Vacuum Distillation Of A Mixture Of Licl-kcl Eutectic Salts And Re Oxidative Precipitates And A Dechlorination And Oxidation Of Re Oxychlorides

摘要

In this study, a vacuum distillation of a mixture of LiCl-KCl eutectic salt and rare-earth oxidative precipitates was performed to separate a pure LiCl-KCl eutectic salt from the mixture. Also, a dechlorination and oxidation of the rare-earth oxychlorides was carried out to stabilize a final waste form. The mixture was distilled under a range of 710-759.5 Torr of a reduced pressure at a fixed heating rate of 4℃/min and the LiCl-KCl eutectic salt was completely separated from the mixture. The required time for the salt distillation and the starting temperature for the salt vaporization were lowered with a reduction in the pressure. Dechlorination and oxidation of the rare-earth oxychlorides was completed at a temperature below 1300℃ and this was dependent on the partial pressure of O_2. The rare-earth oxychlorides (NdOCl/PrOCl) were transformed to oxides (Nd_2O_3/PrO_2) during the dechlorination and oxidation process. These results will be utilized to design a concept for a process for recycling the waste salt from an electrorefining process.