Method for recovering germanium and zinc from germanium-phosphorus-zinc waste

Abstract

The invention provides a method for recycling germanium and zinc from germanium-phosphorus-zinc waste, and belongs to the technical field of resource regeneration, the method comprises the processes of surface corrosion cleaning, pyrolysis, vacuum zinc removal, vacuum zinc removal and the like, and the method adopts a self-made'pyrolysis-vacuum distillation integrated device 'to directly regenerate germanium and zinc metal from the germanium-phosphorus-zinc waste. The blank of the current'germanium phosphorus zinc waste 'regeneration technology is filled up; and the method has the advantages of high direct recovery rate of germanium and zinc, simple process operation, low production cost and the like.

Description

Technical Field

[0001] This invention relates to the field of recycling technology for metal materials, and more particularly to a method for recovering germanium and zinc from germanium-phosphorus-zinc waste. Background Technology

[0002] Germanium zinc phosphorus (GeP2Zn) crystal is an important semiconductor material widely used in optoelectronics, laser technology, and nonlinear optics. Due to its unique optical and electronic properties, germanium zinc phosphorus crystal plays a key role in many high-tech applications.

[0003] The chemical formula for germanium-zinc phosphorus crystal is GeP₂Zn. It belongs to the tetragonal crystal system, with lattice constants a = 6.1 Å and c = 10.7 Å. Its crystal structure can be considered as alternating arrangements of zinc and germanium atoms within a framework formed by phosphorus atoms. The band gap of germanium-zinc phosphorus crystal is approximately 1.5 electron volts, making it suitable for photoelectric detection and laser emission at room temperature.

[0004] The main methods for preparing germanium-phosphorus-zinc crystals include hydrothermal methods, melt growth methods, and chemical vapor deposition methods. Hydrothermal methods, which involve reacting aqueous solutions under high temperature and high pressure, can produce high-quality crystals. Melt growth methods involve melting the raw materials at high temperatures and then cooling them to crystallize, making them suitable for large-scale production. Chemical vapor deposition methods involve depositing crystals onto a substrate surface through a gas reaction, and can typically control the crystal growth rate and morphology. Currently, the utilization rate of germanium-phosphorus-zinc crystal preparation and downstream product manufacturing and R&D in research and small-scale production is low. Some germanium-phosphorus-zinc crystals become waste during synthesis and use, leading to resource waste. The main components of germanium-phosphorus-zinc waste are GeP2Zn and other trace impurities. Germanium is a high-value rare and dispersed metal and a strategic resource, while zinc is also an important metal resource. However, currently, there is a lack of recycling technology for "germanium-phosphorus-zinc waste" in the germanium industry. Given this current lack of recycling technology for "germanium-phosphorus-zinc waste," there is an urgent need for a method to recover germanium and zinc from germanium-phosphorus-zinc waste, ensuring that both germanium and zinc in the waste are fully recovered and utilized. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a simple, fast, and efficient method for recovering germanium and zinc from germanium-phosphorus-zinc waste.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for recovering germanium and zinc from germanium-phosphorus-zinc waste includes the following steps: S1: Surface corrosion cleaning; Germanium-phosphorus-zinc waste was heated in high-purity water, and potassium hydroxide and hydrogen peroxide were added for surface corrosion. The corroded germanium-phosphorus-zinc waste was then rinsed with high-purity water and dried. Surface etching removes the oxide film and stains from the surface of germanium-phosphorus-zinc waste, exposing the pure alloy surface to improve the efficiency of subsequent decomposition. The etching solution is sent to the germanium process for germanium recovery, avoiding the waste of germanium metal contained in the etching solution.

[0007] S2: High-temperature decomposition; The dried germanium-phosphorus-zinc waste is placed in a quartz container and then placed in the high-temperature decomposition chamber of an integrated high-temperature decomposition-vacuum distillation device. Inert gas is introduced to purge air, and this process is continued. Under this inert gas atmosphere, heating causes the germanium-phosphorus-zinc to decompose. Zinc and phosphorus exist in gaseous form at high temperature. The inert gas containing gaseous zinc and phosphorus is collected. First, the collected inert gas is passed into the zinc collection chamber. At a first temperature, the gaseous zinc in the inert gas is cooled and precipitated to obtain metallic zinc. Then, the collected inert gas is passed into the phosphorus collection chamber. At a second temperature, the gaseous phosphorus in the inert gas is cooled and precipitated to obtain solid phosphorus. The inert gas is then discharged, carrying a small amount of phosphorus-containing tail gas, which is then discharged through the exhaust port into a waste gas treatment system for compliant disposal. This avoids the generation of phosphorus-containing gases that pollute the atmospheric environment. Using an inert gas as a carrier gas, zinc vapor (Zn boiling point is about 907℃, easily volatilized at 1100~1300℃) and phosphorus vapor, which volatilize at high temperatures, are moved to the corresponding collection chambers, avoiding the products from remaining in the decomposition chamber and improving collection efficiency.

