Separation of Pure LiCl-KCl Eutectic Salt from a Mixture of LiCl-KCl Eutectic Salt and Rare-Earth Precipitates by Vacuum Distillation

摘要

In this study, the vacuum distillation of LiCl-KCl eutectic salt in a mixture of LiCl-KCl eutectic salt and rare-earth precipitates was carried out to evaluate the vaporization characteristics of LiCl-KCl eutectic salt. It was confirmed that the required time for salt vaporization was reduced by a reduction in the pressure. It appeared that the vaporization of LiCl-KCl eutectic salt containing rare-earth precipitates was decreased in comparison with that of pure salt because the salt adhered to the fine particles of the rare-earth precipitates. However, the distillation of the salt was almost achieved by elevating the surface area and further reducing the pressure. The distilled salt from the mixture consisted of 43.7 wt% LiCl and 56.3 wt% KC1. It is thought that the recovered salt can be reused because its composition is similar to the mixed ratio (44.2 wt% LiCl: 55.8 wt% KCl) of the salt used in an electrorefining process.