A method for preparing and using a deep purification and impurity removal aid in wet zinc smelting

Abstract

This invention discloses a method for preparing and using a deep purification and impurity removal aid in wet zinc smelting. The aid, prepared through batching, modification, and drying, is used in wet zinc smelting. It utilizes an aluminosilicate-calcium-based molecular sieve as a framework. First, surface impurities are removed by acid washing, followed by surface passivation treatment with potassium permanganate. Finally, copper and lead ions are embedded into the surface of the molecular sieve, yielding the impurity removal aid. This aid is applied to the existing purification and impurity removal system in conjunction with zinc powder. It is generally used in high-temperature impurity removal processes; zinc powder is added for 10-30 minutes, followed by the addition of the impurity removal aid. The aid effectively removes specific impurities such as arsenic, antimony, germanium, thallium, and tin, and inhibits the re-dissolution of cobalt and cadmium, reducing the amount of zinc powder required. This invention requires no changes to existing purification and impurity removal equipment and process parameters, offering advantages such as ease of operation and energy saving.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical zinc refining technology, specifically to a method for preparing and using a deep purification and impurity removal aid in hydrometallurgical zinc refining. Background Technology

[0002] Currently, antimony salt purification in domestic hydrometallurgical zinc refining employs a three-stage purification process. This involves using the negatively charged zinc to displace positively charged impurities such as copper, cadmium, and cobalt, while adding antimony salts to reduce the overvoltage of cobalt, thus achieving cobalt removal. Antimony salt cobalt removal is low-cost, but it is a reversible process requiring high temperatures, long reaction times, and excessive zinc powder for cobalt removal. This results in large consumption of zinc powder and antimony salts, high energy consumption, and operational difficulties.

[0003] Currently, there are two types of cobalt removal agents in China: one is organic reagent complexation for cobalt removal, and the other is adding intermediate materials from smelting metals to accelerate the cobalt removal process. However, both of these methods are only effective for removing cobalt and are not effective for removing other conventional and unconventional elements (such as arsenic, antimony, germanium, thallium, and tin). The purification process is an important step in the hydrometallurgical zinc refining process, which directly affects important indicators such as zinc electrowinning production and energy consumption, making zinc electrowinning production difficult and resulting in poor zinc precipitation. Summary of the Invention

[0004] This invention aims to solve the problem of incomplete impurity removal in the second stage of three-stage antimony salt purification, and provides an inexpensive deep purification and impurity removal aid for wet zinc smelting. This aid achieves deep purification, reduces zinc powder usage, lowers reaction time and temperature, and saves production costs. The impurity removal aid is an inorganic salt and does not pollute the environment. Furthermore, this invention does not require changes to the process parameters of the three-stage antimony salt purification, and has advantages such as low cost and simple operation.

[0005] The auxiliary components for deep purification and impurity removal in wet zinc smelting of this invention are as follows: by weight percentage, copper content is 0.5%-1.3%, lead content is 1.5%-4.5%, manganese content is 0.5%-1.5%, and the balance is aluminum-silicon-calcium-based molecular sieve.

[0006] First, the aluminosilicate-calcium molecular sieve is modified, and then inorganic salts are added to obtain the impurity removal aid.

[0007] High-quality powdered aluminosilicate calcium-based molecular sieves are selected, ground, and passed through a 0.074mm sieve. Using the molecular sieve as a framework, surface impurities are first removed by acid washing, then surface passivation is performed with potassium permanganate, and finally copper and lead ions are embedded into the surface of the molecular sieve to obtain the impurity removal aid.

[0008] First, prepare a 5%-10% dilute sulfuric acid solution, then add the aluminosilicate calcium-based molecular sieve at a liquid-to-solid ratio of 2-3:1 by weight. After stirring and soaking for 4-8 hours, centrifuge and filter to obtain the acid-washed aluminosilicate calcium-based molecular sieve.

[0009] After pickling, the aluminum-silicon-calcium-based molecular sieve is added to a stainless steel mixer. First, 3-8% water and 2.0%-5.0% potassium permanganate are added. After mixing and stirring for 4 hours, 2.0%-5.0% copper sulfate and 2.0%-5.0% lead carbonate are added. After mixing and stirring for 1-2 hours, the mixture is taken out and bagged to obtain the impurity removal aid.

[0010] Instructions for use of the impurity removal aid: Apply to the existing purification and impurity removal system in conjunction with zinc powder. Generally used in high-temperature impurity removal processes. The dosage is 15-50 mg / L, depending on the level of arsenic and antimony impurities. Add the impurity removal aid 10-30 minutes after adding the zinc powder. Other technical conditions do not need to be changed.

