A method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution

Abstract

The invention discloses a method for enriching germanium from a low-concentration germanium-containing zinc oxide dust leachate. It belongs to the technical field of hydrometallurgy. The invention adopts a reduction-neutralization precipitation-low acid leaching method to enrich germanium, which specifically comprises the following steps: adding a reducing agent to the zinc oxide dust leachate to reduce to obtain a reduced liquid, adding 10-30 g / L of a neutralizing agent to react, after which liquid-solid separation is performed to obtain a neutralized liquid and a neutralized germanium slag, and the neutralized liquid is returned to the main system of hydrometallurgy to recover zinc. The neutralized germanium slag is mixed with a sulfuric acid solution to prepare a slurry, and after the reaction is completed, liquid-solid separation is performed to obtain a leaching slag and a germanium-rich leachate, and the leaching slag is returned to the lead smelting system, and the germanium-rich leachate is used for subsequent further extraction of germanium. The method of the invention has low cost, high germanium precipitation rate, and strong process adaptability, and can realize the separation of germanium from the main system of hydrometallurgy, avoid the adverse effects of tannic acid organic matter on the zinc electrolysis process, and can also remove harmful impurities such as arsenic in the solution to purify the solution.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution. Background Art

[0002] Germanium (Ge) is a rare metal and the most important semiconductor material besides silicon. It is widely used in optical fibers, solar cells, medicine, catalysts and other fields. It is also an indispensable important metal in the fields of aviation and is an important reserve resource in my country.

[0003] With the development and strategic layout of 5G technology in my country, the demand for 5G application optical cables is increasing, and the demand for germanium and its compounds will also grow. However, the distribution of germanium in the earth's crust is extremely scattered, mainly associated with bauxite, lead-zinc ore and coal mines. As a typical germanium resource, the extraction process of lead-zinc ore is to first enrich germanium in zinc leaching residue and use pyrolysis to obtain germanium-containing zinc oxide dust, and then obtain germanium concentrate through leaching, tannin precipitation of germanium, and oxidative roasting to enter the germanium purification process.

[0004] For the germanium in the solution, the main methods used are solvent extraction and tannin precipitation to enrich it. The extraction method has the advantages of good selectivity and high recovery rate, but the extractant in this method is highly water-soluble and easy to emulsify, has high requirements for equipment, large losses, high costs, and cannot be recycled. It is suitable for processing high-concentration germanium-containing solutions. The tannin precipitation method is the most mature traditional germanium extraction process, which has the advantages of simple operation, fast reaction speed, and high germanium recovery rate. However, the tannic acid in this method is expensive, the amount of tannic acid used is large, the production cost is high, and the tannic acid organic matter has an adverse effect on the main system of hydrometallurgical zinc smelting.

[0005] For low-concentration germanium-containing zinc oxide smoke leachate, it is difficult to achieve effective enrichment of germanium by extraction method. Tannin precipitation method is directly used to precipitate germanium, and tannic acid is added at a high multiple. On the one hand, the company currently needs to consume 25 to 40 times of tannic acid in the production process. As of January 2023, the price of tannic acid is 60,000 yuan / t, and the company's production cost is relatively high; on the other hand, a large amount of tannic acid is added to the zinc main system, and tannic acid organic matter has an adverse effect on the zinc main system. Therefore, it is very necessary to develop a method that can solve the above technical problems. Summary of the invention

[0006] The object of the present invention is to provide a method for enriching germanium from zinc oxide smoke leaching solution containing germanium at a low concentration.