[0008] This invention decomposes germanium, zinc, phosphorus, and zinc into germanium, zinc, and phosphorus at high temperature under the protection of an inert gas. Taking advantage of the significant difference in boiling points among germanium, zinc, and phosphorus, different temperatures are controlled in different regions, so that germanium remains in liquid form in the high-temperature decomposition chamber, while zinc and phosphorus are carried in gaseous form by the inert gas into the zinc collection chamber and phosphorus collection chamber, respectively, and undergo segmented cooling and deposition, thereby fully decomposing and separating germanium, zinc, and phosphorus.

[0009] S3: Vacuum zinc removal; Stop the inert gas supply and control the high-temperature decomposition chamber to a negative pressure. Under the negative pressure environment, the remaining small amount of zinc will deeply volatilize to form zinc vapor. Collect the zinc vapor and cool it in the zinc collection chamber to obtain metallic zinc. Under the negative pressure condition, zinc in germanium is deeply removed by high-temperature distillation. At the same time, zinc is recovered by cooling and settling in the zinc collection chamber, ensuring the purity of the finally recovered crude germanium ingot.

[0010] S4: Discharge; After stopping heating in the high-temperature decomposition chamber and reducing the temperatures of the high-temperature decomposition chamber, zinc collection chamber, and phosphorus collection chamber to safe levels, control the intake air to restore atmospheric pressure. Obtain crude germanium ingots from the quartz container in the high-temperature decomposition chamber, and collect the obtained metallic zinc and solid phosphorus. Ensure safe production processing; the collected crude germanium ingots and metallic zinc can be sold or further purified; the collected solid phosphorus is sent for compliant and environmentally friendly disposal.

[0011] Furthermore, in step S1, the added high-purity water completely wets the germanium-phosphorus-zinc waste, ensuring that the surface of the waste can be fully corroded, guaranteeing that the pure alloy surface is fully exposed. The mass ratio of potassium hydroxide to high-purity water is 0.0002–0.001:1; the concentration of added hydrogen peroxide is 10–30%, and the volume ratio of hydrogen peroxide to high-purity water is 0.001–0.005:1. This effectively controls the reaction rate and effect to remove the oxide film and stains on the surface of the germanium-phosphorus-zinc waste, exposing the pure alloy surface to improve the efficiency of subsequent decomposition, while minimizing the amount of alloy dissolved into the solution.

[0012] Furthermore, in step S2, after introducing inert gas for 20-40 minutes, the heating temperature of the high-temperature decomposition chamber is controlled at 1100-1300℃, and high-temperature decomposition is carried out for 10-18 hours. The first temperature is controlled at 600-700℃, and the second temperature is controlled at ≤200℃. This ensures that the air in the high-temperature decomposition chamber is fully exhausted to prevent oxidation of the waste material with air at high temperatures, thus improving the purity of the recovered waste material. The high-temperature decomposition chamber temperature of 1100-1300℃ ensures complete decomposition of the raw materials, releasing zinc and phosphorus vapors. The 10-18 hour time window ensures that zinc and phosphorus are fully released from the raw materials, avoiding low zinc and phosphorus yields due to incomplete decomposition. Zinc has a melting point of approximately 419℃ and a boiling point of approximately 907℃. At 600-700℃, zinc vapor condenses into liquid / solid zinc, while phosphorus has a boiling point of approximately 280℃. At this temperature, phosphorus remains as vapor and can enter the phosphorus collection chamber, achieving preliminary separation of zinc and phosphorus. Phosphorus vapor will rapidly condense into solid phosphorus at ≤200℃, and the air is isolated by inert gas to prevent phosphorus from burning and being lost, thereby improving production safety and ensuring recovery rate.

[0013] Furthermore, in step S3, the pressure in the high-temperature decomposition chamber is controlled to be ≤200 Pa, the heating temperature is 950–1080 °C, and the temperature is maintained for 6–12 hours to form zinc vapor. The zinc vapor cools down and settles at 200–450 °C to form metallic zinc. By further high-temperature distillation under negative pressure, the negative pressure environment not only lowers the volatilization temperature of zinc decomposition, reducing energy consumption, improving zinc volatilization and separation efficiency, and ensuring product purity, but also enables the process to achieve full volatilization of zinc at a lower temperature. At the same time, it reduces impurity interference and completely distills out the small amount of zinc remaining in the material in the high-temperature decomposition chamber in the form of vacuum distillation. Controlling the temperature to 200–450 °C allows for sufficient condensation and collection of zinc in the zinc collection chamber. In step S2, germanium, phosphorus, and zinc are decomposed, and phosphorus and zinc are initially vaporized and then condensed at high temperature. Because phosphorus has a low boiling point, its separation from the alloy is most thorough in this step. That is, by the end of step S2, the material in the high-temperature decomposition chamber contains only trace amounts of phosphorus. Therefore, in step S3, this invention does not require cooling and condensing of these trace amounts of phosphorus, reducing energy consumption. Simultaneously, the phosphorus collection chamber can be cooled during this process to ensure sufficient cooling and subsequent safe discharge. The obtained metallic zinc contains trace amounts of phosphorus, which is sold as zinc scrap or used for subsequent purification and will not cause any problems.

