Method and device for recovering indium phosphide waste

Abstract

The application provides an indium phosphide waste recovery method and a recovery device. The recovery method comprises the following steps: placing indium phosphide waste in an oxygen-free environment, reacting with chlorine gas after being heated to a first temperature, obtaining indium trichloride gas and phosphorus trichloride gas; placing the indium trichloride gas and the phosphorus trichloride gas in an oxygen-free environment at a second temperature, condensing the indium trichloride gas into indium trichloride solid; leading the phosphorus trichloride gas out of the second temperature environment and cooling it in an oxygen-free environment to obtain phosphorus trichloride liquid; and collecting the indium trichloride solid and the phosphorus trichloride liquid. The recovery device comprises a chlorine gas generating device, a two-section temperature control tube furnace with a vacuum system and a recovery device. The indium phosphide recovery method is simple in operation and short in process, can directly generate high-purity indium trichloride and high-purity phosphorus trichloride in one step, has a lower temperature compared with a traditional thermal decomposition method, recovers yellow phosphorus in the form of liquid phosphorus trichloride, and eliminates the risk of yellow phosphorus spontaneous combustion.

Description

Technical Field

[0001] This invention relates to the field of indium phosphide recycling, and more specifically, to a method and apparatus for recycling indium phosphide waste. Background Technology

[0002] Indium phosphide (InP) semiconductors possess advantages such as high peak electron drift velocity, wide bandgap, high thermal conductivity, and excellent heat dissipation, making them an indispensable component of 5G optical communication systems. In recent years, with the rapid development of electronic information technology, the semiconductor industry's demand for InP has increased rapidly, leading to a corresponding surge in waste.

[0003] Currently, the main methods for recycling indium phosphide waste are vacuum pyrolysis and wet processing. Vacuum pyrolysis mainly recovers and regenerates indium and phosphorus, but controlling the phosphorus conversion rate is difficult, and most of it is produced as spontaneously combusting yellow phosphorus, leading to high recycling difficulty and risk. As for wet recycling, for example, Chinese patent CN116281912A discloses an atmospheric pressure oxidation acid leaching process for treating indium phosphide waste, recovering indium through metal replacement. This method is simple to operate, but the process is lengthy and generates harmful waste liquid.

[0004] In summary, existing indium phosphide waste recycling processes still have significant room for optimization and improvement. It is necessary to further develop comprehensive recycling technologies for indium phosphide waste that are simple to operate, have short processes, high efficiency, low cost, and are environmentally friendly, so as to transform waste into usable materials in one step. Summary of the Invention

[0005] In view of the shortcomings of the prior art, one of the objectives of this invention is to solve one or more problems existing in the prior art. For example, one objective of this invention is to provide a method for recovering indium phosphide waste by preparing high-purity indium trichloride and high-purity phosphorus trichloride in one step.

[0006] One aspect of the present invention provides a method for recycling indium phosphide waste, which may include the following steps: placing the indium phosphide waste in an oxygen-free environment, heating it to a first temperature, and reacting it with chlorine gas to obtain indium trichloride gas and phosphorus trichloride gas; placing the indium trichloride gas and phosphorus trichloride gas in an oxygen-free environment at a second temperature, whereby the indium trichloride gas condenses into indium trichloride solid; removing the phosphorus trichloride gas from the second temperature environment and cooling it in an oxygen-free environment to obtain phosphorus trichloride liquid; and collecting the indium trichloride solid and phosphorus trichloride liquid; wherein the first temperature may be 750°C to 850°C, and the second temperature may be 160°C to 200°C.

[0007] Furthermore, the steps of obtaining indium trichloride gas and phosphorus trichloride gas may also include placing indium phosphide waste in an oxygen-free environment, heating it to 500°C to 600°C, introducing chlorine gas, and then heating it to a first temperature to react with chlorine gas.

[0008] Furthermore, the rate at which chlorine gas is introduced can be 200 ml / min to 300 ml / min.

[0009] Furthermore, the reaction time with chlorine gas after heating to the first temperature can be 2 to 3 hours.

[0010] Furthermore, the heating rate to the first temperature can be 8℃ / min to 12℃ / min, and the heating rate to the second temperature can be 4℃ / min to 5℃ / min.

