A method for preparing germanium concentrate from zinc-germanium leaching solution by neutralization precipitation method

Abstract

The invention discloses a method for preparing germanium concentrate from zinc-germanium leaching solution by a neutralization precipitation method, comprising the following steps: (1) adding zinc oxide fume to the zinc-germanium leaching solution, adjusting the pH value to 3.0-3.5, reacting at a temperature of 50-70°C for 5-60 minutes, separating the liquid from the solid to obtain a pre-neutralized liquid and a pre-neutralized slag, and returning the pre-neutralized slag to a hydrometallurgical zinc smelting system. (2) adding a theoretical amount of 0.6-0.8 times of a neutralizer A to the pre-neutralized liquid obtained in step (1), controlling the reaction temperature to 70-90°C, and reacting for 1-2 hours; then introducing an ultrasonic cavitation generating device, adding a neutralizer B, adjusting the pH value to 5.2-5.4, and reacting for 1-3 hours. After the reaction is completed, separating the liquid from the solid to obtain a neutralized liquid and a neutralized germanium slag, and returning the neutralized liquid to a hydrometallurgical zinc smelting system. (3) washing the neutralized germanium slag obtained in step (2) with water for 2-3 times, and drying to obtain a germanium concentrate. The invention can realize the efficient enrichment of germanium in zinc and germanium leaching solution, the germanium precipitation rate can reach more than 98%, and the germanium grade in the germanium concentrate can reach more than 2%. The method of the invention has the characteristics of low cost, high germanium precipitation rate, low zinc precipitation loss rate, avoiding the adverse effects of tannic acid organic matter on the zinc electrolysis process, good matching with the zinc main system, and easy industrialization.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for preparing germanium concentrate from zinc-germanium leaching solution by a neutralization precipitation method. 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 national defense aviation, space development and other fields. It is an important strategic 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 grow day by day. 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 generally to enrich germanium in zinc leaching residue and use pyrolysis to obtain germanium-containing zinc oxide smoke, then use sulfuric acid leaching to obtain zinc and germanium-containing leaching solution, and then use tannin extract and / or tannic acid to precipitate germanium. The precipitated germanium residue is filtered, dried and roasted to make a germanium concentrate with a germanium content of 5-25%, and then chlorination distillation is carried out to extract germanium.

[0004] To recover germanium from the leachate, 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 (50,000~60,000 yuan / ton), the amount of tannic acid used is large (25~35 times), the production cost is high, and the tannic acid organic matter has an adverse effect on the main system of hydrometallurgical zinc smelting. Therefore, it is necessary to seek an efficient and economical recovery process to reduce the cost of germanium extraction, improve the recovery rate of germanium, and avoid the adverse effects of tannic acid organic matter on the zinc electrolysis process. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing germanium concentrate from zinc-germanium leaching solution by a neutralization precipitation method.

[0006] The object of the present invention is achieved in that the method for preparing germanium concentrate from zinc-germanium leaching solution by neutralization precipitation method comprises pre-neutralization, two-stage neutralization and germanium precipitation and washing steps, specifically comprising:

[0007] A. Pre-neutralization: Add zinc oxide fume to the zinc-germanium leaching solution for pre-neutralization reaction to obtain pre-neutralized liquid a and pre-neutralized slag b;

[0008] B. Two-stage neutralization and germanium precipitation:

[0009] 1) adding a neutralizing agent A to the pre-neutralized solution a and reacting for 1 to 2 hours to obtain a reaction solution c; the neutralizing agent A is one or more of zinc oxide, basic zinc carbonate and zinc carbonate;

[0010] 2) Adding neutralizing agent B to the reaction liquid c, adjusting the pH value to 5.2-5.4, introducing an ultrasonic cavitation generating device to react for 1-3 hours, and separating the liquid and solid to obtain neutralized liquid d and neutralized germanium slag e, and returning the neutralized liquid d to the hydrometallurgical zinc smelting system; the neutralizing agent B is a sodium hydroxide solution or a potassium hydroxide solution;

[0011] C. Washing: Wash the neutralized germanium slag e with water for 2 to 3 times and obtain germanium concentrate after drying.

[0012] The specific operations are as follows:

[0013] (1) Pre-neutralization

[0014] Add zinc oxide fume to the zinc-germanium leaching solution, adjust the pH value to 3.0-3.5, react at a temperature of 50-70°C for 5-60 minutes, separate the liquid and solid to obtain pre-neutralized liquid and pre-neutralized slag, and return the pre-neutralized slag to the hydrometallurgical zinc smelting system.

