Method for preparing nuclear pure grade uranium hexafluoride

Abstract

The invention provides a method for preparing nuclear pure grade uranium hexafluoride, which comprises the following steps: (1) adding fluoride containing molybdenum, tungsten, vanadium, titanium, chromium and antimony and crude uranium hexafluoride of hydrogen fluoride impurities into a distillation kettle, and carrying out pressurized distillation to obtain a gaseous mixture; (2) introducing the gaseous mixture obtained in the step (1) into a calcium fluoride adsorption column, and removing hydrogen fluoride in the mixture through selective adsorption of calcium fluoride; and (3) carrying out single-tower pressurized distillation on the gaseous mixture treated in the step (2) to obtain nuclear pure grade uranium hexafluoride. The method solves the problems of low uranium hexafluoride purity, high energy consumption and high cost of the existing uranium purification conversion technology in the conversion technology of the high-impurity-content natural uranium concentrate, realizes cost reduction and efficiency improvement of uranium hexafluoride purification on the premise of ensuring that uranium hexafluoride reaches the nuclear purity grade standard, and has a wide application prospect. Rapid popularization of a dry uranium purification and conversion process is boosted, and the technical level of uranium purification and conversion in China is further improved.

Description

Technical Field

[0001] This application relates to the field of nuclear fuel cycle technology, and in particular to a method for preparing nuclear-grade uranium hexafluoride. Background Technology

[0002] In the nuclear fuel cycle, uranium purification and conversion is a crucial step in converting natural uranium enrichments into nuclear-grade uranium hexafluoride (UHF). New technologies offer simpler processing procedures for natural uranium enrichments, but when the enrichment contains high levels of impurities, it's difficult to remove multiple components, resulting in lower purity UHF. Conventional purification techniques have some impurity removal capabilities, but their efficiency is low, failing to produce nuclear-grade products. Increasing the number of devices can further improve product purity, but this requires repeated evaporation and condensation, significantly increasing energy consumption and operating costs. Therefore, there is an urgent need to develop a uranium purification and conversion technology for high-impurity natural uranium enrichments. This technology should ensure that UHF meets nuclear-grade standards while reducing costs and increasing efficiency, promoting the rapid adoption of dry uranium purification and conversion processes, and further enhancing my country's uranium purification and conversion technology. Summary of the Invention

[0003] In view of this, this application provides a method for preparing nuclear-grade uranium hexafluoride, the main purpose of which is to solve the problems of low purity of uranium hexafluoride, high energy consumption and high cost in the conversion of natural uranium enrichment with high impurity content in existing uranium purification and conversion technologies.

[0004] To achieve the above objectives, this application provides a method for preparing nuclear-grade uranium hexafluoride, which includes the following steps: (1) Pressure distillation of crude uranium hexafluoride: Crude uranium hexafluoride is added to a distillation vessel, the distillation vessel is heated and the temperature is controlled at 90-120℃ and the pressure is 0.4-1.0MPa. During the distillation process, the vessel is continuously stirred for 0.5-3h to obtain a gaseous mixture. (2) Alkaline earth metal fluoride adsorption: The gaseous mixture obtained in step (1) is adsorbed by alkaline earth metal fluoride. The adsorption temperature is controlled at 90-120℃ and the adsorption contact time is 10-60min. Hydrogen fluoride in the mixture is removed by selective adsorption. (3) Distillation purification: The gaseous mixture after step (2) is passed into the lower part of the distillation packed column, the temperature gradient of the column is controlled, fluorides containing molybdenum, tungsten or vanadium are taken out from the top of the column, uranium hexafluoride is taken out from the middle, and vanadium oxyfluoride is taken out from the bottom of the column.

[0005] In some embodiments, the stirring speed in step (1) is 10-60 r / min.

[0006] In some embodiments, the pressure distillation in step (1) is carried out in a cycle: after each distillation, new crude uranium hexafluoride is added to the distillation vessel and mixed with the remaining solid residue in the vessel, and the pressure distillation operation in step (1) is repeated.

