Method for refining extraction of krypton and xenon

Abstract

The application discloses a krypton-xenon refining and extracting method and relates to the technical field of cryogenic rare gas separation. The method comprises the following steps: pressurizing a tank containing krypton-xenon crude liquid to 0.15 MPa; inputting raw krypton-xenon gas obtained through primary roasting, cooling and purification into a secondary concentration module, and controlling the gaseous side, the liquid side and the oxygen outlet temperature of a secondary concentration tower evaporator; gasifying and filling a bottle with the krypton-xenon mixed liquid, and performing secondary roasting, cooling and purification; inputting the obtained krypton-xenon mixed gas into a krypton-xenon separation module, obtaining crude krypton with ≤1 ppm xenon at the top of the krypton-xenon separation tower, obtaining crude xenon with ≤1 ppm krypton at the bottom of the krypton-xenon separation tower, removing CF4 in a krypton I tower, removing CH4 and oxygen in a krypton II tower, and obtaining high-purity krypton; inputting the crude xenon into a pure xenon module, removing hydrocarbons and NO and C2F6 in a xenon I tower, removing CF4 in a xenon II tower, and obtaining high-purity xenon. The method can improve the utilization rate of krypton-xenon raw liquid, and improve the product purity and yield.

Description

Technical Field

[0001] This invention relates to the field of cryogenic rare gas separation technology, and in particular to a method for refining and extracting krypton and xenon. Background Technology

[0002] In recent years, with the rapid development of companies in the electric light source and semiconductor industries, the consumption of krypton and xenon has increased rapidly, and the purity requirements for rare gases such as krypton and xenon have become increasingly stringent. Because rare gases are present in extremely small amounts in the air, the current air separation units can only produce a very limited quantity of crude krypton-xenon liquid feedstock, and the available liquid feedstock is also extremely scarce. Therefore, to ensure that the krypton-xenon refining unit, given the limited availability of liquid feedstock, can maximize the production capacity of the unit and increase the yield of refined krypton-xenon gas, thereby guaranteeing a product purity exceeding that of similar products on the market.

[0003] Existing krypton-xenon refining units employ safe and reliable high-temperature catalytic methods and low-temperature distillation technology. They separate krypton and xenon based on the differences in their boiling points, using a catalyst to chemically react with impurities in the components and then removing the byproducts. During operation, the crude liquid is pressurized and vaporized by a piston pump before entering the system. To prevent piston cavitation, the piston pressurization pump needs to be vented on average every shift. The vaporized feed gas enters a primary roasting, primary purification, and secondary concentration system to remove impurities. After impurity removal and secondary concentration, the feed gas enters the krypton-xenon refining system, where the components evaporate and condense in a fractionation tower due to differences in their boiling points, and the waste gas is then discharged. In the above refining process, secondary concentration is only used to adjust the temperature and maintain the liquid level by increasing the amount of liquid nitrogen when the exhaust temperature and liquid level change. The krypton-xenon refining system controls the product yield and purity by the amount of mixed gas entering the system. Product yield: krypton 0.673 Nm3 / h, xenon 0.0504 Nm3 / h, krypton purity ≥99.9995%, xenon purity ≥99.9993%.

[0004] The above-mentioned krypton-xenon refining method has the following drawbacks: 1. Although the product purity can meet the design specifications under the current operating conditions, there is still some inefficient utilization of raw material liquids. Although the product purity meets the standards, it does not differentiate itself from krypton and xenon refined products on the market, and does not reflect the maximum value of this krypton-xenon refining unit; 2. During the gasification process, the exhaust gas each shift will cause a large amount of waste of raw material liquids; 3. The removal of impurities from the crude raw material gas can easily lead to the waste of some krypton and xenon components in the raw material gas; 4. The secondary concentration and krypton-xenon refining system is unstable, and there are often gases rich in krypton and xenon discharged, resulting in waste and a large amount of sulfide accumulation, which affects production safety and product purity; 5. There is still a lot of room for improvement in output and product purity. Summary of the Invention

[0005] The purpose of this invention is to provide a method for refining and extracting krypton and xenon, which can improve the utilization rate of krypton and xenon raw material liquid and increase product purity and yield.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows: This krypton-xenon refining and extraction method includes the following steps:

[0007] (1) Storage and pressurized vaporization: The crude krypton-xenon raw material tank containing crude krypton-xenon liquid is pressurized to 0.15 MPa using a krypton-xenon raw material piston pump;

[0008] (2) Primary roasting: The crude krypton xenon feed gas obtained by gasification is fed into the primary roasting furnace and roasted until the hydrocarbons and nitrous oxide of the crude krypton xenon feed gas are completely removed;

[0009] (3) First cooling: Cool the calcined crude krypton xenon feed gas to below 30°C;

[0010] (4) Primary purification: After cooling, the crude krypton xenon raw gas is purified by an adsorber to remove water and CO2, so that the CO2 content in the crude krypton xenon raw gas is less than 1 ppm.

