Method for recovering germanium from germanium-containing waste residue through chlorination distillation
Through pretreatment, extraction, backextraction and refining steps, the problem of low germanium recovery in the prior art is solved, efficient and low-cost germanium recovery is achieved, germanium purity and resource utilization efficiency are improved, and environmental pollution is reduced.
Patent Information
- Application Number
- CN202510437454.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-07-11
AI Technical Summary
The prior art methods for recycling germanium from chlorinated distillation of germanium-containing waste slag have problems such as low germanium recovery rate, complex methods, and high costs. They fail to effectively recover resources, which may cause potential harm to the environment.
The steps of pretreatment, extraction, backextraction, germanium refining and evaporation and drying are adopted to improve the leachate and purity of germanium, reduce impurities and achieve efficient recycling through specific process flows, including crushing residues, washing, extraction agent combination, and phased chlorine and hydrogen reduction.
It significantly improves the recovery rate and purity of germanium, reduces production costs, reduces environmental pollution, and achieves efficient recycling and recycling of resources.
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of germanium recovery, and particularly to a method for recovering germanium by chlorination distillation from germanium-containing waste residues.
Background Art
[0002] Germanium is an important rare metal. As a very important strategic metal element, it is widely used in various industrial, military, and scientific fields. Analyzing from the physical properties and crystal structure of germanium, germanium is a gray crystal, and the commonly seen crystal structure is diamond-shaped. Germanium is also a very important semiconductor material, and the conductivity of this material is between that of a conductor and an insulator, and its conductivity performance can be adjusted by doping. In addition, with the rapid development of new energy, new materials, semiconductors, etc. in recent years, the demand for germanium in various fields has been increasing continuously, and the pressure on the supply of germanium resources in China has also been gradually increasing. Therefore, the research on germanium production and recovery is of great significance for promoting the optimization of the industrial structure and enhancing the national economic competitiveness.
[0003] In the production process of germanium, chlorination distillation is a commonly used separation and purification method, but it will produce a large amount of chlorination distillation residues, and these residues still contain a certain amount of germanium. If not effectively recovered, it will not only cause waste of resources, but also pose potential hazards to the environment.
[0004] Currently, the methods for recovering germanium by chlorination distillation from germanium-containing waste residues have problems such as low germanium recovery rate, complex methods, and high costs. Therefore, it is of great significance to develop a method for efficiently and low-costly recovering germanium by chlorination distillation from germanium-containing waste residues.
Summary of the Invention
[0005] In view of this, the purpose of the present invention is to provide a method for recovering germanium by chlorination distillation from germanium-containing waste residues. Through the method of the present invention, the recovery rate and purity of germanium can be significantly improved, while the production cost can be reduced, environmental pollution can be reduced, and the efficient recovery and recycling of resources can be realized.
[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:
[0007] A method for recovering germanium by chlorination distillation from germanium-containing waste residues, the method comprising the following steps:
[0008] (1) Pretreatment: Take the germanium chlorination distillation residues, crush them, then wash them with deionized water, and then dry them for standby;
[0009] (2) Extraction: Add the dried residue to the extractant and perform extraction at a temperature of 40 - 50°C and a stirring speed of 200 - 300 r / min for 1 - 2 h. Then, back-extract the organic phase loaded with germanium using a sulfuric acid solution with a concentration of 2 - 3 mol / L. The back-extraction temperature is 25 - 35°C, the stirring speed is 150 - 250 r / min, and the back-extraction time is 30 - 60 min. After back-extraction, germanium transfers from the organic phase to the aqueous phase, and a back-extract solution rich in germanium is obtained.
[0010] (3) Germanium refining: Pass liquid ammonia into the back-extract solution to precipitate germanium and obtain germanium concentrate. Then, add the germanium concentrate to a chlorination distillation reactor, add hydrochloric acid to the reactor, and then introduce chlorine in stages. Collect the distilled volatile matter for condensation. Add pure water to the condensed product as the mother liquor for hydrolysis. After hydrolysis, filter to remove the filtrate.
