四氟化铀和四氟化钍的高温水解

为适应钍基熔盐堆核燃料水法后处理的需求,需将乏燃料中难溶的氟化物转化为相应的氧化物形式,因此提出了高温水解的方法来实现这一目的。研究了UF4、ThF4在不同反应温度和反应时间下的高温水解行为,对其水解产物进行了结构表征和溶解实验的研究。结果表明,UF4、ThF4分别在300℃和350℃即可全部转化为相应的氧化物UO2.25和ThO2。溶解实验结果表明,二者的高温水解产物较易溶解在3mol/L HNO3和Thorex试剂中。

Pyrohydrolysis of Uranium Tetrafluoride and Thorium Tetrafluoride

To meet the needs of the aqueous-reprocessing of used fuel from thorium molten salt reactor, the insoluble fluorides need to be converted into their corresponding oxides form. To realize this, a pyrohydrolysis method was proposed. The pyrohydrolysis behavior of UF₄ and ThF₄ under different temperature and time was studied, and the structural characterization of the pyrohydrolysis products and the dissolution tests of the products were performed. The results show that, UF₄ and ThF₄ are entirely converted into their corresponding oxides UO_2.25 and ThO₂ at 300℃ and 350℃. The results of the dissolution tests show that the pyrohydrolysis products of both UF₄ and ThF₄ can easily dissolved in 3 mol/L HNO₃ and Thorex solution, respectively.