A novel method and apparatus for resource conversion of sulfur hexafluoride

Abstract

The application discloses a novel method and device for resource conversion of sulfur hexafluoride. The method comprises the following steps: firstly, performing primary discharge treatment on SF6 to dissociate SF6 into fluorine atoms and low-fluorine sulfides; secondly, performing fluorination reaction of the fluorine atoms and the low-fluorine sulfides with tungsten to convert the fluorine atoms and the low-fluorine sulfides into WF6 and reduce sulfur into elemental sulfur; thirdly, controlling the fluorination reaction temperature to be 120-160 DEG C to make the generated elemental sulfur into liquid state, so that the elemental sulfur is conveniently collected; fourthly, condensing mixed gas containing WF6, collecting the liquefied WF6, mixing the condensed mixed gas with water vapor, and performing secondary discharge treatment on the mixed gas containing water vapor; under the action of the water vapor, the mixed gas is further degraded, and the degradation products tend to be SO2 and HF; fifthly, separating the SO2 and the HF; sixthly, treating the HF by using a "hydrogen fluoride-liquid ammonia" liquid phase method to obtain ammonium fluoride and ammonium bifluoride; and seventhly, treating the SO2 by using a wet ammonia method to obtain ammonium sulfite and ammonium sulfate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of resource utilization of sulfur hexafluoride, and particularly relates to a novel method and device for resource utilization and conversion of sulfur hexafluoride. BACKGROUND

[0002] Sulfur hexafluoride (SF6) is a colorless, odorless, non-toxic, non-flammable, and non-explosive inert gas with a very stable molecular structure. Due to its excellent physical and chemical properties, SF6 is widely used in the power equipment, metal smelting, semiconductor manufacturing, and aerospace industries, among which the use of SF6 in the electrical field accounts for 80% of the total annual use of SF6. However, SF6 has strong infrared radiation absorption capacity and is a strong greenhouse gas with a global warming potential (GWP) of 23500 times that of CO2. In the past five years, the content of SF6 in the atmosphere has increased by 20%, and scientists estimate that its atmospheric content will increase by 75% by 2030.

[0003] However, with the rapid economic development, the demand for SF6 in human society will only be greater than before, and humans are facing increasingly severe SF6 governance problems. In recent years, replacing SF6 with environmentally friendly gases is the trend of the times, but in the field of electric power, its effect is not as good as SF6, and the use of SF6 in today's power system is still huge. At present, more than 10000t of SF6 gas is used every year in the world, of which more than 80% is used in gas-insulated equipment in the power industry. The damage, leakage, and maintenance of gas-insulated equipment will face the problem of SF6 gas treatment. Therefore, how to recycle and discharge SF6 waste gas has become a hot issue in the field of electric power environmental protection.

[0004] In recent years, the main means of degrading SF6 gas include thermal catalytic degradation, photolysis, electrolysis, low-temperature plasma method, etc. Among them, the low-temperature plasma treatment technology has less stringent requirements on reaction conditions compared to other methods, has the advantages of convenience, low energy consumption, and more thorough treatment, and has a very broad application prospect. At the same time, related technologies have been reported to be applied in the treatment of SF6 waste gas.

[0005] At present, the method for treating SF6 gas mainly collects, purifies, and stores SF6 gas, and uses heat cracking and water washing, etc. to treat SF6 waste gas. For the discharge treatment process of SF6, the mainstream method is to use dielectric barrier discharge, microwave discharge, etc. to form a plasma region in a specified reactor to decompose and treat SF6 gas. SF6 needs to be diluted during the treatment process, and the dilution gas is commonly nitrogen, air, etc. Ultimately, more than 90% of the degradation effect can be achieved.

[0006] In essence, SF6 is a molecule with great recycling value and resource conversion potential, and its sulfur and fluorine elements can be used to prepare various sulfur-containing and fluorine-containing industrial raw materials. However, existing SF6 degradation strategies focus on performance improvement, and the toxic and corrosive degradation tail gas such as SO2, SOF2, SO2F2 and HF produced is usually neutralized and absorbed by lye, and the solid waste produced needs to be landfilled for treatment, which consumes a large amount of industrial raw materials and also wastes sulfur and fluorine resources. SUMMARY

[0007] In order to solve the problems existing in the prior art, the present application provides a new method and device for resource conversion of sulfur hexafluoride. The present application not only realizes the degradation of SF6, but also synthesizes industrial raw materials such as tungsten hexafluoride, ammonium fluoride and ammonium bifluoride using SF6 as a fluorine source, and synthesizes industrial raw materials such as elemental sulfur, ammonium sulfate and ammonium sulfite using SF6 as a sulfur source, thereby providing a new idea and method for resource conversion of SF6 waste gas.

