A method for producing germanium metal

Abstract

The application discloses a preparation method of metallic germanium. The preparation method of the metallic germanium comprises the following steps: preparing high-quality metallic germanium by reducing germanium oxide under the condition of 550 DEG C-800 DEG C and vacuum by using polyvinyl alcohol. The germanium dioxide mixed with PVA briquetting, crushing, vacuum sintering and reducing technology is adopted, the scheme is easy to operate, high in safety, avoids the explosion risk of hydrogen reduction, greatly improves the production efficiency of the germanium, reduces the energy consumption, simultaneously improves the recovery rate of the germanium, and the recovery rate is above 99%, and the product purity is not lower than the purity of the raw material germanium dioxide.

Description

Technical Field

[0001] This invention relates to the field of high-purity semiconductor metal materials technology, and in particular to a method for preparing metallic germanium. Background Technology

[0002] Social development and continuous progress in science and technology have driven the rapid growth of market demand for germanium. In recent years, the development of the 5G communication industry has led to a rapid increase in demand for germanium tetrachloride optical fiber. The booming development of the automotive industry has driven the continuous expansion of germanium's application in the civilian field of infrared optics. In addition, the use of fourth-generation solar cells in spacecraft power supplies and the development of new technologies for germanium products have led to a significant increase in global demand for germanium.

[0003] From the current development perspective in China, germanium tetrachloride, germanium dioxide, and germanium ingots are traditional germanium products. However, the high-value-added product that has seen rapid development in recent years is germanium single crystal. Metallic germanium is a crucial raw material for preparing single-crystal germanium, generally prepared by the reduction of germanium dioxide. Common reducing agents include hydrogen, carbon, carbon monoxide, and metals. The high-purity hydrogen reduction process, by controlling hydrogen flow rate, reduction temperature, and system pressure, achieves efficient reduction to produce high-purity metallic germanium. However, during the heating reduction process, temperature changes can lead to the reduction of germanium monoxide. Germanium monoxide is prone to sublimation and volatilization, affecting the yield of metallic germanium.

[0004] Currently used hydrogen or carbon monoxide reduction processes have the following problems: As they are gas-solid reactions occurring on the material surface, the reaction is time-consuming, inefficient, and consumes a large amount of gas; the reduction process produces germanium monoxide, which is easily sublimated and volatilized, affecting product yield. Other reduction processes (such as those using metals or carbon reducing agents) introduce impurities, leading to decreased product purity. Furthermore, using other reducing agents such as hydrogen poses safety risks, including the risk of explosion. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing metallic germanium. This invention first thoroughly mixes germanium dioxide and the reducing agent polyvinyl alcohol (PVA), and then uses die casting to ensure good contact. Finally, it employs vacuum sintering at high temperature, so that the reaction can proceed simultaneously from the inside and outside, resulting in high reaction efficiency, safe process, and almost no volatilization loss.

[0006] This invention is achieved through the following technical solutions:

[0007] A method for preparing metallic germanium includes the following steps: reducing germanium oxide with polyvinyl alcohol at 550℃-800℃ under vacuum conditions to obtain high-quality metallic germanium.

[0008] Preferably, the preparation method specifically includes the following steps: after mixing germanium dioxide with polyvinyl alcohol solution evenly, pressing it into blocks and placing it in a reaction vessel, evacuating the vacuum, and sintering at 550℃-800℃ for 1-5 hours to obtain high-quality metallic germanium.

[0009] Further preferably, the mass concentration of the polyvinyl alcohol solution is 2%-4%. Even more preferably, the mass concentration of the polyvinyl alcohol solution is 3%.

[0010] Further optimization involves compressing the blocks at a pressure of 15-20 MPa / cm. 2 .

[0011] Preferably, the mass ratio of polyvinyl alcohol to germanium dioxide is 0.005-0.010:1.

[0012] Further preferably, the mass ratio of polyvinyl alcohol to germanium dioxide is 0.006:1.