[0011] (4) Evaporation to dryness: Transfer the filter residue obtained in step (3) to an evaporating dish and evaporate to dryness at a heating temperature of 80 - 100°C, stirring continuously during the evaporation process. After evaporation to dryness, the germanium salt obtained is calcined and then reduced to metallic germanium by passing hydrogen, which is the finished germanium.
[0012] In the present invention, further, the particle size of the pulverization in step (1) is 100 - 200 mesh.
[0013] In the present invention, further, the extractant in step (2) is a mixed solution composed of tributyl phosphate, sec-octanol, and kerosene in a volume ratio of 1:1:2 - 3.
[0014] In the present invention, further, the liquid ammonia precipitation of germanium in step (3) is to pass liquid ammonia into the back-extract solution, adjust the pH value of the solution to 9 - 10, react under stirring until the germanium content is less than 400 mg / L, and then perform solid-liquid separation on the reacted slurry. The obtained filter residue is dried to obtain germanium concentrate.
[0015] In the present invention, further, the liquid-solid ratio of hydrochloric acid to germanium concentrate in step (3) is 5:1.
[0016] In the present invention, further, the introduction of chlorine in stages in step (3) is as follows: Pass chlorine for 30 min at 40 - 45°C, then pass chlorine for 40 - 60 min at 50 - 60°C, then pass chlorine for 40 - 60 min at 83 - 90°C, and finally pass chlorine for 25 - 30 min at 90 - 115°C.
[0017] In the present invention, further, the calcination temperature in step (4) is 600 - 800°C, and the calcination time is 2 - 3 h.
[0018] In the present invention, further, in the step (4), the hydrogen reduction temperature is 500 - 600 °C.
[0019] In addition, the filtrate obtained after germanium refining contains Zn and HCl, and can also be used to produce crude zinc chloride. The evaporator uses graphite reaction vessels (V = 2000 L, 2 units) heated by steam. When the evaporation liquid meets the requirements, the evaporation temperature is controlled at 200 °C. It is discharged to a φ2500 crystallization tank (1 unit), and zinc chloride is precipitated by concentration crystallization, and then sent to a centrifugal filter (SX1000 - N, 2 units) for filtration to obtain the product zinc chloride. The liquid after germanium precipitation contains ammonium fluoride and is used to produce ammonium fluoride. The evaporator uses graphite reaction vessels (V = 2000 L, 2 units) heated by steam. When the evaporation liquid meets the requirements, the evaporation temperature is controlled at 200 °C. It is discharged to a φ2500 crystallization tank (1 unit), and ammonium fluoride is precipitated by concentration crystallization, and then sent to a centrifugal filter (SX1000 - N, 2 units) for filtration to obtain the product ammonium fluoride.
[0020] In summary, due to the adoption of the above technical solutions, the present invention has at least the following beneficial effects:
[0021] 1. The present invention provides a method for recovering germanium by chlorination distillation from germanium - containing waste residues, effectively separating germanium from the chlorination distillation residues. The chlorination distillation residues contain 0.4 - 2.0% germanium, and the germanium recovery technology therein is rotary kiln volatilization. For the conventional method, the germanium volatilization rate is about 60%. Based on this, through steps such as pretreatment, extraction, refining, and evaporation to dryness, using a specific process, the leaching rate of germanium is increased. In addition, impurities are further removed, the quality of germanium products is improved, the production cost is reduced, environmental pollution is reduced, and efficient recovery and recycling of resources are realized.
[0022] 2. The present invention first crushes the residues to 100 - 200 mesh in the pretreatment process to increase the contact area of the reaction and improve the subsequent reaction efficiency. Then the residues are washed to remove the soluble impurities attached to the surface. Then extraction and back - extraction are carried out. By adopting specific extraction and back - extraction processes, the extraction rate of germanium is increased, and germanium is more effectively separated from impurities, which can further improve the purity of germanium. Then, by adjusting the pH value, germanium precipitates in the form of germanium hydroxide, and after solid - liquid separation and drying, germanium concentrate is obtained. Combined with the method of introducing chlorine in stages, the temperature is gradually increased, the distilled volatiles are collected and condensed, and then hydrolyzed and evaporated to dryness. Finally, the obtained germanium has high purity and good quality, and the present application realizes the efficient recovery of germanium.
