Method for preferentially depositing copper in copper-containing solution

Abstract

The invention provides a method for preferentially depositing copper in a copper-containing solution, and relates to the technical field of metallurgy. The method for preferentially depositing copper in the copper-containing solution comprises the following steps: adjusting the pH value of the copper-containing solution to be acidic to obtain a reaction stock solution; mixing the reaction stock solution with an excessive amount of vulcanizing agent under the protection of protective gas, and carrying out a multi-section temperature control reaction to obtain a precipitate; and carrying out solid-liquid separation on the precipitate to obtain the copper-containing compound. The purpose of effectively separating copper from other elements is achieved by utilizing the solubility difference of different metal sulfides in the solution. The method for preferentially depositing copper has the advantages of being high in selectivity, high in reaction speed, low in reagent consumption, low in cost, easy to operate, environmentally friendly, easy to achieve industrial application and the like.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a method for preferentially depositing copper in a copper-containing solution. Background Art

[0002] It has high economic value in copper-containing solutions such as battery black powder leachate, electroplating sludge leachate, ore leachate, MHP leachate, etc. However, the existing technology cannot achieve efficient separation of copper and other elements. On the one hand, the heavy metal elements therein will cause environmental pollution, and on the other hand, it will also cause waste of resources. The commonly used metal ion separation methods in the metallurgical field mainly include chemical precipitation, solvent extraction, ion exchange, etc. Among them, the chemical precipitation method can achieve the purpose of efficient extraction by adding one or more chemical reagents to cause certain substances in the solution to undergo chemical reactions to generate insoluble compounds, and then achieve liquid-solid separation. It has the advantages of low cost, large processing capacity, and simple process.

[0003] The sulfide precipitation method selectively precipitates copper based on the difference in solubility between copper sulfide and other metal sulfides in the solution, thereby separating and precipitating copper, while other metals return to the solution in the form of ions. Commonly used sulfiding agents include H2S, Na2S, NaHS, FeS, etc. However, H2S gas is highly toxic and corrosive, and has adverse effects on air, water, soil and organisms. The use of H2S copper precipitation requires high equipment and is prone to environmental pollution and physical harm; Na2S is easy to generate H2S gas in an acidic system, and it is difficult to control S 2- Ion concentration; NaHS copper precipitation requires a large amount of reagents, and the loss of other high-value metal elements such as nickel and cobalt is relatively large; FeS copper precipitation will cause a large amount of ferrous ions to dissolve, increasing the burden of subsequent hydrolysis and iron precipitation. Therefore, how to choose a suitable sulfiding agent, achieve preferential and efficient copper precipitation in copper-containing solutions at a low cost, improve the recovery rate of copper ions and minimize the loss of other ions has become an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present application is to provide a method for preferentially depositing copper in a copper-containing solution to solve the above-mentioned problem.

[0005] To achieve the above objectives, this application adopts the following technical solutions: The present application provides a method for preferentially precipitating copper in a copper-containing solution, comprising: adjusting the pH value of the copper-containing solution to acidity to obtain a reaction stock solution; mixing the reaction stock solution with an excess of a sulfiding agent under the protection of a protective gas, and obtaining a precipitate after a multi-stage temperature-controlled reaction; and subjecting the precipitate to solid-liquid separation to obtain a copper-containing compound.

[0006] Preferably, the copper-containing solution includes battery black powder leachate, electroplating sludge leachate, ore leachate, and MHP leachate.

[0007] Preferably, the concentration of copper in the copper-containing solution is 0.5-20 g / L.

[0008] Preferably, the pH value corresponding to the acidity is 0.5-4.

[0009] Preferably, the vulcanizing agent includes one or more of elemental sulfur, sodium thiosulfate, sodium sulfite, sulfur dioxide, and sodium pyrosulfite.

[0010] Preferably, when the vulcanizing agent is a mixture of sodium thiosulfate and sodium sulfite, the ratio of the sodium thiosulfate to the sodium sulfite is 1:9 to 9:1.

[0011] Preferably, when the vulcanizing agent is a mixture of elemental sulfur and sulfur dioxide, the ratio of the elemental sulfur to the sulfur dioxide is 1:2 to 2:1; Preferably, when the vulcanizing agent is a mixture of elemental sulfur and sodium pyrosulfite, the ratio of the elemental sulfur to the sodium pyrosulfite is 3:1 to 1:1.

[0012] Preferably, the protective gas includes one or more of nitrogen, argon and helium.

