and the 2mm diameter through hole, three circular through holes 25c are arranged horizontally at equal intervals at approximately the same height as the slit 25a.

[0051] Figure 8 shows the effect of the connection conditions between the anode tank 23 and the cathode tank 24 on the current value. Table 4 shows the effect of the connection conditions between the anode tank 23 and the cathode tank 24 on the amount of Au recovered.

[0052] [Table 4]

[0053] As shown in Figure 8 and Table 4, it was confirmed that the connection conditions for slit 5 mm × 1 resulted in a larger amount of Au recovery than slit 2 mm × 1, which had the same connection conditions as slit 25a in Experiment 1.

[0054] Furthermore, the connection conditions of the 2mm x 2 slits are presumed to have caused the flow from the cathode tank 24 to the anode tank 23 to become unstable through the two upper and lower slits 25a and 25b provided in the partition wall 25, resulting in increased inter-electrode resistance as shown as minute waves in the graph of Figure 8, and thus a decrease in the amount of Au recovered. It should be noted that the reason for the decrease in the amount of Au recovered is that a backflow occurred from the anode tank 23 to the cathode tank 24 through the lower slit 25b, causing I3 regenerated in the anode tank 23 to be lost. - It is also possible that a portion of the aqueous solution S1 containing the substance moved to the cathode tank 24 and redissolved the Au.

[0055] Furthermore, it is presumed that the connection conditions for the 5mm diameter through-hole and the 2mm diameter through-hole resulted in a higher inter-electrode resistance compared to the slits described above, leading to a decrease in the amount of Au recovered.

[0056] Thus, it was confirmed that Au can be collected with high efficiency by having the opening provided in the partition wall 25 of the electrolytic cell 20 be a single horizontally elongated slit 25a positioned above the liquid level L1 of the aqueous solution in the electrolytic cell 20.

[0057] As explained above, the gold electrolysis apparatus 1 of this embodiment is I3 -The electrolytic cell 20 electrolyzes an aqueous solution S2 containing gold ions obtained by dissolving Au, and the electrolytic cell 20 has a partition wall 25 separating the anode tank 23 and the cathode tank 24, and the partition wall 25 is configured to separate most of the anode tank 23 and the cathode tank 24, while allowing the remaining part to communicate, so that the anode tank 23 and the cathode tank 24 are connected by a so-called thin liquid layer formed by the partition wall 25, and I3 is regenerated in the anode tank 23. - By utilizing the sedimentation, I3 into the cathode tank 24 - By suppressing the movement of the ions and preventing the redissolution of Au in the cathode tank 24, Au can be collected with high efficiency without using an ion exchange membrane.

[0058] Furthermore, in this embodiment, the gold electrolysis apparatus 1 introduces a gold ion-containing aqueous solution S2 into the cathode tank 24, and the regenerated I3 in the anode tank 23. - By discharging the aqueous solution S1 containing the substance and performing electrolysis, the decrease in the gold ion concentration in the cathode tank 24 is suppressed, thereby increasing reactivity and thus increasing the amount of Au recovered.

[0059] Furthermore, I3 that settled in the anode tank 23 - The aqueous solution S1 containing I3 is discharged from the outlet 20a located at the bottom, into the cathode tank 24. - Because its movement is suppressed, Au can be collected with even greater efficiency.

[0060] Furthermore, by moving the aqueous solution S3 from the cathode tank 24 to the anode tank 23 through the opening provided in the partition wall 25, the flow of the aqueous solution S3 from the cathode tank 24 to the anode tank 23 can be stabilized, and the inter-electrode resistance can be reduced, thereby increasing the amount of Au recovered. In particular, since the opening is a single horizontal slit 25a, the flow of the aqueous solution S3 from the cathode tank 24 to the anode tank 23 can be further stabilized, and only this flow can be formed, thus reducing the amount of I3 in the cathode tank 24. - Its movement is suppressed, allowing for highly efficient collection of Au.

[0061] Furthermore, even though the electrolytic cell 20 is provided with an outlet 20a and an inlet 20b, by moving the aqueous solution S3 from the cathode tank 24 to the anode tank 23 through an opening in the partition wall 25, it is not necessary to adjust the water levels in the anode tank 23 and the cathode tank 24, making the operation of electrolytic extraction of Au easier.

[0062] Furthermore, the opening in the partition wall 25 is positioned above the liquid level L1 of the aqueous solution in the electrolytic cell 20, thereby preventing the sedimentation of I3 in the anode tank 23. - This method more reliably suppresses the transfer of material through the opening to the cathode tank 24, allowing for more efficient collection of Au.

