Device and method for recovering gold ions in copper ammonia thiosulfate leachate

Abstract

The invention discloses a device and a method for recycling gold ions in copper ammonia thiosulfate leachate, and belongs to the technical field of hydrometallurgy and precious metal recycling. An anode chamber and a cathode chamber which are physically and spatially isolated are built, so that the reduction reaction of the gold ions is only carried out in the cathode chamber, and only the oxidation reaction of metal zinc is carried out in the anode chamber. In order to avoid deposition of copper ions in the gold ion reduction process, before gold deposition, the existence form of the copper ions is regulated and controlled, Cu (NH3) 4 < 2 + > in a solution is converted into Cu (S2O3) 35 <-> which is difficult to deposit, then gold deposition is carried out, and after gold deposition is completed, the Cu (S2O3) 35 <-> in the solution is recovered to Cu (NH3) 4 < 2 + > by means of regulation and control of an electrochemical method. And the solution after gold ion deposition can be returned to the leaching stage for recycling under the condition that the copper ion concentration is not interfered.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrometallurgy and precious metal recovery, and in particular relates to a device and a method for recovering gold ions in a copper ammonia thiosulfate leaching solution. Background Art

[0002] Among the wet gold extraction processes, the thiosulfate leaching process, as shown in formula (1), is the most promising non-toxic and environmentally friendly process to replace the cyanide process. However, the recovery of Au(S2O3)2 from the leaching solution 3- The activated carbon adsorption method, which is widely used in the cyanide process, is ineffective in the thiosulfate gold leaching process. This phenomenon is attributed to the Au(S2O3)2 3- In order to improve the affinity of activated carbon to Au(S2O3)2 3- In order to improve the adsorption effect, scholars have studied the modification methods of activated carbon loaded with different organic functional groups in recent years, and achieved certain results. However, grafting organic functional groups on the surface of activated carbon not only complicates the modification process, but also increases the production cost of the method.

[0003] Au + 5S2O3 2- + Cu(NH3)4 2+ →Au(S2O3)2 3- + Cu(S2O3)3 5- + 4NH3 (1)

[0004] Zn + Cu(NH3)4 2+ → Zn(NH3)4 2+ + Cu (2)

[0005] Zn + 2S2O3 2- + 2H2O → Zn(S2O3)2 2- + 2OH - + H2 (3)

[0006] Zn + 4NH3 + 2H2O → Zn(NH3)4 2+ + 2OH - + H2 (4)

[0007] The replacement deposition method has also been used by many scholars to study the recovery of gold from leaching solutions, but this method also has certain defects. There are copper ions, ammonia and thiosulfate ions in the leaching solution, and the active metal also participates in the reaction with the above ions, as shown in formulas (2)-(4). The results of the solution experiment show that when using the replacement method, the amount of reducing agent used must be much larger than the amount required for the chemical reaction in order to achieve satisfactory results. For example, Zn powder is used to replace Au(S2O3)2 in the thiosulfate gold leaching solution. 3- Since Zn reacts with NH3 in the gold leaching solution to generate Zn(NH3)4 2+ , causing excessive consumption of Zn powder; due to Zn(NH3)4 2+ Entering into the solution, the Zn ions in the solution need to be removed after a period of accumulation to meet the recycling requirements of the leachate. When using the traditional replacement method, the co-precipitation of copper and gold will reduce the grade of the deposited gold. In addition, when using more active aluminum as a reducing agent, aluminum oxide is easily generated on the aluminum surface in an alkaline leaching environment, which passivates the aluminum surface.

[0008] The root cause of the above technical problems is that the oxidation reaction of the active metal and the reduction reaction of the gold ions are carried out in the same solution during replacement, which leads to the above-mentioned problems such as large metal consumption, entry of impurity ions into the solution, and easy passivation of the metal surface.

