Thermodynamic analysis of the derydration of light rare-earth chlorides

The dehydration of light rare-earth chlorides, have shown to be the critical step for the production of michmetal by molten salt electrolysis. From the technical literature, unfortunately in their mother language, it was shown that Russian researchers studied this problem for about 30 years ago (1969 to 1973). Recent studies (from 1997 to 1998) on dehydration of neodymium, lanthanum, cerium and samarium chlorides, have shown the use of mixed solvents (water + alcohol) in a preliminary step followed by a thermal treatment with a controlled atmosphere (HCL (g) or HCL (g) + Argon). Complementing this review, this paper presents the thermodynamic evaluation of the dehydration of light rare-earth chlorides, showing the effects of temperature, water vapor pressure, hydrochloric gas pressure and inert gas pressure