Preparation of anhydrous magnesium chloride melts comprising of that type, magnesium chloride, and production of magnesium metal

摘要

In accordance with the present invention, there is now provided a process for the production of anhydrous magnesium chloride-containing melt or electrolyte containing very low levels of MgO, typically less than 0.2 % by weight MgO, directly from hydrated magnesium chloride feeds. More specifically, the process comprises the steps of a) feeding hydrated magnesium chloride in a furnace containing molten eletrolyte from a magnesium electrolysis cell to produce a melt, the temperature in the furnace being maintained between 450 and 650 DEG C; b) simultaneously injecting an anhydrous hydrogen chloride-containing gas into the melt in an amount below the stoichiometric requirement of 2 moles of HC1 per mole of magnesium chloride produced from hydrated magnesium chloride, and agitating the melt to keep any magnesium oxide in suspension in the melt, to dehydrate the magnesium chloride and react with the MgO in the melt so that the melt contains not more than 0.2 % MgO on a 100 % magesium chloride equivalent basis, to form an enriched anhydrous magnesium chloride containing melt.