[0009] To solve the above problems, Patent 202210486249.2 proposes to build a reduction chamber and an oxidation chamber device with physical space isolation, so that the reduction reaction of gold is only carried out in the reduction chamber, and only the oxidation reaction of active metal is carried out in the oxidation chamber. The two half reactions are connected by external wires to complete the gold replacement reaction. Although this method can solve the problems of extra consumption of zinc powder and surface passivation, it is found that the problem of copper co-deposition cannot be completely overcome in actual applications, which affects the subsequent application of copper.

[0010] In addition, copper ions are catalysts in the gold leaching process, and the consumption of copper affects the recycling of the leaching solution back to the leaching stage. Therefore, it is very important to avoid the co-deposition of copper ions while replacing gold for the entire gold leaching process. Using copper powder instead of zinc can effectively avoid this problem. Patent 201180067296.3 discloses a method for electrically recovering gold and silver from a thiosulfate solution. The method uses spontaneous electrolysis to recover gold from a copper thiosulfate solution. In this method, copper is used as the anode, and the anode liquid uses the cathode solution after gold ion extraction. The anode copper is continuously dissolved and returns to the leaching stage after meeting certain requirements. However, in the anode solution containing ammonia, copper will self-corrode, which is also the main process of ammonia leaching in copper wet extraction, as shown in formula (5):

[0011] 2Cu + 8NH3 + 2H2O + O2 → 2Cu(NH3)4 2+ + 4OH - (5)

[0012] This process greatly interferes with the discharge efficiency of the anode copper. Copper is continuously dissolved at the anode, while the reduction of gold ions at the cathode is very slow. The problems caused in the application not only prolong the gold deposition time and reduce production efficiency, but also increase the copper consumption and increase the economic cost. Summary of the invention

[0013] In order to solve the above technical problems, the present invention proposes a device and method for recovering gold ions in copper ammonium thiosulfate leachate. The present invention constructs an anode chamber and a cathode chamber separated by physical space, so that the reduction reaction of gold ions is only carried out in the cathode chamber, and only the oxidation reaction of metal zinc is carried out in the anode chamber. In order to avoid the deposition of copper ions during the reduction of gold ions, before depositing gold, the existence form of copper ions is firstly regulated to make the Cu(NH3)4 2+ Converted to Cu(S2O3)3 which is difficult to deposit 5- , then gold is deposited. After the gold deposition is completed, the Cu(S2O3)3 in the solution is regulated by electrochemical methods. 5- Then it is restored to Cu(NH3)4 2+ After the gold ion deposition is completed, the solution can be returned to the leaching stage for recycling if the copper ion concentration is not disturbed.

[0014] To achieve the above object, the present invention provides the following technical solutions:

[0015] The present invention provides a method for recovering gold ions in a copper ammonia thiosulfate leachate, comprising the following steps:

[0016] (1) introducing a zinc sulfate solution, a copper ammonium thiosulfate leaching solution and a copper sulfate solution into a first reaction chamber, a second reaction chamber and a third reaction chamber separated by an ion exchange membrane, respectively;

[0017] (2) Connect the second electrode in the second reaction chamber and the copper electrode in the third reaction chamber, and wait for the Cu(NH3)4 2+ All converted to Cu(S2O3)3 5- , disconnecting the connection between the second reaction chamber and the third reaction chamber, and connecting the second electrode in the second reaction chamber and the copper electrode in the third reaction chamber to realize the conversion of divalent copper ions in the copper ammonia thiosulfate leachate into monovalent copper ions;

[0018] (3) connecting the zinc electrode of the first reaction chamber and the first electrode of the second reaction chamber to deposit gold, and detecting the gold ion concentration in the second reaction chamber until the gold ion deposition is completed;

[0019] (4) Disconnect the connection between the first reaction chamber and the second reaction chamber, replace the first electrode in the second reaction chamber, use the second electrode as the working electrode, use the replaced first electrode as the auxiliary electrode, and use the calomel electrode as the reference electrode. Control the potential of the working electrode until the Cu(S2O3)3 5- All converted to Cu(NH3)4 2+ .

[0020] In the present invention, the solution in the second reaction chamber is returned to the leaching stage, and the copper ammonia thiosulfate leaching solution is introduced into the second reaction chamber again, and steps (1) to (4) are repeated; the first electrode replaced in step (4) can be reused after gold is separated and recovered.