[0011] (5) Secondary Concentration: The purified crude krypton xenon raw gas is input into the secondary concentration module. The crude krypton xenon raw gas is first cooled to -154℃ by a heat exchanger, then radon is removed by a radon adsorber, and then it enters the secondary concentration tower for distillation. The temperature of the gas side of the evaporator in the tower is controlled to be ≤-167℃ and the temperature of the liquid side is ≥-145℃. Liquid nitrogen is sent to the condenser side of the secondary concentration tower as a refrigerant. The crude krypton xenon raw gas is separated in the secondary concentration tower into a krypton xenon mixture drawn out from the bottom of the evaporator, fluoride and sulfide liquids remaining in the tower, and oxygen discharged from the top of the tower. The oxygen outlet temperature is ≤-167℃.

[0012] (6) Mixed gas filling: vaporize the krypton-xenon mixture and fill the bottle;

[0013] (7) Secondary roasting, cooling and purification: The krypton-xenon mixture is fed into the secondary roasting furnace and roasted until the hydrocarbons and nitrous oxide of the crude krypton-xenon raw material gas are completely removed. The roasted krypton-xenon mixture is cooled to below 30°C. The cooled krypton-xenon mixture is then passed through an adsorber to remove water and CO2, so that the CO2 content in the krypton-xenon mixture is less than 1 ppm.

[0014] (8) Krypton-xenon separation: The purified krypton-xenon mixture is fed into the krypton-xenon separation module and distilled sequentially in the krypton-xenon separation tower, krypton I tower, and krypton II tower. Medium-pressure liquid nitrogen is introduced into the condenser side of each tower. The cooling capacity is controlled by the liquid level on the condenser side to maintain the tower pressure. When the bottom temperature of the krypton-xenon separation tower C2901 is ≤-95℃, the top temperature of the krypton I tower C2911 is ≤-141℃, and the top temperature of the krypton II tower C2921 is ≤-143.5℃, the gas discharge is reduced. The krypton-xenon mixture is initially separated from the xenon in the krypton-xenon separation tower. Crude krypton with ≤1ppm xenon is obtained at the top of the krypton-xenon separation tower and crude xenon with ≤1ppm krypton is obtained at the bottom of the tower. The crude krypton is then de-CF4 in the krypton I tower and de-CH4 and oxygen in the krypton II tower to obtain high-purity krypton.

[0015] (9) Input crude xenon into the pure xenon module and perform distillation in the xenon I column and xenon II column in sequence. When the top temperature of xenon I column is ≤94.3℃ and the top temperature of xenon II column is ≤-97℃, reduce the gas discharge. Remove hydrocarbons, NO and C2F6 in xenon I column and remove CF4 in xenon II column to obtain high-purity xenon.

[0016] In the above-mentioned krypton-xenon refining and extraction method, a more specific technical solution could be: In step S3, the exhaust gas discharge rate is automatically controlled based on the secondary concentration exhaust gas emission temperature and the low liquid temperature at the bottom of the column. The secondary concentration exhaust gas discharge operation formula is as follows:

[0017] FIC2801.SP=0.98*FIS2701.PV-3.00+(TIC2814.MV-50) / 5

[0018] TIC2814.PV=(2.00*TI2805.PV+5*TIS2804.PV) / (2.00+5.00)

[0019] In the formula, FIC2801 is the exhaust flow rate, FIS2701 is the crude krypton xenon gas inlet flow rate, TIC2814 is the crude krypton xenon liquid temperature, TI2805 is the vapor phase temperature of the evaporator in the concentration tower, TIS2804 is the liquid phase temperature of the evaporator in the concentration tower, SP is the set value, PV is the actual value, and MV is the valve opening degree.

[0020] Furthermore, the temperature of the primary roasting furnace in the primary roasting step is ≥500℃.

[0021] Furthermore, during the vaporization process of the krypton-xenon mixture, the liquid side temperature of the evaporator at the bottom of the secondary concentration tower is maintained at ≥-145℃.

