A method for separating and recovering gallium arsenide waste

Abstract

The present invention provides a gallium arsenide waste separation and recovery device and method, the device includes a feeding mechanism, a heating furnace, a vacuum pump group and a condenser; wherein the feeding mechanism includes a support arm, a feeding support arm and a guide rail; the heating furnace includes a front door flange assembly and a furnace chamber, the furnace chamber includes a quartz tube chamber in a heating area, a cooling chamber in a cooling area and a material taking chamber connected in sequence; the vacuum pump group is connected to the furnace chamber; the condenser includes a condenser tube wound outside the cooling chamber. The gallium arsenide waste separation and recovery device and method of the present invention can directly separate high-purity metallic gallium and elemental arsenic, arsenic and gallium are collected separately, and the recovery rate of gallium is high, the cost is low, there is no pollution to the environment, and no toxic substances are produced, which is more conducive to operation and personnel safety, and the maintenance cost is low.

Description

Technical Field

[0001] The invention belongs to the field of chemical industry, and in particular relates to a method for separating and recovering gallium arsenide waste. Background Art

[0002] Because of the superior performance of GaAs, it is widely used in electronic devices and optical devices. However, in nature, it is impossible to form gallium deposits with mining value alone. Metal gallium (Ga) is a rare metal with a very small content in the earth's crust. It is associated with sulfide gallium copper ore and aluminum, zinc, germanium, germanium-containing coal and other mines in a isomorphous state. Gallium can only be comprehensively recovered from the by-products of extracting aluminum, zinc, germanium, etc. At present, the production process of metal gallium in the world mainly includes extraction method and recovery method. Among them, 85% is produced by the recovery method, and the main raw material is gallium arsenide (GaAs) waste. However, in the process of synthesizing GaAs, the final yield is very low, often less than 15%, and a large amount of GaAs waste will be generated.

[0003] Chinese invention patent application publication number CN1693492A discloses a method for recovering gallium and arsenic from gallium arsenide industrial waste. Gallium arsenide industrial waste is used as raw material, and processes such as raw material grinding, nitric acid autocatalytic leaching, sulfide selective precipitation of arsenic, hydroxide precipitation of gallium, gallium hydroxide alkali dissolution, and electrolytic recovery of gallium are adopted. Electrolysis obtains 4N purity metal gallium, which can be further purified to 6N purity high-purity metal gallium. Arsenic sulfide as raw material can be further processed according to the current process to obtain high-purity arsenic. This method is complex and has a long process, and generates a large amount of wastewater that needs further treatment.

[0004] Another Chinese invention patent application, publication number CN101857918A, discloses a method for purifying and recovering gallium and arsenic from waste gallium arsenide. Arsenic and arsenic trioxide are first obtained by high-temperature calcination, and then the arsenic vapor is condensed to obtain arsenic trioxide oxide. Gallium trioxide is dissolved in aqua regia of appropriate concentration and electrolyzed to obtain gallium metal. This method produces highly toxic arsenic trioxide, which is not conducive to operation and personnel safety.

[0005] Patent invention patent application publication number CN103184339A published on July 3, 2013 discloses a gallium arsenide processing device and method, wherein gallium arsenide waste is used as raw material, the gallium arsenide waste is placed in a quartz boat, and then the quartz boat containing the gallium arsenide waste is manually placed in a quartz tube surrounded by a horizontal crystal heating furnace heating zone, the vacuum unit is started, and the horizontal crystal heating furnace is started after the pressure reaches a predetermined pressure of 10Pa, and the heating is kept for 2 to 3 hours, and the gallium arsenide waste is decomposed and then naturally cooled to obtain arsenic and liquid gallium. The shortcomings of this method are: when gallium arsenide waste is manually placed, the quartz tube is easy to break and the operation is inconvenient, and it has high requirements on personnel; the separated liquid gallium remains in the quartz boat, and the gaseous arsenic will condense on the inner wall of the quartz tube and the surface of the quartz boat below 600°C, which is easy to cause secondary pollution; most of the condensed arsenic is on the inner surface of the quartz tube, and the collection is complicated and not conducive to operation and personnel safety; the quartz tube needs to be cleaned frequently and the maintenance cost is high; the equipment and method have low production capacity. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a method for separating and recovering gallium arsenide waste, so as to solve many problems existing in the prior art.

