Method for preparing uranium tetrafluoride by fluorinating U3O8 or UO3 at high temperature

Abstract

The invention provides a method for preparing uranium tetrafluoride by fluorinating U3O8 or UO3 by NH4F at high temperature, which comprises the following steps: firstly, weighing NH4F, U3O8 or UO3 and KF according to a certain proportion, fully conducting grinding, placing the ground materials in a graphite crucible, simultaneously inversely placing an alumina crucible on the graphite crucible, conducting heating to 700 DEG C in a programmed manner, fully conducting reacting for 3 hours, and then ending the reaction. At the moment, the sample in the graphite crucible is changed from black brown or light yellow powder to emerald green powder. Raman analysis and X-ray diffraction analysis are carried out on the product, it is proved that the obtained product is UF4, the fluorination rate is 75% and 69.1% respectively, and after UF4 is dissolved in high-temperature fused salt, the fused salt becomes emerald green from colorless and transparent. The invention provides the method for preparing UF4 in the atmospheric environment, and the operation does not need protective gas, so that the reaction equipment is relatively simple, and the preparation cost is reduced.

Description

technical field [0001] The present invention relates to a kind of U fluoride at high temperature 3 o 8 or UO 3 The method for preparing uranium tetrafluoride can be used in the technical field of spent fuel dry reprocessing. Background technique [0002] As a clean energy, nuclear energy has become an important part of my country's energy structure. my country's nuclear power construction continues the trend of rapid development over the years, and continues to maintain the first place in the world. With the development of nuclear power, the spent fuel of nuclear power plants will be continuously unloaded from the reactor. If it is not stored and processed safely away from the reactor in time, it will bring risks to the safe and stable operation of nuclear power plants. my country's short-term nuclear power plant spent fuel off-reactor storage and reprocessing capabilities are limited, and the demand for nuclear power plant spent fuel off-reactor storage and reprocessing...

AI Technical Summary

Problems solved by technology

[0004] with U 3 o 8 or UO 3 As a raw material, when uranium metal is prepared by molten salt electro-deoxidation, due to U 3 o 8 or UO 3 Insoluble in high-temperature molten salt, resulting in low electrolysis efficiency and long reaction time; at the same time, the U-O ion bond energy is large, and the reaction activation energy is large, which increases the difficulty of electro-deoxidation

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