Method for enriching germanium from germanium-containing material
By combining sulfuric acid leaching and reduced iron powder separation with neutralization and precipitation zinc powder replacement, the problems of complex and energy-intensive germanium separation and enrichment in existing technologies have been solved, achieving efficient and environmentally friendly germanium recovery.
Patent Information
- Application Number
- CN202511376405.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-25
- Publication Date
- 2026-01-30
AI Technical Summary
Existing technologies for separating and enriching germanium from germanium-containing materials are complex, energy-intensive, environmentally unfriendly, and have low germanium recovery rates.
A method combining sulfuric acid leaching with initial separation by reducing iron powder, neutralization precipitation, and zinc powder replacement is employed. By controlling the pH and temperature at the reaction endpoint, germanium is separated and enriched from other elements, including primary and secondary germanium precipitation steps.
It achieves efficient separation and enrichment of germanium, with a germanium recovery rate of over 99%, simplifies the process, reduces energy consumption, and improves environmental friendliness.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of metal recycling technology, specifically relating to a method for enriching germanium from germanium-containing materials. Background Technology
[0002] Germanium lies between tin and silicon in the periodic table, so its chemical properties exhibit a transitional characteristic from metallic to nonmetallic. In nature, germanium exists in a dispersed state, mostly as a polymetallic associated mineral. Global germanium resources are relatively scarce, with proven reserves of only 8,600 tons, and independent deposits are extremely rare.
[0003] Germanium is mainly recovered from roasted sphalerite, lead-zinc oxide, and germanium-bearing coal ash or dust. Due to the diversity of germanium-containing raw materials, the pre-enrichment methods vary greatly, and there are also many methods for further enrichment of germanium-rich raw materials. However, the process for preparing high-purity germanium dioxide from germanium concentrate is basically the same.
[0004] Currently, some domestic enterprises use conventional zinc smelting processes combined with a fuming furnace to volatilize germanium-containing zinc oxide. The germanium-containing zinc oxide dust is then leached with zinc and germanium, and the leaching solution is recovered using tannic acid precipitation. Some enterprises use a direct high-temperature acid leaching process with zinc sulfide concentrate. Due to the high germanium content in their own zinc concentrate, germanium is precipitated using a neutralization method before iron precipitation. The neutralization slag is then extracted and recovered using oxygen pressure leaching. Still other enterprises employ a process that partially treats the leaching slag in a volatilization kiln and partially smelts the slag using side-blown smelting followed by fuming volatilization to enrich germanium in the zinc oxide dust, which is then recovered.
[0005] However, traditional methods for separating and enriching germanium have problems such as complex processes, high energy consumption, environmental unfriendliness, and low germanium recovery rate. Therefore, there is an urgent need to develop a new method for separating and enriching germanium from germanium-containing materials. Summary of the Invention
[0006] The purpose of this invention is to propose a method for enriching germanium from germanium-containing materials, which achieves the separation of germanium from elements such as copper, bismuth, arsenic, tin, and iron, resulting in a high degree of germanium enrichment and recovery with a high recovery rate. This method is highly operable and easy to implement.
[0007] This invention provides a method for enriching germanium from germanium-containing materials, comprising the following steps:
[0008] (1) The germanium-containing material is leached with sulfuric acid once, and the acidity at the leaching endpoint is controlled to be 50-70 g / L to obtain a germanium-containing primary leaching solution. Reduced iron powder is added to the primary leaching solution, and preliminary separation is achieved through reaction to obtain purified residue and purified solution.
[0009] (2) Add a neutralizing agent to the purified liquid obtained in step (1) and adjust the pH to 1.0 to 1.5 so that tin hydrolyzes into the neutralized slag. Then add an excess of zinc powder to perform a first precipitation of germanium. The pH of the first precipitation solution is ≥5.0 so that germanium is separated from other elements and low-grade germanium slag is obtained.
