A method for comprehensively recovering indium and antimony from indium antimonide waste

Abstract

The invention discloses a method for comprehensively recovering indium and antimony from indium antimonide waste. The method comprises leaching indium antimonide waste with hydrochloric acid, subjecting the obtained leaching solution to impurity removal by heating and volatilization and then performing distillation separation to obtain antimony chloride and distillation residues; vaporizing the antimony chloride by heating, and transporting gaseous antimony chloride to an atmosphere furnace through a carrier gas to carry out reduction roasting reaction I to obtain metallic antimony; and placing the distillation residues in a tubular furnace to carry out reduction roasting reaction II to obtain metallic indium. The method has high recovery efficiency for indium and antimony in indium antimonide waste, the obtained metal products have high purity and good quality, and the method is simple, has low requirements for equipment, low cost, is green and environment-friendly, and is suitable for large-scale production.

Description

Technical Field

[0001] The present invention relates to a method for recycling indium antimonide waste, and particularly to a method for comprehensively recycling indium and antimony from indium antimonide waste, belonging to the technical field of solid waste resource recycling and utilization. Background Art

[0002] Indium antimonide products are widely used in military and civilian infrared systems such as infrared tracking, guidance, thermal imaging, surveillance, early warning, and astronomical observation. As the substrate material for infrared devices, the demand for indium antimonide crystals is increasing. In order to fabricate large-scale arrays, highly sensitive, and high-temperature operating infrared detectors, the quality requirements for indium antimonide crystals are getting higher and higher. Preparing high-quality, low-dislocation indium antimonide single crystals is conducive to the rapid development of infrared devices.

[0003] Before the application of indium antimonide single crystals, they need to be cut to regularize the single crystals into single wafers, then ground to remove the marks left by single crystal cutting, and finally polished to achieve global planarization of the surface to meet the usage requirements. Due to the physical and chemical properties of indium antimonide materials, indium antimonide single crystals belong to soft and brittle materials. When using a multi-wire cutting machine to cut, if the indium antimonide material is fixed at the bottom on the machine base of the cutting machine by conventional methods, fragmentation problems are likely to occur, and the yield is relatively low. In addition, currently, traditional grinding uses polishing fluids with abrasives such as aluminum oxide and silica sol during the processing of the indium antimonide wafer surface. A large amount of indium antimonide waste will be generated during these processing processes.

[0004] However, in the prior art, nitric acid is used to leach indium antimonide to recover indium. This method can only recover indium and cannot recover antimony at the same time. Moreover, this method not only cannot recover nitric acid, but also requires a large amount of alkali to neutralize the excessive acid and precipitate the valuable metals leached out later, which is both resource-wasting and environmentally unfriendly. Therefore, there is an urgent need for a method to comprehensively recycle indium antimonide. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a method for comprehensively recycling indium and antimony from indium antimonide waste. This method is simple, easy to operate, requires low equipment requirements, has low costs, and has high recovery efficiencies of indium and antimony, and is suitable for large-scale production.

[0006] To achieve the above technical purpose, the present invention provides a method for comprehensively recycling indium and antimony from indium antimonide waste. In this method, indium antimonide waste is leached with hydrochloric acid, and the obtained leaching solution is distilled and separated after heating and volatilizing to remove impurities, obtaining antimony chloride and distillation residues; the antimony chloride is heated and vaporized, and the gaseous antimony chloride is transported by a carrier gas to an atmosphere furnace for reduction roasting reaction I to obtain metallic antimony; the distillation residues are placed in a tubular furnace for reduction roasting reaction II to obtain metallic indium.

[0007] In the above process, indium antimonide waste is first dissolved in hydrochloric acid, and insoluble impurities can be preliminarily removed by filtration. The leaching solution containing antimony and indium is heated and evaporated to remove low-boiling impurities, including water and HCl. The hydrogen chloride and water evaporated are recycled after recovery. After the leaching solution containing antimony and indium is heated to remove impurities, distillation can be carried out to separate the antimony chloride fraction and the indium-containing distillation residue. The antimony chloride and the indium-containing distillation residue are respectively roasted and reduced to obtain metallic antimony and metallic indium, realizing the efficient recovery of antimony and indium.

[0008] As a preferred solution, the particle size of the indium antimonide waste is -100 mesh. Further preferably, the particle size of the indium antimonide waste is between -100 mesh and +200 mesh. The indium antimonide waste is screened after ball milling. The indium antimonide waste is cutting waste. Since the raw material is in block form with a small specific surface area, which is not conducive to the leaching reaction, it is first ball milled and then screened into different particle sizes for standby. After screening, the particle size of the indium antimonide waste is 74 - 150 μm, and then acid leaching is carried out. Using indium antimonide waste within this particle size range helps the leaching and dissolution of indium antimonide and improves the recovery efficiency.