[0011] The present invention has the following advantages:

[0012] 1. Applied to the purification process of hydrometallurgical zinc refining, it can deeply purify and remove special impurities such as arsenic, antimony, germanium, thallium, and tin, and can inhibit the re-dissolution of cobalt and cadmium, reducing the amount of zinc powder used. No changes to existing purification equipment and process parameters are required during use, offering advantages such as ease of operation and energy saving.

[0013] 2. After the purification process, the content of special impurities such as arsenic, antimony, germanium, thallium, and tin in the solution is significantly reduced, greatly improving the quality of the new solution. The impurity content can be reduced to (mg / L) Co≤0.2, As≤0.02, Sb≤0.02, Ge≤0.02, Tl≤0.2, Sn≤0.05. Attached Figure Description

[0014] Figure 1 This is a process flow diagram of the additive preparation and use method of the present invention. Detailed Implementation

[0015] The technical content of the present invention will be further described below with reference to the embodiments.

[0016] Example 1

[0017] The preparation method of the deep purification and impurity removal aid for wet zinc smelting is carried out according to the following steps:

[0018] ① Take 800g of powdered aluminosilicate calcium-based molecular sieve, grind it, and then pass it through a 0.074mm sieve;

[0019] ② Prepare 1L of 8% dilute sulfuric acid solution, then add 500g of aluminosilicate calcium-based molecular sieve at a liquid-to-solid ratio of 2:1. Stir and soak for 6 hours, then centrifuge and filter to obtain acid-washed aluminosilicate calcium-based molecular sieve.

[0020] ③ Add 200g of acid-washed aluminum-silicon-calcium-based molecular sieve to a stainless steel mixer. First, add 5ml of water and 5g of potassium permanganate. After mixing and stirring for 4 hours, add 5g of copper sulfate and 6g of lead carbonate. Continue mixing and stirring for 1-2 hours until uniform. Then, remove the mixture and bag it to obtain 200g of impurity removal agent.

[0021] Method of using the impurity removal aid: Take a zinc sulfate solution from an electrolytic zinc plant before purification. The impurity analysis results are as follows (mg / L): Co 6.43, As 1.2, Sb 1.3, Ge 0.55, Tl 0.67, Sn 0.33, Fe 5.81, Cd 62.26. With stirring at 75 rpm and heating to 85℃, add 3.5 g / L zinc powder and let it sit for 15 minutes. Then add 30 mg / L of the impurity removal aid and react for another 45 minutes. After vacuum filtration, the impurity analysis results are as follows (mg / L): Co < 0.1, As < 0.01, Sb < 0.01, Ge < 0.02, Tl 0.15, Sn 0.05, Fe 0.61, Cd 0.1. The quality is significantly higher than other purification methods.

[0022] Example 2

[0023] 5.0 L of a zinc electrowinning solution before purification was taken, containing (mg / L): Cu 0.2, Cd 12.1, Ni 1.6, Co 4.86, As 0.4, Sb 1.0, Ge 0.85, Tl 0.77, Sn 0.38, Fe 3.81. The solution was stirred at 75 rpm and heated to 88°C. After adding 3.2 g / L zinc powder for 10 minutes, 25 mg / L of the impurity removal aid prepared in Example 1 was added. The reaction was continued at a constant temperature and volume for 50 minutes, followed by vacuum filtration. The resulting purified solution contained (mg / L) Co 0.11, As <0.01, Sb 0.02, Ge <0.02, Tl 0.14, Sn 0.04, Fe 0.86, Cd 0.3, Ni 0.1, achieving deep impurity removal.

[0024] Example 3

[0025] 5.0 L of a zinc electrowinning solution before purification was taken, containing (mg / L): Cu 0.2, Cd 12.1, Ni 1.6, Co 4.86, As 0.4, Sb 1.0, Ge 0.85, Tl 0.77, Sn 0.38, Fe 3.81. Under a stirring intensity of 75 rpm and a temperature of 86°C, 3.0 g / L zinc powder was added for 15 minutes, followed by the addition of 20 mg / L of the impurity removal aid prepared in Example 1. The reaction was continued at a constant temperature and volume for 45 minutes, then vacuum filtered. The resulting purified solution contained (mg / L) Co 0.14, As <0.01, Sb 0.02, Ge 0.02, Tl 0.17, Sn 0.05, Fe 0.89, Cd 0.37, Ni 0.16, achieving deep impurity removal.

[0026] Example 4

[0027] A method for preparing a deep impurity removal aid in wet zinc smelting is carried out according to the following steps:

[0028] ① Take 600g of powdered aluminosilicate calcium-based molecular sieve, grind it, and then pass it through a 0.074mm sieve;

[0029] ② Prepare 1L of 5% dilute sulfuric acid solution, then add 400g of aluminosilicate calcium-based molecular sieve at a liquid-to-solid ratio of 2.5:1. Stir and soak for 7 hours, then centrifuge and filter to obtain acid-washed aluminosilicate calcium-based molecular sieve.

