A method for recovering germanium from germanium sulfide waste

Abstract

This application belongs to the field of germanium recovery technology and discloses a method for recovering germanium from germanium sulfide waste. The method involves mixing the germanium sulfide waste with a dispersant and then sequentially subjecting it to multi-stage roasting, alkaline leaching, germanium precipitation, and distillation recovery to obtain germanium. The dispersant is composed of calcium oxide and aluminum oxide in a mass ratio of 1:3-5; the mass ratio of germanium sulfide waste to dispersant is 1:0.1-0.5. This application provides a method for recovering germanium from germanium sulfide waste. By combining a specific dispersant combination with a multi-stage roasting process, it effectively solves the problems of material agglomeration and germanium volatilization loss during roasting, improving roasting efficiency and reducing germanium loss.

Description

Technical Field

[0001] This application relates to the field of germanium recovery technology, specifically to a method for recovering germanium from germanium sulfide waste. Background Technology

[0002] Germanium, a rare dispersed metal, is located in the fourth period and group IVA of the periodic table. It is a grayish-white, hard, and lustrous metal belonging to the carbon group, with chemical properties similar to tin and silicon in the same group. It is an important strategic resource with many unique properties, playing a crucial role in numerous high-tech fields and industrial applications. It has wide applications in semiconductor materials, infrared optics, fiber optic communications, chemical catalysts, aerospace measurement and control, nuclear physics detection, solar cells, and biology.

[0003] Therefore, germanium recycling has high value. As a high-germanium-content material, germanium sulfide waste necessitates the development of a recycling method. Based on germanium sulfide waste, we conducted compositional analysis and found that its main components are GeS, GeS2, and Ge2S3.

[0004] The usual acid leaching and alkaline leaching methods cannot effectively dissolve and leach germanium in germanium sulfide waste, so subsequent recovery processes such as ion exchange and extraction cannot be effectively carried out. Based on this, the prior art 1: Chinese patent application 201811537883.4 states: "Perform germanium sulfide volatilization and collect germanium sulfide volatilization dust, or collect mixed volatilization dust of germanium sulfide and germanium dioxide; (3) Perform microwave oxidation roasting or other forms of oxidation roasting on the obtained germanium-containing dust, or directly perform sulfuric acid oxidation leaching."

[0005] The existing technology 1 uses an oxidative roasting process that results in germanium loss due to the entry of germanium into the flue gas and also causes agglomeration. Furthermore, because germanium sulfide waste contains sulfur, the commonly used industrial chlorination distillation process generates hydrogen sulfide, which greatly increases the safety risks of recycling.

[0006] In summary, there is a need to find a new method for recycling germanium sulfide waste to effectively improve the recovery rate of germanium and reduce the safety risks associated with recycling. Summary of the Invention

[0007] One of the objectives of this application is to provide a method for recovering germanium from germanium sulfide waste, which can effectively recover germanium from germanium sulfide waste with minimal germanium loss, high recovery rate, and safe process.

[0008] To achieve the above objectives, this application provides a method for recovering germanium from germanium sulfide waste, wherein the germanium sulfide waste is mixed with a dispersant and then subjected to multi-stage roasting, alkaline leaching, germanium precipitation, and distillation recovery in sequence to obtain germanium;

[0009] The dispersant is composed of calcium oxide and aluminum oxide in a mass ratio of 1:3-5;

[0010] The mass ratio of the germanium sulfide waste to the dispersant is 1:0.1-0.5.

[0011] The dispersant formed by the combination of calcium oxide and aluminum oxide in this application not only avoids agglomeration during the roasting process, but also effectively improves the retention of germanium and increases the recovery rate of germanium during the roasting process.

[0012] Furthermore, the method for recovering germanium from germanium sulfide waste according to this application includes the following steps:

[0013] Step 1: Grind the germanium sulfide waste to obtain waste powder;

[0014] Step 2: Mix the waste powder with the dispersant to obtain a mixture;

[0015] Step 3: Calcine the mixture at a calcination temperature of 200-400℃ for 1-3 hours, continuously introducing air with an oxygen content of 8-12% during the process;

[0016] Step 4: Calcine at 500-600℃ for 2-5 hours to obtain calcined material, continuously introducing air with an oxygen content of 15-20% during the process;

[0017] Step 5: Treat the roasted material with alkali to obtain alkali leaching solution;

[0018] Step 6: Precipitate germanium in the alkaline leaching solution to obtain germanium precipitate;

[0019] Step 7: Distill the germanium precipitate to recover germanium.

