Method for recovering indium oxide and sodium pyroantimonate from indium antimonide waste

Abstract

The invention discloses a method for recovering indium oxide and sodium pyroantimonate from indium antimonide waste, and belongs to the technical field of solid waste resource recycling. The method comprises the following steps: uniformly mixing indium antimonide waste powder and sodium peroxide, calcining, and leaching the calcined product by water to obtain indium-containing precipitate and antimony-containing leachate; washing, drying and calcining the indium-containing precipitate to obtain indium oxide; the antimony-containing leachate is oxidized with hydrogen peroxide to generate antimony-containing precipitates, the antimony-containing precipitates are washed and dried, and sodium pyroantimonate is obtained.According to the method, the recovery efficiency of indium and antimony is high, indium and antimony are recovered in the forms of high-purity indium oxide and sodium pyroantimonate respectively, and the method is simple in process, convenient to operate, low in equipment requirement, low in cost and suitable for industrial production. The method is suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to a method for recycling indium antimonide waste, in particular to a method for comprehensively recycling indium oxide and sodium pyroantimonate from indium antimonide waste, belonging to the technical field of solid waste resource recycling. Background Art

[0002] Indium antimonide (InSb) is a III-V binary compound semiconductor material, which has become a research hotspot for its unique physical and chemical properties and excellent process compatibility. It has an extremely narrow bandgap, a very small electron effective mass and an extremely high electron mobility, especially in the 3-5 μm spectral range, which belongs to intrinsic absorption and has a quantum efficiency of nearly 100%, making it the preferred material for preparing medium-wave infrared detectors. Indium antimonide is not only used in infrared detectors and sensors, but also in optoelectronic devices such as photodiodes, phototransistors and photoelectrodes. These devices have the characteristics of high-speed response, low noise and high signal-to-noise ratio, and are suitable for high-speed communication, photoelectric conversion and spectral analysis. In addition, indium antimonide is also widely used in quantum well structure devices, such as quantum well lasers, modulators and terahertz generators, which can be used in high-speed optical communication, optical storage and measurement. The high carrier mobility of indium antimonide also makes it have potential application prospects in the microelectronics industry and can be used to manufacture high-efficiency transport devices.

[0003] Indium antimonide waste mainly comes from various wastes generated during its production, manufacturing, processing and application. The generation of these wastes involves multiple links, including crystal growth, wafer processing, device manufacturing and device scrapping. The preparation of indium antimonide single crystals usually adopts the melt method (such as the vertical pulling method or the horizontal directional solidification method). During the crystal growth process, improper control or uneven material doping may cause crystal defects or crystal waste. After the growth of indium antimonide single crystals, they need to be cut into thin slices (wafers) and processed by polishing, cleaning and other processes. In these processes, a large amount of waste is generated. When indium antimonide wafers are used to manufacture infrared detectors and high-frequency electronic devices, they need to go through multiple processes such as lithography, etching, cleaning and packaging, which produces indium antimonide waste.

[0004] In the prior art, nitric acid is used to leach indium antimonide to recover indium. This method can recover almost all indium, but the antimony leaching rate is less than 10%. This method not only cannot recover nitric acid, but also requires a large amount of alkali to neutralize excess acid and precipitate the leached valuable metals, which is a waste of resources and not environmentally friendly. Therefore, a method for comprehensively recovering indium antimonide is urgently needed. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for recovering indium oxide and sodium antimonate from indium antimonide waste. The method has a simple process, is easy to operate, has low equipment requirements, is low cost, and the recovered indium oxide and sodium antimonate have high purity, and the recovery efficiency of indium and antimony is high, and the method is suitable for large-scale production.

[0006] In order to achieve the above technical objectives, the present invention provides a method for recovering indium oxide and sodium antimonate from indium antimonide waste, the method comprising the steps of mixing indium antimonide waste powder with sodium peroxide and calcining the mixture, leaching the calcined product with water to obtain an indium-containing precipitate and an antimony-containing leaching solution; washing, drying and calcining the indium-containing precipitate to obtain indium oxide; oxidizing the antimony-containing leaching solution with hydrogen peroxide to generate an antimony-containing precipitate, washing and drying the antimony-containing precipitate to obtain sodium antimonate.