[0008] The technical scheme adopted by the present application to achieve the above-mentioned purposes is as follows:

[0009] A new method for resource conversion of sulfur hexafluoride, characterized in that it comprises the following steps:

[0010] S1, filling tungsten metal in the discharge area of the plasma reactor, or introducing tungsten powder into the discharge area of the plasma reactor;

[0011] S2, introducing background gas and sulfur hexafluoride gas into the discharge area of the first-stage plasma reactor, the background gas being ionized into plasma, and the sulfur hexafluoride gas being ionized into fluorine atoms and low-fluorine sulfides after being activated by the plasma;

[0012] S3, at 120-160℃, the fluorine atoms and low-fluorine sulfides react with the tungsten metal or tungsten powder to generate a mixed gas I containing tungsten hexafluoride gas and liquid elemental sulfur, and the liquid elemental sulfur is collected;

[0013] S4, condensing the mixed gas I containing tungsten hexafluoride gas, and collecting the liquid tungsten hexafluoride gas after condensation;

[0014] S5, mixing the condensed mixed gas I with water vapor to obtain a mixed gas II;

[0015] S6, introducing the mixed gas II into a second-stage plasma reactor with a catalyst filled in the discharge area, and under the action of the catalyst, the mixed gas II is ionized and degraded into a mixed gas III containing SO2 gas and HF gas;

[0016] S7, condensing the mixed gas III again, condensing the HF gas into liquid state for collection, and treating the collected liquid hydrogen fluoride by using a "hydrogen fluoride-liquid ammonia" liquid phase method to obtain ammonium fluoride and / or ammonium bifluoride;

[0017] S8, treating the mixed gas IV containing SO2 after condensation in step S7 by using a wet ammonia method to obtain ammonium sulfate and / or ammonium sulfite.

[0018] Further, the background gas is argon.

[0019] Further, in step S1, if tungsten powder is introduced into the discharge area of the primary plasma reactor, the background gas and sulfur hexafluoride gas are also introduced into the discharge area of the primary plasma reactor.

[0020] Further, the catalyst is γ-alumina or glass beads.

[0021] Further, in step S7, before condensing the mixed gas III, the mixed gas III is heated to make S2F 10 gas pyrolyze into SF6 and SF4 gas.

[0022] A novel device for resource conversion of sulfur hexafluoride, comprising a sulfur hexafluoride gas supply unit, a background gas supply unit, a mixing unit, a primary plasma reactor, a condensation unit I, a water vapor generator, a secondary plasma reactor, a condensation unit II, a "hydrogen fluoride-liquid ammonia" liquid phase treatment unit, and a wet ammonia treatment unit. The sulfur hexafluoride gas supply unit and the background gas supply unit are connected to the mixing unit, which mixes the sulfur hexafluoride gas and the background gas. The mixing unit is connected to the inlet of the primary plasma reactor, which is placed vertically or inclined. The primary plasma reactor is provided with a sulfur single collector at the bottom, which is located below the primary plasma reactor. The primary plasma reactor is provided with a first liquid outlet at the bottom, and the sulfur single collector is in communication with the first liquid outlet. The primary plasma reactor or the sulfur single collector is provided with a first gas outlet.

[0023] The condensation unit I comprises a first condenser and a first liquid collector. The condenser has a second gas outlet and a second liquid outlet. The first liquid collector is in communication with the second liquid outlet. The first gas outlet is in communication with the inlet of the first condenser. The second gas outlet is in communication with the inlet of the water vapor generator. The outlet of the water vapor generator is in communication with the inlet of the secondary plasma generator. The secondary plasma generator is filled with a catalyst.

