Additive for cooperatively controlling chlorine content and sulfur content in cathode copper in high-purity copper electrolysis process and use method of additive

Abstract

The invention discloses an additive for cooperatively controlling the content of chlorine and sulfur in cathode copper in the process of electrolyzing high-purity copper and a using method of the additive, and belongs to the technical field of copper electrolytic refining. The additive is composed of a basic agent and a synergist, the basic agent is gelatin, and the synergist is any one or a combination of more of thiourea, polyethylene glycol, succinic acid, bis (3-sulfopropyl) disulfide, polyvinyl alcohol, benzotriazole, thiosulfuric acid, ammonium thiosulfate and 3-mercaptopropane sulfonic acid; the addition amount of the basic agent is 20-60g / t, and cathode copper is separated out; and the additive amount of the synergist is 0-40g / t-separated cathode copper. All the components of the additive are mixed in proportion and added into the copper electrolyte, and cathode copper is separated out when the total concentration is 30-200 g / t. And the electrolysis process parameters are as follows: the current density is 50-300A / m < 2 >, the electrolysis temperature is 15-60 DEG C, and the cathode electrolysis time is 24-120 hours. The additive is low in cost and simple to use, is applied to electrolytic refining of copper, can be used for obtaining high-purity copper and simultaneously reducing the chlorine content and the sulfur content in cathode copper to be less than or equal to 2ppm and less than or equal to 0.1 ppm respectively, and has a good industrial application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of copper electrolytic refining, and particularly relates to an additive for synergistically controlling the chlorine and sulfur contents in cathode copper during the electrolysis of high-purity copper and a method for using the same. Background Art

[0002] Due to its excellent physical and chemical properties, high-purity copper plays an important role in fields such as integrated circuits, semiconductors, aerospace, etc. However, during the electrolysis of high-purity copper, the control of the contents of impurities such as chlorine and sulfur in cathode copper has always been a technical problem. Traditional electrolysis methods, vacuum distillation methods, zone melting, vacuum induction melting methods, etc. are all difficult to simultaneously reduce the chlorine content to ≤2 ppm and the sulfur content to ≤0.1 ppm. High-purity copper with a purity of HPCu-6N5 and above requires extremely low contents of impurities such as Cl and S. For example, HPCu-6N5 high-purity copper requires the Cl and S contents to be ≤2 ppm and 0.2 ppm respectively, and HPCu-7N high-purity copper requires the Cl and S contents to be ≤1 ppm and 0.1 ppm respectively. Therefore, developing an additive that can synergistically control the Cl and S contents in cathode copper during electrolysis is of great significance for preparing high-purity copper with a purity of HPCu-6N5 and above and improving the efficiency of the preparation process. Summary of the Invention

[0003] The first object of the present invention is to provide an additive for synergistically controlling the chlorine and sulfur contents in cathode copper during the electrolysis of high-purity copper. The second object of the present invention is to provide a method for using the additive.

[0004] The first object of the present invention is achieved as follows: The additive for synergistically controlling the chlorine and sulfur contents in cathode copper during the electrolysis of high-purity copper is composed of a base agent and a synergist. The base agent is gelatin, and the synergist is any one or a combination of thiourea, polyethylene glycol, succinic acid, bis(3-sulfopropyl) disulfide, polyvinyl alcohol (PVA), benzotriazole (BTA), thiosulfuric acid, ammonium thiosulfate, 3-mercaptopropanesulfonic acid; The component composition of the additive is calculated based on cathode copper. The addition amount of the base agent gelatin is 20 - 60 g / t of precipitated cathode copper; the addition amount of the synergist is 0 - 40 g / t of precipitated cathode copper.

[0005] The second object of the present invention is achieved as follows: The method for using the additive includes: mixing the components of the additive in proportion, and then adding the additive to the copper electrolyte, controlling the total concentration of the additive to be 30 - 200 g / t of precipitated cathode copper; When using the additive, the supporting electrolysis process parameters are: the current density is 50 - 300 A / m 2, the electrolysis temperature is 15~60°C, the cathode electrolysis time is 24~120 h, 4N copper is used as the anode, and 316L stainless steel or a titanium plate with a titanium content ≥99.0% is used as the cathode.