[0007] In some embodiments, the pre-operation before removing the residue is as follows: increase the stirring speed to 400-600 r / min, crush the residual solid material for 1-10 min, and increase the distillation temperature to 120-170°C, maintain this temperature and continue distillation for 0-1 h, so as to reduce the residual amount of uranium hexafluoride in the discharged residue.

[0008] In some embodiments, in step (2), the adsorption process adopts the form of adsorption columns connected in series, and each adsorption column is equipped with a heat insulation layer to maintain the adsorption temperature.

[0009] In some embodiments, the alkaline earth metal fluorides are prepared by a hydration method, the method comprising the following steps: The dehydration temperature is controlled at 200-300℃, and the dehydration time is 2-5 hours, resulting in particles with a size of 0.5-2 mm and a specific surface area of ​​0.5-5 m². 2 / g.

[0010] In some embodiments, the alkaline earth metal fluoride in step (2) can be recycled, and the steps are as follows: The saturated alkaline earth metal fluoride is added to the uranium tetrafluoride fluorination fluidized bed, and the fluorination temperature is controlled at 400-500℃ and the reaction time is 10-40min to desorb hydrogen fluoride and uranium hexafluoride. The desorbed alkaline earth metal fluoride is returned to step (2) for recycling. The hydrogen fluoride and uranium hexafluoride produced by desorption are collected by condensation along with the uranium hexafluoride produced by the fluorination reaction.

[0011] In some embodiments, in step (3), the packing of the distillation packed column is a porous packing or a triangular spiral packing, the material of the packing is Monel, and the packing height is ≥1500mm; the pore size of the porous packing is 1-3mm, and the specifications of the triangular spiral packing are (2-5mm)×(2-5mm)×(5-10mm).

[0012] In some embodiments, in step (3), the bottom temperature of the distillation packed column is controlled at 110-120℃, the top temperature is controlled at 95-105℃, the operating pressure inside the column is 0.4-1.0MPa, and the single distillation time is 0.5-1h.

[0013] In some embodiments, the top reflux ratio of the distillation packed column is 10-30:1, and the reflux ratio of uranium hexafluoride is 1-10:1.

[0014] Compared with existing technologies, the method for preparing nuclear-grade uranium hexafluoride described in this application has the following advantages: Impurities such as titanium, chromium, and antimony are removed by pressure distillation, hydrogen fluoride is removed by alkaline earth fluoride adsorption, and molybdenum, tungsten, and vanadium fluorides are separated by rectification. Appropriate purification measures are added, and the purification effect is further improved by using high-efficiency packing. The single-tower multi-line sampling method avoids the repeated operation of rectification vaporization and condensation in multi-tower series. The use of high-efficiency packing ensures rectification efficiency while significantly reducing rectification energy consumption.

[0015] This technology solves the problems of low purity of uranium hexafluoride oil, high energy consumption, and high cost in the existing uranium purification and conversion technology for natural uranium enrichment and conversion with high impurity content. Under the premise of ensuring that uranium hexafluoride meets nuclear purity standards, it achieves cost reduction and efficiency improvement in uranium hexafluoride purification, promotes the rapid promotion of dry uranium purification and conversion technology, and further improves the technical level of uranium purification and conversion in my country. Attached Figure Description

[0016] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic flowchart of the method for preparing nuclear-grade uranium hexafluoride according to Embodiment 1 of this application is shown. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without making inventive steps are within the scope of protection of this application.