[0021] The present invention ensures ion exchange between the first reaction chamber and the second reaction chamber, and ion exchange between the second reaction chamber and the third reaction chamber by constructing a three-stage reaction chamber isolated by an ion exchange membrane, avoids contact between the first reaction chamber and the third reaction chamber, and enables reduction of gold ions and oxidation of zinc to be performed in a separate reaction chamber. Before the deposition of gold ions, copper ions in the copper ammonia thiosulfate leachate in the second reaction chamber are pre-reduced by the action of a copper electrode in the third reaction chamber, effectively avoiding the co-deposition of copper when recovering gold ions, and gold deposition and regulation of the valence state of copper ions in the copper ammonia thiosulfate leachate are performed in the same reaction device. After the gold deposition is completed, the copper ions in the second reaction chamber are restored to the valence state before the gold deposition by applying a controlled potential, thereby ensuring the effective concentration of copper ions in the leachate, and facilitating the recycling of the leachate. The method for recovering gold ions in a copper ammonium thiosulfate leachate provided by the present invention comprises the following steps: regulating the valence state of copper ions in the copper ammonium thiosulfate leachate before gold deposition, and restoring the valence state of copper ions after gold deposition, thereby effectively overcoming the problems of low gold deposition rate, large zinc consumption and copper co-deposition in the existing method; and providing a convenient method for recycling the leachate by restoring the valence state of copper ions in the same reaction field under the premise of ensuring the concentration of copper ions in the solution.

[0022] Preferably, the ion exchange membrane is a cation exchange membrane.

[0023] Preferably, the first electrode is a platinum electrode or a platinum-based inert metal alloy electrode. For example, the first electrode can be a platinum (Pt) electrode, a platinum-iridium alloy electrode, or a platinum-palladium alloy electrode.

[0024] Preferably, the second electrode is a non-metallic conductive material electrode. For example, the second electrode may be a carbon fiber electrode, a graphite electrode or an activated carbon electrode.

[0025] Preferably, the reactions in the first reaction chamber, the second reaction chamber and the third reaction chamber are all carried out under stirring, and the stirring speed is 200 rpm.

[0026] Preferably, the working electrode potential is controlled by an electrochemical workstation.

[0027] Preferably, the potential of the working electrode is controlled to be 80-150 mV.

[0028] The present invention also provides a device for recovering gold ions in a copper ammonia thiosulfate leachate, which is used to implement the above-mentioned method for recovering gold ions in a copper ammonia thiosulfate leachate. The device comprises a first reaction chamber, a second reaction chamber, a third reaction chamber and an electrochemical workstation for controlling a working electrode, wherein ions can be exchanged between the first reaction chamber and the second reaction chamber, and ions can be exchanged between the second reaction chamber and the third reaction chamber, and the first reaction chamber and the third reaction chamber are not in contact with each other;

[0029] The first reaction chamber is provided with a zinc electrode, the second reaction chamber is provided with a first electrode, a second electrode and a reference electrode, and the third reaction chamber is provided with a copper electrode.

[0030] Preferably, a stirring device is provided in each of the first reaction chamber, the second reaction chamber and the third reaction chamber.

[0031] Preferably, ion exchange is performed between the first reaction chamber and the second reaction chamber, and between the second reaction chamber and the third reaction chamber via an ion exchange membrane.

[0032] Compared with the prior art, the present invention has the following advantages and technical effects:

[0033] (1) Through the reaction chamber separated by the ion exchange membrane, the Cu(NH3)4 in the gold leaching solution is reacted by the self-electrochemical reaction process. 2+ Converted to Cu(S2O3)3 which is difficult to deposit 5- , avoiding the co-deposition of copper ions when gold ions are reduced. Compared with patent 202210486249.2, it not only reduces the loss of copper ions, but also meets the requirements of recycling the leaching solution;