[0007] To achieve the above-mentioned and other related purposes, the present invention provides a gallium arsenide waste separation and recovery device, comprising a feeding mechanism, a heating furnace, a vacuum pump group and a condenser, wherein:

[0008] The feeding mechanism comprises a support arm, a feeding support arm and a guide rail, wherein the support arm is slidably connected to the guide rail and is used to support the feeding support arm; a slide rail is provided on the side of the support arm, and the feeding support arm is slidably connected to the support arm through the slide rail and is used to place and transport a quartz material box containing gallium arsenide waste;

[0009] The heating furnace comprises a front door flange assembly and a furnace cavity, wherein the furnace cavity comprises a quartz tube cavity in a heating area, a cooling cavity in a cooling area and a material taking cavity which are connected in sequence, and the front door flange assembly is fixed to one end of the quartz tube cavity;

[0010] The vacuum pump group is in communication with the furnace chamber;

[0011] The condenser comprises a condenser tube wound outside the cooling chamber, which is used to cool the cooling chamber, so that the arsenic vapor separated in the reaction is condensed and deposited in the cooling chamber.

[0012] Preferably, the gallium arsenide waste separation and recovery device also includes a seal, which includes a first seal at the connection between the front door flange assembly and the quartz tube cavity, a second seal at the connection between the quartz tube cavity and the cooling cavity, and a third seal at the connection between the cooling cavity and the vacuum pump group.

[0013] Preferably, the sealing member is a heat-resistant fluororubber ring.

[0014] Preferably, the gallium arsenide waste separation and recovery device further comprises a pressure detection unit connected to the furnace chamber and an arsenic content automatic detection unit connected to the cooling chamber.

[0015] Preferably, the gallium arsenide waste separation and recovery device also includes a control unit and an execution unit, and the control unit is electrically connected to the pressure detection unit, the arsenic content automatic detection unit, and the execution unit respectively; the execution unit includes a robotic arm arranged in the furnace cavity, a temperature sensor, a heating furnace switch controller, and an electromagnetic door lock arranged at the opening of the material collection cavity.

[0016] To achieve the above-mentioned purpose and other related purposes, the present invention provides a gallium arsenide waste separation and recovery method, using the gallium arsenide waste separation and recovery device of the present invention, comprising:

[0017] 1) transporting gallium arsenide waste into the quartz tube cavity;

[0018] 2) Seal the connection between the front door assembly and the furnace chamber, and between the furnace chamber and the vacuum pump assembly through a sealing member;

[0019] 3) turning on the vacuum pump group, and when the pressure in the furnace chamber is less than a predetermined pressure, starting the heating furnace to heat to a predetermined temperature and keep the temperature for a predetermined time, so that the gallium arsenide in the gallium arsenide waste is decomposed to generate liquid gallium and gaseous arsenic;

[0020] 4) Cool naturally under the pressure to recover gallium and arsenic.

[0021] Preferably, the predetermined pressure is 1-10 Pa, the predetermined temperature is 800-1050° C., and the predetermined time is 1-4 hours.

[0022] Preferably, when the gallium arsenide waste separation and recovery device of the present invention is used, the content of gaseous arsenic in the furnace chamber is automatically detected before the material taking chamber is opened when recovering arsenic. Before the content of gaseous arsenic is less than a predetermined content, the electromagnetic door lock is automatically locked and cannot be opened.

[0023] Preferably, step 3) in the gallium arsenide waste separation and recovery method is: 3) turning on the vacuum pump group, and when the pressure in the furnace chamber is less than a predetermined pressure, starting the heating furnace to decompose the gallium arsenide in the gallium arsenide waste to generate liquid gallium and gaseous arsenic; at the same time, turning on the control unit and the execution unit, the control unit obtains arsenic content data from the arsenic content automatic detection unit once every 1-5 minutes, and when the arsenic content data obtained for three consecutive times no longer increases, or when heated to a predetermined temperature, starting the execution unit to keep the heating furnace warm for a predetermined time.

[0024] As described above, the gallium arsenide waste separation and recovery device and method of the present invention have the following beneficial effects:

[0025] The gallium arsenide waste separation and recovery device and method of the present invention can directly separate high-purity metallic gallium and elemental arsenic. Gallium arsenide waste is put into the device through mechanical operation, the quartz tube is not easy to break, the operation is convenient and quick, and the requirements on personnel are not high. A separate cooling chamber and a material taking chamber are provided to avoid secondary pollution caused by condensation of gaseous arsenic on the inner wall of the quartz tube: arsenic and gallium are collected separately and the recovery rate of gallium is high; the collection operation is simple, and an automatic arsenic content detection unit is provided, which is pollution-free to the environment and beneficial to the safety of operators; the cleaning frequency of the quartz tube is greatly reduced, and the maintenance cost is low; the production capacity of the equipment is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of a gallium arsenide waste separation and recovery device according to one embodiment of the present invention.