[0009] As a preferred solution, the leaching conditions are as follows: the mass concentration of hydrochloric acid is not less than 36%, and further preferably 36% - 38%; the solid-liquid ratio is 1 g:3 - 6 mL, the temperature is 40 - 60 °C, and the time is 24 - 48 h.

[0010] Using concentrated hydrochloric acid can improve the leaching efficiency of indium antimonide waste. At the same time, controlling the solid-liquid ratio within a suitable range is beneficial to the efficient leaching of antimony and indium and improves the metal recovery efficiency. When the solid-liquid ratio is too high, not only is the leaching rate of indium antimonide low, but after the hydrochloric acid is consumed, the acidity of the solution decreases, and both the leached antimony chloride and indium chloride may hydrolyze and precipitate; when the solid-liquid ratio is too low, it will cause waste of hydrochloric acid and is not conducive to subsequent distillation. Controlling the temperature and time within a reasonable range during the hydrochloric acid leaching process can improve the leaching rate of metals and contribute to the recovery of antimony and indium.

[0011] As a preferred solution, during the process of heating and volatilizing to remove impurities, the temperature is controlled within the range of 100 - 120 °C. Within this temperature range, low-boiling impurities can be fully evaporated and separated from the leaching solution. If the temperature is too low, the impurity removal is incomplete, and if the temperature is too high, antimony loss is likely to occur.

[0012] As a preferred solution, during the distillation separation process, the temperature is 220 - 230 °C. Controlling the distillation temperature within a suitable range is beneficial to the separation and recovery of antimony chloride.

[0013] As a preferred embodiment, the volume percentage composition of vaporized antimony trichloride to the carrier gas is 46.5 - 93%: 53.5 - 7%; the carrier gas is nitrogen, and the carrier gas flow rate is 20 - 200 mL / min, more preferably 100 - 120 mL / min. The nitrogen is nitrogen with a purity of 5N.

[0014] Controlling the content of antimony trichloride in the mixed gas within a suitable range is beneficial to improving the metal recovery efficiency. When the volume ratio of antimony trichloride to the carrier gas is too large, it is easy to cause the condensation of antimony trichloride vapor into a liquid, and in severe cases, it will solidify into a solid and block the pipeline; when the volume ratio of antimony trichloride to the carrier gas is too small, the concentration of antimony trichloride is too low, which will cause antimony trichloride to be unable to react effectively with hydrogen to form metallic antimony, and the antimony trichloride vapor will be discharged out of the furnace together with hydrogen. In addition, controlling the carrier gas flow rate to adapt to the evaporation rate of antimony trichloride is beneficial to the efficient recovery of metallic antimony. If the carrier gas flow rate does not adapt to the evaporation rate of antimony trichloride, it will change the ratio of the carrier gas to antimony trichloride, thus blocking the pipeline or causing antimony trichloride to be discharged out of the furnace without being reduced.

[0015] As a preferred embodiment, in the reduction roasting reaction I, hydrogen is used as the reducing gas, and the hydrogen flow rate is 1 - 2 L / min. The hydrogen is hydrogen with a purity of 5N. Controlling the flow rate of the reducing hydrogen can ensure the full reduction of antimony trichloride to metallic antimony. A lower hydrogen flow rate is beneficial to the full reduction of antimony trichloride, but if the flow rate is too low, there will be insufficient hydrogen required for the reduction reaction, resulting in the incomplete reduction and recovery of antimony trichloride; while too fast a hydrogen flow rate not only wastes hydrogen but also reduces the reduction reaction time of antimony trichloride, thus bringing the unreacted antimony trichloride out of the furnace.

[0016] As a preferred embodiment, the temperature of the reduction roasting reaction I is 800 - 900 °C, and the time is 2 - 4 h. Controlling the reduction reaction temperature of antimony trichloride within a suitable range can improve the recovery efficiency of metallic antimony. When the roasting temperature is too low, antimony trichloride cannot be effectively reduced by hydrogen, and when the temperature is too high, not only the energy consumption increases, but also higher requirements are imposed on the high-temperature resistance performance of the equipment. Controlling the reduction reaction temperature of antimony trichloride within the above range can ensure a relatively fast reduction reaction rate of antimony trichloride, and at the same time, the metallic antimony particles after the reduction reaction can be melted into blocks, which is convenient for recovery and treatment. The roasting time is related to the amount of antimony trichloride, and the roasting reduction time can be reasonably adjusted according to the amount of antimony trichloride.