[0011] Another aspect of the present invention provides an indium phosphide waste recovery device, which may include a chlorine generator, a two-stage temperature-controlled tubular furnace with a vacuum system, and a recovery unit. One end of the two-stage temperature-controlled tubular furnace is a high-temperature zone for loading indium phosphide waste, and the other end is a low-temperature zone. The inlet of the high-temperature zone is connected to the chlorine generator. After the chlorine reacts with the indium phosphide waste in the high-temperature zone, the resulting indium trichloride gas and phosphorus trichloride gas are introduced into the low-temperature zone. The low-temperature zone is used to condense the indium trichloride gas into indium trichloride solid. The inlet of the recovery unit is connected to the outlet of the low-temperature zone for condensing and recovering phosphorus trichloride.

[0012] Furthermore, it may also include a chlorine recovery mechanism connected to the outlet end of the recoverer.

[0013] Another aspect of the present invention provides an indium phosphide waste recycling device, which may include a chlorine generator, a first temperature control mechanism with a vacuum system, a second temperature control mechanism with a vacuum system, and a recycler. The chlorine generator is connected to one end of the first temperature control mechanism, which is used to react indium phosphide waste with chlorine. One end of the second temperature control mechanism is connected to the other end of the first temperature control mechanism, which is used to condense and recover indium trichloride. One end of the recycler is connected to the other end of the second temperature control mechanism, which is used to recover phosphorus trichloride.

[0014] Furthermore, it may also include a chlorine recovery mechanism connected to the other end of the recoverer.

[0015] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0016] (1) The indium phosphide recovery method of the present invention is simple to operate, has a short process, high efficiency, low cost and environmental friendliness. It can directly generate high-purity indium trichloride and high-purity phosphorus trichloride from indium phosphide in one step. Compared with the traditional thermal decomposition method, the method of the present invention has a lower temperature and recovers yellow phosphorus in the form of liquid phosphorus trichloride, eliminating the risk of spontaneous combustion of yellow phosphorus. It realizes the full utilization of the characteristics of low impurities in indium phosphide raw materials to directly prepare high-purity InCl3 and PCl3 materials.

[0017] (2) The indium phosphide recovery device of the present invention has a simple structure and is easy to operate. It can realize the one-step preparation of indium phosphide into high-purity indium trichloride and high-purity phosphorus trichloride, and complete the recovery of indium phosphide waste. Attached Figure Description

[0018] The above and other objects and features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 This is a schematic diagram of an indium phosphide waste recycling device.

[0020] Explanation of reference numerals in the attached figures:

[0021] 1-Chlorine generator, 2-Quartz tube, 3-First temperature-controlled tubular vacuum furnace, 4-Second temperature-controlled tubular vacuum furnace, 5-Recovery unit, 6-Chlorine recovery mechanism. Detailed Implementation

[0022] The indium phosphide waste recycling method and recycling apparatus according to the present invention will be described in detail below with reference to the accompanying drawings and exemplary embodiments.

[0023] One aspect of the present invention provides a method for recycling indium phosphide waste. In some embodiments, the recycling method may include the following steps:

[0024] Step 1: Place the indium phosphide waste in an oxygen-free environment, heat it to a first temperature, and then react it with chlorine gas to obtain indium trichloride gas and phosphorus trichloride gas. The first temperature can be 750℃~850℃.

[0025] Step 2: Indium trichloride gas and phosphorus trichloride gas are placed in an oxygen-free environment at a second temperature, and the indium trichloride gas condenses into indium trichloride solid. The second temperature can be 160℃~200℃.

[0026] Step 3: After the phosphorus trichloride gas is removed from the second temperature environment, it is condensed in an oxygen-free environment to obtain phosphorus trichloride liquid;

[0027] Step 4: Collect indium trichloride solid and phosphorus trichloride liquid.

[0028] In some implementations, the oxygen-free environment in steps 1, 2, and 3 can be a vacuum environment. For example, the vacuum environment can be a vacuum environment with a pressure of 30 Pa to 100 Pa.

[0029] In some implementations, the first temperature can be a combination of 760°C–840°C, 780°C–820°C, 795°C–815°C, 800°C–808°C, or higher. At the first temperature, the indium phosphide waste can react fully with chlorine gas to generate indium trichloride gas and phosphorus trichloride gas.

[0030] In some implementations, the second temperature can be a combination of 170°C–190°C, 175°C–185°C, 178°C–183°C, or higher. At the second temperature, indium trichloride gas may condense into indium trichloride solid to achieve the recovery of elemental indium.