[0006] The technical solution of the present invention has the following advantages compared with the prior art: Gelatin, the base agent in the additive of the present invention, can adsorb on the cathode surface, prevent the disordered deposition of copper ions, and thus reduce the formation of coarse grains, making the cathode copper more uniform and dense, which is convenient for subsequent processing and utilization. On the other hand, the base agent gelatin can also reduce the precipitation of impurity ions on the cathode and improve the purity of the electrolytic copper.

[0007] The synergist can form complexes with impurity ions in the electrolyte, inhibit the dissolution and precipitation of impurities, improve the purity of the cathode copper, and at the same time slow down the uneven deposition of copper ions, prevent the formation of rough crystals, and improve the morphology and quality of the cathode copper. In addition, by inhibiting the dissolution of impurities in the anode, the generation amount of anode slime can also be reduced, which is beneficial to the cleaning and recycling of the electrolyte.

[0008] In summary, when the additive of the present invention is used for the electrolytic refining of copper, while obtaining high-purity copper such as HPCu-6N5 and HPCu-7N, the chlorine and sulfur contents in the cathode copper can be simultaneously reduced to ≤2 ppm and ≤0.1 ppm. In addition, the additive has a simple usage method and low cost, and has good industrial application prospects. Specific Embodiments

[0009] The following further describes the present invention, but does not limit the present invention in any way. Any transformation or replacement based on the teachings of the present invention belongs to the protection scope of the present invention.

[0010] The additive for co-controlling the chlorine and sulfur contents in the cathode copper during the electrolysis of high-purity copper is composed of a base agent and a synergist. The base agent is gelatin, and the synergist is any one or a combination of more than one of thiourea, polyethylene glycol, succinic acid, bis(3-sulfopropyl) disulfide, polyvinyl alcohol (PVA), benzotriazole (BTA), thiosulfuric acid, ammonium thiosulfate, 3-mercaptopropanesulfonic acid; The component composition of the additive is calculated based on the cathode copper. The addition amount of the base agent gelatin is 20~60 g / t of precipitated cathode copper; the addition amount of the synergist is 0~40 g / t of precipitated cathode copper.

[0011] The addition amount of the synergist is preferably 5~40 g / t of precipitated cathode copper.

[0012] The synergist is preferably any one or a combination of two of polyethylene glycol, succinic acid, benzotriazole (BTA), thiourea, polyvinyl alcohol (PVA), bis(3-sulfopropyl) disulfide.

[0013] The molecular weight of the polyethylene glycol is 800 - 10000 Da, preferably 6000 - 8000 Da.

[0014] The method for using the additive includes: mixing the components of the additive in proportion, and then adding the additive into the copper electrolyte, controlling the total concentration of the additive to be 30 - 200 g / t - precipitated cathode copper; When using the additive, the supporting electrolysis process parameters are: current density of 50 - 300 A / m², electrolysis temperature of 15 - 60 °C, cathode electrolysis time of 24 - 120 h, using 4N copper as the anode, and using 316L stainless steel or a titanium plate with a titanium content of ≥99.0% as the cathode.

[0015] When adding the additive into the copper electrolyte, the total concentration of the additive is preferably 80 - 120 g / t - precipitated cathode copper.

[0016] The copper electrolyte is a copper sulfate electrolyte with a copper ion concentration of 30 - 80 g / L, a sulfuric acid concentration of 50 - 100 g / L, and a hydrochloric acid concentration of 0.05 - 0.4 g / L, or a copper nitrate electrolyte with a copper ion concentration of 30 - 80 g / L, a nitric acid concentration of 1 - 50 g / L, and a hydrochloric acid concentration of 0.05 - 0.4 g / L.

[0017] When using the additive, the supporting electrolysis process parameters are preferably: current density of 150 - 250 A / m 2 , electrolysis temperature of 20 - 40 °C, and cathode electrolysis time of 48 - 96 h.