[0034] (2) After the gold deposition was completed, Cu(S2O3)3 was realized by electrochemical method in the same reaction site. 5- Cu(NH3)4 2+Compared with patent 201180067296.3, the gold recovery method of the present invention not only reduces the consumption of copper, but also shortens the reaction time and simplifies the transfer steps of the leachate between different reaction chambers and different reaction stages to meet the return leaching use. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0036] Figure 1 The present invention is a schematic diagram of the structure of a device used in the method for recovering gold ions in a copper ammonia thiosulfate leachate solution, wherein 120 is a stirring device, 200 is a first reaction chamber, 210 is a zinc electrode, 300 is a second reaction chamber, 310 is a first electrode, 320 is a second electrode, 330 is a reference electrode, 340 is an electrochemical workstation, 400 is a third reaction chamber, 410 is a copper electrode, K1 is a first switch, and K2 is a second switch. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0038] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0039] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0040] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0041] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0042] Unless otherwise specified, the room temperature in the present invention is 25±2°C.

[0043] All raw materials used in the examples of the present invention are commercially available.

[0044] The schematic diagram of the device structure used in the method for recovering gold ions in copper ammonium thiosulfate leachate of the present invention is shown in Figure 1 , wherein 120-stirring device, 200-first reaction chamber, 210-zinc electrode, 300-reaction chamber, 310-first electrode, 320-second electrode, 330-reference electrode, 340-electrochemical workstation, 400-third reaction chamber, 410-copper electrode, K1-first switch, K2-second switch, and the dotted line represents the ion exchange membrane.

[0045] The device of the present invention comprises a first reaction chamber 200, a second reaction chamber 300, a third reaction chamber 400 and an electrochemical workstation 340 for controlling a working electrode. Ions can be exchanged between the first reaction chamber 200 and the second reaction chamber 300, ions can be exchanged between the second reaction chamber 300 and the third reaction chamber 400, and the first reaction chamber 200 and the third reaction chamber 400 are not in contact with each other.

[0046] A zinc electrode 210 is provided in the first reaction chamber 200, a first electrode 310, a second electrode 320 and a reference electrode 330 are provided in the second reaction chamber 300, and a copper electrode 410 is provided in the third reaction chamber 400; a stirring device 120 is provided in the first reaction chamber 200, the second reaction chamber 300 and the third reaction chamber 400; ion exchange is carried out between the first reaction chamber 200 and the second reaction chamber 300, and between the second reaction chamber 300 and the third reaction chamber 400 through an ion exchange membrane.

[0047] In some preferred embodiments, the first electrode 310 is selected from any one of a platinum electrode, a platinum-palladium alloy electrode, and a platinum-iridium alloy electrode.

[0048] In some preferred embodiments, the second electrode 320 is selected from any one of carbon fiber, graphite, and activated carbon.

[0049] In the embodiment of the present invention, the ion exchange membrane is a cation exchange membrane (CMI-7000S) purchased from Hangzhou Huamo Technology Co., Ltd.

[0050] The technical solution of the present invention is further illustrated by the following embodiments.

[0051] Example 1

[0052] 1) Adoption Figure 1 The device shown in the figure (comprising a first reaction chamber 200, a second reaction chamber 300, a third reaction chamber 400 and an electrochemical workstation 340 for controlling a working electrode; ion exchange can be performed between the first reaction chamber 200 and the second reaction chamber 300, ion exchange can be performed between the second reaction chamber 300 and the third reaction chamber 400, and the first reaction chamber 200 and the third reaction chamber 400 are not in contact with each other; a zinc electrode 210 is provided in the first reaction chamber 200, a first electrode 310, a second electrode 320 and a reference electrode 330 are provided in the second reaction chamber 300, and a copper electrode 410 is provided in the third reaction chamber 400; a stirring device 120 is provided in the first reaction chamber 200, the second reaction chamber 300 and the third reaction chamber 400; ion exchange is performed between the first reaction chamber 200 and the second reaction chamber 300, and between the second reaction chamber 300 and the third reaction chamber 400 through an ion exchange membrane), contains 5mmol / L Cu 2+ 、0.5mol / L NH3 / NH4 + 100 mL of copper ammonium thiosulfate leachate with a pH of 10, an Au concentration of 10 mg / L, 0.1 mol / L Na2S2O3 is added to the second reaction chamber 300, the first electrode 310 is made of an inert platinum material (Pt), and the second electrode is made of carbon fiber; the electrolyte in the first reaction chamber 200 is 100 mL of a 0.1 mol / L ZnSO4 solution, and the electrode is a zinc sheet, that is, the first reaction chamber 200 is provided with a zinc electrode 210; the electrolyte in the third reaction chamber 400 is 100 mL of a 0.1 mol / L CuSO4 solution, and the electrode is a copper sheet, that is, the third reaction chamber 400 is provided with a copper electrode 410;

