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CN-121972466-A - Method and device for treating solid impurities

CN121972466ACN 121972466 ACN121972466 ACN 121972466ACN-121972466-A

Abstract

The application belongs to the technical field of uranium enrichment, and particularly relates to a method and a device for treating solid impurities. The method comprises the steps of introducing KrF 2 into a pipeline to be cleaned, so that KrF 2 reacts with uranyl fluoride in the pipeline to be cleaned to obtain UF 6 , kr and O 2 . The reaction byproducts of the method are basically only non-toxic and harmless substances such as inert gases krypton, oxygen and the like, so that the difficulty load and the danger of post-treatment of the products are reduced, the safety and the environment friendliness of the process are ensured, and under the conditions that the amount of the introduced KrF 2 is enough and the reaction condition is suitable, the solid impurities are completely removed.

Inventors

  • WAN YU
  • Fan Zengzu
  • GONG YIJIAN
  • CHEN YONGHAN
  • LI YANGYANG
  • WANG PENG
  • YANG CHANGHUA
  • JIN XIAODONG
  • CHEN FEI
  • FENG XUEZHI

Assignees

  • 中核陕西铀浓缩有限公司

Dates

Publication Date
20260505
Application Date
20251230

Claims (10)

  1. 1. A method of treating solid impurities, the method comprising: KrF 2 is introduced into the pipeline (8) to be cleaned, so that KrF 2 reacts with uranyl fluoride in the pipeline (8) to be cleaned to obtain UF 6 , kr and O 2 .
  2. 2. The method of treating solid impurities of claim 1, further comprising: After the reaction, the residue of the reaction was purged by introducing nitrogen into the pipe (8) to be purged, and UF 6 was recovered and separated from the residue.
  3. 3. The method of treating solid impurities according to claim 1, characterized in that said recovery separates UF 6 from said residue, in particular comprising: Introducing the purged gas into a zero-order cold trap (3), and condensing UF 6 and KrF 2 in the residues into solid state and attaching the solid state to the wall of the cold trap; After condensation is complete, the air inlet is closed, the temperature is raised to sublimate UF 6 out, and KrF 2 is maintained in solid state.
  4. 4. A method of treating solid impurities according to claim 3, wherein said elevating of said temperature to sublimate UF 6 out further comprises thereafter: leading sublimated UF 6 to a primary cold trap (4), and completely condensing UF 6 into a solid state; The air inlet was closed and the UF 6 was sublimated by warming, and UF 6 was purged to a dedicated high pressure storage tank with dry nitrogen.
  5. 5. The method of treating solid impurities according to claim 1, wherein said recovering separates UF 6 from said residue, and thereafter further comprising: The tail gas is led into a secondary cold trap (5) and Kr in the residue is recovered by condensation.
  6. 6. The method for treating solid impurities according to claim 5, wherein said condensing recovers Kr in said residue, in particular comprising: maintaining the temperature in the secondary cold trap (5) at-150 to-196 ℃ to liquefy Kr, and leading the rest tail gas out of the secondary cold trap (5).
  7. 7. The method of treating solid impurities according to claim 6, wherein said condensing recovers Kr in said residue, further comprising thereafter: And (3) introducing the residual tail gas into a copper mesh adsorption tower (6) and a sodium fluoride adsorption tower (7) to treat the escaped F 2 and HF.
  8. 8. A method of treating solid impurities according to any of claims 1-7, characterized in that said passing KrF 2 into the pipe (8) to be cleaned further comprises, before: and (3) breaking the air of the pipeline (8) to be cleaned by compressed nitrogen.
  9. 9. The method for treating solid impurities according to any one of claims 1 to 7, characterized in that said passing KrF 2 into the pipe (8) to be cleaned comprises: The solid KrF 2 in the krypton difluoride generator (1) is heated and vaporized, and is introduced into a pipeline (8) to be cleaned.
  10. 10. The device for treating the solid impurities is characterized by comprising a krypton difluoride generator (1), a liquid nitrogen generator (2), a zero-order cold trap (3), a first-stage cold trap (4), a second-stage cold trap (5), a copper mesh adsorption tower (6) and a sodium fluoride adsorption tower (7); The krypton difluoride generator (1) and the liquid nitrogen generator (2) are respectively communicated with a pipeline (8) to be cleaned, and the rear end of the pipeline (8) to be cleaned is serially connected with a zero-order cold trap (3), a first-order cold trap (4), a second-order cold trap (5), a copper mesh adsorption tower (6) and a sodium fluoride adsorption tower (7) one by one; The krypton difluoride generator (1) is used for introducing KrF 2 into a pipeline (8) to be cleaned so as to enable KrF 2 to react with uranyl fluoride in the pipeline (8) to be cleaned to obtain UF 6 , kr and O 2 ; the liquid nitrogen generator (2) is used for introducing compressed nitrogen into the pipeline (8) to be cleaned, and the pipeline (8) to be cleaned is broken by the compressed nitrogen; The zero-order cold trap (3) is used for recycling KrF 2 ,UF 6 to sublimate and export to the first-order cold trap (4); The primary cold trap (4) is used for completely condensing UF 6 into a solid state, leading out the residual gas to the secondary cold trap (5), sublimating UF 6 through heating, and recycling UF 6 ; The secondary cold trap (5) is used for condensing and recycling Kr in the residues, and the residual gas is led out to the copper mesh adsorption tower (6) and the sodium fluoride adsorption tower (7); The copper mesh adsorption tower (6) and the sodium fluoride adsorption tower (7) are respectively used for treating the escaped F 2 and HF.