[0015] (2) Two-stage neutralization precipitation

[0016] Add 0.6-0.8 times the theoretical amount of neutralizer A to the pre-neutralized liquid obtained in step (1), control the reaction temperature to 70-90°C, and react for 1-2 hours; then introduce an ultrasonic cavitation generator, add neutralizer B, adjust the pH value to 5.2-5.4, and react for 1-3 hours. After the reaction is completed, liquid-solid separation is performed to obtain a neutralized liquid and a neutralized germanium slag, and the neutralized liquid is returned to the hydrometallurgical zinc smelting system.

[0017] (3) Washing

[0018] The neutralized germanium slag obtained in step (2) is slurried and washed 2 to 3 times with water, and dried to obtain germanium concentrate.

[0019] Furthermore, in step (1), the zinc-germanium leaching solution is a leaching solution obtained by leaching germanium-rich materials such as smelting slag and smoke generated in the lead-zinc smelting process with sulfuric acid, wherein the germanium content is not less than 100 mg / L.

[0020] Furthermore, in step (2), the neutralizing agent A is one or more combinations of zinc oxide, basic zinc carbonate, and zinc carbonate.

[0021] Furthermore, in step (2), the frequency of the ultrasonic wave of the ultrasonic cavitation generating device is not less than 20 kHz, and the power density is not less than 0.3 W / cm 2 .

[0022] Furthermore, in step (2), the neutralizing agent B is a solution of one or a combination of sodium hydroxide and potassium hydroxide, and the concentration of the neutralizing agent B is 0.1-5 mol / L.

[0023] Furthermore, in steps (1) and (2), during the entire reaction process, the mechanical stirring rate is 200-600 r / min.

[0024] Furthermore, in step (2), the germanium content of the neutralized liquid is less than 2.0 mg / L.

[0025] Furthermore, in step (3), the washing liquid-to-solid ratio is 1 / 1 to 2 / 1, the washing temperature is room temperature, and the washing time is 5 to 30 minutes.

[0026] Furthermore, in step (3), the germanium concentrate contains no less than 2% germanium.

[0027] Beneficial effects of the present invention:

[0028] The present invention discloses a method for preparing germanium concentrate from zinc-germanium leachate by a neutralization precipitation method. For sulfuric acid leachate with a germanium content of more than 100 mg / L, a pre-neutralization-two-stage neutralization precipitation method is used to enrich and recover germanium. In the first-stage neutralization precipitation process, a neutralizer that can react with sulfuric acid to generate soluble zinc sulfate is added to reduce the yield of germanium concentrate and improve the grade of germanium in the germanium concentrate. In the second-stage neutralization precipitation process, a strong alkaline solution is added as a neutralizer, and ultrasonic coordinated mechanical stirring is used to utilize the high temperature and high-speed jet generated by the ultrasonic cavitation effect. On the one hand, the neutralization, hydrolysis and precipitation reaction of germanium is strengthened, the reaction rate is accelerated, and the precipitation rate of germanium is improved; on the other hand, the added strong alkaline solution can be quickly mixed with the germanium-containing solution to form a uniform mixed solution, thereby preventing the local pH from being too high, and zinc from being hydrolyzed in large quantities to form precipitation, thereby reducing the precipitation loss of zinc and the amount of strong alkaline neutralizer used, and improving the grade of germanium in the germanium concentrate. Compared with the existing process, the advantages are as follows:

[0029] (1) This method has a simple process, a high germanium precipitation rate, and a high germanium grade in the germanium concentrate.

[0030] (2) The method of the present invention introduces fewer impurities, does not have a local pH value that is too high, has a smaller zinc precipitation loss, does not destroy the main components of the zinc and germanium leaching solutions, has good compatibility with the zinc main system, and is easy to industrialize.

[0031] (3) This process uses the neutralization precipitation method to replace the tannin precipitation method. There is no need to add organic matter to the main zinc system, thus avoiding the adverse effects of organic matter on the zinc electrolysis process.

[0032] (4) The present invention does not require the use of expensive germanium precipitation reagents, and the added zinc-containing neutralizing agent can be recovered, which is low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0034] 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.

[0035] The method for preparing germanium concentrate from zinc-germanium leaching solution by neutralization precipitation method of the present invention comprises pre-neutralization, two-stage neutralization and germanium precipitation and washing steps, specifically comprising:

[0036] A. Pre-neutralization: Add zinc oxide fume to the zinc-germanium leaching solution for pre-neutralization reaction to obtain pre-neutralized liquid a and pre-neutralized slag b;

[0037] B. Two-stage neutralization and germanium precipitation:

[0038] 1) adding a neutralizing agent A to the pre-neutralized solution a and reacting for 1 to 2 hours to obtain a reaction solution c; the neutralizing agent A is one or more of zinc oxide, basic zinc carbonate and zinc carbonate;

[0039] 2) Adding neutralizing agent B to the reaction liquid c, adjusting the pH value to 5.2-5.4, introducing an ultrasonic cavitation generating device to react for 1-3 hours, and separating the liquid and solid to obtain neutralized liquid d and neutralized germanium slag e, and returning the neutralized liquid d to the hydrometallurgical zinc smelting system; the neutralizing agent B is a sodium hydroxide solution or a potassium hydroxide solution;

[0040] C. Washing: Wash the neutralized germanium slag e with water for 2 to 3 times and obtain germanium concentrate after drying.

