A system and method for treating tungsten hexafluoride synthesis tail gas

Abstract

The present application relates to a kind of system for processing tungsten hexafluoride synthesis tail gas, including intake pipeline;The one end of the intake pipeline is communicated with tungsten hexafluoride synthesis tail gas discharge pipe, and the other end of the intake pipeline is divided into two-way pipeline, and two-way pipeline is connected adsorption tower A and adsorption tower B respectively, and the adsorption tower A and adsorption tower B are arranged in parallel, and the top of the adsorption tower A and adsorption tower B is connected waste gas absorption tower, and the bottom of the adsorption tower A and adsorption tower B is connected plasma reactor, and the outlet of the plasma reactor is connected product collection tank.The present application relates to a kind of method for processing tungsten hexafluoride synthesis tail gas, including tail gas absorption and adsorption tower regeneration step.The present application realizes trace NF3 and high-purity tungsten powder reaction, further recovers NF3 in tail gas, reduces WF6 production cost and tail gas processing cost.

Description

Technical Field

[0001] This invention belongs to the field of exhaust gas treatment technology, specifically relating to a system and method for treating exhaust gas from tungsten hexafluoride synthesis. Background Technology

[0002] Tungsten hexafluoride (WF6) is primarily used as a raw material in the tungsten chemical vapor deposition (CVD) process in the electronics industry. WSi2, made from WF6, can be used as wiring material in large-scale integrated circuits (LSI). It can also serve as a raw material for semiconductor electrodes, a fluorinating agent, a polymerization catalyst, and an optical material. With the rapid development of the global electronics industry, the demand for WF6 is showing a steady and rapid growth trend.

[0003] Currently, tungsten hexafluoride (WF6) synthesis mainly uses nitrogen trifluoride or fluorine as a fluorinating agent to react with tungsten. Chinese patent CN101070189B discloses a method for preparing tungsten hexafluoride gas. This method involves mixing nitrogen trifluoride with high-purity nitrogen and then feeding it into a pyrolysis unit for cracking. The resulting gas then reacts with the raw material tungsten in a reactor. The resulting tungsten hexafluoride gas is collected by liquefaction in a cryogenic collector. Because nitrogen trifluoride has higher safety than fluorine, most domestic tungsten hexafluoride producers use nitrogen trifluoride in their synthesis. However, during this process, the nitrogen trifluoride may not react completely, resulting in 5%–12% nitrogen trifluoride in the exhaust gas after cryogenic cooling and separation; a small amount of WF6 may also be present.

[0004] Nitrogen trifluoride (NDF) emissions result in some waste, and more importantly, NDF is a greenhouse gas. With increasing environmental regulations, NDF needs to be treated before emission to meet fluoride emission standards. Currently, NDF emission treatment generally employs low-temperature recovery, thermal decomposition, or plasma pyrolysis methods. Low-temperature recovery uses liquid nitrogen to cool and absorb the NDF tail gas, but this method is complex, cumbersome, and energy-intensive, making it unsuitable for recovering small amounts of NF3 from tungsten hexafluoride synthesis tail gas. Chinese patent CN116425118A discloses a method for producing high-purity fluorine gas from NDF pyrolysis and its pyrolysis reactor, which uses a thermal decomposition method. Thermal decomposition typically involves high-temperature decomposition, but this method results in rapid catalyst deactivation, high energy consumption, and cannot continuously process the tail gas continuously emitted from tungsten hexafluoride synthesis for extended periods. Plasma pyrolysis, on the other hand, results in high energy consumption and production costs due to the low NF3 content and predominantly N2 content in the synthesis tail gas. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a system and method for treating the tail gas of tungsten hexafluoride synthesis, in order to solve the problems of complex process, cumbersome operation, high energy consumption, high cost, and inability to continuously treat the tail gas continuously emitted from tungsten hexafluoride synthesis for a long time.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A system for treating tungsten hexafluoride synthesis tail gas includes an inlet pipe; one end of the inlet pipe is connected to a tungsten hexafluoride synthesis tail gas emission pipe, and the other end of the inlet pipe is divided into two pipelines, which are respectively connected to adsorption tower A and adsorption tower B. Adsorption tower A and adsorption tower B are arranged in parallel. The top of adsorption tower A and adsorption tower B are both connected to a waste gas absorption tower, and the bottom of adsorption tower A and adsorption tower B are both connected to a plasma reactor. The outlet of the plasma reactor is connected to a product collection tank.