[0031] In some embodiments, step 1 may further include placing the indium phosphide waste in an oxygen-free environment, heating it to 500°C–600°C before introducing chlorine gas, and then heating it to the first temperature to react with the chlorine gas. Heating to 500°C–600°C before introducing chlorine gas saves on chlorine consumption, as the indium phosphide waste has not yet reacted with the chlorine gas at this temperature. For example, the waste can be heated in an oxygen-free environment to a temperature range of 520°C–580°C, 540°C–570°C, 545°C–558°C, or a combination thereof before introducing chlorine gas. In some embodiments, the chlorine gas introduction rate can be 200 ml / min–300 ml / min. For example, the chlorine gas introduction rate can be 220 ml / min–270 ml / min, 235 ml / min–268 ml / min, 247 ml / min–261 ml / min, 251 ml / min–259 ml / min, or a combination thereof.

[0032] In some implementations, after heating to the first temperature, the reaction time between the indium phosphide waste and chlorine gas can be 2 to 3 hours. This time range ensures sufficient reaction between the indium phosphide waste and chlorine gas. For example, the reaction time between indium phosphide and chlorine gas can be 2.5 hours. After the reaction is complete, the product indium trichloride gas and phosphorus trichloride gas, along with the chlorine gas, enter a second temperature environment. At this point, the indium trichloride gas begins to condense, and after complete condensation, solid indium trichloride can be recovered.

[0033] In some embodiments, the heating rate to the first temperature can be 8°C / min to 12°C / min, and the heating rate to the second temperature can be 4°C / min to 5°C / min. For example, the heating rate to the first temperature can be 9°C / min to 11°C / min, and the heating rate to the second temperature can be 4.2°C / min to 4.8°C / min.

[0034] Another aspect of the present invention provides an indium phosphide waste recycling device. In some embodiments, such as Figure 1As shown, the recovery device may include a chlorine generator 1, a two-stage temperature-controlled tubular furnace with a vacuum system, and a recovery unit 5. The two-stage temperature-controlled tubular furnace may include a first temperature-controlled tubular vacuum furnace 3 and a second temperature-controlled tubular vacuum furnace 4. The first temperature-controlled tubular vacuum furnace 3 is used to load indium phosphide waste and is the high-temperature zone of the two-stage temperature-controlled tubular furnace, used to control the temperature to reach a first temperature so that the indium phosphide waste reacts with chlorine. The second temperature-controlled tubular vacuum furnace 4 is the low-temperature zone of the two-stage temperature-controlled tubular furnace, used to control the temperature to reach a second temperature so that indium trichloride gas condenses into indium trichloride solid. A quartz tube 2 is installed in the middle of the two-stage temperature-controlled tubular furnace, passing through the first temperature-controlled tubular vacuum furnace 3 and the second temperature-controlled tubular vacuum furnace 4, to provide the reaction environment. The inlet end of the first temperature-controlled tubular vacuum furnace 3 is connected to the chlorine generator 1. After the chlorine reacts with the indium phosphide waste, the resulting indium trichloride gas and phosphorus trichloride gas are introduced into the second temperature-controlled tubular vacuum furnace 4. The second temperature-controlled tubular vacuum furnace 4 is used to condense indium trichloride gas into indium trichloride solid. The inlet end of the recovery unit 5 is connected to the outlet end of the second temperature-controlled tubular vacuum furnace 4, and is used to condense and recover phosphorus trichloride to obtain liquid phosphorus trichloride.

[0035] In some embodiments, the recovery device further includes a chlorine recovery mechanism 6 connected to the outlet of the recoverer 5. The chlorine recovery mechanism 6 can hold a NaOH solution to recover unreacted chlorine gas.

[0036] Another aspect of the present invention provides an alternative indium phosphide waste recycling apparatus. In some embodiments, the recycling apparatus may include a chlorine generator, a first temperature control mechanism with a vacuum system, a second temperature control mechanism with a vacuum system, and a recycling unit. The chlorine generator is connected to one end of the first temperature control mechanism. The first temperature control mechanism controls the temperature to reach a first temperature and an oxygen-free condition to allow the indium phosphide waste to react with chlorine. One end of the second temperature control mechanism is connected to the other end of the first temperature control mechanism. The second temperature control mechanism controls the temperature to reach a second temperature and an oxygen-free condition to condense indium trichloride gas into indium trichloride solid for recycling. One end of the recycling unit is connected to the other end of the second temperature control mechanism for condensing phosphorus trichloride gas into phosphorus trichloride liquid for recycling.