[0014] Furthermore, in step S4, the safe temperature is no more than 60°C in the high-temperature decomposition chamber and the zinc collection chamber, and no more than 40°C in the phosphorus collection chamber. This ensures production safety, guarantees that when ventilation returns to normal pressure, the temperature further decreases, and the temperature in the phosphorus collection chamber remains below 40°C, preventing phosphorus spontaneous combustion, avoiding waste, ensuring process safety, preventing harm to human safety, and also saving discharge time.

[0015] Furthermore, the inert gas introduced is nitrogen or argon. It is chemically stable and does not react with the raw materials or decomposition products, creating an inert environment that prevents product oxidation at the source, ensuring the purity of elemental zinc and phosphorus. It also isolates oxygen, reducing equipment corrosion and extending the service life of the high-temperature decomposition chamber and collection chamber.

[0016] Furthermore, the integrated high-temperature decomposition-vacuum distillation device includes a high-temperature decomposition chamber, a zinc collection chamber, a phosphorus collection chamber, and a vacuum system; The high-temperature decomposition chamber, zinc collection chamber, and phosphorus collection chamber are connected in series via pipelines. The vacuum system is connected to the zinc collection chamber. The high-temperature decomposition chamber is equipped with an inlet for inert gas, and the phosphorus collection chamber is equipped with an exhaust port. This ensures that the inert gas can pass through the high-temperature decomposition chamber, zinc collection chamber, and phosphorus collection chamber to vent air. Furthermore, this integrated high-temperature decomposition-vacuum distillation device can directly produce crude germanium ingots and zinc materials through a pyrometallurgical process, which is simple and convenient.

[0017] Furthermore, the high-temperature decomposition chamber includes an air inlet and an air outlet; the air inlet is connected to an inert gas through a first pipe, and an air inlet valve is provided on the air inlet; the air outlet is connected to the zinc collection chamber through a second pipe. The zinc collection chamber is also connected to the phosphorus collection chamber via a third pipe, and a valve for the phosphorus collection chamber is installed on the third pipe. The phosphorus collection chamber is provided with an exhaust port, which is connected to the phosphorus collection chamber. A valve may be installed on the exhaust port to control the flow of exhaust and ensure that the phosphorus collection chamber is fully cooled and settled.

[0018] The zinc collection chamber is also connected to the vacuum system via a fourth pipe, which is equipped with a vacuum system connection valve.

[0019] In use, the dried germanium, phosphorus, and zinc waste is placed in a quartz vessel and then placed in the high-temperature decomposition chamber of a self-made "high-temperature decomposition-vacuum distillation integrated device". The inlet valve and the phosphorus collection chamber inlet valve are opened, and inert gas is introduced into the device for a period of time through the inlet to expel the air in the device. Inert gas is continuously introduced to heat the high-temperature decomposition chamber, causing germanium, phosphorus, and zinc to decompose. Zinc and phosphorus, in gaseous form at high temperature, are carried into the zinc collection chamber by the inert gas flow. The appropriate temperature in the zinc collection chamber is controlled to allow zinc vapor to cool and settle, while phosphorus remains gaseous. Subsequently, the inert gas flow continues to carry phosphorus vapor into the phosphorus collection chamber for cooling and settling. Finally, the inert gas continues to carry a small amount of phosphorus tail gas from the exhaust port into the waste gas treatment system for compliant disposal. During vacuum zinc removal, the inert gas supply is stopped, the inlet valve and the phosphorus collection chamber inlet valve are closed, the vacuum system connection valve is opened, the vacuum system is started, and an appropriate negative pressure range is controlled. The heating temperature of the high-temperature decomposition chamber is lowered and kept constant for a period of time. The small amount of zinc remaining in the metallic germanium in the high-temperature decomposition chamber is deeply volatilized under negative pressure and high temperature conditions. Controlling the appropriate temperature in the zinc collection chamber allows zinc vapor to cool and settle. Finally, stop heating the high-temperature decomposition chamber and wait for the overall temperature inside the device to drop to a safe level. Then, shut down the vacuum system and open the air inlet valve. Crude germanium ingots are obtained from the quartz container in the high-temperature decomposition chamber and can be sold or further purified before being sold. Zinc collected in the zinc collection chamber can be sold directly as zinc material, and phosphorus collected in the phosphorus collection chamber is disposed of as solid waste in compliance with regulations.