[0024] The condensing unit II comprises a second condenser with a third gas outlet and a third liquid outlet, and a second liquid collector in communication with the second liquid outlet, the second condenser inlet is in communication with the secondary plasma reactor outlet, the second liquid collector is in communication with the third liquid outlet, the second liquid collector is connected with the hydrogen fluoride-liquid ammonia liquid phase treatment unit, and the third gas outlet is connected with the wet ammonia treatment unit.

[0025] The background gas supply unit comprises a background gas cylinder, a second supply branch pipe, a second pressure reducing valve and a second electromagnetic valve, one end of the second supply branch pipe is connected with the inert gas cylinder, and the second pressure reducing valve and the second electromagnetic valve are installed on the second supply branch pipe.

[0026] The tungsten powder generator comprises a blast box and a tungsten powder conveying pipe, the blast box comprises a blast box body and a blast fan, the blast fan is installed on the blast box body, one end of the tungsten powder conveying pipe is connected with the blast box body outlet, and the other end of the tungsten powder conveying pipe is connected with the first plasma reactor inlet.

[0027] The inner cavity of the inner shell is provided with a partition plate at the lower part, and the space enclosed by the partition plate, the inner shell and the outer shell is a liquid collector, and the bottom of the liquid collector is provided with a fourth liquid outlet.

[0028] The water vapor generator comprises a water vapor generation chamber, an ultrasonic atomization sheet and a first liquid level meter, the ultrasonic atomization sheet is installed in the water vapor generation chamber, and the first liquid level meter is installed on the side wall of the water vapor generation chamber.

[0029] The heating unit comprises a heater, the secondary plasma reactor outlet is in communication with the heater inlet, and the heater outlet is in communication with the second condenser inlet.

[0030] Compared with the prior art, the application has the following advantages and beneficial effects:

[0031] 1. The background gas of this invention is easily excited and ionized in the discharge reaction region to generate high-energy electrons, which collide with and activate SF6, causing it to break bonds and decompose to generate fluorine particles and low-fluorine sulfides (SF6). x Without background gas, SF6 gas is difficult to ionize and decompose.

[0032] 2. The background gas in this invention also plays a role in diluting SF6, enabling precise dilution ratios and thus improving the degradation effect of SF6.

[0033] 3. This invention first performs a primary discharge treatment on SF6, causing it to dissociate into fluorine atoms and low-fluorine sulfides. The fluorine atoms and low-fluorine sulfides then undergo a fluorination reaction with metallic tungsten, converting the fluorine atoms and low-fluorine sulfides into WF6 while simultaneously reducing sulfur to elemental sulfur. The fluorination reaction temperature is controlled at 120-160℃ to ensure the generated elemental sulfur is liquid, facilitating its collection. The WF6-containing mixed gas is then condensed, and the liquefied WF6 is separated and collected. The condensed mixed gas is then mixed with water vapor, and the water vapor-containing mixed gas undergoes a secondary discharge treatment. Under the action of water vapor, the mixed gas further degrades, with the degradation products becoming more predominantly SO2 and HF. SO2 and HF are then separated. The separated HF is processed using a "hydrogen fluoride-liquid ammonia" liquid-phase method to obtain industrial raw materials ammonium fluoride and ammonium hydrogen fluoride. The separated SO2 is processed using a wet ammonia method to obtain industrial raw materials ammonium sulfite and ammonium sulfate.

[0034] 4. In this invention, the plasma reactor is placed tilted or vertically, and liquid elemental sulfur can flow downward along the tube wall of the plasma reactor. A sulfur collection area is set at the bottom of the plasma reactor to collect the generated elemental sulfur.

[0035] 5. The condenser temperature of the present invention can be adjusted according to the product, and the temperature can be controlled between 5℃ and 15℃. The generated WF6 gas can be cooled down to become liquid, and the WF6 liquid can be collected for long-term storage, transportation and purification.

[0036] 6. This invention is the first to propose using non-toxic SF6 waste gas to replace highly toxic fluorine gas in the reaction with W under plasma conditions to generate WF6. Compared with the traditional method of preparing WF6 with metallic W and fluorine gas (F2) at high temperature, the reaction temperature is greatly reduced, thereby greatly reducing energy consumption. Moreover, the operation is safe, realizing the utilization of sulfur and fluorine resources of SF6 and solving the problem of low SF6 conversion rate. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a method for the resource utilization of sulfur hexafluoride.