[0053] 2) Control the second switch K2 to connect the second electrode 320 of the second reaction chamber and the copper electrode 410 of the third reaction chamber 400 (i.e., close the second switch K2 to make the second switch K2 in a closed state), and the stirring speed is 200 rpm; after 2 hours, 99.5% of the Cu(NH3)4 2+ Transformed into Cu(S2O3)3 5- ;

[0054] 3) disconnecting the second reaction chamber 300 and the third reaction chamber 400 (i.e., opening the second switch K2), connecting the zinc electrode 210 of the first reaction chamber 200 and the first electrode 310 of the second reaction chamber 300 with the first switch K1 (i.e., closing the first switch K1, so that the first switch K1 is in a closed state), and stirring at a speed of 200 rpm; after 4 hours, the gold deposition rate in the second reaction chamber 300 can reach 99.1%, and the copper ion concentration remains unchanged;

[0055] 4) The connection between the first reaction chamber 200 and the second reaction chamber 300 is disconnected (i.e., the first switch K1 is turned on). In the second reaction chamber 300, the platinum electrode loaded with gold is replaced with a new platinum electrode and used as the auxiliary electrode. The carbon fiber is used as the working electrode. The reference electrode 330 is a calomel electrode. The working electrode is controlled to 80 mV by the electrochemical workstation 340 and the stirring speed is 200 rpm. After 1 hour, 99.5% of the Cu(S2O3)3 in the solution is 5- Converted to Cu(NH3)4 2+ , meeting the need for recycling of leaching solution. After the gold ion deposition, the solution can be returned to the leaching stage for recycling if the copper ion concentration is not disturbed.

[0056] Example 2

[0057] 1) Adoption Figure 1 The device shown will contain 5mmol / LCu 2+ 、0.5mol / L NH3 / NH4 + 100 mL of copper ammonium thiosulfate leachate with 0.1 mol / L Na2S2O3, pH of 10 and Au concentration of 20 mg / L is added to the second reaction chamber 300, the first electrode 310 is made of an inert platinum-palladium alloy, and the second electrode 320 is made of graphite; the electrolyte in the first reaction chamber 200 is 100 mL of 0.1 mol / L ZnSO4 solution, and the electrode is a zinc sheet, that is, the first reaction chamber 200 is provided with a zinc electrode 210; the electrolyte in the third reaction chamber 400 is 100 mL of 0.1 mol / L CuSO4 solution, and the electrode is a copper sheet, that is, the third reaction chamber 400 is provided with a copper electrode 410;

[0058] 2) Control the second switch K2 to connect the second electrode 320 of the second reaction chamber 300 and the copper electrode 410 of the third reaction chamber 400, and stir at a speed of 200 rpm. After 2 hours, 99.6% of the Cu(NH3)4 2+ Transformed into Cu(S2O3)3 5- ;

[0059] 3) disconnecting the second reaction chamber 300 and the third reaction chamber 400 (i.e., opening the second switch K2), connecting the zinc electrode 210 of the first reaction chamber 200 and the first electrode 310 (platinum-palladium alloy) of the second reaction chamber 300 with the first switch K1, with the stirring speed of 200 rpm; after 4 hours, the gold deposition rate in the second reaction chamber 300 can reach 99.3%, and the copper ion concentration remains unchanged;