[0020] This application effectively solves the problems of material agglomeration and germanium volatilization loss during the roasting process through a two-stage roasting process, thereby improving roasting efficiency and reducing germanium loss.

[0021] Preferably, the waste powder has a size of 300-500 mesh.

[0022] Furthermore, the specific operation of the alkaline leaching treatment is as follows: water is added to the calcined material at a solid-liquid ratio of 1:4-6 and mixed, and then sodium hydroxide is added to make the concentration of sodium hydroxide 100-250g / L for alkaline leaching. The system temperature is maintained at 90℃ for 2 hours. After the reaction is completed, the alkaline leaching solution is obtained by filtration.

[0023] Furthermore, the specific operation of the germanium precipitation treatment is as follows: add sulfuric acid solution with a mass fraction of 10-15% to the alkaline leaching solution to adjust the pH of the system to 8-9, maintain the pH and stir the reaction for 1 hour, and let it stand to obtain germanium hydroxide precipitate.

[0024] Furthermore, the specific operation of the distillation recovery process is as follows: the germanium hydroxide precipitate is subjected to chlorination distillation to recover germanium.

[0025] Beneficial effects

[0026] Compared with the prior art, this application provides a method for recovering germanium from germanium sulfide waste. By combining a specific dispersant combination with a multi-stage roasting process, the method effectively solves the problems of material agglomeration and germanium volatilization loss during roasting, thereby improving roasting efficiency and reducing germanium loss. Detailed Implementation

[0027] The present application will be further described below with reference to embodiments, but this does not constitute any limitation on the present application. Any limited modifications made within the scope of the claims of the present application shall still be within the scope of the claims of the present application.

[0028] To illustrate the technical content of this application in detail, the following description is provided in conjunction with the embodiments.

[0029] The following examples and comparative examples all used the same batch of germanium sulfide waste, with a germanium content of 15 wt%.

[0030] Example 1

[0031] A type of germanium is recovered from germanium sulfide waste using the following steps:

[0032] Step 1: Grind the germanium sulfide waste to obtain waste powder with a size of 300 mesh;

[0033] Step 2: Mix the waste powder and the dispersant at a mass ratio of 1:0.2 to obtain a mixture, wherein the dispersant is composed of calcium oxide and aluminum oxide at a mass ratio of 1:3;

[0034] Step 3: The mixture is heated to 300℃ at a rate of 5℃ / min and calcined for 3 hours, with air containing 8% oxygen continuously introduced during the process;

[0035] Step 4: Rise the temperature to 500℃ at a heating rate of 3℃ / min and roast for 5 hours to obtain roasted material, continuously introducing air with an oxygen content of 15% during the process.

[0036] Step 5: Add water to the calcined material at a solid-liquid ratio of 1:4 and mix. Then add sodium hydroxide to make the sodium hydroxide concentration 150g / L for alkaline leaching. Maintain the system temperature at 90℃ and react for 2 hours. After the reaction is completed, filter to obtain the alkaline leaching solution.

[0037] Step 6: Add 15% sulfuric acid solution to the alkaline leaching solution to adjust the pH of the system to 8.5, maintain the pH between 8 and 9 and stir the reaction for 1 hour, then let it stand to obtain germanium hydroxide precipitate;

[0038] Step 7: The germanium hydroxide precipitate is recovered by chlorination distillation to obtain germanium.

[0039] Example 2

[0040] A type of germanium is recovered from germanium sulfide waste using the following steps:

[0041] Step 1: Grind the germanium sulfide waste to obtain waste powder with a size of 300 mesh;

[0042] Step 2: Mix the waste powder and the dispersant at a mass ratio of 1:0.3 to obtain a mixture, wherein the dispersant is composed of calcium oxide and aluminum oxide at a mass ratio of 1:4;

[0043] Step 3: The mixture is heated to 300℃ at a rate of 6℃ / min and calcined for 3 hours, with air containing 10% oxygen continuously introduced during the process;

[0044] Step 4: Rise the temperature to 500℃ at a heating rate of 4℃ / min and roast for 5 hours to obtain roasted material, continuously introducing air with an oxygen content of 18% during the process.