[0010] (3) The low-grade germanium slag obtained in step (2) is leached twice with sulfuric acid, and the pH of the leaching endpoint is controlled to be 1.5 to 2.0. Germanium is further enriched in the liquid phase. The zinc powder is added to the secondary leaching solution for secondary germanium precipitation. The pH of the germanium precipitation endpoint is 3.0 to 3.5, and high-grade germanium slag is obtained.
[0011] Furthermore, the temperature for a single leaching is 85–95°C, and the reaction time is 6–8 hours.
[0012] Furthermore, the excess coefficient of the reduced iron powder is 1.3 to 1.5.
[0013] Furthermore, the reaction temperature after adding the reduced iron powder is 50–60°C.
[0014] Furthermore, the reduced iron powder is added in three parts. The first addition is 60-65% of the total amount, and the reaction time is 1.5-2 hours. The second addition is 25-30% of the total amount, and the reaction time is 1-1.5 hours. The third addition is the remaining amount, and the reaction time is 0.5-1 hours.
[0015] Furthermore, the purified residue includes copper and / or bismuth.
[0016] Furthermore, in step (2), the temperature of the neutralization reaction is 50-60℃ and the reaction time is 0.5-1h.
[0017] Furthermore, the temperature for the first germanium deposition is 70–80°C, and the reaction time is 3–5 hours.
[0018] Furthermore, the temperature for the secondary leaching is 85–95°C, and the reaction time is 6–8 hours.
[0019] Furthermore, the secondary germanium deposition temperature is 70–80°C, and the reaction time is 4–6 hours.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0021] (1) The present invention fully considers the valuable elements that may exist in the raw materials, uses reduced iron powder, and further controls its addition amount. By utilizing the different redox potentials between different elements, the initial separation and enrichment of germanium in the raw materials can be achieved. The method of the present invention has strong adaptability.
[0022] (2) This invention uses a method of one-time zinc powder replacement-acid leaching-secondary zinc powder replacement to achieve germanium enrichment. By reasonably controlling the pH value at the end of each reaction process and the organic combination between processes, the orderly separation of germanium from other elements is achieved, and germanium slag with a grade of more than 2% can be obtained. The germanium precipitation rate is more than 99%, which avoids the adverse effects of organic matter introduced by the tannin precipitation method on zinc electrolysis and solves the problem of low grade of conventional zinc powder precipitation of germanium.
[0023] (3) While realizing germanium recovery, this invention also realizes the enrichment and recovery of other valuable elements in the raw materials, improves the grade of other valuable elements, and enhances the comprehensive economic value of recovery.
[0024] (4) The method of the present invention has a simple process, high germanium recovery rate, strong operability, environmental friendliness and high practicality. Attached Figure Description
[0025] The advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0026] Figure 1 This is a process flow diagram for Example 3. Detailed Implementation
[0027] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.
[0028] A method for enriching germanium from germanium-containing materials includes the following steps:
[0029] (1) The germanium-containing material is leached once with sulfuric acid, controlling the final acidity at 50–70 g / L, the leaching temperature at 85–95 °C, and the reaction time at 6–8 h to obtain a germanium-containing primary leaching solution. Reduced iron powder is added to the primary leaching solution, and the reaction temperature after adding the reduced iron powder is 50–60 °C. Preliminary separation is achieved through the reaction, yielding purified residue and purified solution. During this process, elements with more positive potentials, such as copper, bismuth, and arsenic, enter the purified residue, while elements with more negative potentials, such as germanium, tin, and divalent iron, remain in the purified solution. The purified residue contains valuable elements such as copper and bismuth and can be sold externally.
[0030] The excess coefficient of reduced iron powder is 1.3–1.5, specifically referring to adding 1.3–1.5 times the theoretical amount of reduced iron powder required to reduce ferric iron to ferrous iron. The reduced iron powder is added in three stages: the first addition is 60–65% of the total amount, with a reaction time of 1.5–2 hours; the second addition is 25–30% of the total amount, with a reaction time of 1–1.5 hours; and the third addition is the remaining amount, with a reaction time of 0.5–1 hour. If the entire amount is added directly or too much is added initially, it can easily lead to excessively low local reduction potential, generating large amounts of harmful gases such as arsine and hydrogen. Simultaneously, a large amount of germanium is also displaced and lost into the purification slag, resulting in a low germanium recovery rate.
