Engineering-Scale Batch Purification of Ternary MgCl2-KCl-NaCl Salt Using Thermal and Magnesium Contact Treatment

Abstract

High-temperature molten chloride salts are a desirable heat transfer and energy storage media. The NaCl-KCl-MgCl2 is of particular interest because of its low melting point and relatively inexpensive constituents. Moisture and hydroxides must be removed from the salt to control corrosion at high temperatures. Previous studies have developed and demonstrated various techniques for bench-scale salt purifications. This paper details the system, process, and insight gained in the purification of a 200 kg scale batch of NaCl-KCl-MgCl2 salt at Oak Ridge National Laboratory.