[0007] The object of the present invention is achieved in that the method for enriching germanium from a low-concentration germanium-containing zinc oxide smoke leaching solution comprises the steps of reduction, neutralization and precipitation of germanium and low-acid leaching, specifically comprising:

[0008] A. Reduction: adding a reducing agent to the low-concentration germanium-containing zinc oxide smoke leaching solution to be treated to obtain a reduced solution a;

[0009] B. Neutralization and precipitation of germanium: adding a neutralizing agent to the reduced liquid a for reaction, and after the reaction, liquid-solid separation to obtain neutralized liquid b and neutralized germanium slag c; the neutralized liquid b is returned to the main system of hydrometallurgical zinc smelting to recover zinc;

[0010] C. Low-acid leaching: add sulfuric acid solution to the neutralized germanium slag c to prepare the slurry, leach at a temperature of 25-65°C for 30-120 minutes, and separate the liquid and solid to obtain the leaching slag d and the germanium-rich leaching solution e; the leaching slag d is returned to the lead smelting system, and the germanium-rich leaching solution e is used for further germanium extraction.

[0011] The present invention can efficiently enrich germanium from low-concentration germanium-containing zinc oxide dust leaching solution, realize the separation of germanium from the main system of hydrometallurgical zinc smelting, and avoid the adverse effects of tannic acid organic matter on the zinc electrolysis process. 3+ The content is lower than 10 mg / L, which inhibits the formation of germanium-iron co-precipitation with trivalent iron during germanium neutralization and hydrolysis precipitation, thereby increasing the leaching rate of germanium in the neutralized germanium slag.

[0012] The method for enriching germanium in a low-concentration germanium-containing zinc oxide dust leachate of the present invention is specifically performed as follows:

[0013] (1) Restoration

[0014] Add 0.5-5.0 times the theoretical amount of reducing agent to the zinc oxide fume leaching solution, reduce it at a temperature of 50-70°C for 10-30 minutes to obtain a reduced solution;

[0015] (2) Neutralization of germanium deposition

[0016] Add 10-30 g / L zinc oxide fume or zinc oxide as a neutralizing agent to the reduced liquid obtained in step (1), react at a reaction temperature of 70-90° C. for 2-4 hours, and after the reaction is completed, separate the liquid and solid to obtain a neutralized liquid and a neutralized germanium slag, and return the neutralized liquid to the main system of hydrometallurgical zinc smelting to recover zinc;

[0017] (3) Low acid leaching

[0018] The neutralized germanium slag obtained in step (2) is mixed with sulfuric acid solution at a liquid-to-solid volume mass ratio of 2.5 / 1 to 4 / 1 to prepare a slurry, and leached at a temperature of 25 to 65° C. for 30 to 120 min. After the reaction is completed, the liquid and solid are separated to obtain leached slag and germanium-rich leaching solution. The leached slag is returned to the lead smelting system, and the germanium-rich leaching solution is used for subsequent further germanium extraction.

[0019] Furthermore, in step (1), the germanium concentration in the zinc oxide fume leaching solution is 10-60 mg / L, and the Fe 2+The concentration is 1~10g / L, Fe 3+ The concentration is 0~5g / L, and the H2SO4 concentration is 1~10g / L.

[0020] Furthermore, in step (1), the reducing agent is one of zinc sulfide concentrate, zinc sulfite and zinc sulfide.

[0021] Further, in step (1), after reduction, Fe 3+ The content is less than 10mg / L.

[0022] Furthermore, in step (2), the neutralization reaction end point pH value is 5.2-5.4.

[0023] Furthermore, in step (2), the germanium content of the neutralized liquid is less than 2.0 mg / L.

[0024] Furthermore, in step (3), the sulfuric acid solution is a combination of one or more of waste electrolyte, sulfuric acid and water.

[0025] Furthermore, in step (3), the sulfuric acid concentration at the leaching endpoint is controlled to be 1-10 g / L.

[0026] Furthermore, in step (3), the germanium concentration in the germanium-rich leaching solution is enriched by 10 to 20 times.