[0031] (2) Add a neutralizing agent, such as sodium hydroxide or sodium carbonate, to the purified solution obtained in step (1). Adjust the pH to 1.0–1.5. The neutralization reaction temperature is 50–60°C, and the reaction time is 0.5–1 h. This allows tin to hydrolyze and enter the neutralization slag. If the pH is below this range, tin will not hydrolyze or will not hydrolyze completely. If the pH exceeds this range, germanium may hydrolyze and be lost, entering the hydrolysis slag and affecting the recovery rate. Then add excess zinc powder for a second germanium precipitation. The temperature for the second precipitation is 70–80°C, and the reaction time is 3–5 h. The pH of the first germanium precipitation solution should be ≥5.0 to separate germanium from other elements, ensuring complete precipitation and obtaining low-grade germanium slag. If the pH is <5.0, the solution is strongly acidic, which will reduce the precipitation efficiency of germanium.
[0032] The germanium precipitate obtained in step (2) can be repeated in step (1).
[0033] (3) The low-grade germanium slag obtained in step (2) is subjected to a second leaching with sulfuric acid at a temperature of 85–95°C and a reaction time of 6–8 h. The pH at the leaching endpoint is controlled to be 1.5–2.0, allowing germanium to be further enriched in the liquid phase. If the pH value is greater than this range, the leaching efficiency of germanium decreases significantly, ultimately reducing the total recovery rate of germanium. Zinc powder is added to the second leaching solution for a second germanium precipitation at a temperature of 70–80°C and a reaction time of 4–6 h. The final pH at the germanium precipitation endpoint is 3.0–3.5, yielding high-grade germanium slag.
[0034] The secondary leaching residue obtained in step (3) can be repeated in step (1), and the secondary germanium precipitation solution can be repeated in step (3).
[0035] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.
[0036] Example 1
[0037] The germanium-containing material in this embodiment comprises 13.18% copper, 6.10% arsenic, 0.15% germanium, 0.41% tin, 6.01% bismuth, and 4.46% iron. A method for enriching germanium from the germanium-containing material includes the following steps:
[0038] (1) 100g of germanium-containing material was leached once with sulfuric acid, with the final acidity controlled at 50g / L, the leaching temperature at 85℃, and the leaching time at 6h, yielding a germanium-containing primary leachate. Reduced iron powder was added to the primary leachate, and the reaction temperature after adding the reduced iron powder was 50℃. Preliminary separation was achieved through the reaction, yielding purified residue and purified liquid. During this process, elements with more positive potentials, such as copper, bismuth, and arsenic, entered the purified residue, while elements with more negative potentials, such as germanium, tin, and divalent iron, remained in the purified liquid. The purified residue was rich in valuable elements such as copper and bismuth, with a copper grade of 27.5%.
[0039] The excess coefficient of reduced iron powder is 1.3. The reduced iron powder is added in three parts. The first addition is 60% of the total amount, and the reaction time is 1.5 hours. The second addition is 30% of the total amount, and the reaction time is 1 hour. The third addition is the remaining amount, and the reaction time is 0.5 hours.
[0040] (2) Add sodium hydroxide to the purified liquid obtained in step (1) to adjust the pH to 1.5. The temperature of the neutralization reaction is 50℃ and the reaction time is 0.5h. This allows the tin to hydrolyze into the neutralization slag. Then add excess zinc powder to perform a first precipitation of germanium. The temperature of the first precipitation of germanium is 70℃ and the reaction time is 3h. The pH of the first precipitation solution is ≥5.0, which separates germanium from other elements. Germanium is completely precipitated, and a germanium slag with a grade of 0.5% is obtained.
[0041] The germanium precipitate obtained in step (2) can be repeated in step (1).