[0022] Furthermore, the liquid level on the evaporator side of each tower in both the krypton-xenon separation module and the pure xenon separation module is greater than 200 mm.

[0023] Furthermore, in the secondary concentration step, low-pressure nitrogen gas is heated by an electric heater and then enters the secondary concentration tower from the bottom as an auxiliary heat source.

[0024] This invention improves the utilization rate of liquid krypton-xenon feedstock by pressurizing the crude krypton-xenon feedstock tank to prevent cavitation in the krypton-xenon feedstock pump; it also prevents hydrocarbons from freezing in the krypton-xenon separation system, thus avoiding impacts on production and product purity; cooling and purifying the calcined feedstock gas removes calcination products; and finally, the purified crude feedstock gas is fed into a secondary concentration module for concentration, and after radon removal, it enters a secondary concentration tower for distillation. During distillation, controlling the temperature of the gaseous and liquid sides of the evaporator allows for separation at low temperatures, improving the distillation efficiency. This process allows for more efficient separation of the feed gas, contributing to improved product quality and purity. The separation yields a mixed liquid, fluorides, sulfide liquids, and oxygen, increasing the utilization rate of the feed gas and generating commercially valuable byproducts. After vaporization and bottling, the lighter components in the mixed liquid further volatilize and rise, while the heavier components remain in the liquid phase, further enhancing product purity. During the initial distillation in the secondary concentration module, some organic matter or impurities may still remain in the mixed liquid. Secondary roasting can further decompose and remove these substances, followed by cooling and purification. To prevent potential chemical reactions or decompositions during the next distillation stage and to remove roasted products, thus improving product purity, the purified krypton-xenon mixture is input into a krypton-xenon separation module with three-stage distillation: a krypton-xenon separation tower, a krypton I tower, and a krypton II tower. Through distillation in the krypton-xenon separation tower, krypton and xenon are initially separated. Further removal of CF4, CH4, and oxygen occurs in the krypton I and krypton II towers. By controlling the bottom and top temperatures of the krypton-xenon separation tower, krypton I tower, and krypton II tower, the distillation process can be precisely controlled to ensure product quality. When the temperature of each tower reaches a preset value, gas emissions are reduced. The quantity of xenon can be further optimized to improve the production process, increase efficiency, and reduce the loss of krypton and xenon content, resulting in high-purity krypton. The crude xenon is fed into the pure xenon module of the two-stage distillation process for distillation, which can remove impurities such as hydrocarbons, NO, and C2F6, thereby improving the purity of xenon. By controlling the top temperature of the xenon I and xenon II columns, the distillation process can be precisely controlled to ensure product quality. When the temperature of each column reaches the preset value, the amount of gas discharged is reduced, which can further optimize the production process, increase efficiency, reduce the loss of xenon content, and result in high-purity xenon.

[0025] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0026] 1. Pressurizing the crude krypton xenon raw material tank to 0.15MPa to vaporize the crude krypton xenon liquid can significantly reduce the cavitation phenomenon of the crude krypton xenon raw material piston pump. The piston pump can be kept running normally without venting it every shift. Based on 0.5m³ per day, 182.5m³ of raw material liquid can be saved per year.

[0027] 2. One-time roasting can reduce hydrocarbons and nitrous oxide in the equipment, avoiding the possibility that hydrocarbons and nitrous oxide will freeze in the krypton-xenon separation system, affecting production and product purity.

[0028] 3. By establishing a formula for the discharge of waste gas from secondary concentration and reducing the pressure of the secondary concentration tower, the discharge temperature of the mixed gas has decreased from -165℃ to -166.4℃, significantly reducing the emission of krypton-xenon-containing gases from secondary concentration and essentially eliminating the loss of krypton-xenon content in the mixed gas. The mixed gas production can be reduced by 10 Nm³ / h, increasing the daily mixed gas production by 240 Nm³, and raising the krypton-xenon content in the mixed gas from 95% to 99%.

[0029] 4. Product output and purity have been significantly improved. Krypton emissions have been reduced from 20 NL / h to 8 NL / h, a reduction of 288 NL per day. Xenon emissions have been reduced from 8 NL / h to 3 NL / h, a reduction of 2.7 NL per day. Annually, krypton emissions have been reduced by 105,120 NL / h and xenon emissions by 23,652 NL / h. Krypton purity has been increased to ≥99.9999% and xenon purity to ≥99.9999%, differentiating the products in the market and gaining customer trust. Attached Figure Description

[0030] Figure 1 This is a flowchart of the secondary concentration module in this invention.