[0041] The pH value of the pre-neutralization reaction in step A is controlled at 3.0-3.5.

[0042] The temperature of the pre-neutralization reaction in step A is 50-70° C., and the reaction time is 5-60 min.

[0043] B. The reaction temperature in step 1) is 70-90°C.

[0044] B. In step 2), the frequency of the ultrasonic wave of the ultrasonic cavitation generator is not less than 20kHz, and the power density is not less than 0.3W / cm 2 .

[0045] During the neutralization reaction in step A and step B, the mechanical stirring rate is maintained at 200-600 r / min for stirring.

[0046] The zinc-germanium leaching solution is a leaching solution obtained by leaching germanium-rich materials such as smelting slag and smoke generated in the lead-zinc smelting process with sulfuric acid, wherein the germanium content is not less than 100 mg / L.

[0047] The present invention is further described below with specific implementation cases:

[0048] Example 1

[0049] The main components of the zinc-germanium leaching solution used in this embodiment are as follows: 2 SO 4 Concentration: 11.27 g / L, Zn: 124.74 g / L, Ge: 177.3 mg / L, Fe: 2+ 5.47g / L, Fe5.86g / L, the main components of neutralizer zinc oxide smoke are as follows: Zn 60.14%, Pb12.09%, Fe1.26%.

[0050] Add zinc oxide fume to 1000mL zinc-germanium leaching solution, adjust the pH value to 3.0-3.5, control the stirring rate to 500r / min, react for 30min at 60℃, separate the liquid and solid to obtain pre-neutralized liquid and pre-neutralized slag, and return the pre-neutralized slag to the hydrometallurgical zinc smelting system.

[0051] Add 0.8 times the theoretical amount of zinc oxide to the obtained pre-neutralized solution, control the reaction temperature to 80°C, and react for 1 hour at a stirring rate of 500 r / min. Then introduce an ultrasonic cavitation generator and generate the cavitation product at an ultrasonic power density of 10 W / cm 2 , add 1 mol / L sodium hydroxide solution under ultrasonic frequency of 25kHz, adjust pH value to 5.2-5.4, react for 2h, after reaction, liquid-solid separation to obtain neutralized liquid and neutralized germanium slag, neutralized liquid returns to hydrometallurgical zinc smelting system. Neutralized liquid contains 1.5mg / L germanium.

[0052] The neutralized germanium slag was washed with water for 3 times, with a washing liquid-solid ratio of 1 / 1, washing temperature at room temperature, washing time of 20 minutes, and dried to obtain germanium concentrate, which contained 2.51% germanium.

[0053] During the neutralization precipitation process, the germanium precipitation rate was 99.15%.

[0054] Example 2

[0055] The main components of the zinc-germanium leaching solution used in this embodiment are as follows: 2 SO 4 Concentration: 11.27 g / L, Zn: 124.74 g / L, Ge: 177.3 mg / L, Fe: 2+ 5.47g / L, Fe 5.86g / L, the main components of neutralizer zinc oxide smoke are as follows: Zn 60.14%, Pb12.09%, Fe1.26%.

[0056] Add zinc oxide fume to 1000mL zinc-germanium leaching solution, adjust the pH value to 3.0-3.5, control the stirring rate to 500r / min, react for 30min at 60℃, separate the liquid and solid to obtain pre-neutralized liquid and pre-neutralized slag, and return the pre-neutralized slag to the hydrometallurgical zinc smelting system.

[0057] Add 0.8 times the theoretical amount of basic zinc carbonate to the obtained pre-neutralized solution, control the reaction temperature to 80°C, and react for 1 hour at a stirring rate of 500 r / min. Then introduce an ultrasonic cavitation generator and heat the mixture at an ultrasonic power density of 10 W / cm 2 At an ultrasonic frequency of 25kHz, add a potassium hydroxide solution with a concentration of 1 mol / L, adjust the pH value to 5.2-5.4, and react for 2 hours. After the reaction is completed, liquid-solid separation is performed to obtain a neutralized liquid and a neutralized germanium slag, and the neutralized liquid is returned to the hydrometallurgical zinc smelting system. The neutralized liquid contains 1.7 mg / L germanium.