[0013] Preferably, the excess coefficient of the vulcanizing agent is 0.8-4.0.

[0014] Preferably, the multi-stage temperature-controlled reaction includes a front-stage reaction and a back-stage reaction; the front-stage reaction and / or the back-stage reaction each independently include no less than one reaction section.

[0015] Preferably, the temperature of the front-end reaction is 65-80°C, and the temperature of the back-end reaction is 80-95°C.

[0016] Compared with the prior art, the beneficial effects of this application include: The present application utilizes the difference in solubility of different metal sulfides in solution, and realizes preferential copper precipitation in copper-containing solution by multi-stage temperature control under the protection of protective gas, thereby reducing the consumption of sulfiding agent and achieving the purpose of effectively separating copper from other elements. The method for preferential copper precipitation provided by the present application has the advantages of high selectivity, fast reaction speed, low reagent consumption, low cost, simple operation, environmental friendliness, and easy industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0018] Figure 1A schematic diagram of a process flow of preferential copper deposition provided in an embodiment; Figure 2 Schematic diagram of the temperature control device used in the embodiment. DETAILED DESCRIPTION

[0019] As used herein: "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0020] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0021] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0022] In these examples, parts and percentages are by mass unless otherwise indicated.

[0023] "Mass parts" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass parts of component A are a parts and the mass parts of component B are b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts.

[0024] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0025] In order to better explain the technical solution provided by this application, before the embodiments, the technical solution is first described as a whole, as follows: The pH value of the copper-containing solution is adjusted to acidic to obtain a reaction stock solution; The reaction stock solution is mixed with an excess of a sulfiding agent under the protection of a protective gas, and subjected to a multi-stage temperature-controlled reaction to obtain a precipitate; the precipitate is subjected to solid-liquid separation to obtain a copper-containing compound.

[0026] After liquid-solid separation, copper exists in the slag in the form of copper sulfide, and other ions exist in the solution, achieving preferential copper precipitation.

[0027] In an optional embodiment, the copper-containing solution includes battery black powder leaching solution, electroplating sludge leaching solution, ore leaching solution, and MHP leaching solution. Among them, the battery black powder leaching refers to the process of extracting soluble substances from battery black powder with chemical solvents, and the black powder includes various battery black powders such as nickel cobalt manganese oxide ternary positive electrode, lithium cobalt oxide, lithium iron phosphate, and lithium manganese iron phosphate; the electroplating sludge leaching refers to the process of extracting soluble substances from various complex precipitates generated in the electroplating wastewater treatment process with chemical solvents; the ore leaching refers to the process of extracting soluble substances from ores with chemical solvents based on the physical and chemical properties of certain minerals; the MHP leaching refers to the process of extracting soluble substances from crude or refined nickel cobalt hydroxide with chemical solvents.

[0028] In an optional embodiment, the concentration of copper in the copper-containing solution is 0.5~20g / L.

[0029] Optionally, the concentration of copper in the copper-containing solution can be 0.5 g / L, 2.0 g / L, 4.0 g / L, 6.0 g / L, 8.0 g / L, 10.0 g / L, 12.0 g / L, 14.0 g / L, 16.0 g / L, 18.0 g / L, 20.0 g / L, or any value between 0.5 and 20 g / L.

[0030] In an optional embodiment, the pH value corresponding to the acidity is 0.5-4.

[0031] Optionally, the pH value corresponding to the acidity may be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, or any value between 0.5 and 4.

[0032] In an optional embodiment, the vulcanizing agent includes one or more of elemental sulfur, sodium thiosulfate, sodium sulfite, sulfur dioxide, and sodium pyrosulfite. The vulcanizing agent refers to a substance that can react chemically with metal elements such as copper, nickel, cobalt, and manganese under certain conditions to generate sulfide precipitates. The use of the vulcanizing agent can convert different metal ions into corresponding precipitates and then separate the metal ions from the solution.

[0033] In an optional embodiment, when the vulcanizing agent is a mixture of sodium thiosulfate and sodium sulfite, the ratio of the sodium thiosulfate to the sodium sulfite is 1:9 to 9:1.

[0034] In an optional embodiment, when the vulcanizing agent is a mixture of elemental sulfur and sulfur dioxide, the ratio of the elemental sulfur to the sulfur dioxide is 1:2 to 2:1; In an optional embodiment, when the vulcanizing agent is a mixture of elemental sulfur and sodium pyrosulfite, the ratio of the elemental sulfur to the sodium pyrosulfite is 3:1 to 1:1.

