Employing high-temperature gas flux in a residual salt separation technique for pyroprocessing

Abstract

Residual salt separation is an essential step in pyroprocessing because its reaction products, as prepared by electrochemical unit processes, contain frozen residual electrolyte species, which are generally composed of alkali-metal chloride salts (e.g., LiCl, KCl). In this study, a simple technique that utilizes high-temperature gas flux as a driving force to melt and push out the residual salt in the reaction products was developed. This technique is simple as it only requires the use of a heating gun in combination with a gas injection system. Consequently, LiNO3–ZrO2 and LiCl–ZrO2 mixtures were successfully separated by the high-temperature gas injection (separation efficiency > 93%), thereby demonstrating the viability of this simple technique for residual salt separation. Keywords: Pyroprocessing, Molten salt, Residual salt separation, Liquid-solid separation, Heating gun