[0008] Preferably, the adsorption tower A and adsorption tower B are filled with 5A molecular sieve packing material, and the tower body is provided with a cold insulation layer.

[0009] Preferably, the two pipelines of the air intake pipe are respectively equipped with an inlet valve for adsorption tower A and an inlet valve for adsorption tower B;

[0010] The top of adsorption tower A is equipped with a pressure detection point P1 and a temperature detection point T1; the top of adsorption tower B is equipped with a pressure detection point P2 and a temperature detection point T2.

[0011] Adsorption tower A is equipped with an outlet valve at the top of adsorption tower A, and adsorption tower B is equipped with an outlet valve at the top of adsorption tower B. The outlets of the outlet valves of adsorption tower A and adsorption tower B are connected to the waste gas absorption tower.

[0012] The exhaust gas absorption tower is equipped with an alkaline spray system inside and a chimney outlet at the top.

[0013] Preferably, the lower part of the adsorption tower A is provided with a regeneration pipeline, and the regeneration pipeline is provided with a regeneration valve for adsorption tower A. The outlet of the regeneration valve for adsorption tower A is connected to the inlet of the vacuum pump and a bypass pipeline, and a bypass valve is provided on the bypass pipeline.

[0014] The lower part of adsorption tower B is equipped with a regeneration pipeline, and the regeneration valve of adsorption tower B is installed on the regeneration pipeline. The outlet of the regeneration valve of adsorption tower B is connected to the inlet of the vacuum pump and the bypass pipeline.

[0015] Preferably, the vacuum pump outlet is equipped with a vacuum pump outlet valve;

[0016] The vacuum pump outlet pipe and bypass pipe are connected to the plasma reactor after they merge.

[0017] Preferably, the product collection tank includes product collection tank A and product collection tank B, the plasma reactor outlet is connected to product collection tank A and product collection tank B respectively, an inlet valve for product collection tank A is provided between the plasma reactor and product collection tank A, and an inlet valve for product collection tank B is provided between the plasma reactor and product collection tank B.

[0018] Preferably, product collection tank A and product collection tank B have the same structure, both being jacketed low-temperature collection tanks with heating tiles at the bottom.

[0019] Preferably, the top of the product collection tank A is provided with a product outlet pipe and a tail gas emission pipe. The product outlet pipe at the top of the product collection tank A is equipped with a product outlet valve, and the tail gas emission pipe at the top of the product collection tank A is equipped with a tail gas emission outlet valve.

[0020] Product collection tank B is equipped with a product outlet pipe and a tail gas emission pipe at the top. The product outlet pipe at the top of product collection tank B is equipped with a product outlet valve, and the tail gas emission pipe at the top of product collection tank B is equipped with a tail gas emission outlet valve.

[0021] Both the exhaust gas outlet valves of product collection tank A and product collection tank B are connected to the waste gas absorption tower.

[0022] A method for treating tail gas from tungsten hexafluoride synthesis includes the following steps:

[0023] S1. Tail Gas Absorption: Open the inlet valve of adsorption tower A and the outlet valve of top adsorption tower A to pass the tail gas from the tungsten hexafluoride synthesis reaction into adsorption tower A. NF3 and WF6 in the tail gas are adsorbed on the surface of the adsorbent. Nitrogen enters the waste gas absorption tower through the top pipe and is discharged from the top chimney. When the pressure at the top of waste gas adsorption tower A reaches a certain value, the adsorbent is saturated. Close the inlet valve of adsorption tower A and the outlet valve of top adsorption tower A, and adsorption tower A enters the regeneration stage. At the same time, open the inlet valve of adsorption tower B and the outlet valve of top adsorption tower B, and adsorption tower B enters the adsorption stage.

[0024] S2. Adsorption Tower Regeneration: Tungsten powder is added to the plasma reactor, the plasma reactor is started, and the regeneration valve and bypass valve at the bottom of adsorption tower A are opened. Fluorine-containing gas in adsorption tower A enters the plasma reactor and undergoes ionization at high temperature, decomposing into F... - The product WF6 is generated by reacting with tungsten powder. WF6 is then carried by the airflow into a low-temperature product collection tank for condensation and collection, and is separated from nitrogen. The separated nitrogen enters the waste gas absorption tower and is discharged from the top chimney.