[0060] 4) The connection between the first reaction chamber 200 and the second reaction chamber 300 is disconnected (i.e., the first switch K1 is turned on). In the second reaction chamber 300, the electrode loaded with gold is replaced with a new platinum-palladium alloy electrode, and this is used as the auxiliary electrode. Graphite is used as the working electrode, and the reference electrode 330 is a calomel electrode. The working electrode is controlled to be 100 mV by the electrochemical workstation 340, and the stirring speed is 200 rpm. After 40 minutes, 99.5% of the Cu(S2O3)3 in the solution is 5- Converted to Cu(NH3)4 2+ , meeting the need for recycling of leaching solution. After the gold ion deposition, the solution can be returned to the leaching stage for recycling if the copper ion concentration is not disturbed.

[0061] Example 3

[0062] 1) Adoption Figure 1 The device shown will contain 5mmol / LCu 2+ 、0.5mol / L NH3 / NH4 + 100 mL of copper ammonium thiosulfate leachate with 0.1 mol / L Na2S2O3, pH of 10 and Au concentration of 20 mg / L is added to the second reaction chamber 300, the first electrode 310 is an inert platinum-iridium alloy, and the second electrode 320 is activated carbon; the electrolyte in the first reaction chamber 200 is 100 mL of 0.1 mol / L ZnSO4 solution, and the electrode is a zinc sheet, that is, the first reaction chamber 200 is provided with a zinc electrode 210; the electrolyte in the third reaction chamber 400 is 100 mL of 0.1 mol / L CuSO4 solution, and the electrode is a copper sheet, that is, the third reaction chamber 400 is provided with a copper electrode 410;

[0063] 2) Control the second switch K2 to connect the second electrode 320 of the second reaction chamber 300 and the copper electrode 410 of the third reaction chamber 400, and stir at a speed of 200 rpm. After 2 hours, 99.7% of the Cu(NH3)4 2+ Transformed into Cu(S2O3)3 5- ;

[0064] 3) disconnecting the second reaction chamber 300 and the third reaction chamber 400 (i.e., opening the second switch K2), connecting the zinc electrode 210 of the first reaction chamber 200 and the first electrode 310 (platinum-iridium alloy electrode) of the second reaction chamber 300 with the first switch K1, with the stirring speed of 200 rpm; after 4 hours, the gold deposition rate in the second reaction chamber 300 can reach 99.5%, and the copper ion concentration remains unchanged;

[0065] 4) The connection between the first reaction chamber 200 and the second reaction chamber 300 is disconnected (i.e., the first switch K1 is turned on). In the second reaction chamber 300, the electrode loaded with gold is replaced with a new platinum-iridium alloy electrode, and this electrode is used as the auxiliary electrode. The activated carbon is used as the working electrode, and the reference electrode 330 is a calomel electrode. The working electrode is controlled to be 150 mV by the electrochemical workstation 340, and the stirring speed is 200 rpm. After 30 minutes, 99.8% of the Cu(S2O3)3 in the solution is 5- Converted to Cu(NH3)4 2+ , meeting the need for recycling of leaching solution. After the gold ion deposition, the solution can be returned to the leaching stage for recycling if the copper ion concentration is not disturbed.

[0066] Comparative Example 1

[0067] According to the method of patent 202210486249.2, zinc was used as the anode, 100 mL of 0.1 mol / L ZnSO4 solution was added to the anode chamber, platinum was used as the cathode, and 5 mmol / L Cu was added to the cathode chamber. 2+ 、0.5mol / L NH3 / NH4 + , 0.1mol / LNa2S2O3, pH 10, Au concentration of 10mg / L in 100mL leaching solution, the stirring speed of the cathode and anode chambers was 200 rpm, and after 4 hours, the gold recovery rate was equivalent to that of Example 1. However, the copper ion in the solution remained 3.8mmol / L, and the copper ion in the solution was 0.1mol / LNa2S2O3, pH 10, and Au concentration of 10mg / L. The stirring speed of the cathode and anode chambers was 200 rpm. After 4 hours, the gold recovery rate was equivalent to that of Example 1. 5- The leaching solution cannot be directly recycled, and the copper loss is 24%. The lost copper and gold ions co-precipitate, reducing the grade of the recovered gold. In Example 1, there is basically no loss of copper ions in the solution. It can be seen that the present invention effectively ensures the stability of copper ions in the leaching solution and realizes Cu(NH3)4 in the same reaction site. 2+ recovery.