[0018] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0019] Those skilled in the art will understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0020] like Figure 1 As shown, one embodiment of this application provides a method for preparing nuclear-grade uranium hexafluoride, the method comprising the following steps: (1) Pressure distillation of crude uranium hexafluoride: Crude uranium hexafluoride is added to a distillation vessel, the distillation vessel is heated and the temperature is controlled at 90-120℃ and the pressure is 0.4-1.0MPa. During the distillation process, the vessel is continuously stirred for 0.5-3h to obtain a gaseous mixture. Specifically, the crude uranium hexafluoride mentioned above is crude uranium hexafluoride containing fluorides of molybdenum, tungsten, vanadium, titanium, chromium, and antimony, as well as hydrogen fluoride impurities. Mechanical stirring is used. The gaseous mixture includes fluorides such as uranium hexafluoride, molybdenum hexafluoride, tungsten hexafluoride, vanadium pentafluoride, vanadium oxyfluoride, and hydrogen fluoride. Titanium tetrafluoride, chromium tetrafluoride, antimony tetrafluoride, and trace amounts of undistilled uranium hexafluoride remain in the distillation vessel. The pressure distillation is carried out in a cycle: after each distillation, the titanium tetrafluoride, chromium tetrafluoride, and antimony tetrafluoride remaining from step (1) are continued to be pressure distilled. Before discharging the residue, the stirring speed is increased to 400-600 r / min, the residual solid material is crushed for 1-10 min, and the distillation temperature is increased to 150℃. Distillation is then carried out for 0.5 h to reduce the amount of uranium hexafluoride residue in the discharged material.

[0021] (2) Adsorption of alkaline earth metal fluorides: The gaseous mixture obtained in step (1) is passed into a calcium fluoride adsorption column, and the adsorption temperature is controlled at 90-120℃ and the adsorption contact time is 10-60 min. Hydrogen fluoride in the mixture is removed by the selective adsorption of calcium fluoride. Alkaline earth metal fluorides include calcium fluoride or magnesium fluoride.

[0022] Specifically, the adsorption column is a three-column series configuration, each equipped with an insulation layer to maintain the adsorption temperature; calcium fluoride is prepared by hydration, with the dehydration temperature controlled at 200-300℃ and the dehydration time at 2-5 hours, yielding particles with a size of 0.5-2 mm and a specific surface area of ​​0.5-5 m². 2 / g of calcium fluoride adsorbent. After adsorption saturation, the calcium fluoride is discharged and added to a uranium tetrafluoride fluorination fluidized bed. The fluorination temperature is controlled at 400-500℃, and the reaction time is 10-40 min. Desorption is completed with the generation of hydrogen fluoride and uranium hexafluoride. The desorbed calcium fluoride is returned to the adsorption column for reuse. The hydrogen fluoride and uranium hexafluoride generated during desorption, along with the uranium hexafluoride produced during the fluorination reaction, are condensed and collected to recover uranium hexafluoride.

[0023] (3) Distillation purification: The gaseous mixture after step (2) is passed into the lower part of the distillation packed column. The temperature gradient of the column is controlled. Tungsten hexafluoride, molybdenum hexafluoride and vanadium pentafluoride are collected from the top of the column, uranium hexafluoride is collected from the middle part, and vanadium oxyfluoride is collected from the bottom of the column.

[0024] Specifically, the packing material of the distillation packed column is porous packing or triangular spiral packing, made of Monel. The porous packing has a pore size of 1-3mm, with all pores randomly connected. The triangular spiral packing has a specification of (2-5mm)×(2-5mm)×(5-10mm), and a packing height ≥1500mm. The bottom temperature of the distillation packed column is controlled at 110-120℃, the top temperature at 95-105℃, the pressure at 0.4-1.0MPa, and the single distillation time at 0.5-1h. The top reflux ratio is 10-30:1, and the uranium hexafluoride reflux ratio is 1-10:1.

[0025] Example 1 In this embodiment, the impurity content of crude uranium hexafluoride is as follows: antimony 10 μg / gU, titanium 8 μg / gU, chromium 23 μg / gU, molybdenum 102 μg / gU, vanadium 95 μg / gU, tungsten 65 μg / gU, and hydrogen fluoride 0.05%.

[0026] This embodiment uses the following process steps to prepare nuclear-grade uranium hexafluoride: (1) Pressure distillation of crude uranium hexafluoride Uranium hexafluoride containing fluorides such as molybdenum, tungsten, vanadium, titanium, chromium, and antimony, as well as hydrogen fluoride impurities, was added to a distillation vessel. The vessel was heated and the temperature was controlled at 90°C, and the pressure at 0.4 MPa. Stirring was continuous during distillation at a speed of 10 r / min, and the distillation time was 3 hours. This pressurized distillation process was repeated 6 times. After each distillation, 20% of the residue was discharged. Before discharging the uranium hexafluoride residue, the stirring speed was increased to 600 r / min, the crushing time was 1 minute, and the distillation temperature was increased to 150°C for another 0.5 hours of distillation.