[0031] Figure 2 This is a flowchart of the krypton-xenon separation module in this invention.

[0032] Figure 3 This is a flowchart of the pure xenon separation module in this invention. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0034] The krypton-xenon refining extraction method in this embodiment is to refine the krypton-xenon feedstock liquid after primary concentration from the air separation unit. Temperature control at each stage is crucial for product yield and purity. During operation, the temperature of each separation tower must be strictly controlled, and temperature fluctuations should be adjusted promptly. Exhaust gas emissions should be reduced in a timely manner, while increasing the purity of the mixed gas entering the krypton-xenon separation tower and increasing the evaporator power will achieve the goal of improving product purity and yield.

[0035] Figures 1 to 3 These are the three main modules in the system of this invention, among which, Figure 1 The secondary concentration module mainly includes heat exchanger E2801, radon adsorber A2801, secondary concentration tower C2801, evaporator K2801, condenser K2802, electric heater EH2801, and liquid nitrogen tank PV2801. Liquid nitrogen tank PV2801 is used to buffer nitrogen and supply liquid nitrogen to condenser K2802 located above secondary concentration tower C2801 as the condensing working medium. Low-pressure nitrogen gas is input to evaporator K2801 below secondary concentration tower C2801 via electric heater as an auxiliary heat source. The krypton-xenon feedstock liquid (crude krypton-xenon) pipeline is connected to secondary concentration tower C2801 via heat exchanger E2801 and radon adsorber A2801. Figure 2 The krypton-xenon separation module mainly includes a liquid nitrogen tank PV2801, a krypton-xenon separation tower C2901, a condenser K2901, an evaporator K2902, a krypton I tower C2911, a condenser K2911, an evaporator K2912, a krypton II tower C2921, a condenser K2921, and an evaporator K2922. The liquid nitrogen tank PV2801 is connected to the condenser side of the krypton-xenon separation towers C2901, C2911, and C2921 via pipelines to supply a stable liquid nitrogen as a cold source. The condensers in the krypton-xenon separation towers C2901, C2911, and C2921 are all double-layered two-stage condensers, which can more accurately control the gas discharge, thereby reducing the loss of krypton and xenon due to discharge. Figure 3 The pure xenon module mainly includes xenon I tower C2931, condenser K2931, evaporator K2932, xenon II tower C2941, condenser K2941 and evaporator K2942. Condenser K2931 and condenser K2941 are both two-stage condensers.

[0036] The krypton-xenon refining and extraction method of this embodiment includes the following steps:

[0037] (1) Storage and pressurized vaporization: The pressure of the crude krypton-xenon raw material tank containing crude krypton-xenon liquid is increased from 85 kPa to 0.15 MPa using a krypton-xenon raw material piston pump;

[0038] (2) Primary roasting: The crude krypton xenon raw material gas obtained by gasification is fed into the primary roasting furnace to increase the temperature of the primary roasting furnace to ≥500℃, and roasting until the hydrocarbons and nitrous oxide of the crude krypton xenon raw material gas are completely removed.

[0039] (3) First cooling: Cool the calcined crude krypton xenon feed gas to below 30°C;

[0040] (4) Primary purification: After cooling, the crude krypton xenon raw gas is purified by an adsorber to remove water and CO2, so that the CO2 content in the crude krypton xenon raw gas is less than 1 ppm.

[0041] (5) Secondary Concentration: The purified crude krypton-xenon feed gas is input into the secondary concentration module. The crude krypton-xenon feed gas is first cooled to -154℃ by a heat exchanger, then radon is removed by a radon adsorber, and then it enters the secondary concentration tower for distillation. Liquid nitrogen is sent as a refrigerant to the condenser side of the secondary concentration tower. Low-pressure nitrogen gas is heated by an electric heater and enters the tower from the bottom of the secondary concentration tower as an auxiliary heat source. The temperature of the gaseous side of the evaporator in the tower is controlled to be ≤-167℃ and the temperature of the liquid side is ≥-145℃ to ensure secondary concentration. System separation effect: The crude krypton-xenon feed gas is separated in the secondary concentration tower into a krypton-xenon mixture drawn from the bottom of the evaporator, fluoride and sulfide liquids remaining in the tower, and oxygen discharged from the top of the tower. The oxygen outlet temperature is ≤-167℃. Based on the secondary concentration exhaust gas emission temperature and the low liquid temperature at the bottom of the tower, the exhaust gas discharge rate is automatically controlled to reduce the loss of krypton-xenon content in the mixture, improve the purity of the krypton-xenon mixture, and ensure that the oxygen content of the krypton-xenon mixture is ≤1%. The secondary concentration exhaust gas discharge operation formula is as follows:

[0042] FIC2801.SP=0.98*FIS2701.PV-3.00+(TIC2814.MV-50) / 5

[0043] TIC2814.PV=(2.00*TI2805.PV+5*TIS2804.PV) / (2.00+5.00)

[0044] In the formula, FIC2801 is the exhaust gas flow rate, FIS2701 is the crude krypton xenon gas inlet flow rate, TIC2814 is the crude krypton xenon liquid temperature, TI2805 is the vapor phase temperature of the evaporator in the concentration tower, TIS2804 is the liquid phase temperature of the evaporator in the concentration tower, SP is the set value, PV is the actual value, and MV is the valve opening degree.

[0045] (6) Mixed gas filling: The krypton-xenon mixture is vaporized and filled into a bottle. During the vaporization process, the liquid side temperature of the evaporator at the bottom of the secondary concentration tower is maintained at ≥-145℃.

[0046] (7) Secondary roasting, cooling and purification: The krypton-xenon mixture is fed into the secondary roasting furnace and roasted until the hydrocarbons and nitrous oxide of the crude krypton-xenon raw material gas are completely removed. The roasted krypton-xenon mixture is cooled to below 30°C. The cooled krypton-xenon mixture is then passed through an adsorber to remove water and CO2, so that the CO2 content in the krypton-xenon mixture is less than 1 ppm.

[0047] (8) Krypton-xenon separation: The purified krypton-xenon mixture is input into the krypton-xenon separation module and is distilled sequentially in the krypton-xenon separation tower, krypton I tower, and krypton II tower. Medium-pressure liquid nitrogen is introduced into the condenser side of each tower. The cooling capacity is controlled by the liquid level on the condenser side to maintain the tower pressure. The liquid level on the evaporator side of each separation tower is greater than 200 mm. When the bottom temperature of the krypton-xenon separation tower C2901 is ≤-95℃, the top temperature of the krypton I tower C2911 is ≤-141℃, and the top temperature of the krypton II tower C2921 is ≤-143.5℃, the gas discharge is reduced. The difference in condensation temperature of the krypton-xenon components is used for distillation separation. The krypton-xenon mixture is initially separated from the xenon in the krypton-xenon separation tower. At the top of the krypton-xenon separation tower, gaseous crude krypton with ≤1ppm xenon is obtained, and liquid crude xenon with ≤1ppm krypton is obtained at the bottom of the tower. CF4 is removed in the krypton I tower, and nitrogen, hydrogen and oxygen are removed in the krypton II tower to obtain liquid high-purity krypton.

[0048] (9) Input the liquid crude xenon into the pure xenon module and perform distillation in the xenon I tower and xenon II tower in sequence. When the top temperature of the xenon I tower is ≤94.3℃ and the top temperature of the xenon II tower is ≤-97℃, reduce the gas discharge. Remove hydrocarbons, NO and C2F6 in the xenon I tower and remove oxygen, nitrogen and hydrogen in the xenon II tower to obtain liquid high-purity xenon.

[0049] After adopting this krypton-xenon refining and extraction method, cavitation in the krypton-xenon feedstock pump is completely eliminated, significantly reducing the discharge of raw material liquid. This substantial reduction in unnecessary emissions results in a significant increase in product yield, with krypton production reaching 1.01 Nm³. 3 xenon production: 0.0757 Nm³ / h 3 / h; Achieved a 100% pass rate for krypton-xenon product gas, with a purity of ≥99.9999%.