[0018] Example 1 Additive components: The base agent is gelatin, with an addition amount of 40 g / t - precipitated cathode copper; the synergist is polyethylene glycol (molecular weight 6000 Da), with an addition amount of 20 g / t - precipitated cathode copper.

[0019] Additive use: Mix the above components of the additive in proportion, and then add the additive into the copper sulfate electrolyte. The copper sulfate electrolyte has a copper ion concentration of 50 g / L, a sulfuric acid concentration of 70 g / L, and a hydrochloric acid concentration of 0.2 g / L, controlling the total concentration of the additive to be 100 g / t - precipitated cathode copper.

[0020] When using the additive, the supporting electrolysis process parameters are: current density of 200 A / m 2 , electrolysis temperature of 30 °C, cathode electrolysis time of 72 h, using 4N copper as the anode, and using 316L stainless steel as the cathode.

[0021] After electrolysis, the chlorine content in the cathode copper is reduced to 1.50 ppm, and the sulfur content is reduced to 0.08 ppm, meeting the requirements of HPCu-6N5 high-purity copper.

[0022] Example 2

[0023] Additive components: The base agent is gelatin, and the addition amount is 30 g / t of precipitated cathode copper; the synergist is succinic acid, and the addition amount is 10 g / t of precipitated cathode copper.

[0024] Additive use: Mix the above components of the additive in proportion, and then add the additive to the copper nitrate electrolyte. The copper ion concentration of the copper nitrate electrolyte is 40 g / L, the nitric acid concentration is 30 g / L, and the hydrochloric acid concentration is 0.15 g / L. Control the total concentration of the additive to be 80 g / t of precipitated cathode copper.

[0025] When using the additive, the supporting electrolysis process parameters are: current density is 180 A / m 2 , electrolysis temperature is 25 °C, cathode electrolysis time is 48 h, using 4N copper as the anode and titanium plate with titanium content ≥ 99.0% as the cathode.

[0026] After electrolysis, the chlorine content in the cathode copper is reduced to 1.80 ppm, and the sulfur content is reduced to 0.09 ppm, meeting the requirements of HPCu-6N5 high-purity copper.

[0027] Example 3 Additive components: The base agent is gelatin, and the addition amount is 50 g / t of precipitated cathode copper; the synergist is benzotriazole (BTA), and the addition amount is 5 g / t of precipitated cathode copper.

[0028] Additive use: Mix the above components of the additive in proportion, and then add the additive to the copper sulfate electrolyte. The copper ion concentration of the copper sulfate electrolyte is 60 g / L, the sulfuric acid concentration is 80 g / L, and the hydrochloric acid concentration is 0.3 g / L. Control the total concentration of the additive to be 120 g / t of precipitated cathode copper.

[0029] When using the additive, the supporting electrolysis process parameters are: current density is 220 A / m 2 , electrolysis temperature is 35 °C, cathode electrolysis time is 96 h, using 4N copper as the anode and 316L stainless steel as the cathode.

[0030] After electrolysis, the chlorine content in the cathode copper is reduced to 0.94 ppm, and the sulfur content is reduced to 0.07 ppm, meeting the requirements of HPCu-7N high-purity copper.

[0031] Example 4

[0032] Additive components: The base agent is gelatin, and the addition amount is 25 g / t of precipitated cathode copper; the synergist is a combination of thiourea and polyvinyl alcohol (PVA). The addition amount of thiourea is 8 g / t of precipitated cathode copper, and the addition amount of PVA is 12 g / t of precipitated cathode copper.

[0033] Additive usage: Mix the above components of the additive in proportion, and then add the additive to the copper sulfate electrolyte. The copper ion concentration of the copper sulfate electrolyte is 45 g / L, the sulfuric acid concentration is 60 g / L, and the hydrochloric acid concentration is 0.1 g / L. Control the total concentration of the additive to be 90 g / t of precipitated cathode copper.