[0025] When the pressure of adsorption tower A drops to atmospheric pressure, close the bypass valve and turn on the vacuum pump to further achieve negative pressure desorption and regeneration of adsorption tower A. When the pressure of adsorption tower reaches -0.098MPa, continue to evacuate for 1 hour and then turn off the plasma reactor and vacuum pump. The regeneration of adsorption tower A is over, and it is ready to enter the next absorption stage.

[0026] S3. Alternating operation of adsorption towers: Adsorption tower A and adsorption tower B repeat the above steps and alternate operation.

[0027] Preferably, in step S1, when the pressure at the top of the waste gas adsorption tower A reaches 0.18MPa-0.23MPa, the adsorbent becomes saturated, and adsorption tower A is shut down.

[0028] The temperature at which S2 is collected by condensation is -160 to -140℃.

[0029] The beneficial effects of this invention are:

[0030] This invention utilizes molecular sieve adsorption to separate NF3 and N2 under low-temperature conditions, effectively avoiding the explosion risk caused by adsorption exotherm; it utilizes low-temperature negative pressure desorption to ensure the safe operation of the adsorption system; at the same time, it reduces the amount of tail gas introduced into the plasma reactor, and uses plasma technology to ionize NF3 under low-temperature and negative pressure conditions, realizing the reaction of trace amounts of NF3 with high-purity tungsten powder, further recovering NF3 in the tail gas, and reducing the production cost of WF6 and the cost of tail gas treatment. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the system structure of the present invention;

[0032] Among them, 0. Synthesis reaction tail gas pipe; 1. Adsorption tower A; 2. Adsorption tower B; 3. Vacuum pump; 4. Plasma reactor; 5. Product collection tank A; 6. Product collection tank B; 7. Inlet valve of adsorption tower A; 8. Outlet valve of adsorption tower A; 9. Regeneration valve of adsorption tower A; 10. Inlet valve of adsorption tower B; 11. Outlet valve of adsorption tower B; 12. Regeneration valve of adsorption tower B; 13. Bypass valve; 14. Inlet valve of product collection tank A; 15. Inlet valve of product collection tank B; 16. Tail gas discharge outlet valve of product collection tank A; 17. Tail gas discharge outlet valve of product collection tank B; 18. Vacuum pump outlet valve; 19. Tail gas absorption tower; 20. Product outlet valve of product collection tank A; 21. Product outlet valve of product collection tank B; 22. Heating tile. Detailed Implementation

[0033] Equipment Example

[0034] like Figure 1As shown, a system for treating tungsten hexafluoride synthesis tail gas includes an inlet pipe 0; one end of the inlet pipe 0 is connected to the tungsten hexafluoride synthesis tail gas discharge pipe, and the other end of the inlet pipe 0 is divided into two pipelines. An inlet valve 7 for adsorption tower A and an inlet valve 10 for adsorption tower B are respectively installed on the two pipelines of the inlet pipe 0. The two pipelines are connected to adsorption tower A1 and adsorption tower B2 respectively. A pressure detection point P1 and a temperature detection point T1 are provided at the top of adsorption tower A1; a pressure detection point P2 and a temperature detection point T2 are provided at the top of adsorption tower B2; the adsorption towers A1 and B2 are filled with 5A molecular sieve packing material, and the tower bodies are provided with a cold insulation layer. The adsorption towers A1 and B2 are connected in parallel. The tops of both adsorption towers A1 and B2 are connected to a waste gas absorption tower 19. Adsorption tower A1 has an outlet valve 8 at its top, and adsorption tower B2 has an outlet valve 11 at its top. The outlets of both outlet valves 8 and 11 are connected to the waste gas absorption tower 19. The waste gas absorption tower 19 has an alkaline spray system inside and a chimney outlet at its top. Adsorption tower A1 has a regeneration pipe at its lower part, with an adsorption tower A regeneration valve 9 installed on it. The outlet of adsorption tower A regeneration valve 9 is connected to the inlet of vacuum pump 3 and a bypass pipe, with a bypass valve 13 installed on the bypass pipe. Adsorption tower B2 also has a regeneration pipe at its lower part, with an adsorption tower B regeneration valve 12 installed on it. The outlet of adsorption tower B regeneration valve 12 is connected to the inlet of vacuum pump 3 and a bypass pipe. Vacuum pump 3 has an outlet valve 18 at its outlet. The outlet pipe of vacuum pump 3 and the bypass pipe merge and connect to the plasma reactor 4. Both adsorption towers A1 and B2 are connected to plasma reactor 4 at their bottoms. The outlet of plasma reactor 4 is connected to product collection tanks, including product collection tank A5 and product collection tank B6. Product collection tanks A5 and B6 have the same structure, both being jacketed low-temperature collection tanks with heating tiles 22 at the bottom. The outlet of plasma reactor 4 is connected to product collection tanks A5 and B6 respectively. An inlet valve 14 for product collection tank A is installed between plasma reactor 4 and product collection tank A5, and an inlet valve 15 for product collection tank B is installed between plasma reactor 4 and product collection tank B6. Product collection tank A5 is equipped with a product outlet pipe and a tail gas emission pipe at its top. The product outlet pipe at the top of product collection tank A5 is equipped with a product outlet valve 20, and the tail gas emission pipe at the top of product collection tank A5 is equipped with a tail gas emission outlet valve 16. Product collection tank B6 is equipped with a product outlet pipe and a tail gas emission pipe at its top. The product outlet pipe at the top of product collection tank B6 is equipped with a product outlet valve 21, and the tail gas emission pipe at the top of product collection tank B6 is equipped with a tail gas emission outlet valve 17. Both the tail gas emission outlet valve 16 of product collection tank A and the tail gas emission outlet valve 17 of product collection tank B are connected to the waste gas absorption tower 19.