Claims

1. A method for refining and extracting krypton and xenon, characterized in that... Includes the following steps: (1) Storage and pressurized vaporization: The crude krypton-xenon raw material tank containing crude krypton-xenon liquid is pressurized to 0.15 MPa using a krypton-xenon raw material piston pump; (2) Primary roasting: The crude krypton xenon feed gas obtained by gasification is fed into the primary roasting furnace and roasted until the hydrocarbons and nitrous oxide of the crude krypton xenon feed gas are completely removed; (3) First cooling: Cool the calcined crude krypton xenon feed gas to below 30°C; (4) Primary purification: After cooling, the crude krypton xenon raw gas is purified by an adsorber to remove water and CO2, so that the CO2 content in the crude krypton xenon raw gas is less than 1 ppm. (5) Secondary Concentration: The purified crude krypton xenon raw gas is input into the secondary concentration module. The crude krypton xenon raw gas is first cooled to -154℃ by a heat exchanger, then radon is removed by a radon adsorber, and then it enters the secondary concentration tower for distillation. The temperature of the gas side of the evaporator in the tower is controlled to be ≤-167℃ and the temperature of the liquid side is ≥-145℃. Liquid nitrogen is sent to the condenser side of the secondary concentration tower as a refrigerant. The crude krypton xenon raw gas is separated in the secondary concentration tower into a krypton xenon mixture drawn out from the bottom of the evaporator, fluoride and sulfide liquids remaining in the tower, and oxygen discharged from the top of the tower. The oxygen outlet temperature is ≤-167℃. (6) Mixed gas filling: vaporize the krypton-xenon mixture and fill the bottle; (7) Secondary roasting, cooling and purification: The krypton-xenon mixture is fed into the secondary roasting furnace and roasted until the hydrocarbons and nitrous oxide of the crude krypton-xenon raw material gas are completely removed. The roasted krypton-xenon mixture is cooled to below 30°C. The cooled krypton-xenon mixture is then passed through an adsorber to remove water and CO2, so that the CO2 content in the krypton-xenon mixture is less than 1 ppm. (8) Krypton-xenon separation: The purified krypton-xenon mixture is input into the krypton-xenon separation module and is distilled sequentially in the krypton-xenon separation tower, krypton I tower, and krypton II tower. Medium-pressure liquid nitrogen is introduced into the condenser side of each tower. The cooling capacity is controlled by the liquid level on the condenser side to maintain the tower pressure. When the bottom temperature of the krypton-xenon separation tower C2901 is ≤-95℃, the top temperature of the krypton I tower C2911 is ≤-141℃, and the top temperature of the krypton II tower C2921 is ≤-143.5℃, the gas discharge is reduced. The krypton-xenon mixture is initially separated from the xenon in the krypton-xenon separation tower. Crude krypton with ≤1ppm xenon is obtained at the top of the krypton-xenon separation tower and crude xenon with ≤1ppm krypton is obtained at the bottom of the tower. The crude krypton is then de-CF4 in the krypton I tower and de-CH4 and oxygen in the krypton II tower to obtain high-purity krypton. (9) Input crude xenon into the pure xenon module and perform distillation in the xenon I column and xenon II column in sequence. When the top temperature of xenon I column is ≤94.3℃ and the top temperature of xenon II column is ≤-97℃, reduce the gas discharge. Remove hydrocarbons, NO and C2F6 in xenon I column and remove CF4 in xenon II column to obtain high-purity xenon.

2. The method for refining and extracting krypton and xenon according to claim 1, characterized in that: In step S3, the exhaust gas discharge rate is automatically controlled based on the secondary concentration exhaust gas temperature and the low liquid temperature at the bottom of the tower. The formula for the secondary concentration exhaust gas discharge operation is as follows: FIC2801.SP=0.98*FIS2701.PV-3.00+(TIC2814.MV-50) / 5 TIC2814.PV=(2.00*TI2805.PV+5*TIS2804.PV) / (2.00+5.00) In the formula, FIC2801 is the exhaust flow rate, FIS2701 is the crude krypton xenon gas inlet flow rate, TIC2814 is the crude krypton xenon liquid temperature, TI2805 is the vapor phase temperature of the evaporator in the concentration tower, TIS2804 is the liquid phase temperature of the evaporator in the concentration tower, SP is the set value, PV is the actual value, and MV is the valve opening degree.

3. The method for refining and extracting krypton and xenon according to claim 1, characterized in that: The temperature of the primary roasting furnace in the primary roasting process is ≥500℃.

4. The method for refining and extracting krypton and xenon according to claim 1, characterized in that: During the vaporization of the krypton-xenon mixture, the liquid side temperature of the evaporator at the bottom of the secondary concentration tower is maintained at ≥-145℃.

5. The method for refining and extracting krypton and xenon according to claim 1, characterized in that: The liquid level on the evaporator side of each tower in both the krypton-xenon separation module and the pure xenon separation module is greater than 200 mm.

6. The method for refining and extracting krypton and xenon according to any one of claims 1 to 5, characterized in that: In the secondary concentration step, low-pressure nitrogen gas is heated by an electric heater and then enters the secondary concentration tower from the bottom as an auxiliary heat source.

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