[0038] Among them, 1-gas distributor, 2-blower box, 3-blower fan, 4-tungsten powder conveying pipe, 5-first-stage plasma reactor, 6-quartz wool, 7-sedimentation tank, 8-inner shell, 9-outer shell, 10-main air inlet pipe, 11-liquid outlet branch pipe, 12-gas outlet branch pipe, 13-partition plate, 14-liquid collection chamber, 15-collection port, 16-first injection port, 17-discharge port, 18-water vapor generation chamber, 19-ultrasonic atomizing plate, 20-first liquid level gauge, 21-second injection port, 22-second-stage plasma reactor, 23-γ-alumina, 24-heater, 25-heating gas chamber, 26-second condenser, 27-collection tank. Detailed Implementation

[0039] The novel apparatus for resource-based conversion of sulfur hexafluoride according to the present invention will now be described in detail with reference to the accompanying drawings.

[0040] Example 1

[0041] The structure of the novel resource-based sulfur hexafluoride conversion device provided in this embodiment is as follows: Figure 1 As shown, it includes a sulfur hexafluoride gas supply unit, a background gas supply unit, a mixing unit, a tungsten powder generator, a primary plasma reactor 5, a condensation unit I, a water vapor generator, a secondary plasma reactor 22, a heater 24, a condensation unit II, a "hydrogen fluoride-liquid ammonia" liquid phase treatment unit, and a wet ammonia treatment unit.

[0042] Sulfur hexafluoride gas supply unit ( Figure 1 (Not shown in the diagram) Includes a sulfur hexafluoride (SF6) cylinder, a first gas supply branch pipe, a first pressure reducing valve, and a first solenoid valve. The inlet of the first gas supply branch pipe is connected to the SF6 cylinder. The first pressure reducing valve and the first solenoid valve are respectively installed on the first gas supply branch pipe, and are distributed sequentially along the direction from the inlet to the outlet of the first gas supply branch pipe. The SF6 in the cylinder is depressurized by the first pressure reducing valve before entering the gas mixing device.

[0043] Inert gas supply unit ( Figure 1 (Not shown in the diagram) This includes an argon cylinder, a second gas supply branch pipe, a second pressure reducing valve, and a second solenoid valve. The inlet of the second gas supply branch pipe is connected to the argon cylinder. The second pressure reducing valve and the second solenoid valve are respectively installed on the second gas supply branch pipe, and are distributed sequentially along the direction from the inlet to the outlet of the second gas supply branch pipe. The argon gas in the argon cylinder is reduced in pressure by the second pressure reducing valve before entering the gas mixing instrument.

[0044] The mixing unit is a gas mixer 1, which is a GC500 four-channel intelligent dynamic gas mixer manufactured by Jiangsu Tanggao Electric. The outlet of the first gas supply branch pipe and the outlet of the second gas supply branch pipe are respectively connected to the two inlets of the gas mixer 1, and the outlet of the gas mixer 1 is connected to the inlet of the first-stage plasma reactor 5.

[0045] The tungsten powder generator comprises a blast box and a tungsten powder conveying pipe 4, the blast box comprises a blast box body 2 and a blast fan 3 installed on the side wall of the blast box body 2, one end of the tungsten powder conveying pipe 4 is connected with the outlet of the blast box body 2, and the other end of the tungsten powder conveying pipe 4 is connected with the inlet of the primary plasma reactor 5. The tungsten powder is placed in the blast box body 2 at a position opposite to the blast fan, and the outlet of the blast box body 2 is opposite to the blast fan. When the blast fan works, the tungsten powder is blown into the tungsten powder conveying pipe 4, and then enters the primary plasma reactor.

[0046] The primary plasma reactor 5 is a coaxial double-layer dielectric barrier discharge reactor, and is vertically placed. The inlet of the primary plasma reactor 5 is located at the top center of the primary plasma reactor 5, and the outlet of the primary plasma reactor 5 is located at the bottom center of the primary plasma reactor 5. A mass of quartz wool 6 is arranged at the discharge area of the primary plasma reactor 5 close to the bottom of the primary plasma reactor 5, which prevents the tungsten powder from entering the subsequent device to cause the blocking phenomenon. The outer side of the discharge area of the primary plasma reactor 5 is filled with the quartz wool 6, which functions to heat preservation of the primary plasma reactor, so that the temperature of the primary plasma reactor is maintained at 120-160℃.