[0020] Furthermore, the exhaust port is connected to the waste gas treatment system via a pipeline. This ensures that the emitted phosphorus-containing exhaust gas is treated to prevent atmospheric pollution. The end of the vacuum system is also connected to the waste gas treatment system to ensure that the high-temperature decomposition chamber is evacuated, reducing the gas pressure and preventing residual sulfur-containing gases from polluting the environment.

[0021] Compared with existing technologies, the beneficial effects of this invention are as follows: First, it fills the gap in current recycling technology for "germanium, phosphorus, and zinc waste". This invention decomposes germanium, phosphorus, and zinc into germanium, zinc, and phosphorus at high temperature under the protection of inert gas. Taking advantage of the significant difference in boiling points of germanium, zinc, and phosphorus, different temperatures are controlled in different areas, so that germanium remains in liquid form in the high-temperature decomposition chamber, while zinc and phosphorus are carried in gaseous form by the inert gas into the zinc collection chamber and phosphorus collection chamber, and undergo segmented cooling and deposition, thereby fully decomposing and separating germanium, zinc, and phosphorus. The recycling process is simple, efficient, and low-cost; and the metal recovery is thorough, with a direct recovery rate of germanium greater than 99% and a direct recovery rate of zinc greater than 90%, resulting in a high direct recovery rate of germanium and zinc.

[0022] Secondly, this invention utilizes a pyrometallurgical process, producing crude germanium ingots and zinc materials that can be directly sold or purified in just four core steps. It eliminates the need for complex hydrometallurgical processes, simplifying operation and shortening the process. The reagents used are conventional industrial raw materials, and the self-made integrated device reduces equipment investment and floor space requirements, lowering production costs and making it suitable for industrial applications.

[0023] This invention utilizes a modular design of a self-made high-temperature decomposition-vacuum distillation integrated device. By controlling the temperature and airflow direction based on the differences in the boiling points of germanium, zinc, and phosphorus, precise separation of germanium, phosphorus, and zinc can be achieved within the same device. This eliminates the need for additional complex separation equipment, avoids cross-contamination, ensures product purity, and lays the foundation for subsequent purification, processing, or sale.

[0024] Finally, the corrosive liquid generated by this invention is sent to the germanium process to recover germanium and undergoes compliant treatment to avoid waste liquid pollution and resource loss; phosphorus is collected and disposed of in compliance with regulations, and a small amount of phosphorus tail gas is sent to the waste gas treatment system for emission in compliance with standards, thus eliminating air and water pollution and conforming to the concept of green and sustainable development. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the integrated high-temperature decomposition-vacuum distillation apparatus of the present invention; 1-High temperature decomposition chamber, 2-Zinc collection chamber, 3-Phosphorus collection chamber, 4-Vacuum system, 5-Inlet, 6-Exhaust port, 7-Inlet valve, 8-Phosphorus collection chamber valve, 9-Vacuum system connection valve. Detailed Implementation

[0026] To provide a further understanding of the purpose, structure, features, and functions of the present invention, detailed descriptions are provided below with reference to specific embodiments.

[0027] Please combine Figure 1 The present invention provides a self-made high-temperature decomposition-vacuum distillation integrated device; the high-temperature decomposition-vacuum distillation integrated device includes a high-temperature decomposition chamber 1, a zinc collection chamber 2, a phosphorus collection chamber 3, and a vacuum system 4; The high-temperature decomposition chamber 1, zinc collection chamber 2, and phosphorus collection chamber 3 are connected in series via pipelines. The vacuum system 4 is connected to the zinc collection chamber 2. The high-temperature decomposition chamber 1 is equipped with an air inlet 5, which is connected to an inert gas. The phosphorus collection chamber 3 is also equipped with an exhaust port 6. This ensures that the inert gas can pass through the high-temperature decomposition chamber 1, zinc collection chamber 2, and phosphorus collection chamber 3 to vent air. Furthermore, this integrated high-temperature decomposition-vacuum distillation device can directly produce crude germanium ingots and zinc materials through a pyrometallurgical process, which is simple and convenient.

[0028] Furthermore, the high-temperature decomposition chamber 1 includes an air inlet 5 and an air outlet; the air inlet 5 is connected to an inert gas through a first pipe, and an air inlet valve 7 is provided on the air inlet 5; the air outlet is connected to the zinc collection chamber 2 through a second pipe. The zinc collection chamber 2 is also connected to the phosphorus collection chamber 3 via a third pipe, and a phosphorus collection chamber valve 8 is installed on the third pipe; the phosphorus collection chamber 3 is provided with an exhaust port 6, which is connected to the phosphorus collection chamber 3, and a valve is installed on the exhaust port; The zinc collection chamber 2 is also connected to the vacuum system 4 via a fourth pipe, which is equipped with a vacuum system connection valve 9. This ensures that the vacuum system 4 can control the zinc collection chamber 2 and the high-temperature decomposition chamber 1 to maintain a negative pressure, ensuring the deep evaporation of residual zinc and ensuring that zinc vapor can smoothly enter the zinc collection chamber, preventing air from mixing in during the process of zinc vapor entering the zinc collection chamber, thus improving production safety.

