温度与气压对LiF蒸发速率的影响

摘要

Low pressure distillation is a preferred technology for recycling the fluoride carrier (7 LiF-BeF2 )of molten salt reactor system.In this study,the thermal weight reductions of the LiF salt during low pressure distillation were observed using a salt evaporation furnace for the thermogravimetric analysis,and the evaporation rate of LiF salt was investigated under different pressures and evaporation temperatures.It was found that the evaporation rate of LiF increased sharply with increasing evaporation temperature as well as decreasing pressure.This may contribute to the boiling of LiF salt under low pressures.The effect of the boiling of LiF salt on the recovery of fluoride was also studied in this work.These re-sults are not only important to understand the distillation behaviors of LiF salt but also pro-vide critical information for parameter optimization of the carrier recovery.%减压蒸馏技术是钍基熔盐反应堆燃料处理中回收和纯化核燃料载体氟盐(7 LiF-BeF2)可选的技术。本工作使用自行设计并研制的热失重蒸发炉，通过观察燃料载体盐的主要成分 LiF在减压蒸馏过程中的失重行为，研究了蒸发温度和气压对 LiF蒸发速率的影响。结果表明：LiF 的蒸发速率在随着蒸发温度的升高以及气压下降而增大的变化中存在着明显的拐点，蒸发速率的突变可以用熔盐在低气压条件下的沸腾来解释。并进一步讨论了熔盐的沸腾对减压蒸馏回收和纯化燃料载体氟盐的影响。