[0047] A deposition pool 7 for collecting elemental sulfur is arranged at the bottom of the primary plasma reactor 5, the deposition pool 7 is in a cylindrical shape, the primary plasma reactor 5 and the deposition pool 7 are coaxially arranged, the deposition pool 7 is located directly below the primary plasma reactor 5, and the deposition pool 7 is in communication with the outlet of the primary plasma reactor 5. The temperature in the deposition pool 7 is controlled to be 40-100℃, so that the elemental sulfur is stored in a solid form. A gas outlet 27 is arranged at the top of the side wall of the deposition pool 7, which is used for discharging the mixed gas containing tungsten hexafluoride. A switchable working door is arranged at the lower part of the side wall of the deposition pool 7, which is used for collecting the solid elemental sulfur.

[0048] The condensing unit I comprises a first condenser and a gas-liquid separation pipeline, and the first condenser is in a double-layer structure. The first condenser comprises an inner shell 8 and an outer shell 9, the inner shell 8 is in an L shape, the bottom of the inner shell 8 is connected with the bottom of the outer shell 9 and the side wall of the outer shell 9 respectively, and a cooling cavity is formed between the inner shell 8 and the outer shell 9. The gas-liquid separation pipeline comprises a gas inlet main pipe 10, a liquid outlet branch pipe 11 and a gas outlet branch pipe 12, the gas inlet main pipe 10 is located in the cooling cavity, and the gas inlet main pipe 10 is wound on the outer side wall of the inner shell 8. The inlet of the gas inlet main pipe 10 is in communication with the gas outlet 27, and the inlets of the liquid outlet branch pipe 11 and the gas outlet branch pipe 12 are connected with the outlet of the gas inlet main pipe 10 respectively. A circulating cooling pipeline (not shown) is arranged on the inner wall of the inner shell 16, which is used for cooling and cooling the WF6 electronic special gas in the cooling cavity, so as to liquefy the WF6 electronic special gas.

[0049] The lower part of the cavity in the inner shell 8 is provided with a partition plate 13, and the space enclosed by the partition plate 13, the inner shell 8 and the outer shell 9 constitutes a liquid collecting cavity 14. The outlet of the liquid outlet branch pipe 11 is connected to the top of the side wall of the liquid collecting cavity 14, and the bottom of the liquid collecting cavity 14 is provided with a collecting opening 15 arranged on the bottom of the side wall of the outer shell 9.

[0050] The top center of the outer shell 9 is provided with a first injection opening 16, and the side wall of the outer shell 9 is provided with a discharge opening 17 near the bottom. When the condenser is used, ice water and ice blocks are added into the cooling cavity from the first injection opening 16 to further enhance the cooling effect, so that the WF6 electronic special gas is quickly liquefied and separated from the mixed gas after degradation. When the temperature in the cooling cavity does not meet the requirements, the water in the cooling cavity is discharged through the discharge opening 17, and then ice water and ice blocks are added again through the first injection opening 16 for further cooling.

[0051] The water vapor generator includes a water vapor generating chamber 18, an ultrasonic atomizing sheet 19 and a first liquid level meter 20. The ultrasonic atomizing sheet 19 is installed in the water vapor generating chamber 18, and the function of the ultrasonic atomizing sheet 19 is to atomize water into water mist, so that the mixed gas passing into the water vapor generating chamber 18 is mixed with water vapor. The outlet of the gas outlet branch pipe 12 is located in the water vapor generating chamber 18, and the first liquid level meter 20 is installed on the side wall of the water vapor generating chamber 18. The lowest liquid level of the water vapor generating chamber 18 is the lowest water level required for the normal operation of the ultrasonic atomizing sheet 19, and the liquid level in the water vapor generating chamber 18 is monitored by the first liquid level meter 20. Before the ultrasonic atomizing sheet 19 works, the liquid level of the first liquid level meter 20 should be checked to confirm that the water level in the water vapor generating chamber 18 can make the ultrasonic atomizing sheet 19 work normally. The top of the water vapor generating chamber 18 is provided with a second injection opening 21, and water is added through the second injection opening 21 when the water level in the water vapor generating chamber 18 is not enough.