[0027] (2) Adsorption of calcium fluoride The gaseous mixture obtained in step (1) is passed into a calcium fluoride adsorption column. The adsorption temperature is 90℃ and the adsorption contact time is 60min. The adsorption column is a three-column series adsorption. Hydrogen fluoride in the mixture is removed by selective adsorption of calcium fluoride.

[0028] Calcium fluoride was prepared by hydration. The dehydration temperature was 200℃ and the dehydration time was 5 hours, resulting in particles with a size of 0.5 mm and a specific surface area of ​​5 m². 2 / g of calcium fluoride adsorbent.

[0029] After adsorption saturation, the calcium fluoride is discharged and added to a uranium tetrafluoride fluorination fluidized bed. The fluorination temperature is controlled at 400℃ and the reaction time is 40 min. The calcium fluoride is desorbed along with the desorption of hydrogen fluoride and uranium hexafluoride. The desorbed calcium fluoride is then returned to the adsorption column for reuse.

[0030] (3) Distillation purification The gaseous mixture processed in step (2) is fed into the lower part of a packed distillation column. The temperature gradient of the column is controlled, with the bottom temperature at 110℃, the top temperature at 95℃, the pressure at 0.4MPa, and the single distillation time at 1h. The top reflux ratio is 20:1, and the uranium hexafluoride reflux ratio is 5:1. The packing material of the distillation column is porous Monel material with a pore size of 1mm and a packing height of 1500mm.

[0031] The impurity content of uranium hexafluoride after distillation purification is as follows: antimony 0.5 μg / gU, titanium 0.4 μg / gU, chromium 3 μg / gU, molybdenum 1.0 μg / gU, vanadium 1.1 μg / gU, tungsten 0.8 μg / gU, and hydrogen fluoride 0.005%, which meets the standard for nuclear-grade uranium hexafluoride.

[0032] Example 2 In this embodiment, the impurity content of crude uranium hexafluoride is as follows: antimony 10 μg / gU, titanium 8 μg / gU, chromium 23 μg / gU, molybdenum 102 μg / gU, vanadium 95 μg / gU, tungsten 65 μg / gU, and hydrogen fluoride 0.05%.

[0033] This embodiment uses the following process steps to prepare nuclear-grade uranium hexafluoride: (1) Pressure distillation of crude uranium hexafluoride Uranium hexafluoride containing fluorides such as molybdenum, tungsten, vanadium, titanium, chromium, and antimony, as well as hydrogen fluoride impurities, was added to a distillation vessel. The vessel was heated and the temperature was controlled at 120°C, and the pressure at 1.0 MPa. During distillation, the vessel was continuously stirred at a speed of 60 r / min for 0.5 h. This pressurized distillation process was repeated 7 times. After each distillation, 20% of the residue was discharged. Before discharging the uranium hexafluoride residue, the stirring speed was increased to 400 r / min, the crushing time was 10 min, and the distillation temperature was increased to 150°C for another 0.5 h of distillation.

[0034] (2) Adsorption of calcium fluoride The gaseous mixture obtained in step (1) is passed into a calcium fluoride adsorption column. The adsorption temperature is 120℃ and the adsorption contact time is 10min. The adsorption column is a three-column series adsorption. Hydrogen fluoride in the mixture is removed by selective adsorption of calcium fluoride.

[0035] Calcium fluoride was prepared by hydration. The dehydration temperature was 300℃ and the dehydration time was 2 hours, resulting in particles with a diameter of 2 mm and a specific surface area of ​​0.5 m². 2 / g of calcium fluoride adsorbent.

[0036] After adsorption saturation, the calcium fluoride is discharged and added to a uranium tetrafluoride fluorination fluidized bed. The fluorination temperature is controlled at 500℃, and the reaction time is 10 min. The calcium fluoride is desorbed along with the desorption of hydrogen fluoride and uranium hexafluoride. The desorbed calcium fluoride is then returned to the adsorption column for reuse.