[0017] As a preferred embodiment, in the reduction roasting reaction II, hydrogen is used as the reducing gas, and the hydrogen flow rate is 2 - 20 L / min, more preferably 2 - 5 L / min. The hydrogen is hydrogen with a purity of 4N. Since the raw material in this reaction process is a solid indium-containing material, maintaining a slightly positive pressure of hydrogen in the furnace during reduction can achieve better recovery of metallic indium, while too large a hydrogen flow rate will cause waste of hydrogen and increase the cost.

[0018] As a preferred solution, the temperature of the reduction roasting reaction II is 600-800°C, and the time is 3-6h. Controlling the temperature and time in the reaction process within a reasonable range is beneficial to improving the recovery efficiency of indium metal. If the reaction temperature is too low or the time is too short, the recovery efficiency of indium metal will be reduced. If the reaction temperature is too high, not only will the energy consumption increase, but also higher requirements for the high-temperature resistance performance of the equipment will be imposed. If the reaction time is too long, the energy consumption will also increase, raising the cost.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The recovery rates of antimony and indium metals are high, and the metal purity is high. The purity of the recovered antimony and indium reaches over 99%.

[0021] (2) The method is simple, the operation is convenient, the requirements for equipment are low, and the cost is low.

[0022] (3) No secondary pollution is generated, it is green and environmentally friendly. The hydrogen chloride and water generated during the recovery process can be recycled, which is beneficial to resource comprehensive utilization. Specific embodiments

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] The elemental composition of the indium antimonide waste used in the present invention is shown in Table 1 below.

[0025] Table 1 Elemental composition of indium antimonide waste

[0026]

[0027] Example 1

[0028] Crush 500 g of indium antimonide waste and pass it through a sieve to obtain D 50Particles of 100 mesh (150 μm) were added to 3000 mL of concentrated hot hydrochloric acid (mass concentration 36%) and leached at 40 °C for 24 hours. Insoluble impurities were removed by filtration. The obtained clear leaching solution was heated and evaporated at 100 °C to remove low-boiling water and HCl (water and HCl were recovered by condensation for reuse). Then, the solution with low-boiling components removed was further heated to 220 °C for short-path distillation to separate out antimony trichloride. The antimony trichloride was further heated to boiling, and a 5N nitrogen gas stream was used as the carrier gas with a flow rate of 20 mL / min. After mixing with the antimony trichloride vapor, it was fed into an atmosphere furnace. Among them, the content of antimony trichloride vapor was 93%. At the same time, hydrogen with a purity of 5N was introduced into the atmosphere furnace with a flow rate of 1 L / min. The temperature of the atmosphere furnace was controlled at 800 °C. After reacting for 3 h, it was cooled to obtain 247 g of metallic antimony. The hydrolysis residue distilled at 220 °C was placed in a quartz tube resistance furnace, and 4N hydrogen was introduced into the quartz tube with a flow rate of 2 L / min. The quartz tube resistance furnace was controlled at 600 °C. After reacting for 4 h, it was cooled to obtain 231 g of metallic indium.

[0029] Example 2

[0030] 700 g of indium antimonide waste was crushed and sieved to obtain particles of 50 100 mesh (150 μm), which were added to 3500 mL of concentrated hot hydrochloric acid (mass concentration 36%) and leached at 40 °C for 36 hours. Insoluble impurities were removed by filtration. The obtained clear leaching solution was heated and evaporated at 120 °C to remove low-boiling water and HCl (water and HCl were recovered by condensation for reuse). Then, the solution with low-boiling components removed was further heated to 230 °C for short-path distillation to separate out antimony trichloride. The antimony trichloride was further heated to boiling, and a 5N nitrogen gas stream was used as the carrier gas with a flow rate of 100 mL / min. After mixing with the antimony trichloride vapor, it was fed into an atmosphere furnace. Among them, the content of antimony trichloride vapor was 85%. At the same time, hydrogen with a purity of 5N was introduced into the atmosphere furnace with a flow rate of 2 L / min. The temperature of the atmosphere furnace was controlled at 850 °C. After reacting for 2 h, it was cooled to obtain 349 g of metallic antimony. The hydrolysis residue distilled at 230 °C was placed in a quartz tube resistance furnace, and 4N hydrogen was introduced into the quartz tube with a flow rate of 10 L / min. The quartz tube resistance furnace was controlled at 700 °C. After reacting for 4.5 h, it was cooled to obtain 326 g of metallic indium.