[0063] Furthermore, the gold electrolytic extraction apparatus 1 of this embodiment is I3 - A smelting tank 10 dissolves Au, a liquid transfer pump 30 transfers the gold ion-containing aqueous solution S2 containing Au smelted in the smelting tank 10 to the electrolytic cell 20, and the gold ion-containing aqueous solution S2 electrolyzed in the electrolytic cell 20, i.e., I3 regenerated in the anode tank 23. - The system includes a return pump 40 that returns the aqueous solution S1 containing I3 to the smelting tank 10, thereby enabling the regeneration of I3 by electrolysis in the electrolytic cell 20. - Since the aqueous solution S1 containing can be reused in the smelting of Au in the smelting tank 10, the raw material cost of iodine used in the smelting of Au can be reduced.

[0064] Furthermore, the gold electrolytic extraction apparatus 1 uses a thin liquid layer connection via a partition wall 25 without using an ion exchange membrane in the electrolytic cell 20 to electrolyze Au and I3 - Because it enables regeneration, the manufacturing cost of the electrolytic cell 20 can be reduced, and the pH adjustment of the aqueous solution and other operations are not required, making the electrolytic extraction of Au easier.

[0065] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0066] For example, in the above embodiment, a configuration was described in which a thin liquid layer is formed by providing an opening in the partition wall 25 separating the anode tank 23 and the cathode tank 24 of the electrolytic cell 20. However, the invention is not limited to this, and for example, as shown in the modified electrolytic cell in Figure 9, the liquid level of the aqueous solution in the electrolytic cell 20 may be set higher than the upper end of the partition wall 225, so that the aqueous solutions in the anode tank 23 and the cathode tank 24 are connected by a thin liquid layer without providing an opening in the partition wall 225.

[0067] Furthermore, the partition wall 25 is an insulator and can be made of any material that is not corroded by the aqueous solution in the electrolytic cell; for example, it may be made of glass or resin.

[0068] Furthermore, although the above embodiment described the slits 25a and 25b, which serve as openings in the partition wall 25, as being formed in a straight line, the invention is not limited to this, and the slits may also be, for example, wave-shaped or arc-shaped.

[0069] Furthermore, in the above embodiment, I2 is I3 - Although we have described an embodiment using a highly versatile and inexpensive aqueous solution of KI for dissolution, it is not limited to KI; it is also possible to dissolve I in water. - Any iodine compound that produces the compound will suffice, for example, sodium iodide (NaI).

[0070] Furthermore, in the above embodiment, a gold ion-containing aqueous solution S2 is introduced into the cathode tank 24 of the electrolytic cell 20, and the regenerated I3 in the anode tank 23 - Although an embodiment in which electrolysis is performed while draining an aqueous solution S1 containing the above has been described, the electrolytic cell 20 is not limited to this, and it is not necessary to circulate the aqueous solutions, but rather to simply put each aqueous solution into the anode tank 23 and the cathode tank 24 as an initial addition. [Explanation of symbols]

[0071] 1 Electrowinning device 10 smelting tanks 20 Electrolytic cell 20a Outlet 20b Inlet 21 Anodes 22 Cathode 23 Anode Tank 24 Cathode Tanks 25 Bulkhead 25a, 25b Slit (opening) 25c Through hole (opening) 30. Liquid transfer pump (liquid transfer means) 31 Piping 40. Return liquid pump (return liquid means) 41 Piping S1 Aqueous solution S2 Gold ion-containing aqueous solution S3 aqueous solution

Claims

1. The system is equipped with an electrolytic cell that electrolyzes an aqueous solution containing gold ions, obtained by dissolving gold with triiodide ions. The electrolytic cell has a partition wall separating the anode tank and the cathode tank. The electrolytic gold extraction apparatus is characterized in that the partition wall is configured to separate most of the anode tank and the cathode tank, while allowing the remaining portion to communicate.

2. The gold electrolysis apparatus according to claim 1, characterized in that the gold ion-containing aqueous solution is introduced into the cathode tank and the aqueous solution from the anode tank is discharged to perform electrolysis.

3. The gold electrolytic extraction apparatus according to claim 2, characterized in that an outlet for discharging the aqueous solution is provided below the anode tank.

4. The gold electrolytic extraction apparatus according to claim 1, characterized in that the partition wall is provided with an opening that connects the anode tank and the cathode tank.

5. The gold electrolytic extraction apparatus according to claim 4, characterized in that the opening is a horizontally elongated slit.

6. The gold electrolytic extraction apparatus according to claim 5, characterized in that the slit is a single slit.

7. The gold electrolytic extraction apparatus according to claim 5, characterized in that the width of the slit is approximately the same as the width of the electrode.

8. The gold electrolytic extraction apparatus according to claim 4, characterized in that the opening is positioned above the liquid level of the electrolytic cell.

9. A smelting tank for dissolving gold using triiodide ions, A liquid transfer means for transferring a gold ion-containing aqueous solution containing gold refined in the aforementioned smelting tank to an electrolytic cell according to any one of claims 1 to 8, A gold electrolytic extraction apparatus characterized by comprising a return liquid means for returning the gold ion-containing aqueous solution, which has been electrolyzed by the electrolytic cell, to the smelting tank.

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