Specific Embodiments
[0023] The following embodiments can help those skilled in the art to understand the present invention more comprehensively, but cannot limit the present invention in any way.
[0024] Example 1
[0025] This embodiment provides a method for recovering germanium by chlorination distillation from germanium-containing waste residue, and the method comprises the following steps:
[0026] (1) Pretreatment: Take the germanium chlorination distillation residue, crush it to a particle size of 100 mesh, then wash it with deionized water, and then dry it for standby;
[0027] (2) Extraction: Add the dried residue to the extractant, and the extractant is a mixed solution composed of tributyl phosphate, sec-octanol and kerosene according to a volume ratio of 1:1:2. Carry out extraction at a temperature of 40 °C and a stirring speed of 200 r / min for 1 h; then carry out back-extraction of the germanium-loaded organic phase with a sulfuric acid solution with a concentration of 2 mol / L. The back-extraction temperature is 25 °C, the stirring speed is 150 r / min, and the back-extraction time is 30 min. After back-extraction, germanium is transferred from the organic phase to the aqueous phase, that is, a back-extracted solution rich in germanium is obtained;
[0028] (3) Germanium refining: Pass liquid ammonia into the back-extracted solution to precipitate germanium to obtain germanium concentrate. The liquid ammonia precipitation of germanium is to pass liquid ammonia into the back-extracted solution, adjust the pH value of the solution to 9, and react under stirring conditions until the germanium content is less than 400 mg / L. Then carry out solid-liquid separation on the reacted slurry, and dry the obtained filter residue to obtain germanium concentrate. Then add the germanium concentrate to a chlorination distillation reactor, add hydrochloric acid to the reactor, and the liquid-solid ratio of hydrochloric acid to germanium concentrate is 5:1. Then introduce chlorine in stages. The chlorine introduced in stages is as follows: pass chlorine for 30 min at 40 °C, then pass chlorine for 60 min at 50 °C, then pass chlorine for 60 min at 83 °C, and finally pass chlorine for 30 min at 90 °C. Then collect the distillation volatiles for condensation, add pure water to the condensed product as the mother liquor for hydrolysis, and filter to remove the filtrate after hydrolysis;
[0029] (4) Drying to dryness: Transfer the filter residue obtained in step (3) to an evaporating dish, carry out drying to dryness at a heating temperature of 80 °C, continuously stir during the drying to dryness process, and after drying to dryness, roast the obtained germanium salt, and reduce germanium dioxide with hydrogen at a temperature of 500 °C to obtain metallic germanium; the above roasting temperature is 800 °C and the roasting time is 2 h, which is the finished germanium.
[0030] Example 2
[0031] This embodiment provides a method for recovering germanium by chlorination distillation from germanium-containing waste residue, and the method comprises the following steps:
[0032] (1) Pretreatment: Take the germanium chlorination distillation residue, crush it to a particle size of 150 mesh, then wash it with deionized water, and then dry it for standby;
[0033] (2) Extraction: Add the dried residue into the extractant, which is a mixed solution composed of tributyl phosphate, sec-octanol and kerosene in a volume ratio of 1:1:2. Carry out extraction at a temperature of 45 °C and a stirring speed of 250 r / min for 1.5 h. Then, back-extract the germanium-loaded organic phase with a sulfuric acid solution with a concentration of 2.5 mol / L at a back-extraction temperature of 30 °C, a stirring speed of 200 r / min, and a back-extraction time of 45 min. After back-extraction, germanium is transferred from the organic phase to the aqueous phase, and a germanium-rich back-extract solution is obtained.
[0034] (3) Germanium refining: Pass liquid ammonia into the back-extract solution to precipitate germanium to obtain germanium concentrate. The process of precipitating germanium with liquid ammonia is to pass liquid ammonia into the back-extract solution, adjust the pH value of the solution to 9.5, and react under stirring conditions until the germanium content is less than 400 mg / L. Then, carry out solid-liquid separation on the reacted slurry, and dry the obtained filter residue to obtain germanium concentrate. Then, add the germanium concentrate into a chlorination distillation reactor, add hydrochloric acid into the reactor, and the liquid-solid ratio of hydrochloric acid to germanium concentrate is 5:1. Then, introduce chlorine in stages. The stages of introducing chlorine are as follows: introduce chlorine at 42 °C for 30 min, then introduce chlorine at 55 °C for 50 min, then introduce chlorine at 85 °C for 50 min, and finally introduce chlorine at 95 °C for 27 min. Then, collect the distilled volatiles for condensation, add pure water as the mother liquor to the condensed product for hydrolysis, and filter to remove the filtrate after hydrolysis.