[0045] Step 5: Add water to the calcined material at a solid-liquid ratio of 1:5 and mix. Then add sodium hydroxide to make the sodium hydroxide concentration 200g / L for alkaline leaching. Maintain the system temperature at 90℃ and react for 2 hours. After the reaction is completed, filter to obtain the alkaline leaching solution.

[0046] Step 6: Add 15% sulfuric acid solution to the alkaline leaching solution to adjust the pH of the system to 8.5, maintain the pH between 8 and 9 and stir the reaction for 1 hour, then let it stand to obtain germanium hydroxide precipitate;

[0047] Step 7: The germanium hydroxide precipitate is recovered by chlorination distillation to obtain germanium.

[0048] Example 3

[0049] A type of germanium is recovered from germanium sulfide waste using the following steps:

[0050] Step 1: Grind the germanium sulfide waste to obtain waste powder with a size of 300 mesh;

[0051] Step 2: Mix the waste powder and the dispersant at a mass ratio of 1:0.5 to obtain a mixture, wherein the dispersant is composed of calcium oxide and aluminum oxide at a mass ratio of 1:5;

[0052] Step 3: The mixture is heated to 300℃ at a rate of 8℃ / min and calcined for 3 hours, with air containing 12% oxygen continuously introduced during the process;

[0053] Step 4: Rise the temperature to 500℃ at a heating rate of 5℃ / min and roast for 5 hours to obtain roasted material, continuously introducing air with an oxygen content of 20% during the process.

[0054] Step 5: Add water to the calcined material at a solid-liquid ratio of 1:5 and mix. Then add sodium hydroxide to make the sodium hydroxide concentration 250g / L for alkaline leaching. Maintain the system temperature at 90℃ and react for 2 hours. After the reaction is completed, filter to obtain the alkaline leaching solution.

[0055] Step 6: Add 15% sulfuric acid solution to the alkaline leaching solution to adjust the pH of the system to 8.5, maintain the pH between 8 and 9 and stir the reaction for 1 hour, then let it stand to obtain germanium hydroxide precipitate;

[0056] Step 7: The germanium hydroxide precipitate is recovered by chlorination distillation to obtain germanium.

[0057] Comparative Example 1

[0058] It is largely the same as in Example 1, except that the dispersant is only calcium oxide.

[0059] Comparative Example 2

[0060] It is largely the same as Example 1, except that the dispersant is only aluminum oxide.

[0061] Comparative Example 3

[0062] The process is largely the same as in Example 1, except that step 4 is changed to: heating the material to a calcination temperature of 400°C at a heating rate of 3°C / min and calcining it for 5 hours to obtain the calcined material, with air containing 15% oxygen continuously introduced during the process.

[0063] Comparative Example 4

[0064] The process is largely the same as in Example 1, except that step 4 is changed to: heating the material to a calcination temperature of 900°C at a heating rate of 3°C / min and calcining it for 5 hours to obtain the calcined material, with air containing 15% oxygen continuously introduced during the process.

[0065] Germanium recovery rate detection and calculation

[0066] 1. Detection method: Germanium content is detected by ICP instrument.

[0067] 2. The germanium recovery rate is calculated as follows: germanium content in alkaline leaching solution / (germanium content in residual filter cake after filtration + germanium content in alkaline leaching solution) × 100%, with subsequent precipitation and chlorination recovery rates greater than 99%.

[0068] 3. Germanium loss: (Germanium content before calcination - Germanium content after calcination) / Germanium content before calcination × 100%.

[0069] The above methods were used to test and calculate Examples 1-3 and Comparative Examples 1-4, and the results are shown in Table 1.

[0070] Table 1. Calculation results of germanium recovery rate and germanium loss

[0071] Germanium recovery rate % Germanium loss % Example 1 97 0.78 Example 2 98 0.70 Example 3 97 0.84 Comparative Example 1 90 2.16 Comparative Example 2 91 2.24 Comparative Example 3 85 3.01 Comparative Example 4 82 7.65

[0072] According to the results in Table 1:

[0073] As can be seen from Embodiments 1-3 of this application, the technical solution of this application can effectively maintain low germanium loss while effectively recovering germanium with a germanium recovery rate of over 97%.