[0030] ③ Add 300g of acid-washed aluminum-silicon-calcium-based molecular sieve to a stainless steel mixer. First, add 7ml of water and 10g of potassium permanganate. After mixing and stirring for 4 hours, add 6g of copper sulfate and 12g of lead carbonate. Continue mixing and stirring for 1-2 hours until uniform. Then, remove the mixture and bag it to obtain 300g of impurity removal agent.

[0031] Method of using the impurity removal aid: Take 5.0L of zinc sulfate solution from a certain electrolytic zinc plant before purification, as described in Example 1. With a stirring intensity of 75 rpm and a temperature of 85°C, add 3.0g / L zinc powder and let it sit for 15 minutes. Then add 35mg / L of the impurity removal aid and react for another 45 minutes. After vacuum filtration, the impurity analysis results are as follows (mg / L): Co 0.11, As 0.02, Sb 0.01, Ge 0.02, Tl 0.16, Sn 0.05, Fe 0.96, Cd 0.18. The quality is significantly higher than other purification methods.

[0032] Example 5

[0033] Take 5.0 L of the pre-purification solution from a zinc electrowinning plant used in Example 3. With stirring at 75 rpm and heating to 88°C, add 3.5 g / L zinc powder for 10 minutes, then add 40 mg / L of the impurity removal aid prepared in Example 4. Continue the reaction at constant temperature and volume for 50 minutes, followed by vacuum filtration. The resulting purified solution contains (mg / L) Co < 0.1, As < 0.01, Sb < 0.02, Ge < 0.02, Tl < 0.1, Sn < 0.02, Fe 0.96, Cd < 0.1, Ni < 0.1, achieving deep impurity removal.

[0034] Example 6

[0035] Take 5.0 L of the pre-purification solution from a zinc electrowinning plant used in Example 3. Its contents (mg / L) are: Cu 0.2, Cd 12.1, Ni 1.6, Co 4.86, As 0.4, Sb 1.0, Ge 0.85, Tl 0.77, Sn 0.38, Fe 3.81. With stirring at 80 rpm and heating to 85°C, add 2.8 g / L zinc powder for 15 minutes, then add 22 mg / L of the impurity removal aid prepared in Example 1. Continue the reaction at a constant temperature and volume for 45 minutes, then vacuum filter. The resulting purified solution contains (mg / L) Co 0.14, As 0.02, Sb 0.02, Ge 0.02, Tl 0.2, Sn 0.05, Fe 0.78, Cd 0.31, Ni 0.13, achieving deep impurity removal.

[0036] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a deep purification and impurity removal aid in wet zinc smelting, characterized in that: The preparation method is as follows: using an aluminum-silicon-calcium-based molecular sieve as a framework and grinding and sieving, first acid washing to remove surface impurities, then surface passivation treatment with potassium permanganate, and finally embedding copper and lead ions into the surface of the molecular sieve to obtain the impurity removal aid. The impurity removal aid, by weight percentage, contains 0.5%-1.3% copper, 1.5%-4.5% lead, and 0.5%-1.5% manganese, with the balance being aluminosilicate-calcium molecular sieve.

2. The preparation method of the deep purification and impurity removal aid for wet zinc smelting according to claim 1, characterized in that: In the preparation method, the grinding and sieving process of the aluminosilicate calcium-based molecular sieve is to pass it through a 0.074mm sieve after grinding.

3. The preparation method of the deep purification and impurity removal aid for wet zinc smelting according to claim 1, characterized in that: In the preparation method, the process of removing surface impurities by acid washing is as follows: first, prepare a 5%-10% dilute sulfuric acid solution, then add aluminum-silicon-calcium-based molecular sieve at a liquid-to-solid ratio of 2-3:1 by weight, stir and soak for 4-8 hours, then centrifuge and filter to obtain the acid-washed aluminum-silicon-calcium-based molecular sieve.

4. The preparation method of the deep purification and impurity removal aid for wet zinc smelting according to claim 3, characterized in that: After pickling, the aluminum-silicon-calcium-based molecular sieve is added to a stainless steel mixer. First, 3-8% water and 2.0%-5.0% potassium permanganate are added. After mixing and stirring for 4 hours, 2.0%-5.0% copper sulfate and 2.0%-5.0% lead carbonate are added. After mixing and stirring for another 1-2 hours, the impurity removal agent is obtained.

5. The method for preparing the impurity removal aid of the wet zinc smelting deep purification and removal agent according to any one of claims 1-4, characterized in that: The impurity removal aid is used in the purification system of wet zinc-antimony salt refining, in conjunction with zinc powder.

6. The method of use according to claim 5, characterized in that: The impurity removal aid is applied in the high-temperature impurity removal process. After adding zinc powder for 10-30 minutes, the impurity removal aid is added, with a dosage of 15-50 mg / L.

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