The evaporation behaviors of rare-earth-doped FLiNaK melts during low-pressure distillation

Abstract

Low pressure distillation of FLiNaK containing rare earth fluorides was carried out to investigate evaporation behaviors of FLiNaK as well as decontamination of rare earth fluorides. Evaporation rate of NdF3–FLiNaK increased with rising temperature. Decontamination factors (DFs) of six rare earth elements were around 103 and 104 except europium due to the formation of EuF2. A higher DF of europium up to 1.4 × 103 was obtained upon the addition of oxidant CeF4. A hundred-gram scale experiment on FLiNaK containing NdF3 and EuF3 was performed, with a recovery ratio of 94.2% and the DF of europium to 2.4 × 103 at 900 °C.