[0029] Exhaust port 6 is connected to the exhaust gas treatment system via a pipe to prevent residual trace amounts of phosphorus from polluting the atmosphere.

[0030] The present invention discloses a method for recovering germanium and zinc from germanium-phosphorus-zinc waste, comprising the following steps: S1: Surface corrosion cleaning: The germanium-phosphorus-zinc waste is heated in high-purity water, and potassium hydroxide and hydrogen peroxide are added for surface corrosion. After corrosion, the germanium-phosphorus-zinc waste is taken out, rinsed with high-purity water and dried. The corrosion solution is sent to the germanium process to recover germanium.

[0031] S2: High-Temperature Decomposition: The dried germanium-phosphorus-zinc waste obtained in step S1 is placed in a quartz container and then placed in the high-temperature decomposition chamber 1 of the self-made "high-temperature decomposition-vacuum distillation integrated device". The inlet valve 7 and the phosphorus collection chamber valve 8 are opened, and inert gas is introduced into the device for a period of time through the inlet to expel the air in the device. The inert gas is continued to be introduced to heat the high-temperature decomposition chamber 1 to decompose germanium-phosphorus-zinc. Zinc and phosphorus are carried into the zinc collection chamber in gaseous form at high temperature with the inert gas flow. The appropriate temperature in the zinc collection chamber 2 is controlled to allow the zinc vapor to cool and settle in the collection chamber, while the phosphorus remains in a gaseous state. Subsequently, the inert gas flow continues to carry the phosphorus vapor into the phosphorus collection chamber 3 for cooling and settling. Finally, the inert gas continues to carry a small amount of phosphorus tail gas from the exhaust port 6 into the waste gas treatment system for compliant disposal.

[0032] S3: Vacuum zinc removal: Stop the inert gas supply, close the inlet valve 7 and the phosphorus collection chamber valve 8, open the vacuum system connection valve 9, start the vacuum system 4, and control the appropriate negative pressure range. Lower the heating temperature of the high-temperature decomposition chamber 1 and keep it at a constant temperature for a period of time. The small amount of zinc remaining in the metallic germanium in the high-temperature decomposition chamber 1 will deeply volatilize under negative pressure and high temperature conditions. Controlling the appropriate temperature of the zinc collection chamber 2 can allow the zinc vapor to cool down and settle in the collection chamber.

[0033] S4: Discharge: Stop heating the high-temperature decomposition chamber 1. After the overall temperature inside the device drops to a safe temperature, shut off the vacuum system 4 and open the air inlet valve 7. After restoring normal pressure, take crude germanium ingots from the quartz container in the high-temperature decomposition chamber. They can be sold or further purified before being sold. The zinc collected in the zinc collection chamber can be sold directly as zinc material. The phosphorus collected in the phosphorus collection chamber is disposed of as solid waste in compliance with regulations.

[0034] This invention removes the oxide film and stains from the surface of germanium-phosphorus-zinc waste in step S1 to expose a pure alloy surface, thereby improving the efficiency of subsequent decomposition. The process involves the following reactions: GeO2 + 2KOH = K2GeO3 + H2O (1) ZnO + KOH = K2ZnO2 + H2O (2) P4O6+ 12KOH +4H2O2= 4K3PO4+10H2O (3) P4O 10 +12KOH=4K3PO4+6H2O (4) GeP2Zn +10KOH +8H2O2= K2GeO3+2K3PO4+K2ZnO2+13H2O (5) In step S2, this invention utilizes a self-made dedicated "high-temperature decomposition-vacuum distillation integrated device" to decompose germanium, phosphorus, and zinc into germanium, zinc, and phosphorus at high temperatures under the protection of an inert gas. Taking advantage of the significant differences in the boiling points of germanium, zinc, and phosphorus, different temperatures are controlled in different regions, allowing germanium to remain in a liquid state in the high-temperature decomposition chamber, while zinc and phosphorus are carried in gaseous form by the inert gas into the zinc collection chamber and phosphorus collection chamber, respectively, where they undergo segmented cooling and deposition, thereby fully decomposing and separating germanium, zinc, and phosphorus.

[0035] In step S3, zinc in germanium is deeply removed by high-temperature distillation under negative pressure, while zinc is recovered by cooling and settling in the zinc collection chamber.

[0036] In step S4, the crude germanium ingots and zinc materials are collected and can be sold or further purified; the phosphorus is collected and sent for compliant and environmentally friendly disposal.