[0027] Beneficial effects of the present invention:

[0028] The present invention realizes the efficient enrichment of germanium in low-concentration germanium-containing zinc oxide dust leaching solution by the method of reduction-neutralization precipitation-low acid leaching. 3+ Reduction to Fe 2+ , to prevent Fe 3+ In the process of germanium neutralization, hydrolysis and precipitation, it forms germanium iron co-precipitation with germanium, thereby improving the leaching rate of germanium in the neutralized germanium slag. Compared with the existing process, the advantages are as follows:

[0029] (1) It can process low-concentration germanium-containing solutions with high germanium recovery rate;

[0030] (2) The process is simple, does not require special equipment, and is easy to industrialize;

[0031] (3) The method of the present invention basically does not introduce impurities, there is no local pH value that is too high, the precipitation loss of zinc is small, the main components of the zinc oxide fume leaching solution are not destroyed, and the compatibility with the main zinc system is good;

[0032] (4) This process does not require the addition of organic matter into the main zinc system, thus avoiding the adverse effects of organic matter on the zinc electrolysis process;

[0033] (5) The present invention does not require the use of expensive reagents, and the added reducing agent and neutralizing agent can be recovered, so the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0036] The method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution of the present invention comprises the steps of reduction, neutralization and precipitation of germanium and low-acid leaching, specifically comprising:

[0037] A. Reduction: adding a reducing agent to the low-concentration germanium-containing zinc oxide smoke leaching solution to be treated to obtain a reduced solution a;

[0038] B. Neutralization and precipitation of germanium: adding a neutralizing agent to the reduced liquid a for reaction, and after the reaction, liquid-solid separation to obtain neutralized liquid b and neutralized germanium slag c; the neutralized liquid b is returned to the main system of hydrometallurgical zinc smelting to recover zinc;

[0039] C. Low-acid leaching: add sulfuric acid solution to the neutralized germanium slag c to prepare the slurry, leach at a temperature of 25-65°C for 30-120 minutes, and separate the liquid and solid to obtain the leaching slag d and the germanium-rich leaching solution e; the leaching slag d is returned to the lead smelting system, and the germanium-rich leaching solution e is used for further germanium extraction.

[0040] The germanium concentration in the low-concentration germanium-containing zinc oxide smoke leaching solution is 10-60 mg / L, and the Fe 2+ The concentration is 1~10g / L, Fe 3+ The concentration is 0~5g / L, and the H2SO4 concentration is 1~10g / L.

[0041] The reducing agent described in step A is zinc sulfide concentrate, zinc sulfite or zinc sulfide.

[0042] The amount of reducing agent added is 0.5 to 5.0 times the theoretical amount.

[0043] The reduction reaction temperature in step A is 50-70°C.

[0044] The time of the reduction reaction in step A is 10 to 30 minutes.

[0045] The neutralizing agent described in step B is zinc oxide fume or zinc oxide.

[0046] The amount of the neutralizer added is 10-30 g / L.

[0047] The reaction temperature in step B is 70-90°C and the reaction time is 2-4 hours.

[0048] In step C, the solid-liquid mass volume ratio of the neutralized germanium slag c and the sulfuric acid solution is 1: (2.5~4).

[0049] The present invention is further described below with specific implementation cases:

[0050] Example 1

[0051] The main components of the zinc oxide smoke leaching solution used in this embodiment are as follows: H2SO4 concentration 4.94g / L, Zn 116.82g / L, Ge 46.1mg / L, Fe 2+ 2.30g / L, Fe 3+ 0.30g / L, As 1.02g / L; the main components of zinc oxide smoke are as follows: Zn52.56%, Ge502.3g / t, Pb 13.75%, Fe 2.61%, As0.51%; the main components of zinc sulfide concentrate are as follows: Zn49.38%, Pb 2.24%, Fe 7.61%, As 0.0047%.

[0052] Add 2.0 times the theoretical amount of zinc sulfide concentrate to 1000mL zinc oxide fume leaching solution, reduce it at 70℃ for 20min, then add 19.00g zinc oxide fume, react at 80℃ for 4h, separate liquid and solid to obtain neutralized liquid and neutralized germanium slag, and return the neutralized liquid to the main system of hydrometallurgical zinc smelting to recover zinc. The neutralized liquid contains 1.1mg / L germanium and 0.17g / L arsenic.