[0042] (3) The low-grade germanium slag obtained in step (2) is leached twice with sulfuric acid at a temperature of 85°C and a reaction time of 6 hours. The pH at the leaching endpoint is controlled to be 1.5, and germanium is further enriched in the liquid phase. The leached slag can be repeated in step (1). Zinc powder is added to the leaching solution for secondary germanium precipitation at a temperature of 70°C and a reaction time of 4 hours. The pH at the precipitation endpoint is 3.0, resulting in high-grade germanium slag with a composition of 2.14% germanium, 6.30% zinc, and 3.72% iron. The secondary germanium precipitation solution can be repeated in step (3).
[0043] In this embodiment, the germanium precipitation rate reaches 99.5%.
[0044] Example 2
[0045] The composition of the germanium-containing material in this embodiment is the same as in Embodiment 1. A method for enriching germanium from germanium-containing materials includes the following steps:
[0046] (1) 100g of germanium-containing material was leached once with sulfuric acid, with the final acidity controlled at 65g / L, the leaching temperature at 90℃, and the leaching time at 6.5h, to obtain a germanium-containing primary leachate. Reduced iron powder was added to the primary leachate, and the reaction temperature after adding the reduced iron powder was 55℃. Preliminary separation was achieved through the reaction, yielding purified residue and purified liquid. The purified residue was rich in valuable elements such as copper and bismuth, with a copper grade of 28.3%.
[0047] The excess coefficient of reduced iron powder is 1.4. The reduced iron powder is added in three parts: the first addition is 65% of the total amount, and the reaction time is 2 hours; the second addition is 30% of the total amount, and the reaction time is 1 hour; the third addition is the remaining amount, and the reaction time is 0.5 hours.
[0048] (2) Add sodium carbonate to the purified liquid obtained in step (1) to adjust the pH to 1.0. The temperature of the neutralization reaction is 55℃ and the reaction time is 1h, so that the tin is hydrolyzed into the neutralization slag. Then add excess zinc powder to carry out the first precipitation of germanium. The temperature of the first precipitation of germanium is 75℃ and the reaction time is 4h. The pH of the first precipitation solution is ≥5.0, so that germanium is separated from other elements and germanium is completely precipitated, and germanium slag with a grade of 0.55% is obtained.
[0049] (3) The low-grade germanium slag obtained in step (2) was leached twice with sulfuric acid at a temperature of 90°C for 7 hours. The pH at the leaching endpoint was controlled to be 2.0, and germanium was further enriched in the liquid phase. Zinc powder was added to the secondary leaching solution for secondary germanium precipitation at a temperature of 75°C for 5 hours. The pH at the precipitation endpoint was 3.5, resulting in high-grade germanium slag with a composition of 2.06% germanium, 7.10% zinc, and 3.88% iron.
[0050] In this embodiment, the germanium precipitation rate reaches 99.63%.
[0051] Example 3
[0052] The composition of the germanium-containing material in this embodiment is the same as in Example 1. A method for enriching germanium from germanium-containing materials is described below. Figure 1 As shown, it includes the following steps:
[0053] (1) 100g of germanium-containing material was leached once with sulfuric acid, with the final acidity controlled at 70g / L, the leaching temperature at 95℃, and the leaching time at 8h, to obtain a germanium-containing primary leachate. Reduced iron powder was added to the primary leachate, and the reaction temperature after adding the reduced iron powder was 60℃. Preliminary separation was achieved through the reaction, yielding purified residue and purified liquid. The purified residue was rich in valuable elements such as copper and bismuth, with a copper grade of 30.85%.
[0054] The excess coefficient of reduced iron powder is 1.5. The reduced iron powder is added in three parts. The first addition is 65% of the total amount, and the reaction time is 2 hours. The second addition is 25% of the total amount, and the reaction time is 1.5 hours. The third addition is the remaining amount, and the reaction time is 0.5 hours.
[0055] (2) Add sodium hydroxide to the purified liquid obtained in step (1) to adjust the pH to 1.5. The temperature of the neutralization reaction is 60℃ and the reaction time is 1h. This allows tin to hydrolyze into the neutralization slag. Then add excess zinc powder to perform a first precipitation of germanium. The temperature of the first precipitation of germanium is 75℃ and the reaction time is 5h. The pH of the first precipitation solution is ≥5.0, which separates germanium from other elements. Germanium is completely precipitated, and a germanium slag with a grade of 0.59% is obtained.
