METHOD OF PRODUCING MAGNESIUM FROM SULFATE-CONTAINING RAW MATERIAL Russian patent published in 1997 - IPC

FIELD: electrolytic metal production. SUBSTANCE: method includes producing magnesium chloride solutions by way of interacting magnesium sulfate with calcium chloride (from lime milk), electrolytic chlorine and hydrogen chloride contained in effluent gases from dehydration stage; separating calcium sulfate; producing carnallite or bischofite from magnesium chloride solutions; their dehydration and electrolysis to yield magnesium and chlorine. Method is distinguished by that at least a part of electrolytic chlorine is first reduced in the torch of burning hydrogen-containing fuel to form heated HCl-containing furnace gases which are used to dehydrate magnesium chloride raw material. Hydrogen chloride is then neutralized by way of absorbing it in lime milk and produced calcium chloride at least partly is used in production of magnesium chloride solutions. Dehydration of raw material with furnace gas can be performed in fluidized layer, and final dehydration stage in electrolyzer melt. EFFECT: reduced magnesium and chlorine loss. 3 cl