[0035] In an optional embodiment, the protective gas includes one or more of nitrogen, argon, and helium.

[0036] In an optional embodiment, the excess coefficient of the vulcanizing agent is 0.8~4.0.

[0037] Optionally, the excess coefficient of the vulcanizing agent can be 0.8, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, or any value between 0.8 and 4.0.

[0038] Taking sodium thiosulfate as an example, the main reaction equation occurring during copper deposition is: S2O3 2- +Cu 2+ +H2O=CuS↓+2H + However, the following side effects may also occur: 2Na2S2O3+3O2=2Na2SO4+2SO2(↑) S2O3 2- +2H3O + =SO2(↑)+S+3H2O It can be seen that the side reaction will generate pollutants SO2, which will damage the environment, increase the consumption of sulfiding agents, and increase costs. Therefore, gas protection can isolate oxygen in the air, prevent the oxidation of sulfiding agents, reduce side reactions, thereby increasing the precipitation rate of copper, reducing the consumption of sulfiding agents, and reducing costs.

[0039] In an optional technical solution, the multi-stage temperature control reaction includes a front-stage reaction and a rear-stage reaction; the front-stage reaction and / or the rear-stage reaction each independently include no less than one reaction section. The temperature of the continuous reaction tank is set to be low in the front and high in the back, and the temperature is controlled in sections. The low temperature of the first one or several reaction tanks can inhibit side reactions, reduce the generation of pollutants SO2, and thus reduce reagent consumption, thereby reducing costs. The high temperature of the last one or several reaction tanks can increase the precipitation rate of copper and ensure the final copper deposition effect.

[0040] In an optional embodiment, the temperature of the front-end reaction is 65-80°C, and the temperature of the back-end reaction is 80-95°C.

[0041] Optionally, the temperature of the front-end reaction can be 65° C., 66° C., 67° C., 68° C., 69° C., 70° C., 71° C., 72° C., 73° C., 74° C., 75° C., 76° C., 77° C., 78° C., 79° C., 80° C., or any value between 65 and 80° C. The temperature of the back-end reaction can be 80° C., 81° C., 82° C., 83° C., 84° C., 85° C., 86° C., 87° C., 88° C., 89° C., 90° C., or any value between 80 and 95° C.

[0042] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0043] The copper-containing solution used in this application is introduced as follows: Taking the black powder leaching solution of waste lithium-ion batteries from a domestic factory as the copper-containing solution, its main element analysis is shown in Table 1: Table 1 Main element components of black powder leaching solution from waste lithium-ion battery of a domestic factory