[0027] Component number description

[0028] 1 Support arm

[0029] 2 Loading support arm

[0030] 3 Guide rails

[0031] 4 Front door flange assembly

[0032] 5 Quartz tube

[0033] 6 Cooling chamber

[0034] 7. Material taking cavity

[0035] 8 Vacuum pump set

[0036] 9 Condenser

[0037] 91 Condenser

[0038] 10 Furnace cover

[0039] 11 Quartz material box DETAILED DESCRIPTION

[0040] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0041] See also Figure 1. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0042] The present invention provides a gallium arsenide waste separation and recovery device, comprising a feeding mechanism, a heating furnace, a vacuum pump group, a condenser and a sealing member; wherein the feeding mechanism comprises a support arm 1, a feeding support arm 2 and a guide rail 3, wherein the support arm 1 is slidably connected to the guide rail 3 and is used to support the feeding support arm 2; a slide rail is provided on the side of the support arm 1, and the feeding support arm 2 is slidably connected to the support arm 1 through the slide rail, and is used to place and transport a quartz material box 11 containing gallium arsenide waste; the heating furnace comprises a front door flange assembly 4 and a furnace cavity, wherein the furnace cavity comprises a quartz tube cavity 5 in a heating area, a cooling cavity 6 in a cooling area and a material taking cavity 7 which are connected in sequence, and the front door flange assembly 4 is fixed to one end of the quartz tube cavity 4; the vacuum pump group 8 is connected to the furnace cavity; the condenser 9 comprises a condensing tube 91 wound around the outside of the cooling cavity 6, and is used to cool the cooling cavity 6, so that the arsenic vapor separated in the reaction is condensed and deposited in the cooling cavity 6, and the cooling cavity 6 is provided with a furnace cover 10, which is used to seal and clean the cooling cavity 6. The seals include a first seal at the connection between the front door flange assembly and the quartz tube cavity, a second seal at the connection between the quartz tube cavity 5 and the cooling cavity 6, and a third seal at the connection between the cooling cavity 6 and the vacuum pump group 8. The seals are made of materials with good thermal stability, preferably heat-resistant fluorine rubber rings.

[0043] In another embodiment, the gallium arsenide waste separation and recovery device further includes a pressure detection unit connected to the furnace chamber and an arsenic content automatic detection unit connected to the cooling chamber 8, as well as a control unit and an execution unit, wherein the control unit is electrically connected to the pressure detection unit, the arsenic content automatic detection unit, and the execution unit respectively; the execution unit includes a mechanical arm arranged in the furnace chamber, a temperature sensor, and an electromagnetic door lock arranged at the opening of the material taking chamber. The arsenic content automatic detection unit is an arsenic content automatic detector. The mechanical arm is used to move the quartz material box containing gallium arsenide waste. According to needs, one or more groups of quartz material boxes can be selected for heating each separation and processing operation. The arsenic content automatic detection unit is used in conjunction with the electromagnetic door lock. Before opening the electromagnetic door lock, the arsenic content in the furnace chamber is first detected. If the arsenic content is higher than the preset value, the electromagnetic door lock is locked and cannot be opened. The electromagnetic door lock will not be unlocked until the detected arsenic content is lower than the preset value. At this time, the material taking chamber opening can be manually opened. In this way, the pollution of the environment by gaseous arsenic and the personal injury to the operator can be avoided.

[0044] The gallium arsenide waste separation and recovery device of the present invention is used to separate and recover metallic gallium and elemental arsenic:

[0045] Example 1

[0046] Gallium arsenide waste is irregular flakes and small granular powder with a thickness of about 2mm. Take 12Kg of gallium arsenide waste as raw material, add it to the quartz material box, and place the quartz material box on the loading arm of the loading mechanism. Use the loading mechanism to put the quartz material box through the front door assembly into the heating zone of the horizontal heating furnace. The quartz tube cavity is located outside the rear end of the heating zone of the horizontal heating furnace. It is placed in the air and connected to the vacuum pump group. Turn on the vacuum pump group. When the pressure in the quartz tube is 1pa, start the horizontal heating furnace heating program to raise the temperature to 1050℃ and keep it warm for 2h. Naturally cool in a vacuum state to obtain 3.9Kg of gallium and 1.7Kg of slag (mainly gallium). Because the separated liquid gallium buries the gallium arsenide raw material, the remaining slag is taken out and accumulated for secondary purification.