[0052] The secondary plasma reactor 22 is a coaxial double-layer dielectric barrier discharge reactor, and the secondary plasma reactor 22 is horizontally placed. The discharge area of the secondary plasma reactor 22 is filled with γ-alumina 23. The water vapor generating chamber 18 is connected to the inlet of the secondary plasma reactor through a pipeline. In the discharge area of the secondary plasma reactor 22, under the action of active gas water vapor and catalyst γ-alumina, the mixed gas of tungsten hexafluoride separated out is further ionized and degraded, and the degradation products tend to generate SO2 and HF.

[0053] The heating unit includes a heater, and the heater is provided with a heating gas cavity. The outlet of the secondary plasma reactor is connected to the inlet of the heating gas cavity through a pipeline. The temperature of the heating gas cavity is kept at 300℃, so that a small amount of S2F 10 is pyrolyzed into SF6 and SF4 gas.

[0054] In order to reduce the space occupied by the device, the water vapor generating chamber, the secondary plasma reactor and the heater are sequentially arranged from top to bottom.

[0055] The structure of the condensing unit II can be the same as or different from that of the condensing unit I. The condensing unit II comprises a second condenser and a collection pool, the top of the collection pool being connected with the bottom of the second condenser. The outlet of the heating gas cavity is communicated with the inlet of the second condenser, and the collection pool is communicated with the liquid outlet of the second condenser. The second collection pool is connected with a "hydrogen fluoride-liquid ammonia" liquid phase treatment unit, for converting the separated liquid hydrogen fluoride into ammonium fluoride and ammonium bifluoride. The gas outlet of the second condenser is connected with a wet ammonia treatment unit, for converting the separated SO2 into ammonium sulfite and ammonium sulfate.

[0056] The method for resourcefully converting sulfur hexafluoride according to the application will be described in detail below in combination with the above-described device.

[0057] Example 2

[0058] S1, fill the primary plasma reactor 5 with quartz wool, and fill the secondary plasma reactor 22 with γ-alumina 23.

[0059] S2, assemble and connect the device for resourcefully converting sulfur hexafluoride according to the connection relationship (as shown in the above-described device). Figure 1

[0060] S3, put tungsten powder into the blast box 2.

[0061] S4, open the second pressure reducing valve and the second electromagnetic valve, and introduce argon to detect the airtightness of the device, so as to prevent the leakage of toxic gas during the reaction from causing harm to the workers and ensure the stable and orderly progress of the reaction. After the detection is completed, close the second pressure reducing valve.

[0062] S5, start the primary plasma reactor 5, the ultrasonic atomization sheet 19 and the secondary plasma reactor 22, set the input voltage of the primary plasma reactor 5 to 15 kV, and set the input power to 90 W. At the beginning, the temperature in the primary plasma reactor 5 will rise, and after 30 minutes, the temperature in the primary plasma reactor 5 will tend to stabilize at 130℃, and at the same time, the temperature in the deposition pool 7 is controlled to be 50℃. Set the input voltage of the secondary plasma reactor 22 to 15 kV, and set the input power to 90 W. At the same time, start the first condenser and the second condenser, so that the first condenser reaches the liquefaction temperature 10℃ of WF6 gas, and the second condenser reaches the liquefaction temperature 16℃ of HF gas.

[0063] ​S6, open the first pressure reducing valve, the first electromagnetic valve, the second pressure reducing valve and the second electromagnetic valve, the sulfur hexafluoride gas in the sulfur hexafluoride cylinder and the argon in the argon cylinder are decompressed and enter the gas mixing instrument 1 to mix uniformly, the dilution ratio of SF6 and the flow of the mixed gas can be accurately controlled through the gas mixing instrument. At the same time, the air blower 3 is opened, and the tungsten powder is blown into the first plasma reactor 5;