[0035] The following method embodiments all use the system of the device example.

[0036] Method Example 1

[0037] A method for treating the tail gas from tungsten hexafluoride synthesis is as follows: The inlet valve 7 and outlet valve 8 of adsorption tower A1 are opened, allowing the tail gas from the tungsten hexafluoride synthesis reaction to be introduced into adsorption tower A1. The tail gas pressure is 0.2 MPa, the temperature is -78℃, and the flow rate is controlled at 50 L / min. The tail gas contains 8.35% NF3, 86.76% N2, 4.68% NxOy, and 0.21% WF6. NF3 and WF6 are adsorbed onto the surface of the adsorbent, and a large amount of nitrogen gas is discharged through the top pipe of adsorption tower A1. Analysis of the discharged gas shows an NF3 content of 2.5 ppm, a NO content of 1.25 ppm, and a NO2 content of 1.75 ppm.

[0038] When the pressure at the top of adsorption tower A1 reaches 0.18MPa, close the inlet valve 7 and outlet valve 8 of adsorption tower A1, and simultaneously open the inlet valve 10 and outlet valve 11 of adsorption tower B2. Adsorption tower A1 enters the regeneration stage, and adsorption tower B2 enters the adsorption stage.

[0039] A certain amount of tungsten powder with a purity of 99.9% is added to plasma reactor 4, and plasma reactor 4 is started. The regeneration valve 9 and bypass valve 13 at the bottom of adsorption tower A1 are opened, allowing fluorine-containing gas from adsorption tower A1 to enter plasma reactor 4 at a flow rate controlled at 50 L / min. The fluorine content is 85% NF3 and 4.35% NxOy. The voltage of plasma reactor 4 is 100V, the pressure is 0.01 MPa, and the temperature is 25℃. The F- from the decomposition of NF3 reacts with the tungsten powder to produce WF6. WF6 is carried by the gas flow into the low-temperature product collection tank 5 for condensation and collection, with the temperature of the collection tank controlled at -160 to -140℃.

[0040] When the pressure in adsorption tower A1 drops to 0.002 MPa, bypass valve 13 is closed, vacuum pump outlet valve 18 is opened, and vacuum pump 3 is started. The gas outlet from vacuum pump 3 enters plasma reactor 4, where the F- from NF3 decomposes reacts with tungsten powder to produce WF6. WF6 is carried by the gas flow into low-temperature product collection tank A5 for condensation and collection, with the tank temperature controlled at -160 to -140°C. Uncondensed N2 enters waste gas absorption tower 19 and is discharged from the top chimney, with an F- content of 3.2 ppm in the exhaust gas. Product collection tanks A5 and B6 are used alternately; when product collection tank A5 reaches its limit, the system switches to product collection tank B6 for further collection.

[0041] Method Example 2

[0042] A method for treating the tail gas from tungsten hexafluoride synthesis is as follows: The inlet valve 10 and outlet valve 11 of adsorption tower B2 are opened to allow the tail gas from the tungsten hexafluoride synthesis reaction to be introduced into adsorption tower B2. The tail gas pressure is 0.25 MPa, the temperature is -80℃, and the flow rate is controlled at 50 L / min. The tail gas contains 6.55% NF3, 89.16% N2, 4.21% NxOy, and 0.18% WF6. NF3 and WF6 are adsorbed onto the surface of the adsorbent, and a large amount of nitrogen is discharged through the top pipe of adsorption tower B2. Analysis of the discharged gas shows an NF3 content of 2 ppm, a NO content of 1.5 ppm, and a NO2 content of 1.05 ppm.

