Process for purification of molten salt electrolytes

摘要

A process for purification of molten salt electrolytes containing magnesium chloride in which oxygen-containing impurities such as magnesium hydroxychloride are destroyed both electrolytically and chemically. The process comprises passing a direct current through a magnesium chloride-containing molten salt electrolyte, thereby electrolyzing a portion of the oxygen-containing impurities at the anode. In addition, the voltage and current of the direct current are sufficiently high to cause electrolysis of a small proportion of the magnesium chloride present in the electrolyte to thereby produce finely dispersed droplets of elemental magnesium in the electrolyte. The droplets of elemental magnesium react chemically with oxygen-containing impurities present in the electrolyte. The purified electrolyte is transferred to an electrolytic cell for the production of magnesium metal and chlorine gas.