[0035] (4) Drying to dryness: Transfer the filter residue obtained in step (3) to an evaporating dish, and carry out drying to dryness at a heating temperature of 90 °C. Keep stirring during the drying process to dryness. After drying to dryness, the obtained germanium salt is roasted, and germanium dioxide is reduced by hydrogen at a temperature of 550 °C to obtain metallic germanium. The above roasting temperature is 700 °C and the roasting time is 2.5 h, which is the finished germanium.
[0036] Example 3
[0037] This example provides a method for recovering germanium by chlorination distillation from germanium-containing waste residue, and the method includes the following steps:
[0038] (1) Pretreatment: Take the germanium chlorination distillation residue and crush it to a particle size of 200 mesh, then wash it with deionized water, and then dry it for standby.
[0039] (2) Extraction: Add the dried residue into the extractant, which is a mixed solution composed of tributyl phosphate, sec-octanol, and kerosene in a volume ratio of 1:1:3. Perform extraction at a temperature of 50 °C and a stirring speed of 300 r / min for 2 h. Then, back-extract the organic phase loaded with germanium with a sulfuric acid solution with a concentration of 3 mol / L at a back-extraction temperature of 35 °C, a stirring speed of 250 r / min, and a back-extraction time of 60 min. After back-extraction, germanium transfers from the organic phase to the aqueous phase, and a back-extract solution rich in germanium is obtained.
[0040] (3) Germanium refining: Pass liquid ammonia into the back-extract solution to precipitate germanium to obtain germanium concentrate. The process of precipitating germanium with liquid ammonia is to pass liquid ammonia into the back-extract solution, adjust the pH value of the solution to 10, and react under stirring conditions until the germanium content is less than 400 mg / L. Then, perform solid-liquid separation on the reacted slurry, and dry the obtained filter residue to obtain germanium concentrate. Then, add the germanium concentrate into a chlorination distillation reactor, add hydrochloric acid into the reactor, and the liquid-solid ratio of hydrochloric acid to germanium concentrate is 5:1. Then, introduce chlorine in stages. The stages of introducing chlorine are as follows: introduce chlorine at 45 °C for 30 min, then introduce chlorine at 60 °C for 40 min, then introduce chlorine at 90 °C for 40 min, and finally introduce chlorine at 115 °C for 25 min. Then, collect the distilled volatiles for condensation, add pure water as the mother liquor to the condensed product for hydrolysis, and filter to remove the filtrate after hydrolysis.
[0041] (4) Evaporation to dryness: Transfer the filter residue obtained in step (3) to an evaporating dish, and evaporate to dryness at a heating temperature of 100 °C, continuously stirring during the evaporation process. After evaporation to dryness, the obtained germanium salt is calcined, and germanium dioxide is reduced by hydrogen at a temperature of 600 °C to obtain metallic germanium. The above calcination temperature is 600 °C, and the calcination time is 3 h, which is the finished germanium.
[0042] To illustrate the practical value of the germanium recovery method of this application, the applicant compares the purity and recovery rate of germanium obtained by the recovery processes of the following groups. The grouping is as follows:
[0043] The first group: Use the germanium recovery method described in Example 2 of this application;
[0044] The second group: Remove the pulverization step in the pretreatment, and the other methods are the same as those in the first group;
[0045] The third group: Remove the back-extraction, and the other methods are the same as those in the first group;
[0046] The fourth group: Remove tributyl phosphate in the extractant, and the other methods are the same as those in the first group;
[0047] The fifth group: The introduction of chlorine is as follows: introduce chlorine at 85 °C for 150 min, and the other methods are the same as those in the first group;
[0048] Group 6: The sec - octanol in the extractant is replaced with isooctanol, and other methods are the same as those in Group 1;
[0049] Group 7: The chlorine gas is introduced as follows: chlorine gas is introduced at 55 °C for 150 min, and other methods are the same as those in Group 1.