[0037] (3) Distillation purification The gaseous mixture processed in step (2) is fed into the lower part of a packed distillation column. The temperature gradient of the column is controlled, with the bottom temperature at 120℃, the top temperature at 105℃, the pressure at 1MPa, and the single distillation time at 0.5h. The top reflux ratio is 30:1, and the uranium hexafluoride reflux ratio is 10:1. The packing material of the distillation column is triangular spiral packing made of Monel material, with specifications of 2mm×2mm×5mm and a packing height of 1600mm.

[0038] The impurity content of uranium hexafluoride after distillation purification is as follows: antimony 0.4 μg / gU, titanium 0.5 μg / gU, chromium 4 μg / gU, molybdenum 0.9 μg / gU, vanadium 1.0 μg / gU, tungsten 0.7 μg / gU, and hydrogen fluoride 0.006%, which meets the standard for nuclear-grade uranium hexafluoride.

[0039] Example 3 In this embodiment, the impurity content of crude uranium hexafluoride is as follows: antimony 10 μg / gU, titanium 8 μg / gU, chromium 23 μg / gU, molybdenum 102 μg / gU, vanadium 95 μg / gU, tungsten 65 μg / gU, and hydrogen fluoride 0.05%.

[0040] This embodiment uses the following process steps to prepare nuclear-grade uranium hexafluoride: (1) Pressure distillation of crude uranium hexafluoride Uranium hexafluoride containing fluorides such as molybdenum, tungsten, vanadium, titanium, chromium, and antimony, as well as hydrogen fluoride impurities, was added to a distillation vessel. The vessel was heated and the temperature was controlled at 110°C, and the pressure at 0.8 MPa. During distillation, the vessel was continuously stirred at a speed of 30 r / min for 1.5 h. This pressurized distillation process was repeated 5 times, and 20% of the residue was discharged after each distillation. Before discharging the uranium hexafluoride residue, the stirring speed was increased to 500 r / min, the crushing time was 5 min, and the distillation temperature was increased to 150°C for another 0.5 h of distillation.

[0041] (2) Adsorption of calcium fluoride The gaseous mixture obtained in step (1) is passed into a calcium fluoride adsorption column. The adsorption temperature is 100℃ and the adsorption contact time is 30min. The adsorption column is a three-column series adsorption. Hydrogen fluoride in the mixture is removed by selective adsorption of calcium fluoride.

[0042] Calcium fluoride was prepared by hydration. The dehydration temperature was 260℃ and the dehydration time was 3 hours, resulting in particles with a diameter of 1 mm and a specific surface area of ​​3 m². 2 / g of calcium fluoride adsorbent.

[0043] After adsorption saturation, the calcium fluoride is discharged and added to a uranium tetrafluoride fluorination fluidized bed. The fluorination temperature is controlled at 150℃, and the reaction time is 30 min. The calcium fluoride is desorbed along with the desorption of hydrogen fluoride and uranium hexafluoride. The desorbed calcium fluoride is then returned to the adsorption column for reuse.

[0044] (3) Distillation purification The gaseous mixture processed in step (2) is fed into the lower part of a packed distillation column. The temperature gradient of the column is controlled, with the bottom temperature at 115℃, the top temperature at 100℃, the pressure at 0.7MPa, and the single distillation time at 40min. The top reflux ratio is 30:1, and the uranium hexafluoride reflux ratio is 10:1. The packing material of the distillation column is triangular spiral packing made of Monel material, with specifications of 5mm×5mm×10mm and a packing height of 2000mm.

[0045] The impurity content of uranium hexafluoride after distillation purification is as follows: antimony 0.7 μg / gU, titanium 0.5 μg / gU, chromium 6 μg / gU, molybdenum 0.8 μg / gU, vanadium 0.9 μg / gU, tungsten 0.6 μg / gU, and hydrogen fluoride 0.007%, which meets the standard for nuclear-grade uranium hexafluoride.

[0046] Those skilled in the art will understand that the steps, measures, and solutions in the various operations, methods, and processes discussed in this application can be alternated, modified, combined, or deleted. Furthermore, other steps, measures, and solutions in the various operations, methods, and processes discussed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and solutions in the prior art that are similar to those disclosed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted.