[0037] In some implementations, a chlorine recovery mechanism is also included, connected to the other end of the recoverer. This chlorine recovery mechanism can contain a NaOH solution to recover any unreacted chlorine gas.

[0038] To better understand the present invention, specific examples are provided below to further illustrate the content of the present invention, but the content of the present invention is not limited to the examples below.

[0039] Example 1

[0040] Utilize Figure 1The indium phosphide waste recycling device shown recycles indium phosphide waste, and the recycling methods may include:

[0041] Step 1: Weigh 60g of indium phosphide waste and place it in an alumina crucible, then place it in the first temperature-controlled tube vacuum furnace.

[0042] Step 2: To prevent indium and phosphorus from oxidizing, gas purging is performed first. First, turn on the vacuum pump to evacuate the pressure in the quartz tube to 40 Pa, and then introduce inert gas for 10 minutes to keep the environment in the quartz tube oxygen-free and dry.

[0043] Step 3: Turn on the temperature control devices of the first temperature-controlled tube vacuum furnace and the second temperature-controlled tube vacuum furnace. The temperature in the first temperature-controlled tube vacuum furnace is increased at a rate of 9°C / min, and the temperature in the second temperature-controlled tube vacuum furnace is increased at a rate of 4°C / min.

[0044] Step 4: When the temperature inside the first temperature-controlled tube vacuum furnace reaches 500℃, chlorine gas is introduced at a rate of 200ml / min. The chlorine gas is washed with concentrated sulfuric acid and then enters the quartz tube to ensure its dryness. When the first temperature inside the first temperature-controlled tube vacuum furnace reaches 760℃ (i.e., the reaction temperature), the second temperature range inside the first temperature-controlled tube vacuum furnace can be stabilized at 170℃.

[0045] Step 5: After maintaining the temperature reached in step 4 for 2 hours, the indium phosphide waste reacts with chlorine gas in the first temperature-controlled tubular vacuum furnace to generate indium trichloride gas and phosphorus trichloride gas. After the indium trichloride gas and phosphorus trichloride gas enter the second temperature-controlled tubular vacuum furnace, the indium trichloride gas begins to condense to generate indium trichloride solid, while the phosphorus trichloride gas still enters the recovery unit in gaseous state and condenses into phosphorus trichloride liquid.

[0046] Step 6: After the heat preservation is completed, the equipment is allowed to cool down naturally until it reaches room temperature before the material is removed. Indium trichloride is condensed on the quartz tube wall in the second temperature-controlled tubular vacuum furnace for recovery, while phosphorus trichloride is condensed in the recovery unit. XPS and ICP-MS analysis showed that the purity of the InCl3 and PCl3 products reached over 99.9%, classifying them as high-purity InCl3 and PCl3.

[0047] Example 2

[0048] Utilize Figure 1 The indium phosphide waste recycling device shown recycles indium phosphide waste, and the recycling methods may include:

[0049] Step 1: Weigh 95g of indium phosphide waste and place it in an alumina crucible, then place it in the first temperature-controlled tube vacuum furnace.

[0050] Step 2: To prevent indium and phosphorus from oxidizing, gas purging is performed first. First, turn on the vacuum pump to evacuate the pressure in the quartz tube to 100 Pa, and then introduce inert gas for 10 minutes to keep the environment in the quartz tube oxygen-free and dry.

[0051] Step 3: Turn on the temperature control devices of the first and second temperature-controlled tube vacuum furnaces. The temperature in the first temperature-controlled tube vacuum furnace is increased at a rate of 12℃ / min, and the temperature in the second temperature-controlled tube vacuum furnace is increased at a rate of 5℃ / min.

[0052] Step 4: When the temperature inside the first temperature-controlled tube vacuum furnace reaches 600℃, chlorine gas is introduced at a rate of 300ml / min. The chlorine gas is washed with concentrated sulfuric acid and then enters the quartz tube to ensure its dryness. When the first temperature inside the first temperature-controlled tube vacuum furnace reaches 840℃ (i.e., the reaction temperature), the second temperature range inside the first temperature-controlled tube vacuum furnace can be stabilized at 190℃.