[0047] In terms of mass, gallium arsenide waste was initially purified to produce 3.9 kg of liquid gallium and 5.8 kg of solid arsenic.

[0048] Example 2

[0049] Gallium arsenide waste is irregular flakes and small granular powder with a thickness of about 2mm. Take 24Kg of gallium arsenide waste as raw material, add it to the quartz material box, and place the quartz material box on the loading arm of the loading mechanism. Use the loading mechanism to put the quartz material box through the front door assembly into the heating zone of the horizontal heating furnace. The quartz tube cavity is located outside the rear end of the horizontal heating furnace heating zone and is placed in the air and connected to the vacuum pump group. Turn on the vacuum pump group. When the pressure in the quartz tube is 5pa, start the horizontal heating furnace heating program to raise the temperature to 1050℃ and keep it warm for 4h. Cool naturally in the vacuum state to obtain 8.6Kg of gallium and 6.95Kg of slag (mainly gallium). Because the separated liquid gallium buries the gallium arsenide raw material, the remaining slag is taken out and accumulated for secondary purification.

[0050] In terms of mass, the gallium arsenide waste was initially purified to produce 8.6 kg of liquid gallium and 7.8 kg of solid arsenic.

[0051] Example 3

[0052] Gallium arsenide waste is irregular flakes and small granular powder with a thickness of about 2mm. Take 24Kg of gallium arsenide waste as raw material, add it to the quartz material box, and place the quartz material box on the loading arm of the loading mechanism. Use the loading mechanism to put the quartz material box through the front door assembly into the heating zone of the horizontal heating furnace. The quartz tube cavity is located outside the rear end of the horizontal heating furnace heating zone and is placed in the air and connected to the vacuum pump group. Turn on the vacuum pump group. When the pressure in the quartz tube is 10pa, start the horizontal heating furnace heating program to raise the temperature to 1050℃ and keep it warm for 3h. Cool naturally in the vacuum state to obtain 8.15Kg of gallium and 8.25Kg of slag (mainly gallium). Because the separated liquid gallium buries the gallium arsenide raw material, the remaining slag is taken out and accumulated for secondary purification.

[0053] In terms of mass, the gallium arsenide waste was initially purified to produce 8.15 kg of liquid gallium and 7.0 kg of solid arsenic.

[0054] Example 4

[0055] Gallium arsenide waste is irregular flakes and small granular powder with a thickness of about 2mm. Take 24Kg of gallium arsenide waste as raw material, add it to the quartz material box, and place the quartz material box on the loading arm of the loading mechanism. Use the loading mechanism to put the quartz material box through the front door assembly into the heating zone of the horizontal heating furnace. The quartz tube cavity is located outside the rear end of the horizontal heating furnace heating zone and is placed in the air and connected to the vacuum pump group. Turn on the vacuum pump group. When the pressure in the quartz tube is 10pa, start the horizontal heating furnace heating program to raise the temperature to 1050℃ and keep it warm for 4h. Cool naturally in the vacuum state to obtain 8.4Kg of gallium and 7.8Kg of slag (mainly gallium). Because the separated liquid gallium buries the gallium arsenide raw material, the remaining slag is taken out and accumulated for secondary purification.

[0056] In terms of mass, the gallium arsenide waste was initially purified to produce 8.4 kg of liquid gallium and 6.9 kg of solid arsenic.

[0057] Example 5

[0058] A total of 24.7 kg of slag was collected, and a total of 27.5 kg of arsenic was taken out by weighing four experiments. 24 kg of slag was placed in a quartz material box, and the quartz material box was placed on the loading arm of the loading mechanism. The quartz material box was placed in the heating zone of the horizontal heating furnace through the front door assembly by the loading mechanism. The quartz tube cavity was located outside the rear end of the heating zone of the horizontal heating furnace and placed in the air and connected to the vacuum pump group. The vacuum pump group was turned on. When the pressure in the quartz tube was 10 pa, the horizontal heating furnace heating program was started to heat up to 1050 ° C and keep warm for 2 hours. Natural cooling in the vacuum state obtained 10.2 kg of gallium, 12.1 kg of arsenic, and 2.4 kg of slag, and a total of 39.25 kg of gallium and 39.6 kg of arsenic were obtained.