[0044] Example 1 like Figure 1 As shown, this embodiment provides a method for preferentially depositing copper in a copper-containing solution, and the specific process is as follows: The pH value of the black powder leaching solution was adjusted to 0.9 to obtain a reaction stock solution. Figure 2The equipment shown in the figure was used for continuous experiments. Sodium thiosulfate with an excess coefficient of 1.4 was added to the reaction stock solution under the protection of nitrogen. The reaction temperature of tank T1 was set to 75°C, and the reaction temperature of tanks T2 to T5 was set to 85°C. After the sulfidation precipitation reaction, the precipitate was obtained. After filtering the precipitate, it was tested and the copper precipitation rate was 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0045] Example 2 This embodiment provides a method for preferentially depositing copper in a copper-containing solution, and the specific process is as follows: The pH value of the black powder leaching solution was adjusted to 1.5 to obtain a reaction stock solution. Figure 2 The equipment shown in the figure was used for continuous experiments. Sodium thiosulfate with an excess coefficient of 1.3 was added to the reaction stock solution under the protection of nitrogen. The reaction temperature of tank T1 was set to 75°C, and the reaction temperature of tanks T2 to T5 was set to 80°C. After the sulfidation precipitation reaction, the precipitate was obtained. After filtering the precipitate, it was tested and the copper precipitation rate was measured to be 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0046] Example 3 This embodiment provides a method for preferentially depositing copper in a copper-containing solution, and the specific process is as follows: The pH value of the black powder leaching solution was adjusted to 1.5 to obtain a reaction stock solution. Figure 2 The equipment shown in the figure was used for continuous experiments. Sodium thiosulfate with an excess coefficient of 1.3 was added to the reaction stock solution under the protection of nitrogen. The reaction temperature of tank T1 was set to 75°C, and the reaction temperature of tanks T2 to T5 was set to 85°C. After the sulfidation precipitation reaction, a precipitate was obtained. After filtering the precipitate, it was tested and the copper precipitation rate was 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0047] Example 4 This embodiment provides a method for preferentially depositing copper in a copper-containing solution, and the specific process is as follows: The pH value of the black powder leaching solution was adjusted to 0.9 to obtain a reaction stock solution. Figure 2 The equipment shown in the figure was used for continuous experiments. Sodium thiosulfate with an excess coefficient of 1.4 was added to the reaction stock solution under the protection of nitrogen, the reaction temperature of tank T1 was set to 65°C, and the reaction temperature of tanks T2 to T5 was set to 80°C; after the sulfidation precipitation reaction, a precipitate was obtained, which was filtered and tested, and the copper precipitation rate was measured to be 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0048] Example 5 This embodiment provides a method for preferentially depositing copper in a copper-containing solution, and the specific process is as follows: The pH value of the black powder leaching solution was adjusted to 0.9 to obtain a reaction stock solution. Figure 2The equipment shown in the figure was used for continuous experiments. Sodium thiosulfate with an excess coefficient of 1.4 was added to the reaction stock solution under the protection of nitrogen, the reaction temperature of tank T1 was set to 80°C, and the reaction temperature of tanks T2 to T5 was set to 95°C; after the sulfidation precipitation reaction, a precipitate was obtained, which was filtered and tested, and the copper precipitation rate was measured to be 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0049] Example 6 This embodiment provides a method for preferentially depositing copper in a copper-containing solution, and the specific process is as follows: The pH value of the black powder leaching solution was adjusted to 4 to obtain a reaction stock solution. Figure 2 The equipment shown in the figure was used for continuous experiments. Sodium thiosulfate with an excess coefficient of 1.4 was added to the reaction stock solution under the protection of nitrogen. The reaction temperature of tank T1 was set to 75°C, and the reaction temperature of tanks T2 to T5 was set to 85°C. After the sulfidation precipitation reaction, the precipitate was obtained. After filtering the precipitate, it was tested and the copper precipitation rate was 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0050] Example 7 The pH value of the black powder leaching solution was adjusted to 0.9 to obtain a reaction stock solution. Figure 2 The equipment shown in the figure was used for continuous experiments. Under the protection of nitrogen, the reaction stock solution was added with a mixture of sodium thiosulfate and sodium sulfite with an excess coefficient of 1.4 and a ratio of 8:2. The reaction temperature of tank T1 was set to 75°C, and the reaction temperature of tanks T2 to T5 was set to 85°C. After the sulfidation precipitation reaction, a precipitate was obtained, which was filtered and tested. The copper precipitation rate was 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0051] Example 8 The pH value of the black powder leaching solution was adjusted to 0.9 to obtain a reaction stock solution. Figure 2 The equipment shown in the figure was used for continuous experiments. A mixture of sulfur and sulfur dioxide with an excess coefficient of 1.4 and a ratio of 1:1 was added to the reaction stock solution under the protection of nitrogen. The reaction temperature of tank T1 was set to 75°C, and the reaction temperature of tanks T2 to T5 was set to 85°C. After the sulfidation precipitation reaction, a precipitate was obtained. After filtering the precipitate, it was tested and the copper precipitation rate was 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0052] Example 9 The pH value of the black powder leaching solution was adjusted to 0.9 to obtain a reaction stock solution. Figure 2The equipment shown in the figure was used for continuous experiments. A mixture of sulfur and sodium pyrosulfite with an excess coefficient of 1.4 and a ratio of 2:1 was added to the reaction stock solution under the protection of nitrogen. The reaction temperature of tank T1 was set to 75°C, and the reaction temperature of tanks T2 to T5 was set to 85°C. After the sulfidation precipitation reaction, a precipitate was obtained. After filtering the precipitate, it was tested and the copper precipitation rate was 99.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0053] Comparative Example 1 This comparative example provides a copper deposition method of a copper-containing solution, and the specific process is as follows: The pH value of the black powder leachate was adjusted to 0.9, and the Figure 2 The equipment shown was used for continuous experiments. Sodium thiosulfate was added with an excess coefficient of 1.3 under air atmosphere, and the reaction temperature of tanks T1 to T5 was set at 85°C. The copper precipitation rate was 97.0%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0054] Comparative Example 2 This comparative example provides a copper deposition method of a copper-containing solution, and the specific process is as follows: The pH value of the black powder leachate was adjusted to 0.9, and the Figure 2 The equipment shown was used for continuous experiments. Sodium thiosulfate was added with an excess coefficient of 1.3 under air atmosphere, and the reaction temperature of tanks T1 to T5 was set to 75°C. The copper precipitation rate was 94.9%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0055] Comparative Example 3 This comparative example provides a copper deposition method of a copper-containing solution, and the specific process is as follows: The pH value of the black powder leachate was adjusted to 1.5, and the Figure 2 The equipment shown was used for continuous experiments. Sodium thiosulfate was added with an excess coefficient of 1.3 under nitrogen protection, and the reaction temperature of tanks T1 to T5 was set to 75°C. The copper precipitation rate was 96.1%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0056] Comparative Example 4 This comparative example provides a copper deposition method of a copper-containing solution, and the specific process is as follows: The pH value of the black powder leachate was adjusted to 0.9, and the Figure 2 The equipment shown was used for continuous experiments. Sodium thiosulfate was added with an excess coefficient of 1.3 under nitrogen protection, and the reaction temperature of tanks T1 to T5 was set to 95°C. The copper precipitation rate was 99.7%, and the nickel and cobalt precipitation rates were less than 0.2%.