[0013] Preferably, the vacuum condition is to evacuate to below 10 Pa.

[0014] Preferably, the specific steps for pressing the material into blocks and placing it into the reaction vessel are as follows: pressing it into blocks, then breaking it into small pieces, placing it into a high-purity graphite or quartz boat, and loading it into a high-temperature vacuum furnace sintering furnace.

[0015] Preferably, the sintering conditions are sintering at 550℃-800℃ for 1-5 hours. More preferably, the sintering conditions are sintering at 650℃-711℃ for 3-5 hours.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The technology of germanium dioxide mixed with PVA briquetting, crushing, and vacuum sintering reduction adopted in the present invention is easy to operate, has high safety, avoids the explosion risk of hydrogen reduction, greatly improves the production efficiency of germanium, reduces energy consumption, and at the same time improves the recovery rate of germanium, with a recovery rate of over 99%, and the purity of the product is not lower than the purity of the raw material germanium dioxide. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are considered to be commercially available materials and reagents that can be obtained through conventional markets and other commercial channels.

[0018] Example 1:

[0019] A method for preparing metallic germanium includes the following steps:

[0020] (1) Prepare a 3% polyvinyl alcohol 1799 type (PVA) solution: Weigh 3g PVA, then add 90℃-95℃ deionized water, and stir continuously until completely dissolved to obtain a 3% PVA solution.

[0021] (2) Weigh 20g of germanium dioxide powder, mix it evenly with 4g of 3% PVA solution, and then press it into blocks using an automatic briquetting machine at a pressure of 18MPa / cm. 2 The compressed briquette was broken into small pieces, placed in a high-purity graphite boat, and then loaded into a high-temperature vacuum furnace for sintering. The vacuum was evacuated to below 10 Pa, heated to 550°C and held for 1 hour, and then cooled to room temperature to remove the vacuum, yielding 13.33 g of metallic germanium with a product yield of 96.0%.

[0022] Example 2:

[0023] A method for preparing metallic germanium includes the following steps:

[0024] (1) Prepare a 3% polyvinyl alcohol 1799 type (PVA) solution: Weigh 3g PVA, then add hot deionized water at 90℃-95℃, and stir continuously until completely dissolved to obtain a 3% PVA solution.

[0025] (2) Weigh 200g of germanium dioxide powder, mix it evenly with 40g of 3% PVA solution, and then press it into blocks using an automatic briquetting machine at a pressure of 18MPa / cm. 2 The compressed briquette was broken into small pieces, placed in a high-purity graphite boat, and then loaded into a high-temperature vacuum furnace sintering furnace. The furnace was evacuated to below 10 Pa, heated to 650°C, held for 3 hours, and then cooled to room temperature to remove the vacuum, yielding 136.71 g of metallic germanium with a product yield of 98.5%.

[0026] Example 3:

[0027] A method for preparing metallic germanium includes the following steps:

[0028] (1) Prepare a 3% polyvinyl alcohol 1799 type (PVA) solution: Weigh 3g PVA, then add hot deionized water at 90℃-95℃, and stir continuously until completely dissolved to obtain a 3% PVA solution.

[0029] (2) Weigh 200g of germanium dioxide powder, mix it evenly with 40g of 3% PVA solution, and then press it into blocks using an automatic briquetting machine at a pressure of 18MPa / cm. 2 The compressed briquette was broken into small pieces, placed in a high-purity graphite boat, and then loaded into a high-temperature vacuum furnace sintering furnace. The furnace was evacuated to below 10 Pa, heated to 680°C, held for 3 hours, and then cooled to room temperature to remove the vacuum, yielding 136.98 g of metallic germanium with a product yield of 98.7%.

[0030] Example 4:

[0031] A method for preparing metallic germanium includes the following steps:

[0032] (1) Prepare a 3% polyvinyl alcohol 1799 type (PVA) solution: Weigh 30g PVA, then add hot deionized water at 90℃-95℃, and stir continuously until completely dissolved to obtain a 3% PVA solution.