[0007] The technical solution of the present invention uses sodium peroxide as an oxidant to achieve phase transformation of indium antimonide under high temperature conditions, so that indium antimonide is fully transformed into indium trioxide and antimony trioxide. The specific reaction formula is as follows: 2InSb+ 6Na2O2=In2O3+Sb2O3+6Na2O. After the high-temperature calcined product is added to water, sodium oxide is hydrolyzed into sodium hydroxide and releases a large amount of heat. The reaction formula is as follows: Na2O+H2O=2NaOH. Antimony trioxide dissolves in sodium hydroxide solution under heating conditions. The reaction formula is as follows: Sb2O3+2NaOH=2NaSbO2+H2O. Indium trioxide is almost insoluble, thereby achieving efficient separation of indium and antimony. NaSbO2 is further oxidized by hydrogen peroxide to oxidize +3-valent antimony into +5-valent antimony, and NaSbO2 is transformed into NaSbO3 with lower solubility. The reaction formula is as follows: NaSbO2+H2O2=NaSbO3↓+H2O, and antimony is efficiently recovered in the form of NaSbO3.

[0008] As a preferred solution, the mass ratio of the sodium peroxide to the indium antimonide is 1 to 1.5:1. Controlling the mass ratio of sodium peroxide to indium antimonide within a suitable range is beneficial to the separation of indium and antimony, improving the quality of the recovered indium oxide and sodium pyroantimonate, and improving the recovery rate of indium and antimony. If the mass ratio of sodium peroxide to indium antimonide is too low, the reaction of indium antimonide and sodium peroxide is incomplete, resulting in an excessively high impurity content in the recovered indium oxide and a reduced recovery rate of antimony; if the mass ratio of sodium peroxide to indium antimonide is too high, it will cause a waste of sodium peroxide, and will cause the alkalinity of the solution to be too high after subsequent water dissolution, which is not conducive to cleaning. The mass ratio of sodium peroxide to indium antimonide is further preferably 1.1 to 1.3:1.

[0009] As a preferred solution, the D50 particle size of the indium antimonide waste powder is -100 mesh (passing through a 100 mesh sieve, sieved material). The indium antimonide waste is mainly cutting waste. Since the raw material is in block form, it cannot be mixed evenly with sodium peroxide, which is not conducive to the reaction with sodium peroxide. Therefore, ball milling pretreatment can be performed, and after screening, the D50 particle size of the indium antimonide waste is -100 mesh, more preferably 74 to 150 μm. The use of indium antimonide waste in this particle size range is conducive to the reaction of indium antimonide with sodium peroxide and improves the recovery efficiency.

[0010] As a preferred solution, the calcination conditions are: temperature of 460-650°C and time of 4-8 hours. Controlling the calcination temperature and time within a suitable range can make the reaction of indium antimonide and sodium peroxide complete, which is beneficial to the separation of antimony and indium.

[0011] As a preferred solution, the water leaching conditions are: temperature of 40-90°C, time of 2-4h, and solid-liquid ratio of 1g:1-3mL. Antimony is converted into components that are easily soluble in hot water during the calcination process. By controlling the water dissolution temperature, time, and solid-liquid ratio within a suitable range, the antimony oxide in the calcined product can be completely dissolved in the solution, which is beneficial to the separation of antimony and indium.

[0012] As a preferred solution, the oxidation conditions are: the amount of hydrogen peroxide is 1.0 to 1.1 times the theoretical amount, the temperature is 80 to 95°C, and the time is 1 to 2 hours, wherein the theoretical amount is the molar amount of hydrogen peroxide required to oxidize all trivalent antimony into pentavalent antimony. Using hydrogen peroxide as an oxidant will not introduce new impurities, and the amount of hydrogen peroxide is further preferably 1.02 to 1.05 times the theoretical amount. The oxidation temperature is further preferably 85 to 90°C.

[0013] Compared with the prior art, the present invention has the following beneficial technical effects: (1) The recovery rate of indium and antimony is high, reaching more than 97%; (2) The recovered indium oxide and sodium antimonate are of high purity, with the purity of indium oxide reaching over 99.9% and the purity of sodium antimonate reaching over 99.5%. DETAILED DESCRIPTION

[0014] For the convenience of the reader, the above description focuses on representative examples of all possible embodiments, which introduce the principles of the present invention and illustrate the best way to implement the present invention. This description does not attempt to exhaust all possible variations. There may also be other variations or changes that are not described.

[0015] The element composition of the indium antimonide waste used in the present invention is shown in Table 1 below.

[0016]

[0017] Example 1 1000 g of indium antimonide waste was mixed and crushed with 1000 g of sodium peroxide by ball milling, and then sieved to obtain mixed particles with a D50 of 100 mesh (150 μm); the mixture was placed in a calcining furnace and calcined at 460° C. for 8 h, and the obtained mixed oxide was placed in 2 L of 40° C. water for dissolution for 4 h, and filtered to obtain precipitate A and filtrate A; the obtained precipitate A was washed, dried, and calcined to obtain 460.1 g of indium oxide; 168 g of 30% hydrogen peroxide (1.0 times the theoretical amount) was added to the obtained filtrate A for oxidation at 80° C. for 2 h to produce precipitate B, which was washed and dried to obtain 355.3 g of sodium pyroantimonate.