[0043] When the pressure at the top of adsorption tower B2 reaches 0.23MPa, close the inlet valve 10 and outlet valve 11 of adsorption tower B2, and simultaneously open the inlet valve 7 and outlet valve 8 of adsorption tower A1. Adsorption tower B2 enters the regeneration stage, and adsorption tower A1 enters the adsorption stage.

[0044] A certain amount of tungsten powder with a purity of 99.9% is added to plasma reactor 4, and plasma reactor 4 is started. The regeneration valve 12 and bypass valve 13 at the bottom of adsorption tower B2 are opened, and the fluorine-containing gas in the adsorption tower enters plasma reactor 4 at a flow rate controlled at 50 L / min, containing 80% NF3 and 4.5% NxOy. The voltage of plasma reactor 4 is 100V, the pressure is 0.015 MPa, and the temperature is 28℃; the fluorine gas decomposed from NF3... - The product WF6 is generated by reacting with tungsten powder. WF6 is then carried by the airflow into the low-temperature product collection tank B6 for condensation and collection. The temperature of the collection tank is controlled at -160 to -140℃.

[0045] When the pressure in adsorption tower B2 drops to 0.0015 MPa, bypass valve 13 is closed, vacuum pump outlet valve 18 is opened, and vacuum pump 3 is started. The outlet gas of vacuum pump 3 enters plasma reactor 4, and the F decomposed from NF3... - The N2 reacts with tungsten powder to produce WF6. WF6 is then carried by the airflow into a low-temperature product collection tank B6 for condensation and collection, with the tank temperature controlled between -160°C and -140°C. Uncondensed N2 enters the waste gas absorption tower 19 and is emitted from the top chimney. The exhaust gas contains 2.5 ppm F-, 1.25 ppm NO, and 1.15 ppm NO2. Product collection tanks A5 and B6 are used alternately; when product collection tank B6 reaches its limit, the system switches to product collection tank A5.

[0046] This invention includes, but is not limited to, the above embodiments. Any equivalent substitutions or partial improvements made under the spirit and principles of this invention shall be considered to be within the scope of protection of this invention.

Claims

1. A method of treating a tungsten hexafluoride synthesis tail gas, characterized by: It includes intake pipeline (0), one end of the intake pipeline (0) is communicated with tungsten hexafluoride synthesis tail gas discharge pipe, the other end of the intake pipeline (0) is divided into two-way pipeline, two-way pipeline is connected with adsorption tower A (1) and adsorption tower B (2) respectively, adsorption tower A (1) and adsorption tower B (2) are arranged in parallel, the top of adsorption tower A (1) and adsorption tower B (2) is connected with waste gas absorption tower (19), the bottom of adsorption tower A (1) and adsorption tower B (2) is connected with plasma reactor (4), the outlet of plasma reactor (4) is connected with product collection tank; It includes the following steps: S1, tail gas absorption: open adsorption tower A inlet valve (7) and top adsorption tower A outlet valve (8) of adsorption tower A (1) inlet, the tail gas of tungsten hexafluoride synthesis reaction is passed into adsorption tower A (1), NF3 and WF6 in the tail gas are adsorbed on the surface of adsorbent, nitrogen is passed into waste gas absorption tower (19) through the top pipeline and is discharged from the top chimney, when the pressure at the top of waste gas adsorption tower A (1) reaches a certain value, the adsorbent is saturated, close adsorption tower A inlet valve (7) and top adsorption tower A outlet valve (8) of adsorption tower A (1) inlet, adsorption tower A (1) enters the regeneration stage, at the same time, open adsorption tower B inlet valve (10) and top adsorption tower B outlet valve (11) of adsorption tower B (1) inlet, adsorption tower B (2) enters the adsorption stage; S2, adsorption tower regeneration: add tungsten powder in the plasma reactor (4), start the plasma reactor (4), open the adsorption tower A (1) bottom adsorption tower A regeneration valve (9) and bypass valve (13), the fluorine-containing gas in the adsorption tower A (1) enters the plasma reactor (4) and ionizes at high temperature, and the F - React with tungsten powder to generate WF6 product; WF6 enters the low-temperature product collection tank with the gas flow and is condensed and collected, and is separated from nitrogen; the separated nitrogen enters the waste gas absorption tower (19) and is discharged from the top chimney; When the pressure of adsorption tower A (1) drops to normal pressure, close bypass valve (13), open vacuum pump (3) to make adsorption tower A (1) further realize negative pressure desorption regeneration, when the pressure of adsorption tower reaches-0.098MPa, after continuing to vacuumize for 1 hour, close plasma reactor (4) and vacuum pump (3), adsorption tower A (1) regeneration ends, and is ready for entering the next absorption stage; S3, adsorption tower alternate operation: adsorption tower A (1) and adsorption tower B (2) repeat the above steps and alternately operate repeatedly.