[0074] According to the data comparison between Example 1 and Comparative Examples 1 and 2, it can be seen that when only alumina or calcium oxide is used as a dispersant, the recovery rate decreases significantly and the germanium loss increases significantly. It is speculated that although alumina or calcium oxide can effectively disperse the powder and improve the oxidation efficiency of germanium, it cannot effectively capture germanium oxide, thus resulting in a high germanium loss.

[0075] According to the data comparison between Example 1 and Comparative Example 3, although a combination of alumina and calcium oxide was used, the calcium oxide and alumina could not form a partial calcium aluminate phase at low temperature, which could not capture germanium oxide, resulting in germanium loss. At the same time, due to the low temperature of 400°C, the low temperature would affect the oxidation of germanium sulfide to germanium oxide. The incomplete oxidation would affect the leaching, resulting in a low germanium recovery rate.

[0076] According to the data comparison between Example 1 and Comparative Example 4, calcium oxide and aluminum oxide formed a stable calcium aluminate framework at high temperature in Comparative Example 4. However, the germanium loss did not decrease compared to Example 1, and the germanium recovery rate was even significantly reduced. It is speculated that this is because the formation of a stable calcium aluminate framework makes it difficult to leach and affects germanium recovery. In addition, germanium volatilization occurs at high temperature, resulting in germanium loss.

[0077] The embodiments presented herein are merely selected implementations based on combinations of all possible embodiments. The appended claims should not be limited to the embodiments described herein. Some numerical ranges used in the claims include sub-ranges within them, and variations within these ranges should also be covered by the appended claims.

Claims

1. A method for recovering germanium from germanium sulfide waste, characterized in that, Germanium sulfide waste is mixed with a dispersant and then subjected to multi-stage roasting, alkaline leaching, germanium precipitation, and distillation recovery to obtain germanium. The dispersant is composed of calcium oxide and aluminum oxide in a mass ratio of 1:3-5; The mass ratio of the germanium sulfide waste to the dispersant is 1:0.1-0.

5.

2. The method for recovering germanium from germanium sulfide waste according to claim 1, characterized in that, Includes the following steps: Step 1: Grind the germanium sulfide waste to obtain waste powder; Step 2: Mix the waste powder with the dispersant to obtain a mixture; Step 3: Calcine the mixture at a calcination temperature of 200-400℃ for 1-3 hours, continuously introducing air with an oxygen content of 8-12% during the process; Step 4: Calcine at 500-600℃ for 2-5 hours to obtain calcined material, continuously introducing air with an oxygen content of 15-20% during the process; Step 5: Treat the roasted material with alkali to obtain alkali leaching solution; Step 6: Precipitate germanium in the alkaline leaching solution to obtain germanium precipitate; Step 7: Distill the germanium precipitate to recover germanium.

3. The method for recovering germanium from germanium sulfide waste according to claim 2, characterized in that, The waste powder has a size of 300-500 mesh.

4. The method for recovering germanium from germanium sulfide waste according to claim 2, characterized in that, The specific operation of the alkaline leaching treatment is as follows: water is added to the roasted material at a solid-liquid ratio of 1:4-6 and mixed. Then sodium hydroxide is added to make the concentration of sodium hydroxide 100-250g / L for alkaline leaching. The system temperature is maintained at 90℃ for 2 hours. After the reaction is completed, the alkaline leaching solution is obtained by filtration.

5. The method for recovering germanium from germanium sulfide waste according to claim 2, characterized in that, The specific operation of the germanium precipitation treatment is as follows: add sulfuric acid solution with a mass fraction of 10-15% to the alkaline leaching solution to adjust the pH of the system to 8-9, maintain the pH and stir the reaction for 1 hour, and let it stand to obtain germanium hydroxide precipitate.

6. The method for recovering germanium from germanium sulfide waste according to claim 5, characterized in that, The specific operation of the distillation recovery process is as follows: germanium hydroxide precipitate is recovered by chlorination distillation to obtain germanium.