[0053] Step 5: After maintaining the temperature reached in step 4 for 3 hours, the indium phosphide waste reacts with chlorine gas in the first temperature-controlled tubular vacuum furnace to generate indium trichloride gas and phosphorus trichloride gas. After the indium trichloride gas and phosphorus trichloride gas enter the second temperature-controlled tubular vacuum furnace, the indium trichloride gas begins to condense to generate indium trichloride solid, while the phosphorus trichloride gas still enters the recovery unit in gaseous state and condenses into phosphorus trichloride liquid.

[0054] Step 6: After the heat preservation is completed, the equipment is allowed to cool down naturally until it reaches room temperature before the material is removed. Indium trichloride is condensed on the quartz tube wall in the second temperature-controlled tubular vacuum furnace for recovery, while phosphorus trichloride is condensed in the recovery unit. XPS and ICP-MS analysis showed that the purity of the InCl3 and PCl3 products reached over 99.9%, classifying them as high-purity InCl3 and PCl3.

[0055] Although the invention has been described above in conjunction with exemplary embodiments, those skilled in the art will understand that various modifications and changes can be made to the exemplary embodiments of the invention without departing from the spirit and scope defined by the claims.

Claims

1. A method for recycling indium phosphide waste, characterized in that, Includes the following steps: Indium phosphide waste was placed in an oxygen-free environment, heated to a first temperature, and then reacted with chlorine gas to obtain indium trichloride gas and phosphorus trichloride gas. When indium trichloride gas and phosphorus trichloride gas are placed in an oxygen-free environment at a second temperature, indium trichloride gas condenses into indium trichloride solid. Phosphorus trichloride gas was extracted from the second temperature environment and then condensed in an oxygen-free environment to obtain phosphorus trichloride liquid. Solid indium trichloride and liquid phosphorus trichloride were collected; among them, The first temperature is 750℃~850℃, and the second temperature is 160℃~200℃.

2. The method for recycling indium phosphide waste according to claim 1, characterized in that, The steps for obtaining indium trichloride gas and phosphorus trichloride gas also include placing indium phosphide waste in an oxygen-free environment, heating it to 500℃~600℃, then introducing chlorine gas, and then heating it to a first temperature to react with chlorine gas.

3. The method for recycling indium phosphide waste according to claim 2, characterized in that, The rate at which chlorine gas is introduced is 200 ml / min to 300 ml / min.

4. The method for recycling indium phosphide waste according to any one of claims 1 to 3, characterized in that, After heating to the first temperature, the reaction time with chlorine is 2 to 3 hours.

5. The method for recycling indium phosphide waste according to any one of claims 1 to 3, characterized in that, The heating rate to the first temperature is 8℃ / min to 12℃ / min, and the heating rate to the second temperature is 4℃ / min to 5℃ / min.

6. An indium phosphide waste recycling apparatus for implementing the indium phosphide waste recycling method according to any one of claims 1 to 5, characterized in that, It includes a chlorine generator, a two-stage temperature-controlled tubular furnace with a vacuum system, and a recovery unit, among which, One end of the two-section temperature-controlled tube furnace is a high-temperature zone for loading indium phosphide waste, and the other end is a low-temperature zone; The inlet of the high-temperature zone is connected to a chlorine generator. After the chlorine gas and indium phosphide waste react in the high-temperature zone, the resulting indium trichloride gas and phosphorus trichloride gas are introduced into the low-temperature zone. The low-temperature zone is used to condense the indium trichloride gas into indium trichloride solid. The inlet of the recovery unit is connected to the outlet of the low-temperature zone for condensation and recovery of phosphorus trichloride.

7. The indium phosphide waste recycling device according to claim 6, characterized in that, It also includes a chlorine recovery unit connected to the outlet of the recoverer.

8. An indium phosphide waste recycling apparatus for implementing the indium phosphide waste recycling method according to any one of claims 1 to 5, characterized in that, It includes a chlorine generator, a first temperature control mechanism with a vacuum system, a second temperature control mechanism with a vacuum system, and a recovery unit, wherein, The chlorine generator is connected to one end of the first temperature control mechanism, which is used to react indium phosphide waste with chlorine. One end of the second temperature control mechanism is connected to the other end of the first temperature control mechanism. The second temperature control mechanism is used to condense and recover indium trichloride. One end of the recovery unit is connected to the other end of the second temperature controller for recovering phosphorus trichloride.

9. The indium phosphide waste recycling device according to claim 8, characterized in that, It also includes a chlorine recovery unit connected to the other end of the recoverer.

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