[0064] S7, the mixed gas in the gas mixing instrument 1 and the tungsten powder enter the first plasma reactor 5 respectively, the argon is ionized into high-energy electrons (plasma) in the first plasma reactor 5, the sulfur hexafluoride gas is decomposed into fluorine atoms and low fluorine sulfide gas (such as SF5, SF4, etc.) under the activation of high-energy electrons, the fluorine atoms and low fluorine sulfide gas react with the tungsten powder to generate WF6-containing gas and a small amount of liquid sulfur element, the liquid S element flows downward into the deposition pool 7 for collection, and the mixed gas I containing WF6 gas flows into the condenser for liquefaction, and then flows into the liquid collection chamber 14, so as to separate WF6 from the mixed gas I;

[0065] S8, the mixed gas I after condensation enters the water vapor generating chamber 18 and mixes with the water vapor in the water vapor generating chamber 18 to obtain the mixed gas II;

[0066] S9, the mixed gas II enters the second plasma reactor 22, and under the action of active gas water vapor and catalyst γ-alumina 23, the mixed gas II is ionized and decomposed into mixed gas III containing SO2 gas and HF gas.

[0067] S 10 , the mixed gas III is introduced into the heating gas cavity of the heater, and the temperature of the heating gas cavity is kept at 300℃, and a small amount of S2F 10 gas in the mixed gas III is pyrolyzed into SF6 and SF4;

[0068] S 11 , the mixed gas III after pyrolysis is condensed again, and the HF gas is condensed into liquid state for collection, and the collected liquid hydrogen fluoride is treated by using "hydrogen fluoride-liquid ammonia" liquid phase method, different amounts of liquid ammonia are introduced according to needs, and ammonium fluoride or ammonium bifluoride is obtained;

[0069] S 12 , the step S 11 , the SO2-containing mixed gas IV after condensation is treated by using wet ammonia method treatment unit to obtain ammonium sulfate and ammonium sulfite.

[0070] S 13, when there is no liquid flowing out of the first condenser, the first pressure reducing valve and the first electromagnetic valve are closed, ten minutes later, the first stage plasma reactor 5 is closed and argon gas is continuously introduced, so that the gas in the first stage plasma reactor 5 is driven to pass through the condensing unit I, the water vapor generating chamber 18, the second stage plasma reactor 22, the heater 24 and the second condenser in turn, and ten minutes later, the second pressure reducing valve, the second electromagnetic valve, the first condenser, the water vapor generating chamber 18, the second stage plasma reactor 22, the heater 24 and the second condenser are closed.

Claims

1. A novel method of resourceful conversion of sulfur hexafluoride, characterized in that The method comprises the following steps: S1, filling tungsten in the discharge area of a primary plasma reactor or introducing tungsten powder into the discharge area of the primary plasma reactor; S2, introducing argon and sulfur hexafluoride into the discharge area of the primary plasma reactor, ionizing the argon into plasma, and ionizing the sulfur hexafluoride into fluorine atoms and low fluorine sulfides after being activated by the plasma; S3, reacting the fluorine atoms and low fluorine sulfides with the tungsten or tungsten powder at 120-160 ℃ to generate a mixed gas I containing tungsten hexafluoride and liquid sulfur, and collecting the liquid sulfur; S4, condensing the mixed gas I containing tungsten hexafluoride, and collecting the condensed tungsten hexafluoride in liquid state; S5, mixing the condensed mixed gas I with water vapor to obtain a mixed gas II; S6, introducing the mixed gas II into a secondary plasma reactor filled with a catalyst in the discharge area, and ionizing and degrading the mixed gas II into a mixed gas III containing SO2 and HF under the action of the catalyst, wherein the catalyst is γ-alumina or glass beads; S7, re-condensing the mixed gas III to condense the HF into liquid state for collection, and treating the collected liquid hydrogen fluoride by using a "hydrogen fluoride-ammonia" liquid phase method to obtain ammonium fluoride and / or ammonium bifluoride; S8, treating the condensed mixed gas IV containing SO2 obtained in step S7 by using a wet ammonia method to obtain ammonium sulfate and / or ammonium sulfite.

2. The novel method of resourceful conversion of sulfur hexafluoride as claimed in claim 1, wherein: In step S1, if tungsten powder is introduced into the discharge area of the primary plasma reactor, argon and sulfur hexafluoride are simultaneously introduced into the discharge area of the primary plasma reactor.