[0056] The germanium precipitate obtained in step (2) can be repeated in step (1).
[0057] (3) The low-grade germanium slag obtained in step (2) is leached twice with sulfuric acid at a temperature of 90°C for 8 hours. The pH at the leaching endpoint is controlled to be 1.5, and germanium is further enriched in the liquid phase. The leached slag can be repeated in step (1). Zinc powder is added to the leaching solution for secondary germanium precipitation at a temperature of 80°C for 6 hours. The pH at the precipitation endpoint is 3.5, resulting in high-grade germanium slag with a composition of 2.48% germanium, 6.59% zinc, and 3.43% iron. The secondary germanium precipitation solution can be repeated in step (3).
[0058] In this embodiment, the germanium precipitation rate reaches 99.78%.
[0059] Comparative Example 1
[0060] The composition of the germanium-containing material in this comparative example is the same as that in Example 1. Enriching germanium from the germanium-containing material includes the following steps:
[0061] (1) Same as step (1) in Example 1. The copper content in the purified slag is 27.5%.
[0062] (2) Add sodium hydroxide to the purified liquid obtained in step (1) to adjust the pH to 3.5. The temperature of the neutralization reaction is 50℃ and the reaction time is 0.5h. Then add excess zinc powder to carry out the first precipitation of germanium. The temperature of the first precipitation of germanium is 50℃ and the reaction time is 3h. The pH of the first precipitation solution is ≥5.0, and a germanium slag with a grade of 0.1% is obtained.
[0063] (3) The low-grade germanium slag obtained in step (2) is leached twice with sulfuric acid at a temperature of 50°C for 2 hours, and the pH at the leaching endpoint is controlled to be 1.5. Zinc powder is added to the secondary leaching solution for secondary germanium precipitation at a temperature of 50°C for 2 hours, and the pH at the precipitation endpoint is 5.0, resulting in germanium slag with a germanium grade of 0.45%.
[0064] The precipitation rate of germanium in this comparative example was 68.3%.
[0065] Comparative Example 2
[0066] The composition of the germanium-containing material in this comparative example is the same as that in Example 1. Enriching germanium from the germanium-containing material includes the following steps:
[0067] (1) 100g of germanium-containing material was leached once with sulfuric acid, with the final acidity controlled at 65g / L, the leaching temperature at 90℃, and the leaching time at 6.5h, yielding a germanium-containing primary leachate. Reduced iron powder was added to the primary leachate, and the reaction temperature after adding the reduced iron powder was 55℃, yielding purified residue and purified liquid. The copper content in the purified residue was 16.4%.
[0068] The excess coefficient of reduced iron powder is 1.4. The reduced iron powder is added in three parts. The first addition is 80% of the total amount, and the reaction time is 2 hours. The second addition is 10% of the total amount, and the reaction time is 1 hour. The third addition is the remaining amount, and the reaction time is 0.5 hours.
[0069] (2) Add sodium hydroxide to the purified liquid obtained in step (1) to adjust the pH to 0.5. The temperature of the neutralization reaction is 80℃ and the reaction time is 0.5h. Then add excess zinc powder to carry out the first precipitation of germanium. The temperature of the first precipitation of germanium is 55℃ and the reaction time is 2h. The pH of the first precipitation solution is 4.0, and a germanium slag with a grade of 0.12% is obtained.
[0070] (3) The low-grade germanium slag obtained in step (2) is leached twice with sulfuric acid at a temperature of 60°C for 5 hours, and the pH at the leaching endpoint is controlled to be 1.5. Zinc powder is added to the secondary leaching solution for secondary germanium precipitation at a temperature of 65°C for 3 hours, and the pH at the precipitation endpoint is 4.0, resulting in germanium slag with a germanium grade of 0.37%.
[0071] The precipitation rate of germanium in this comparative example was 63.71%.