[0031] Example 3

[0032] 1200 g of indium antimonide waste was crushed and sieved to obtain particles of 50Particles of 100 mesh were added to 4800 mL of concentrated hot hydrochloric acid (mass concentration of 36%) and leached at 40 °C for 48 hours. Insoluble impurities were removed by filtration. The obtained clear leaching solution was heated and evaporated at 120 °C to remove low-boiling water and HCl (water and HCl were recovered by condensation and reused). Then, the solution with low-boiling components removed was further heated to 230 °C for short-path distillation to separate antimony trichloride. The antimony trichloride was further heated to boiling, and 5N nitrogen gas flow was used as the carrier gas with a flow rate of 200 mL / min. After mixing with the antimony trichloride vapor, it was sent into an atmosphere furnace. Among them, the content of antimony trichloride vapor was 70%. At the same time, hydrogen with a purity of 5N was introduced into the atmosphere furnace with a flow rate of 2 L / min. The temperature of the atmosphere furnace was controlled in a reduction furnace at 900 °C. After reacting for 4 hours and cooling, 595 g of metallic antimony was obtained. The hydrolysis residue distilled at 230 °C was placed in a quartz tube resistance furnace, and 4N hydrogen was introduced into the quartz tube with a flow rate of 20 L / min. The quartz tube resistance furnace was controlled at 800 °C. After reacting for 6 hours, 560 g of metallic indium was obtained.

[0033] The recovery rates and purities of metallic antimony and indium in Examples 1 to 3 are shown in Table 2 below:

[0034] Table 2

[0035]

[0036]

[0037] As can be seen from Table 2, the present invention has a high comprehensive recovery efficiency for indium antimonide waste. Among them, the recovery rates of both antimony and indium reach over 95%, and the recovered product has a high purity and good quality.

[0038] Comparative Example 1

[0039] The indium antimonide waste was recovered by the method of Example 1 under the same other conditions, except that: the volume percentage content of antimony trichloride vapor was reduced to 5%, and at the same time, the hydrogen flow rate was increased to 15 L / min. During this reaction process, when the antimony trichloride vapor, the carrier gas, and hydrogen passed through the quartz tube of the tubular furnace, no obvious reduction reaction occurred, resulting in a decrease in the efficiency of forming metallic antimony and a decline in the recovery rate of metallic antimony.

[0040] Comparative Example 2

[0041] The indium antimonide waste was recovered by the method of Example 1, except that: the hydrolysis residue after distillation at 220 °C was placed in a quartz tube resistance furnace, and the reaction time was adjusted to 1.5 h. It was found that the cooled product was not completely reduced to metallic indium, resulting in a decline in the recovery rate of metallic indium.

Claims

1. A method for comprehensively recovering indium and antimony from indium antimonide waste, characterized in that: The indium antimonide waste is leached with hydrochloric acid. The obtained leaching solution is heated to volatilize and remove impurities and then subjected to distillation separation to obtain antimony chloride and distillation residues. The antimony chloride is heated to vaporize, and the gaseous antimony chloride is transported by a carrier gas to an atmosphere furnace for reduction roasting reaction I to obtain metallic antimony. The distillation residues are placed in a tubular furnace for reduction roasting reaction II to obtain metallic indium. The leaching conditions are as follows: the mass concentration of hydrochloric acid is not less than 36%; the solid-liquid ratio is 1 g: 3-6 mL, the temperature is 40-60 °C, and the time is 24-48 h. During the process of heating to volatilize and remove impurities, the temperature is controlled within the range of 100-120 °C. During the distillation separation process, the temperature is 220-230 °C. The volume percentage composition of the gaseous antimony chloride and the carrier gas is 46.5-93%: 53.5-7%. In the reduction roasting reaction I, hydrogen is used as the reducing gas, and the reaction temperature is 800-900 °C. In the reduction roasting reaction II, hydrogen is used as the reducing gas.

2. A method for comprehensively recovering indium and antimony from indium antimonide waste according to claim 1, characterized in that: The particle size of the indium antimonide waste is -100 mesh.

3. A method for comprehensively recovering indium and antimony from indium antimonide waste according to claim 1, characterized in that: The carrier gas is nitrogen, and the carrier gas flow rate is 20-200 mL / min.

4. A method for comprehensively recovering indium and antimony from indium antimonide waste according to claim 1, characterized in that: The hydrogen gas flow rate in the reduction roasting reaction I is 1-2 L / min.

5. A method for comprehensively recovering indium and antimony from indium antimonide waste according to claim 1, characterized in that: The reaction time of the reduction roasting reaction I is 2-4 h.

6. A method for comprehensively recovering indium and antimony from indium antimonide waste according to claim 1, characterized in that: The hydrogen gas flow rate in the reduction roasting reaction II is 2-20 L / min.

7. A method for comprehensively recovering indium and antimony from indium antimonide waste according to claim 1 or 6, characterized in that: The temperature of the reduction roasting reaction II is 600-800 °C, and the time is 3-6 h.

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