3. The novel method of resourceful conversion of sulfur hexafluoride as claimed in claim 1, wherein: In the step S7, before the mixed gas III is condensed, the mixed gas III is heated to make S2F 10 The gas is pyrolyzed into SF6and SF4gas.

4. A novel device for resourceful conversion of sulfur hexafluoride, characterized by: The method comprises a sulfur hexafluoride gas supply unit, an argon gas supply unit, a mixing unit, a primary plasma reactor, a condensing unit I, a water vapor generator, a secondary plasma reactor, a condensing unit II, a "hydrogen fluoride-ammonia" liquid phase treatment unit, and a wet ammonia treatment unit. The sulfur hexafluoride gas supply unit and the argon gas supply unit are connected to the mixing unit, the mixing unit mixes the sulfur hexafluoride gas and the argon, the mixing unit is connected to the inlet of the primary plasma reactor, the primary plasma reactor is vertically or obliquely placed, the bottom of the primary plasma reactor is provided with a sulfur collector, the sulfur collector is located below the primary plasma reactor, the bottom of the primary plasma reactor is provided with a first liquid outlet, the sulfur collector is communicated with the first liquid outlet, and the primary plasma reactor or the sulfur collector is provided with a first gas outlet; The condensing unit I comprises a first condenser and a first liquid collector, the condenser is provided with a second gas outlet and a second liquid outlet, the first liquid collector is communicated with the second liquid outlet, the first gas outlet is communicated with the inlet of the first condenser, the second gas outlet is communicated with the inlet of the water vapor generator, the outlet of the water vapor generator is communicated with the inlet of the secondary plasma reactor, and the secondary plasma reactor is filled with a catalyst. The condensing unit II comprises a second condenser and a second liquid collector, the second condenser has a third gas outlet and a third liquid outlet, the secondary plasma reactor outlet is communicated with the second condenser inlet, the second liquid collector is communicated with the third liquid outlet, the second liquid collector is connected with the "hydrogen fluoride-liquid ammonia" liquid phase treatment unit, and the third gas outlet is connected with the wet ammonia treatment unit.

5. The novel device for resourceful conversion of sulfur hexafluoride according to claim 4, characterized by: The tungsten powder generator comprises a blast box and a tungsten powder conveying pipe, the blast box comprises a blast box body and a blast fan, the blast fan is installed on the blast box body, one end of the tungsten powder conveying pipe is connected with the blast box body outlet, and the other end of the tungsten powder conveying pipe is connected with the primary plasma reactor inlet.

6. The novel device for resourceful conversion of sulfur hexafluoride as claimed in claim 4, wherein: The condensing unit I further comprises a gas-liquid separation pipeline, the condenser is a double-layer structure, the condenser comprises an inner shell and an outer shell, the inner shell is fixed on the outer shell, a cooling cavity is formed between the inner shell and the outer shell, the gas-liquid separation pipeline comprises a gas inlet main pipe, a liquid outlet branch pipe and a gas outlet branch pipe, the gas inlet main pipe is located in the cooling cavity, the gas inlet main pipe inlet is communicated with the first gas outlet, the liquid outlet branch pipe inlet and the gas outlet branch pipe inlet are respectively connected with the gas inlet main pipe outlet, the gas outlet branch pipe outlet is connected with the water vapor generator inlet, and the liquid outlet branch pipe outlet is communicated with the liquid collector.

7. The novel device for resourceful conversion of sulfur hexafluoride according to claim 6, characterized by: The lower part of the cavity in the inner shell is provided with a partition plate, the space enclosed by the partition plate, the inner shell and the outer shell is a liquid collector, and the bottom of the liquid collector is provided with a fourth liquid outlet.

8. The novel device for resourceful conversion of sulfur hexafluoride as claimed in claim 4 wherein: The water vapor generator comprises a water vapor generation chamber, an ultrasonic atomization sheet and a first liquid level meter, the ultrasonic atomization sheet is installed in the water vapor generation chamber, and the first liquid level meter is installed on the side wall of the water vapor generation chamber.

9. The novel device for resourceful conversion of sulfur hexafluoride as claimed in claim 4 wherein: The heating unit comprises a heater, the secondary plasma reactor outlet is communicated with the heater inlet, and the heater outlet is communicated with the second condenser inlet.

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