[0057] Comparative Example 5 This comparative example provides a copper deposition method of a copper-containing solution, and the specific process is as follows: The pH value of the black powder leaching solution was adjusted to 7.0 to obtain a reaction stock solution. Figure 2 The equipment shown in the figure was used for continuous experiments. Sodium thiosulfate with an excess coefficient of 1.4 was added to the reaction stock solution under the protection of nitrogen, the reaction temperature of tank T1 was set to 75°C, and the reaction temperature of tanks T2 to T5 was set to 85°C; after the sulfidation precipitation reaction, the precipitate was obtained, and the precipitate was filtered and tested, and the copper precipitation rate was measured to be 87.3%, and the nickel and cobalt precipitation rates were higher than 1%.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0059] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for preferentially depositing copper in a copper-containing solution, characterized in that: include, The pH value of the copper-containing solution is adjusted to acidic to obtain a reaction stock solution; The reaction stock solution is mixed with an excess of a sulfiding agent under the protection of a protective gas and subjected to a multi-stage temperature-controlled reaction to obtain a precipitate; The precipitate is subjected to solid-liquid separation to obtain a copper-containing compound.

2. The method for preferentially depositing copper in a copper-containing solution according to claim 1, wherein The copper-containing solution includes battery black powder leaching solution, electroplating sludge leaching solution, ore leaching solution and MHP leaching solution.

3. The method for preferentially depositing copper in a copper-containing solution according to claim 1, characterized in that: The concentration of copper in the copper-containing solution is 0.5-20 g / L.

4. The method for preferentially depositing copper in a copper-containing solution according to claim 1, characterized in that: The pH value corresponding to the acidity is 0.5-4.

5. The method for preferentially depositing copper in a copper-containing solution according to claim 1, characterized in that: The vulcanizing agent includes one or more of sodium thiosulfate, sodium sulfite, elemental sulfur, sulfur dioxide, and sodium pyrosulfite.

6. The method for preferentially depositing copper in a copper-containing solution according to claim 5, characterized in that: At least one of the following conditions is met: a. The vulcanizing agent is a mixture of sodium thiosulfate and sodium sulfite, and the ratio of the sodium thiosulfate to the sodium sulfite is 1:9~9:1; b. The vulcanizing agent is a mixture of elemental sulfur and sulfur dioxide, and the ratio of the elemental sulfur to the sulfur dioxide is 1:2~2:1; c. The vulcanizing agent is a mixture of elemental sulfur and sodium pyrosulfite, and the ratio of the elemental sulfur to the sodium pyrosulfite is 3:1~1:

1.

7. The method for preferentially depositing copper in a copper-containing solution according to claim 1, characterized in that: The protective gas includes one or more of nitrogen, argon and helium.

8. The method for preferentially depositing copper in a copper-containing solution according to claim 1, characterized in that: The excess coefficient of the vulcanizing agent is 0.8-4.

0.

9. The method for preferential copper deposition in a copper-containing solution according to any one of claims 1 to 8, characterized in that: The multi-stage temperature-controlled reaction includes a front-stage reaction and a back-stage reaction; the front-stage reaction and / or the back-stage reaction each independently include no less than one reaction.

10. The method for preferentially depositing copper in a copper-containing solution according to claim 9, characterized in that: The temperature of the front-end reaction is 65-80°C, and the temperature of the back-end reaction is 80-95°C.

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