Thermal dehydration of lanthanum chloride heptahydrate: thermodynamic approach

Abstract

Production of rare-earth metals from molten chloride electrolysis demands the use of anhydrous chloride in order to increase current efficiency. The main difficulty in obtaining these chlorides is due to oxychloride formation. Any thin film of the oxychloride or oxide will tend to inhibit the reduction process. The main purpose of this work was to develop an operational diagram related to the dehydration of lanthanum chloride heptahydrate. This diagram agrees with previous experimental data which have shown that dehydration of light rare-earth chlorides can be effective at relatively low temperatures in a dry HCl gas atmosphere.