[0034] When using the additive, the supporting electrolysis process parameters are: the current density is 160 A / m 2 , the electrolysis temperature is 20 °C, the cathode electrolysis time is 60 h, using 4N copper as the anode and a titanium plate with a titanium content of ≥99.0% as the cathode.

[0035] After electrolysis, the chlorine content in the cathode copper is reduced to 1.41 ppm, and the sulfur content is reduced to 0.06 ppm, meeting the requirements of HPCu-6N5 high-purity copper.

[0036] Example 5 Additive components: The base agent is gelatin, and the addition amount is 35 g / t of precipitated cathode copper; the synergist is bis(3-sulfopropyl) disulfide, and the addition amount is 15 g / t of precipitated cathode copper.

[0037] Additive usage: Mix the above components of the additive in proportion, and then add the additive to the copper nitrate electrolyte. The copper ion concentration of the copper nitrate electrolyte is 35 g / L, the nitric acid concentration is 20 g / L, and the hydrochloric acid concentration is 0.25 g / L. Control the total concentration of the additive to be 110 g / t of precipitated cathode copper.

[0038] When using the additive, the supporting electrolysis process parameters are: the current density is 240 A / m 2 , the electrolysis temperature is 40 °C, the cathode electrolysis time is 80 h, using 4N copper as the anode and 316L stainless steel as the cathode.

[0039] After electrolysis, the chlorine content in the cathode copper is reduced to 1.00 ppm, and the sulfur content is reduced to 0.05 ppm, meeting the requirements of HPCu-7N high-purity copper.

Claims

1. An additive for collaboratively controlling the chlorine and sulfur contents in cathode copper during electrolysis of high-purity copper, characterized in that: The additive is composed of a base agent and a synergist, wherein the base agent is gelatin, and the synergist is any one or more of thiourea, polyethylene glycol, succinic acid, bis(3-sulfopropyl) disulfide, polyvinyl alcohol, benzotriazole, thiosulfuric acid, ammonium thiosulfate, and 3-mercaptopropane sulfonic acid. The component composition of the additive is calculated based on cathode copper, the addition amount of the base agent gelatin is 20-60 g / t-precipitated cathode copper; the addition amount of the synergist is 0-40 g / t-precipitated cathode copper.

2. The additive according to claim 1, characterized in that The addition amount of the synergist is 5-40 g / t-precipitated cathode copper.

3. The additive according to any one of claims 1 or 2, characterized in that The synergist is any one of polyethylene glycol, succinic acid, benzotriazole, thiourea, polyvinyl alcohol, and bis(3-sulfopropyl) disulfide, or a combination of two of them.

4. The additive according to claim 3, characterized in that The molecular weight of the polyethylene glycol is 800-10000Da.

5. A method for using the additive according to any one of claims 1 or 2, characterized in that: The components of the additive are mixed in proportion, and then the additive is added to the copper electrolyte, and the total concentration of the additive is controlled to be 30-200 g / t-to precipitate cathode copper; When the additive is used, the supporting electrolysis process parameters are: current density of 50~300A / m², electrolysis temperature of 15~60°C, cathode electrolysis time of 24~120 h, 4N copper as anode, and 316L stainless steel or titanium plate with a titanium content of ≥99.0% as cathode.

6. The method of use according to claim 5, characterized in that: The additive is added into the copper electrolyte, and the total concentration of the additive is controlled to be 80-120 g / t-to precipitate cathode copper.

7. The method of use according to claim 5, characterized in that: The copper electrolyte is a copper sulfate electrolyte with a copper ion concentration of 30-80 g / L, a sulfuric acid concentration of 50-100 g / L, and a hydrochloric acid concentration of 0.05-0.4 g / L, or a copper nitrate electrolyte with a copper ion concentration of 30-80 g / L, a nitric acid concentration of 1-50 g / L, and a hydrochloric acid concentration of 0.05-0.4 g / L.

8. The method of use according to claim 5, characterized in that: The current density is 150~250A / m 2 .

9. The method of use according to claim 5, characterized in that: The electrolysis temperature is 20-40°C.

10. The method of use according to claim 5, characterized in that: The cathode electrolysis time is 48 to 96 hours.