[0050] The recovery rate and purity of germanium under the recovery methods of the above - mentioned groups are respectively tested, and the recorded data are shown in Table 1:
[0051] Table 1 Recovery rate and purity of germanium in each group
[0052] Recovery rate (%) Purity (%) The first group 92.4％ 99.5％ The second group 85.3％ 98.1％ The third group 90.5％ 95.2％ The fourth group 91.8％ 96.4％ The fifth group 94.1％ 89.2％ The sixth group 92.5％ 90.8％ The seventh group 88.6％ 96.8％
[0053] According to the results in Table 1, it can be seen that by using the method of this application to recover germanium from germanium chlorination distillation residue, the recovery rate of germanium is high and its purity is high. This shows that the method of the present invention can significantly improve the recovery rate and purity of germanium, effectively realizing the efficient recovery and recycling of resources, and has important practical significance and economic value.
[0054] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.
Claims
1. A method for recovering germanium by chlorination distillation from germanium-containing waste residues, characterized in that, The method includes the following steps: (1) Pretreatment: The germanium chloride distillation residue is taken and crushed, then washed with deionized water, and then dried for standby; (2) Extraction: The dried residue is added to the extractant, and extraction is carried out under the conditions of a temperature of 40 - 50 °C and a stirring speed of 200 - 300 r / min for 1 - 2 h; then the organic phase loaded with germanium is back-extracted with a sulfuric acid solution with a concentration of 2 - 3 mol / L, the back-extraction temperature is 25 - 35 °C, the stirring speed is 150 - 250 r / min, and the back-extraction time is 30 - 60 min. After back-extraction, germanium is transferred from the organic phase to the aqueous phase, that is, a back-extracted solution rich in germanium is obtained; (3) Germanium refining: Liquid ammonia is introduced into the back-extracted solution to precipitate germanium to obtain germanium concentrate. Then the germanium concentrate is added to a chlorination distillation reactor, hydrochloric acid is added to the reactor, and then chlorine gas is introduced in stages. The distilled volatiles are collected and condensed. Pure water is added to the condensed product as the mother liquor for hydrolysis, and after hydrolysis, filtration is carried out to remove the filtrate; (4) Drying to dryness: The filter residue obtained in step (3) is transferred to an evaporating dish and dried to dryness under the condition of a heating temperature of 80 - 100 °C. During the drying process, continuous stirring is carried out. After drying, the germanium salt obtained is roasted and then reduced to metallic germanium by introducing hydrogen, which is the finished germanium.
2. The method according to claim 1, wherein The particle size of the crushing in step (1) is 100 - 200 mesh.
3. The method according to claim 1, characterized in that, The extractant in step (2) is a mixed solution composed of tributyl phosphate, sec-octanol and kerosene in a volume ratio of 1:1:2 - 3.
4. The method according to claim 1, characterized in that, The liquid ammonia precipitation of germanium in step (3) is to introduce liquid ammonia into the back-extracted solution, adjust the pH value of the solution to 9 - 10, react under stirring conditions until the germanium content is less than 400 mg / L, then carry out solid-liquid separation on the reacted slurry, and the obtained filter residue is dried to obtain germanium concentrate.
5. The method according to claim 1, characterized in that The liquid-solid ratio of hydrochloric acid to germanium concentrate in step (3) is 5:
1.
6. The method according to claim 1, characterized in that The chlorine gas is introduced in stages in step (3) as follows: chlorine gas is introduced at 40 - 45 °C for 30 min, then chlorine gas is introduced at 50 - 60 °C for 40 - 60 min, then chlorine gas is introduced at 83 - 90 °C for 40 - 60 min, and finally chlorine gas is introduced at 90 - 115 °C for 25 - 30 min.
7. The method according to claim 1, characterized in that The roasting temperature in step (4) is 600 - 800 °C, and the roasting time is 2 - 3 h.
8. The method according to claim 1, wherein The hydrogen reduction temperature in step (4) is 500 - 600 °C.