Description

Method and device for treating solid impurities Technical Field The application belongs to the technical field of uranium enrichment, and particularly relates to a method and a device for treating solid impurities. Background Uranium hexafluoride (UF 6) gas is the core medium for uranium enrichment by centrifugation. In the uranium enrichment centrifugal cascade operation process, UF 6 is easy to react with moisture, pipes and the like due to unavoidable factors such as leakage, corrosion loss and the like of the system, and solid impurities such as uranyl fluoride (UO 2F2), uranium tetrafluoride (UF 4) and the like in the cascade system are generated. These solid impurities will deposit and block at key positions such as orifice plates, equipment material pipes, etc., causing frequent replacement, damage, etc. of key equipment, reducing production efficiency of the whole uranium enrichment factory, and bringing challenges to subsequent retirement work of uranium enrichment engineering. Disclosure of Invention The application aims to provide a method and a device for treating solid impurities, which solve the problems that in the prior art, the solid impurities are deposited and blocked at key parts such as a pore plate, a material pipe of equipment and the like, and the production efficiency of the whole uranium concentration plant is reduced. The technical scheme for realizing the purpose of the application comprises the following steps: a first aspect of an embodiment of the present application provides a method of treating solid impurities, the method comprising: KrF 2 was introduced into the pipe to be cleaned to react KrF 2 with uranyl fluoride in the pipe to be cleaned to give UF 6, kr and O 2. Optionally, the method further comprises: After the reaction is finished, nitrogen is introduced into the pipeline to be cleaned to purge the residue of the reaction, and UF 6 in the residue is recovered and separated. Optionally, the recovering and separating UF 6 in the residue specifically includes: Introducing the purged gas into a zero-order cold trap, and condensing UF 6 and KrF 2 in the residues into solid state and attaching the solid state to the wall of the cold trap; After condensation is complete, the air inlet is closed, the temperature is raised to sublimate UF 6 out, and KrF 2 is maintained in solid state. Optionally, the heating is performed to sublimate UF 6 out, and then further includes: leading sublimated UF 6 to a primary cold trap, and completely condensing UF 6 into a solid state; The air inlet was closed and the UF 6 was sublimated by warming, and UF 6 was purged to a dedicated high pressure storage tank with dry nitrogen. Optionally, the recovering and separating UF 6 in the residue further comprises: the tail gas is led into a secondary cold trap, and Kr in the residue is recovered by condensation. Optionally, the condensing recovers Kr in the residue, specifically including: Maintaining the temperature in the secondary cold trap at-150 to-196 ℃ to liquefy Kr, and leading the rest tail gas out of the secondary cold trap. Optionally, the condensing recovers Kr in the residue, and then further comprises: And introducing the residual tail gas into a copper mesh adsorption tower and a sodium fluoride adsorption tower to treat the escaped F 2 and HF. Optionally, the KrF 2 is introduced into the pipeline to be cleaned, and the method further comprises the following steps: and (5) breaking the air of the pipeline to be cleaned by using compressed nitrogen. Optionally, the KrF 2 is introduced into the pipeline to be cleaned, which specifically includes: the solid KrF 2 in the krypton difluoride generator is heated and vaporized, and then is introduced into a pipeline to be cleaned. The second aspect of the embodiment of the application provides a device for treating solid impurities, which comprises a krypton difluoride generator, a liquid nitrogen generator, a zero-order cold trap, a first-order cold trap, a second-order cold trap, a copper mesh adsorption tower and a sodium fluoride adsorption tower; The krypton difluoride generator and the liquid nitrogen generator are respectively communicated with a pipeline to be cleaned, and the rear end of the pipeline to be cleaned is serially connected with a zero-order cold trap, a first-order cold trap, a second-order cold trap, a copper mesh adsorption tower and a sodium fluoride adsorption tower one by one; The krypton difluoride generator is used for introducing KrF 2 into a pipeline to be cleaned so as to enable KrF 2 to react with uranyl fluoride in the pipeline to be cleaned to obtain UF 6, kr and O 2; the liquid nitrogen generator is used for introducing compressed nitrogen into the pipeline to be cleaned, and breaking the air of the pipeline to be cleaned by using the compressed nitrogen; The zero-order cold trap is used for recycling KrF 2,UF6 to sublimate and export to the first-order cold trap; The first-stage cold trap is used for comp