[0068] Comparative Example 2

[0069] According to the method of patent 201180067296.3, copper is used as the anode and 0.5 mol / L NH3 / NH4 is added to the anode chamber. +, 0.1mol / L Na2S2O3, pH 10 solution, platinum as cathode, 5mmol / L Cu 2+ 、0.5mol / LNH3 / NH4 + In 100mL of leaching solution with 0.1mol / L Na2S2O3, pH of 10, and Au concentration of 10mg / L, the stirring speed of the cathode and anode chambers was 200 rpm. After 4 hours, the gold recovery rate was only about 10%. When extended to 10 hours, the gold recovery rate was only 30%. The copper ions in the cathode liquid were Cu(S2O3)3 5- The gold recovery rate of Example 1 of the present invention can reach 99.1% within 4 hours.

[0070] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for recovering gold ions in a copper ammonium thiosulfate leachate, characterized in that: The following steps are involved: (1) introducing a zinc sulfate solution, a copper ammonium thiosulfate leaching solution and a copper sulfate solution into a first reaction chamber, a second reaction chamber and a third reaction chamber separated by an ion exchange membrane, respectively; (2) Connect the second electrode in the second reaction chamber and the copper electrode in the third reaction chamber, and wait for the Cu(NH3)4 2+ All converted to Cu(S2O3)3 5- , disconnecting the connection between the second reaction chamber and the third reaction chamber; (3) connecting the zinc electrode of the first reaction chamber and the first electrode of the second reaction chamber to deposit gold; (4) Disconnect the connection between the first reaction chamber and the second reaction chamber, replace the first electrode in the second reaction chamber, use the second electrode as the working electrode, use the replaced first electrode as the auxiliary electrode, and use the calomel electrode as the reference electrode. Control the potential of the working electrode until the Cu(S2O3)3 5- All converted to Cu(NH3)4 2+ .

2. The method for recovering gold ions in a copper ammonium thiosulfate leachate according to claim 1, wherein: The ion exchange membrane is a cation exchange membrane.

3. The method for recovering gold ions in a copper ammonia thiosulfate leachate according to claim 1, wherein: The working electrode potential was controlled by an electrochemical workstation.

4. The method for recovering gold ions in a copper ammonia thiosulfate leachate according to claim 3, wherein: The potential of the working electrode was controlled to be 80-150 mV.

5. A device for recovering gold ions from a copper ammonium thiosulfate leachate, characterized in that: A method for recovering gold ions from a copper ammonia thiosulfate leachate according to any one of claims 1 to 4, the device comprising a first reaction chamber (200), a second reaction chamber (300), a third reaction chamber (400) and an electrochemical workstation (340) for controlling a working electrode, wherein ions can be exchanged between the first reaction chamber (200) and the second reaction chamber (300), ions can be exchanged between the second reaction chamber (300) and the third reaction chamber (400), and the first reaction chamber (200) and the third reaction chamber (400) are not in contact with each other; The first reaction chamber (200) is provided with a zinc electrode (210), the second reaction chamber (300) is provided with a first electrode (310), a second electrode (320) and a reference electrode (330), and the third reaction chamber (400) is provided with a copper electrode (410).

6. The device for recovering gold ions in a cuprammonia thiosulfate leachate according to claim 5, characterized in that: A stirring device (120) is provided in each of the first reaction chamber (200), the second reaction chamber (300) and the third reaction chamber (400).

7. The device for recovering gold ions in a copper ammonia thiosulfate leachate according to claim 5, characterized in that: Ion exchange is performed between the first reaction chamber (200) and the second reaction chamber (300), and between the second reaction chamber (300) and the third reaction chamber (400) via an ion exchange membrane.

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