2. The method of claim 1, wherein: The inside of adsorption tower A (1) and adsorption tower B (2) is filled with 5A molecular sieve packing, and the tower body is provided with a cold insulation layer.

3. The method of claim 2, wherein: The two-way pipelines of the intake pipeline (0) are respectively provided with adsorption tower A inlet valve (7) and adsorption tower B inlet valve (10); The top of adsorption tower A (1) is provided with pressure detection point P1 and temperature detection point T1, and the top of adsorption tower B (2) is provided with pressure detection point P2 and temperature detection point T2. The top of adsorption tower A (1) is provided with adsorption tower A outlet valve (8), and the top of adsorption tower B (2) is provided with adsorption tower B outlet valve (11), and the outlets of adsorption tower A outlet valve (8) and adsorption tower B outlet valve (11) are connected with waste gas absorption tower (19). The inside of waste gas absorption tower (19) is provided with alkali liquor spraying, and the top is provided with chimney discharge port.

4. The method of claim 2, wherein: The lower part of adsorption tower A (1) is provided with a regeneration pipeline, the regeneration pipeline is provided with adsorption tower A regeneration valve (9), the outlet of adsorption tower A regeneration valve (9) is connected with the inlet of vacuum pump (3) and bypass pipeline, and the bypass pipeline is provided with bypass valve (13). The lower part of adsorption tower B (2) is provided with a regeneration pipeline, the regeneration pipeline is provided with adsorption tower B regeneration valve (12), and the outlet of adsorption tower B regeneration valve (12) is connected with the inlet of vacuum pump (3) and bypass pipeline.

5. The method of claim 4, wherein: The vacuum pump (3) outlet is provided with a vacuum pump outlet valve (18); The vacuum pump (3) outlet pipeline and the bypass pipeline are connected to the plasma reactor (4).

6. The method of claim 5, wherein: The product collection tank includes a product collection tank A (5) and a product collection tank B (6), the plasma reactor (4) outlet is connected to the product collection tank A (5) and the product collection tank B (6) respectively, the product collection tank A inlet valve (14) is arranged between the plasma reactor (4) and the product collection tank A (5), and the product collection tank B inlet valve (15) is arranged between the plasma reactor (4) and the product collection tank B (6).

7. The method of claim 6, wherein: The product collection tank A (5) and the product collection tank B (6) are of the same structure and are jacketed low-temperature collection tanks, and are provided with heating tiles (22) at the bottom.

8. The method of claim 6, wherein: The product collection tank A (5) is provided with a product outlet pipeline and a tail gas discharge pipeline at the top, the product collection tank A product outlet valve (20) is arranged on the product outlet pipeline at the top of the product collection tank A (5), and the product collection tank A tail gas discharge outlet valve (16) is arranged on the tail gas discharge pipeline at the top of the product collection tank A (5); The product collection tank B (6) is provided with a product outlet pipeline and a tail gas discharge pipeline at the top, the product collection tank B product outlet valve (21) is arranged on the product outlet pipeline at the top of the product collection tank B (6), and the product collection tank B tail gas discharge outlet valve (17) is arranged on the tail gas discharge pipeline at the top of the product collection tank B (6); The product collection tank A tail gas discharge outlet valve (16) and the product collection tank B tail gas discharge outlet valve (17) are connected to the waste gas absorption tower (19).

9. The method for treating the tail gas of tungsten hexafluoride synthesis according to claim 1, characterized in that, In S1, when the pressure at the top of the waste gas adsorption tower A (1) reaches 0.18-0.23 MPa, the adsorbent is saturated, and the adsorption tower A (1) is closed; In S2, the temperature of the condensed collection is-160--140 ℃.

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