[0059] Calculation results:

[0060] Calculated by mass, the batch recovery rate of gallium arsenide is 93.8%. Finally, the GDMS test results of the samples taken in the embodiment are given. The GDMS test was conducted by an inspection and testing company (Suzhou Bofeik Analytical Technology Service Co., Ltd.).

[0061] It can be seen from Table 1 and Table 2 that the product Ga reaches 7N purity and the product As reaches 5N purity.

[0062] Table 1 Detection results of Ga in Example product (unit: ppm)

[0063]

[0064]

[0065] Note: After subtracting all measured impurity elements, the purity of this Ga is calculated to be approximately 99.99996%.

[0066] Table 2 Detection results of As in the example product (unit: ppm)

[0067]

[0068]

[0069] Note: After subtracting all impurity elements, the purity of As is calculated to be approximately 99.9977%

[0070] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for separating and recovering gallium arsenide waste, characterized in that: The gallium arsenide waste separation and recovery device comprises a feeding mechanism, a heating furnace, a vacuum pump group and a condenser, wherein: The feeding mechanism comprises a support arm, a feeding support arm and a guide rail, wherein the support arm is slidably connected to the guide rail and is used to support the feeding support arm; a slide rail is provided on the side of the support arm, and the feeding support arm is slidably connected to the support arm through the slide rail and is used to place and transport a quartz material box containing gallium arsenide waste; The heating furnace comprises a front door flange assembly and a furnace cavity, wherein the furnace cavity comprises a quartz tube cavity in a heating area, a cooling cavity in a cooling area and a material taking cavity which are connected in sequence, and the front door flange assembly is fixed to one end of the quartz tube cavity; The vacuum pump group is in communication with the furnace chamber; The condenser includes a condenser tube wound outside the cooling chamber, which is used to cool the cooling chamber so that the arsenic vapor separated in the reaction is condensed and deposited in the cooling chamber; The gallium arsenide waste separation and recovery device also includes a seal, which includes a first seal at the connection between the front door flange assembly and the quartz tube cavity, a second seal at the connection between the quartz tube cavity and the cooling cavity, and a third seal at the connection between the cooling cavity and the vacuum pump group; The sealing member is a heat-resistant fluorine rubber ring; The gallium arsenide waste separation and recovery device also includes a pressure detection unit connected to the furnace chamber and an arsenic content automatic detection unit connected to the cooling chamber; The gallium arsenide waste separation and recovery device also includes a control unit and an execution unit, wherein the control unit is respectively connected to the pressure detection unit, the arsenic content automatic detection unit, and the execution unit for control; the execution unit includes a mechanical arm, a temperature sensor, a heating furnace power switch controller, and an electromagnetic door lock arranged at the opening of the material taking cavity. The gallium arsenide waste separation and recovery method comprises the following steps: 1) transporting gallium arsenide waste into the quartz tube cavity; 2) Seal the connection between the front door assembly and the furnace chamber, and between the furnace chamber and the vacuum pump assembly through a sealing member; 3) Turn on the vacuum pump group, and when the pressure in the furnace chamber is less than a predetermined pressure, start the heating furnace to decompose the gallium arsenide in the gallium arsenide waste to generate liquid gallium and gaseous arsenic; at the same time, turn on the control unit and the execution unit, and the control unit obtains arsenic content data from the arsenic content automatic detection unit once every 1-5 minutes, and when the arsenic content data obtained for three consecutive times no longer increases, or when the temperature is heated to a predetermined temperature, start the execution unit to make the heating furnace perform heat preservation operation for a predetermined time; 4) Cool naturally under the pressure to recover gallium and arsenic.

2. The gallium arsenide waste separation and recovery method according to claim 1, characterized in that: The predetermined pressure is 1-10 Pa, the predetermined temperature is 800-1050° C., and the predetermined time is 1-4 hours.

3. The gallium arsenide waste separation and recovery method according to claim 1, characterized in that: Before opening the material taking chamber when recovering arsenic, the arsenic content automatic detection unit is turned on to automatically detect the content of gaseous arsenic in the furnace chamber. Before the content of gaseous arsenic is less than the predetermined safety content, the electromagnetic door lock is automatically locked and cannot be opened to ensure safety.

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