[0053] The neutralized germanium slag was mixed with 120g / L sulfuric acid solution at a liquid-solid mass ratio of 3.5 / 1, and leached for 60 minutes at a temperature of 65°C. After the reaction, the liquid-solid separation was performed to obtain leached slag and germanium-rich leaching solution. The leached slag was returned to the lead smelting system, and the germanium-rich leaching solution was used for subsequent further germanium extraction. The germanium-rich leaching solution contained 735.0mg / L germanium.

[0054] The germanium precipitation rate in the neutralization precipitation process was 97.61%, the arsenic removal rate was 83.33%, and the germanium leaching rate in the neutralization germanium slag low-acid leaching process was 99.05%.

[0055] The low-concentration germanium-containing zinc oxide smoke leaching solution was treated by reduction-neutralization precipitation-low acid leaching process, and the germanium was enriched by 15.94 times.

[0056] Example 2

[0057] The main components of the zinc oxide smoke leaching solution used in this embodiment are as follows: H2SO4 concentration 4.94g / L, Zn 116.82g / L, Ge 46.1mg / L, Fe 2+ 2.30g / L, Fe 3+ 0.30g / L, As 1.02g / L.

[0058] Add 2.0 times the theoretical amount of zinc sulfite to 1000mL zinc oxide fume leaching solution, reduce it at 70℃ for 20min, then add 16.00g zinc oxide, react at 80℃ for 4h, separate the liquid and solid to obtain neutralized liquid and neutralized germanium slag, and return the neutralized liquid to the main system of hydrometallurgical zinc smelting to recover zinc. The neutralized liquid contains 1.2mg / L germanium and 0.20g / L arsenic.

[0059] The neutralized germanium slag was mixed with 250g / L sulfuric acid solution at a liquid-to-solid mass ratio of 4 / 1, and leached for 60 minutes at a temperature of 65°C. After the reaction, the liquid and solid were separated to obtain leached slag and germanium-rich leaching solution. The leached slag was returned to the lead smelting system, and the germanium-rich leaching solution was used for subsequent further germanium extraction. The germanium-rich leaching solution contained 658.7mg / L germanium.

[0060] The germanium precipitation rate in the neutralization precipitation process was 97.40%, the arsenic removal rate was 80.39%, and the germanium leaching rate in the neutralization germanium slag low-acid leaching process was 99.75%.

[0061] The low-concentration germanium-containing zinc oxide smoke leaching solution was treated by reduction-neutralization precipitation-low acid leaching process, and the germanium was enriched by 14.29 times.

[0062] Example 3

[0063] The main components of the zinc oxide smoke leaching solution used in this embodiment are as follows: H2SO4 concentration 5.25g / L, Zn 124.74g / L, Ge 48.66mg / L, Fe 2+ 5.47g / L, Fe 3+ 0.39g / L, As 0.55g / L.

[0064] Add 2.0 times the theoretical amount of zinc sulfite to 1000mL zinc oxide fume leaching solution, reduce at 60℃ for 30min, then add 19.00g zinc oxide, react at 85℃ for 4h, separate liquid and solid to obtain neutralized liquid and neutralized germanium slag, return the neutralized liquid to the main system of hydrometallurgical zinc smelting to recover zinc. The neutralized liquid contains 1.0mg / L germanium and 0.14g / L arsenic.

[0065] The neutralized germanium slag was mixed with 290g / L sulfuric acid solution at a liquid-solid mass ratio of 3.5 / 1, and leached for 60 minutes at a temperature of 65°C. After the reaction, the liquid-solid separation was performed to obtain leached slag and germanium-rich leaching solution. The leached slag was returned to the lead smelting system, and the germanium-rich leaching solution was used for subsequent further germanium extraction. The germanium-rich leaching solution contained 679.87mg / L germanium.