[0018] Example 2 1000 g of indium antimonide waste was mixed and crushed with 1200 g of sodium peroxide by ball milling, and then sieved to obtain mixed particles with a D50 of 100 mesh (150 μm); the mixture was placed in a calcining furnace and calcined at 550°C for 6 hours, and the obtained mixed oxide was dissolved in 3L of 60°C water for 3 hours, and filtered to obtain precipitate A and filtrate A; the obtained precipitate A was washed, dried, and calcined to obtain 461.2 g of indium oxide; 175 g of 30% hydrogen peroxide (1.05 times the theoretical amount) was added to the obtained filtrate A for oxidation at 90°C for 1.5 hours to produce precipitate B, which was washed and dried to obtain 355.8 g of sodium pyroantimonate.

[0019] Example 3 1000 g of indium antimonide waste was mixed and crushed with 1400 g of sodium peroxide by ball milling, and then sieved to obtain mixed particles with a D50 of -100 mesh; the mixture was placed in a calcining furnace and calcined at 600°C for 4 hours, and the obtained mixed oxide was placed in 4L of 80°C water for dissolution for 2 hours, and filtered to obtain precipitate A and filtrate A; the obtained precipitate A was washed, dried, and calcined to obtain 463.3 g of indium oxide; 183 g of 30% hydrogen peroxide (1.1 times the theoretical amount) was added to the obtained filtrate A for oxidation at 95°C for 1 hour to produce precipitate B, which was washed and dried to obtain 356.9 g of sodium pyroantimonate.

[0020] The recovery rates of indium and antimony and the purity of indium oxide and sodium pyroantimonate in Examples 1 to 3 are shown in Table 2 below:

[0021] It can be seen from Table 2 that the present invention has a high comprehensive recovery efficiency for indium antimonide waste, wherein the recovery rates of indium and antimony both reach over 97%, and the recovered products have high purity and good quality.

[0022] Comparative Example 1 The method of Example 1 was used to recover indium antimonide waste, except that the amount of sodium peroxide was reduced to 800 g. It was found that after water dissolution, a large amount of unreacted indium antimonide remained, resulting in low purity of the recovered indium oxide and low recovery rate of antimony.

[0023] Comparative Example 2 The method of Example 1 was used to recover indium antimonide waste, except that the calcination temperature was lowered to 400° C. It was found that indium antimonide did not react with sodium peroxide, and indium and antimony could not be recovered.

[0024] Comparative Example 3 The method of Example 1 was used to recover indium antimonide waste, except that the water dissolution temperature was lowered to room temperature and the water dissolution time was reduced to 1 hour. It was found that the recovered indium oxide had low purity and contained a large amount of antimony trioxide, resulting in a low recovery rate of antimony.

Claims

1. A method for recovering indium oxide and sodium pyroantimonate from indium antimonide waste, characterized in that: The indium antimonide waste powder is mixed with sodium peroxide and then calcined. The calcined product is leached with water to obtain an indium-containing precipitate and an antimony-containing leaching solution. The indium-containing precipitate is washed, dried and calcined to obtain indium oxide. The antimony-containing leaching solution is oxidized with hydrogen peroxide to generate an antimony-containing precipitate. The antimony-containing precipitate is washed and dried to obtain sodium pyroantimonate.

2. The method for recovering indium oxide and sodium pyroantimonate from indium antimonide waste according to claim 1, characterized in that: The mass ratio of the sodium peroxide to the indium antimonide is 1-1.5:

1.

3. The method for recovering indium oxide and sodium pyroantimonate from indium antimonide waste according to claim 1, characterized in that: The D50 particle size of the indium antimonide waste powder is -100 mesh.

4. A method for recovering indium oxide and sodium pyroantimonate from indium antimonide waste according to any one of claims 1 to 3, characterized in that: The calcination conditions are: temperature of 460-650° C. and time of 4-8 hours.

5. The method for recovering indium oxide and sodium pyroantimonate from indium antimonide waste according to claim 1, characterized in that: The water leaching conditions are: temperature of 40-90° C., time of 2-4 h, and solid-liquid ratio of 1 g:1-3 mL.

6. The method for recovering indium oxide and sodium pyroantimonate from indium antimonide waste according to claim 1, characterized in that: The oxidation conditions are: the amount of hydrogen peroxide is 1.0-1.1 times of the theoretical amount, the temperature is 80-95° C., and the time is 1-2 hours, wherein the theoretical amount is the molar amount of hydrogen peroxide required to oxidize all trivalent antimony into pentavalent antimony.

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