[0033] (2) Weigh 2000g of germanium dioxide powder, mix it evenly with 400g of 3% PVA solution, and then press it into blocks using an automatic briquetting machine at a pressure of 18MPa / cm. 2 The compressed briquette was broken into small pieces, placed in a high-purity graphite boat, and then loaded into a high-temperature vacuum furnace for sintering. The vacuum was evacuated to below 10 Pa, the temperature was raised to 711°C, and held for 5 hours. The temperature was then lowered to room temperature and the vacuum was released, yielding 1378.34 g of metallic germanium, with a product yield of 99.3%. After reduction, the temperature can be further raised to 1050°C under vacuum to melt and cast into ingots.

[0034] Example 5:

[0035] A method for preparing metallic germanium includes the following steps:

[0036] (1) Prepare a 3% polyvinyl alcohol 1799 (PVA) solution: Weigh 30g of PVA, then add hot deionized water at 90-95℃, and stir continuously until completely dissolved to obtain a 3% PVA solution.

[0037] (2) Weigh 2000g of germanium dioxide powder, mix it evenly with 400g of 3% PVA solution, and then press it into blocks using an automatic briquetting machine at a pressure of 18MPa / cm. 2 The compressed briquette was broken into small pieces, placed in a high-purity graphite boat, and then loaded into a high-temperature vacuum furnace for sintering. The vacuum was evacuated to below 10 Pa, the temperature was raised to 711°C, and held for 5 hours. The temperature was then lowered to room temperature to release the vacuum, resulting in a product yield of over 98%. The temperature was further raised to 1100°C to melt and cast into ingots.

[0038] Example 6:

[0039] Same as Example 1, except that: the mass concentration of the polyvinyl alcohol solution is 2%, the mass ratio of polyvinyl alcohol to germanium dioxide is 0.005:1, and the pressure for pressing into blocks is 15 MPa / cm. 2 Sinter at 550℃ for 5 hours.

[0040] Example 7:

[0041] Same as Example 1, except that: the mass concentration of the polyvinyl alcohol solution is 4%, the mass ratio of polyvinyl alcohol to germanium dioxide is 0.010:1, and the pressure for pressing into blocks is 20 MPa / cm. 2 Sinter at 800℃ for 1 hour.

[0042] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for producing germanium metal, characterized by, The method comprises the following steps: reducing germanium dioxide with polyvinyl alcohol at 550-800 DEG C under vacuum to obtain high-quality germanium metal.

2. The method of producing germanium metal according to claim 1, wherein The method comprises the following steps: mixing germanium dioxide with polyvinyl alcohol solution, pressing into blocks, placing into a reaction container, vacuumizing, sintering at 550-800 DEG C for 1-5 hours to obtain high-quality germanium metal.

3. The method of producing germanium metal according to claim 2, wherein The mass concentration of the polyvinyl alcohol solution is 2-4%.

4. The method of producing germanium metal according to claim 3, wherein The mass concentration of the polyvinyl alcohol solution is 3%.

5. The method of producing germanium metal according to claim 2, wherein The pressure for pressing into a block is 15-20 MPa / cm 2 .

6. The method of producing germanium metal according to any one of claims 1 to 3, wherein The mass ratio of the polyvinyl alcohol to germanium dioxide is 0.005-0.010:

1.

7. The method of producing germanium metal according to claim 6, wherein The mass ratio of the polyvinyl alcohol to germanium dioxide is 0.006:

1.

8. The method of producing germanium metal according to any one of claims 1 to 3, wherein The vacuum condition is vacuumizing to below 10 Pa.

9. The method of producing germanium metal according to any one of claims 1 to 3, wherein The specific step of pressing into blocks and placing into a reaction container is: pressing into blocks, crushing into small blocks, placing into a high-purity graphite or quartz boat, and placing into a high-temperature vacuum sintering furnace.

10. The method of producing germanium metal according to any one of claims 1 to 3, wherein The sintering condition is sintering at 550-711 DEG C for 1-5 hours.