[0037] Preferably, in step S1, the added high-purity water must completely wet the germanium-phosphorus-zinc waste. The mass ratio of potassium hydroxide to high-purity water is 0.0002–0.001:1, the concentration of hydrogen peroxide is 10–30%, and the volume ratio of hydrogen peroxide to high-purity water is 0.001–0.005:1. This ratio can effectively control the reaction rate and effect, remove the oxide film and stains on the surface of the germanium-phosphorus-zinc waste to expose the pure alloy surface, thereby improving the efficiency of subsequent decomposition, while minimizing the amount of alloy dissolved into the solution.

[0038] Preferably, in step S2, the inert gas introduced is nitrogen or argon. After introducing nitrogen or argon for 20 to 40 minutes, the heating temperature of the high-temperature decomposition chamber is controlled at 1100 to 1300°C, the temperature in the zinc collection chamber is controlled at 600 to 700°C, and the temperature in the phosphorus collection chamber is controlled at ≤200°C; the high-temperature decomposition time is controlled at 10 to 18 hours.

[0039] Preferably, in step S3, the pressure in the high-temperature decomposition chamber is controlled to be ≤200 Pa, the heating temperature in the decomposition chamber is controlled to be 950~1080℃, the constant temperature time is 6~12h, and the temperature in the zinc collection chamber is controlled to be 200~450℃.

[0040] Preferably, in step S4, after the temperature in the heating chamber and the zinc collection chamber is no greater than 60°C and the temperature in the phosphorus collection chamber is no greater than 40°C, the air inlet valve 7 is opened, and finally the device is opened to remove germanium, zinc material and solid waste phosphorus.

[0041] In the following examples, each batch of germanium-phosphorus-zinc waste with a net weight of 1000g was used, wherein the percentage of germanium was 36.34%, phosphorus was 30.95%, and zinc was 32.71%, that is, the germanium content was 363.4g, the phosphorus content was 309.5g, and the zinc content was 327.1g.

[0042] Example 1

[0043] S1: Surface Corrosion Cleaning: The germanium-phosphorus-zinc waste is placed in high-purity water and heated. The high-purity water must completely wet the waste. The mass ratio of potassium hydroxide to high-purity water is 0.0002:1, and the hydrogen peroxide concentration is 30%, with a volume ratio of hydrogen peroxide to high-purity water of 0.001:1. After corrosion, the germanium-phosphorus-zinc waste is removed, rinsed with high-purity water, and dried. The corrosion solution is sent to the germanium process for germanium recovery.

[0044] S2: High-Temperature Decomposition: The dried germanium-phosphorus-zinc waste is placed in a quartz container and then placed in the high-temperature decomposition chamber 1 of a self-made "high-temperature decomposition-vacuum distillation integrated device". The inlet valve 7 and the phosphorus collection chamber valve 8 are opened, and nitrogen or argon is introduced into the device through the inlet 5 for 40 minutes to purge the air inside. Nitrogen or argon is continued to be introduced, and the high-temperature decomposition chamber 1 is heated to 1250–1300℃ to decompose the germanium-phosphorus-zinc. Zinc and phosphorus, in gaseous form at high temperature, are carried into the zinc collection chamber 2 by the inert gas flow. The temperature inside the zinc collection chamber 2 is controlled at 680–700℃, allowing the zinc vapor to cool and settle, while the phosphorus remains gaseous. Subsequently, the inert gas flow continues to carry the phosphorus vapor into the phosphorus collection chamber 3 for cooling and settling. The temperature inside the phosphorus collection chamber 3 is controlled at ≤200℃. Finally, the inert gas continues to carry a small amount of phosphorus tail gas from the exhaust port into the waste gas treatment system for compliant disposal. The entire high-temperature decomposition process is controlled within 16 hours.

[0045] S3: Vacuum zinc removal: Stop the inert gas supply, close the inlet valve 7 and the phosphorus collection chamber valve 8, open the vacuum system connection valve 9, start the vacuum system 4, control the pressure in the high-temperature decomposition chamber 1 to ≤100pa, lower the heating temperature of the high-temperature decomposition chamber 1 to 1000~1050℃ and keep it at a constant temperature for 10h. The small amount of zinc remaining in the metallic germanium in the high-temperature decomposition chamber 1 will deeply volatilize under negative pressure and high temperature conditions. Control the temperature of the zinc collection chamber 2 to 400~450℃ so that the zinc vapor cools down and settles in the collection chamber.

[0046] S4: Discharge: Stop heating the high-temperature decomposition chamber 1. After the temperature in the high-temperature decomposition chamber 1 and the zinc collection chamber 2 reaches 60°C and the temperature in the phosphorus collection chamber reaches 40°C, close the vacuum system 4 and open the air inlet valve 7. Obtain crude germanium ingots from the quartz container in the high-temperature decomposition chamber. They can be sold or further purified before being sold. The zinc collected in the zinc collection chamber 2 can be sold directly as zinc material. The phosphorus collected in the phosphorus collection chamber 3 is disposed of as solid waste in compliance with regulations.