[0066] The germanium precipitation rate in the neutralization precipitation process was 97.94%, the arsenic removal rate was 74.55%, and the germanium leaching rate in the neutralization germanium slag low-acid leaching process was 99.86%.

[0067] The low-concentration germanium-containing zinc oxide smoke leaching solution was treated by reduction-neutralization precipitation-low acid leaching process, and the germanium was enriched by 13.97 times.

[0068] Example 4

[0069] The main components of the zinc oxide smoke leaching solution used in this embodiment are as follows: H2SO4 concentration 8.91g / L, Zn 128.65g / L, Ge 55.78mg / L, Fe 2+ 9.45g / L, Fe 3+ 4.23g / L, As 0.94g / L.

[0070] Add 1.5 times the theoretical amount of zinc sulfite to 1000mL zinc oxide fume leaching solution, reduce at 60℃ for 30min, then add 22.00g zinc oxide fume, react at 85℃ for 4h, separate liquid and solid to obtain neutralized liquid and neutralized germanium slag, return the neutralized liquid to the main system of hydrometallurgical zinc smelting to recover zinc. The neutralized liquid contains 1.5mg / L germanium and 0.16g / L arsenic.

[0071] The neutralized germanium slag was mixed with 135g / L sulfuric acid solution at a liquid-to-solid mass ratio of 3 / 1, and leached for 60 minutes at a temperature of 60°C. After the reaction, the liquid-solid separation was performed to obtain leached slag and germanium-rich leaching solution. The leached slag was returned to the lead smelting system, and the germanium-rich leaching solution was used for further germanium extraction. The germanium-rich leaching solution contained 784.39mg / L germanium.

[0072] The germanium precipitation rate in the neutralization precipitation process was 97.31%, the arsenic removal rate was 82.98%, and the germanium leaching rate in the neutralization germanium slag low-acid leaching process was 99.71%.

[0073] The low-concentration germanium-containing zinc oxide smoke leaching solution was treated by reduction-neutralization precipitation-low acid leaching process, and the germanium was enriched by 14.06 times.

[0074] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution, characterized in that: The method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution comprises reduction, neutralization and germanium precipitation and low-acid leaching steps, specifically comprising: A. Reduction: Add a reducing agent to the low-concentration germanium-containing zinc oxide dust leaching solution to obtain a reduced solution a, wherein the reducing agent is zinc sulfide concentrate, zinc sulfite or zinc sulfide, and the germanium concentration in the low-concentration germanium-containing zinc oxide dust leaching solution is 10-60 mg / L, and Fe 2+ Concentration is 1~10g / L, Fe 3+ The concentration is 0~5g / L, and the H2SO4 concentration is 1~10g / L; B. Neutralization and precipitation of germanium: adding a neutralizing agent to the reduced liquid a for reaction, wherein the neutralizing agent is zinc oxide fume or zinc oxide, and after the reaction, liquid-solid separation is performed to obtain a neutralized liquid b and a neutralized germanium slag c; the neutralized liquid b is returned to the main system of hydrometallurgical zinc smelting to recover zinc; C. Low-acid leaching: add sulfuric acid solution to the neutralized germanium slag c to prepare the slurry, leach at a temperature of 25-65°C for 30-120 minutes, and separate the liquid and solid to obtain the leaching slag d and the germanium-rich leaching solution e; the leaching slag d is returned to the lead smelting system, and the germanium-rich leaching solution e is used for further germanium extraction.

2. The method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: The amount of reducing agent added is 0.5 to 5.0 times the theoretical amount.

3. The method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: The reaction temperature of the reduction in step A is 50-70°C.

4. The method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: The reduction reaction time in step A is 10 to 30 minutes.

5. The method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: The amount of the neutralizer added is 10-30 g / L.

6. The method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: The reaction temperature in step B is 70-90°C and the reaction time is 2-4 hours.

7. The method for enriching germanium from low-concentration germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: In step C, the solid-liquid mass volume ratio of the neutralized germanium slag c and the sulfuric acid solution is 1: (2.5~4).

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