[0058] The neutralized germanium slag was washed with water for 3 times, with a washing liquid-solid ratio of 1 / 1, washing temperature at room temperature, washing time of 20 minutes, and dried to obtain germanium concentrate, which contained 2.44% germanium.

[0059] During the neutralization precipitation process, the germanium precipitation rate was 99.04%.

[0060] Example 3

[0061] The main components of the zinc-germanium leaching solution used in this embodiment are as follows: 2 SO 4 Concentration: 28.65 g / L, Zn: 115.04 g / L, Ge: 256.0 mg / L, Fe: 2+ 21.25g / L, Fe 21.30g / L, the main components of the neutralizer zinc oxide smoke are as follows: Zn 60.14%, Pb12.09%, Fe1.26%.

[0062] Add zinc oxide fume to 1000mL zinc-germanium leaching solution, adjust the pH value to 3.0-3.5, control the stirring rate to 500r / min, react for 20min at 70℃, separate the liquid and solid to obtain pre-neutralized liquid and pre-neutralized slag, and return the pre-neutralized slag to the hydrometallurgical zinc smelting system.

[0063] Add 0.6 times the theoretical amount of zinc oxide to the obtained pre-neutralized solution, control the reaction temperature to 85°C, and react for 1 hour at a stirring rate of 500 r / min. Then introduce an ultrasonic cavitation generator and generate the cavitation product at an ultrasonic power density of 20 W / cm 2 , add 2 mol / L sodium hydroxide solution under ultrasonic frequency of 25kHz, adjust pH value to 5.2-5.4, react for 1h, after reaction, liquid-solid separation to obtain neutralized liquid and neutralized germanium slag, neutralized liquid returns to hydrometallurgical zinc smelting system. Neutralized liquid contains 1.9 mg / L germanium.

[0064] The neutralized germanium slag was washed with water for 3 times, with a washing liquid-solid ratio of 2 / 1, a washing temperature of room temperature, a washing time of 20 minutes, and dried to obtain a germanium concentrate containing 3.63% germanium.

[0065] During the neutralization precipitation process, the germanium precipitation rate was 99.26%.

[0066] 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 preparing germanium concentrate from zinc-germanium leaching solution by neutralization precipitation method, It is characterized in that The method for preparing germanium concentrate from zinc-germanium leaching solution by neutralization precipitation method comprises pre-neutralization, two-stage neutralization and germanium precipitation and washing steps, specifically comprising: A. Pre-neutralization: Add zinc oxide fume to the zinc-germanium leaching solution for pre-neutralization reaction to obtain pre-neutralized liquid a and pre-neutralized slag b; B. Two-stage neutralization and germanium precipitation: 1) adding a neutralizing agent A to the pre-neutralized solution a and reacting for 1 to 2 hours to obtain a reaction solution c; the neutralizing agent A is one or more of zinc oxide, basic zinc carbonate and zinc carbonate; 2) Adding neutralizing agent B to the reaction liquid c, adjusting the pH value to 5.2-5.4, introducing an ultrasonic cavitation generating device to react for 1-3 hours, and separating the liquid and solid to obtain neutralized liquid d and neutralized germanium slag e, and returning the neutralized liquid d to the hydrometallurgical zinc smelting system; the neutralizing agent B is a sodium hydroxide solution or a potassium hydroxide solution; C. Washing: Wash the neutralized germanium slag e with water 2-3 times, and obtain germanium concentrate after drying; The zinc-germanium leaching solution is a leaching solution obtained by leaching smelting slag and smoke generated in the lead-zinc smelting process with sulfuric acid, wherein the germanium content is not less than 100 mg / L.

2. The method for preparing germanium concentrate from zinc-germanium leaching solution by the neutralization precipitation method according to claim 1, It is characterized in that The pH value of the pre-neutralization reaction in step A is controlled at 3.0-3.

5.

3. The method for preparing germanium concentrate from zinc-germanium leaching solution by the neutralization precipitation method according to claim 1, It is characterized in that The temperature of the pre-neutralization reaction in step A is 50-70° C., and the reaction time is 5-60 min.

4. The method for preparing germanium concentrate from zinc-germanium leaching solution by the neutralization precipitation method according to claim 1, It is characterized in that B. The reaction temperature in step 1) and step 2) is 70-90°C.

5. The method for preparing germanium concentrate from zinc-germanium leaching solution by the neutralization precipitation method according to claim 1, It is characterized in that B. In step 2), the frequency of the ultrasonic wave of the ultrasonic cavitation generator is not less than 20kHz, and the power density is not less than 0.3W / cm 2 .

6. The method for preparing germanium concentrate from zinc-germanium leaching solution by the neutralization precipitation method according to claim 1, It is characterized in that During the neutralization reaction in step A and step B, the mechanical stirring rate is maintained at 200-600 r / min for stirring.

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