[0047] The weights of the crude germanium ingot and zinc material were weighed to obtain a net weight of 364.06g for the crude germanium ingot and a net weight of 306.07g for the zinc material. Chemical analysis of the crude germanium ingot and zinc material revealed that the percentage content of germanium was 99.42% and the percentage content of zinc was 99.07%, respectively.

[0048] Calculate the direct recovery rates of germanium and zinc using the following formulas:

[0049]

[0050] The final direct recovery rate for germanium was 99.6%, and for zinc it was 92.7%.

[0051] Example 2

[0052] S1: With other conditions unchanged, the mass ratio of potassium hydroxide to high-purity water added is 0.001:1, the concentration of hydrogen peroxide added is 10%, and the volume ratio of hydrogen peroxide to high-purity water is 0.005:1. S2: With other conditions unchanged, nitrogen or argon is introduced into the device through the air inlet 5 for 20 minutes to purge the air in the device. Then, nitrogen or argon is introduced to heat the high-temperature decomposition chamber 1 to a temperature of 1100-1150℃, control the temperature in the zinc collection chamber 2 to 600-620℃, control the temperature in the phosphorus collection chamber 3 to ≤200℃, and control the high-temperature decomposition time to 12h.

[0053] S3: With other conditions unchanged, control the pressure inside the high-temperature decomposition chamber 1 to ≤200pa, lower the heating temperature of the high-temperature decomposition chamber 1 to 950~980℃ and keep it constant for 12h, and control the temperature of the zinc collection chamber 2 to 250~300℃.

[0054] S4: With other conditions unchanged, after the temperature in the heating chamber and zinc collection chamber 2 reaches 50°C and the temperature in the phosphorus collection chamber 3 reaches 35°C, close the vacuum system 4 and open the air inlet valve 7. The weights of the crude germanium ingot and zinc material were weighed to obtain a net weight of 361.91g for the crude germanium ingot and a net weight of 314.62g for the zinc material. Chemical analysis of the crude germanium ingot and zinc material revealed a germanium content of 99.71% and a zinc content of 98.25%, respectively.

[0055] The final direct recovery rate for germanium was calculated to be 99.3%, and the direct recovery rate for zinc was 94.5%.

[0056] Example 3

[0057] S1: With other conditions unchanged, the mass ratio of potassium hydroxide to high-purity water added is 0.0006:1, the concentration of hydrogen peroxide added is 20%, and the volume ratio of hydrogen peroxide to high-purity water is 0.002:1. S2: With other conditions unchanged, nitrogen or argon is introduced into the device through the air inlet 5 for 30 minutes to purge the air in the device. Then, nitrogen or argon is introduced to heat the high-temperature decomposition chamber 1 to a temperature of 1200-1250℃, control the temperature in the zinc collection chamber 2 to 650-670℃, control the temperature in the phosphorus collection chamber 3 to ≤200℃, and control the high-temperature decomposition time to 15h.

[0058] S3: With other conditions unchanged, control the pressure inside the high-temperature decomposition chamber 1 to ≤200pa, lower the heating temperature of the high-temperature decomposition chamber 1 to 1020~1050℃ and keep it constant for 10h, and control the temperature of the zinc collection chamber 2 to 350~400℃.

[0059] S4: With other conditions unchanged, after the temperature in the high-temperature decomposition chamber 1 and zinc collection chamber 2 reaches 50°C and the temperature in the phosphorus collection chamber reaches 35°C, close the vacuum system 4 and open the air inlet valve 7. The weights of the crude germanium ingot and zinc material were weighed to obtain a net weight of 362.56 g for the crude germanium ingot and a net weight of 310.28 g for the zinc material. Chemical analysis of the crude germanium ingot and zinc material revealed a germanium content of 99.63% and a zinc content of 98.78%, respectively.

[0060] The final direct recovery rate for germanium was calculated to be 99.4%, and the direct recovery rate for zinc was 93.7%.

[0061] In summary, this invention employs a self-made "high-temperature decomposition-vacuum distillation integrated device," which directly produces crude germanium ingots and zinc materials through a pyrometallurgical process. The crude germanium ingots can be sold or sent for further purification and production, while the zinc materials can be sold directly. This invention features a simple recycling process, high efficiency, and low cost; moreover, metal recovery is thorough, with a direct recovery rate of over 99% for germanium and over 90% for zinc.

[0062] The present invention has been described in the above-described embodiments; however, these embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the present invention. Conversely, any modifications and refinements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention.