[0047] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A process for the production of nuclear pure grade uranium hexafluoride, characterized in that, The method comprises the following steps: (1) Pressure distillation of crude uranium hexafluoride: crude uranium hexafluoride is added to a distillation kettle, the distillation kettle is heated and the temperature is controlled at 90-120°C, the pressure is controlled at 0.4-1.0 MPa, and stirring is continuously performed during the distillation process, the stirring time being 0.5-3 h, to obtain a gaseous mixture; (2) Absorption by alkaline earth metal fluoride: the gaseous mixture obtained in step (1) is subjected to absorption by alkaline earth metal fluoride, the absorption temperature being controlled at 90-120°C and the absorption contact time being 10-60 min, so as to remove hydrogen fluoride in the mixture by selective absorption; (3) Purification by rectification: the gaseous mixture treated in step (2) is introduced into the lower part of a rectification packed column, the temperature gradient of the column body is controlled, and the fluorides containing molybdenum, tungsten or vanadium are collected from the top of the column, uranium hexafluoride is collected from the middle of the column, and vanadyl fluoride is collected from the bottom of the column.

2. A process for the production of nuclear pure uranium hexafluoride according to claim 1, characterized in that, The stirring speed in step (1) is 10-60 r / min.

3. The process for the production of nuclear pure uranium hexafluoride as claimed in claim 1, wherein, The pressure distillation in step (1) is performed in a cycle: after each distillation, new crude uranium hexafluoride is added to the distillation kettle, mixed with the residual solid residue in the kettle, and the pressure distillation operation of step (1) is repeated.

4. A process for the production of nuclear pure uranium hexafluoride according to claim 3, characterized in that, The pre-operation before the discharge of the residue is as follows: the stirring speed is increased to 400-600 r / min, the residual solid material is crushed, the crushing time being 1-10 min, and the distillation temperature is increased to 120-170°C, the temperature being maintained to continue the distillation, the distillation time being 0-1 h, so as to reduce the residual amount of uranium hexafluoride in the discharged residue.

5. The method of claim 1 wherein the method is characterized by, In step (2), the absorption process is performed in the form of a series connection of absorption columns, and the absorption columns are all provided with heat preservation layers to maintain the absorption temperature.

6. The method of claim 1, wherein the method further comprises, The alkaline earth metal fluoride is prepared by a hydration method, the method comprising the following steps: The dehydration temperature is controlled at 200-300°C, the dehydration time is 2-5h, the particle size is 0.5-2mm, and the specific surface area is 0.5-5m 2 / g.

7. The method of claim 1, wherein the method further comprises, The alkaline earth metal fluoride in step (2) can be recycled and regenerated, and the steps are as follows: The absorption-saturated alkaline earth metal fluoride is added to a uranium tetrafluoride fluorination fluidized bed, the fluorination temperature is controlled at 400-500°C, and the reaction time is 10-40 min, so as to desorb hydrogen fluoride and uranium hexafluoride, the desorbed alkaline earth metal fluoride is returned to step (2) for recycling, and the desorbed hydrogen fluoride and uranium hexafluoride are collected together with the uranium hexafluoride generated by the fluorination reaction.

8. The method of claim 1, wherein the method further comprises, In step (3), the packing of the rectification packed column is porous packing or triangular spiral packing, the material of the packing is Monel material, and the packing height is ≥1500 mm; the pore size of the porous packing is 1-3 mm, and the specification of the triangular spiral packing is (2-5 mm)×(2-5 mm)×(5-10 mm).

9. The method of claim 1, wherein the method further comprises, In step (3), the temperature of the column kettle of the rectification packed column is controlled at 110-120°C, the temperature at the top of the column is controlled at 95-105°C, the operating pressure in the column is 0.4-1.0 MPa, and the single rectification time is 0.5-1 h.

10. A process for the production of nuclear pure uranium hexafluoride according to claim 9, characterized in that, The reflux ratio of the top of the rectification packed column is 10-30:1, and the reflux ratio of the collected uranium hexafluoride is 1-10:1.

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