[0072] Comparative Example 3
[0073] The composition of the germanium-containing material in this comparative example is the same as that in Example 1. Enriching germanium from the germanium-containing material includes the following steps:
[0074] (1) Same as step (1) in Example 3. The copper content in the purified slag is 30.85%.
[0075] (2) Same as step (2) in Example 3.
[0076] (3) The low-grade germanium slag obtained in step (2) is leached twice with sulfuric acid at a temperature of 45°C for 3 hours, and the pH at the leaching endpoint is controlled to be 2.5. Zinc powder is added to the secondary leaching solution for secondary germanium precipitation at a temperature of 80°C for 6 hours, and the pH at the precipitation endpoint is 3.5, resulting in germanium slag with a germanium grade of 0.6%.
[0077] The precipitation rate of germanium in this comparative example was 65.9%.
[0078] The comparison results between Examples 1-3 and Comparative Examples 1-3 show that the method used in the embodiments of the present invention can better separate and enrich germanium, with copper slag grade exceeding 30% and secondary germanium slag grade as high as 2.48%, and all technical indicators are significantly better than those of the comparative examples.
[0079] It should be understood that the embodiments of the present invention are merely preferred implementations and are not intended to limit the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A process for the enrichment of germanium from germanium-containing material, characterized in that, The method comprises the following steps: (1) primary leaching of germanium-containing material with sulfuric acid, controlling the terminal leaching acidity to be 50-70 g / L to obtain a primary leaching solution containing germanium, adding reduced iron powder to the primary leaching solution to realize preliminary separation through reaction, and obtaining a purified residue and a purified solution; (2) adding a neutralizing agent to the purified solution obtained in step (1) to adjust pH to 1.0-1.5, hydrolyzing tin into a neutralizing residue, and then adding excess zinc powder to carry out primary germanium precipitation, with the primary germanium precipitation solution having a pH of 5.0 or higher, so that germanium is separated from other elements, and a low-grade germanium residue is obtained; (3) secondary leaching of the low-grade germanium residue obtained in step (2) with sulfuric acid, controlling the terminal leaching pH to be 1.5-2.0, further enriching germanium in the liquid phase, adding the zinc powder to the secondary leaching solution to carry out secondary germanium precipitation, with the terminal pH of the germanium precipitation being 3.0-3.5, and obtaining a high-grade germanium residue.
2. The method of claim 1, wherein the germanium is enriched from the germanium- containing material by, The temperature of the primary leaching is 85-95 ℃, and the reaction time is 6-8 h.
3. The method of claim 1, wherein the germanium is enriched from the germanium- containing material by, The excess coefficient of the reduced iron powder is 1.3-1.
5.
4. The method for enriching germanium from germanium-containing material according to claim 1, characterized in that, The reaction temperature after adding the reduced iron powder is 50-60 ℃.
5. The method of claim 1, wherein the germanium is enriched from the germanium- containing material by a factor of at least 2. The reduced iron powder is added in three times, the first time amount is 60-65% of the total amount, the reaction time is 1.5-2 h, the second time amount is 25-30% of the total amount, the reaction time is 1-1.5 h, and the third time amount is the remaining amount, and the reaction time is 0.5-1 h.
6. The method of claim 1, wherein the germanium is enriched from the germanium- containing material by a factor of at least 2. The purified residue contains copper and / or bismuth.
7. The method of claim 1, wherein the germanium is enriched from the germanium- containing material by a factor of at least 2. In step (2), the neutralization reaction temperature is 50-60 ℃, and the reaction time is 0.5-1 h.
8. The method of claim 1, wherein the germanium is enriched from the germanium- containing material by a factor of at least 2. The temperature of the primary germanium precipitation is 70-80 ℃, and the reaction time is 3-5 h.
9. The method of claim 1, wherein the germanium is enriched from the germanium- containing material by a factor of at least 2. The temperature of the secondary leaching is 85-95 ℃, and the reaction time is 6-8 h.
10. The method for enriching germanium from germanium-containing material according to claim 1, characterized in that, The temperature of the secondary germanium precipitation is 70-80 ℃, and the reaction time is 4-6 h.