Claims

1. A method for recovering germanium and zinc from germanium-phosphorus-zinc waste, characterized in that: Includes the following steps: S1: Surface corrosion cleaning; Germanium-phosphorus-zinc waste was heated in high-purity water, and potassium hydroxide and hydrogen peroxide were added for surface corrosion. The corroded germanium-phosphorus-zinc waste was then rinsed with high-purity water and dried. S2: High-temperature decomposition; The dried germanium-phosphorus-zinc waste was placed in a quartz container and then placed in the high-temperature decomposition chamber of a high-temperature decomposition-vacuum distillation integrated device. Inert gas was introduced to purge the air, and the inert gas was continuously introduced. Under the atmosphere of inert gas, the germanium-phosphorus-zinc was heated to decompose. Zinc and phosphorus existed in gaseous form at high temperature. The inert gas containing gaseous zinc and phosphorus was collected. The collected inert gas was first introduced into the zinc collection chamber. At the first temperature, the gaseous zinc contained in the inert gas was cooled and precipitated to obtain metallic zinc. Then, the collected inert gas was introduced into the phosphorus collection chamber. At the second temperature, the gaseous phosphorus contained in the inert gas was cooled and precipitated to obtain solid phosphorus. S3: Vacuum zinc removal; Stop the inert gas supply and control the high-temperature decomposition chamber to be under negative pressure. Under negative pressure, the remaining small amount of zinc will deeply volatilize to form zinc vapor. Collect the zinc vapor and cool it down in the zinc collection chamber to obtain metallic zinc. S4: Discharge; After stopping the heating of the high-temperature decomposition chamber and reducing the temperatures of the high-temperature decomposition chamber, zinc collection chamber, and phosphorus collection chamber to safe temperatures, the intake gas is controlled to return to normal pressure. Crude germanium ingots are then obtained from the quartz container in the high-temperature decomposition chamber, and the obtained metallic zinc and solid phosphorus are collected.

2. The method for recovering germanium and zinc from germanium-phosphorus-zinc waste as described in claim 1, characterized in that: In step S1, the added high-purity water completely soaks the germanium-phosphorus-zinc waste, and the mass ratio of potassium hydroxide to high-purity water is 0.0002 to 0.001:1; the added hydrogen peroxide concentration is 10 to 30%, and the volume ratio of hydrogen peroxide to high-purity water is 0.001 to 0.005:

1.

3. The method for recovering germanium and zinc from germanium-phosphorus-zinc waste as described in claim 1, characterized in that: In step S2, after introducing inert gas for 20 to 40 minutes, the heating temperature of the high-temperature decomposition chamber is controlled at 1100 to 1300℃, and the high-temperature decomposition is carried out for 10 to 18 hours. The first temperature is controlled at 600 to 700℃, and the second temperature is controlled at ≤200℃.

4. The method for recovering germanium and zinc from germanium-phosphorus-zinc waste as described in claim 1, characterized in that: In step S3, the pressure in the high-temperature decomposition chamber is controlled to be ≤200 Pa, the heating temperature is 950~1080℃, and the temperature is kept constant for 6~12 hours to form zinc vapor. The zinc vapor is cooled and settled at 200~450℃ to form metallic zinc.

5. The method for recovering germanium and zinc from germanium-phosphorus-zinc waste as described in claim 1, characterized in that: In step S4, the safe temperature is that the temperature in the high-temperature decomposition chamber and the zinc collection chamber does not exceed 60°C, and the temperature in the phosphorus collection chamber does not exceed 40°C.

6. The method for recovering germanium and zinc from germanium-phosphorus-zinc waste as described in claim 1, characterized in that: The inert gas introduced is either nitrogen or argon.

7. The method for recovering germanium and zinc from germanium-phosphorus-zinc waste as described in claim 1, characterized in that: The integrated high-temperature decomposition-vacuum distillation device includes a high-temperature decomposition chamber, a zinc collection chamber, a phosphorus collection chamber, and a vacuum system; The high-temperature decomposition chamber, zinc collection chamber, and phosphorus collection chamber are connected in series via pipelines. The vacuum system is connected to the zinc collection chamber. The high-temperature decomposition chamber is equipped with an air inlet, which is connected to an inert gas. The phosphorus collection chamber is also equipped with an exhaust port.

8. The method for recovering germanium and zinc from germanium-phosphorus-zinc waste as described in claim 7, characterized in that: The high-temperature decomposition chamber includes an air inlet and an air outlet; the air inlet is connected to an inert gas through a first pipe, and an air inlet valve is provided on the air inlet; the air outlet is connected to the zinc collection chamber through a second pipe. The zinc collection chamber is also connected to the phosphorus collection chamber via a third pipe, and a valve for the phosphorus collection chamber is installed on the third pipe; the phosphorus collection chamber is provided with an exhaust port, which is connected to the phosphorus collection chamber. The zinc collection chamber is also connected to the vacuum system via a fourth pipe, which is equipped with a vacuum system connection valve.

9. The method for recovering germanium and zinc from germanium-phosphorus-zinc waste as described in claim 7, characterized in that: The exhaust port is connected to the waste gas treatment system via a pipe.

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