METHOD FOR PRODUCTION OF MAGNESIUM FROM OXYGEN- CONTAINING STOCK THROUGH AMMONIUM CARNALLITE Russian patent published in 1999 - IPC

FIELD: nonferrous metallurgy. SUBSTANCE: invention can be, in particular, used when producing magnesium from magnesite with complete or partial consumption of chlorine as recycling product required for converting magnesium oxide compounds into chlorides. Raw material is crushed, leached with hydrochloric acid and ammonium chloride solution. Resulting solution is treated with chlorine, freed of impurities, and subjected to absorption with ammonium chloride. Solution containing less than 23 wt % of magnesium chloride is evaporated to crystallize ammonium carnallite, which is dehydrated and decomposed in the melt of depleted electrolyte. Released magnesium chloride is electrolyzed and ammonium chloride is treated with post-leaching solution supplemented by mother solution after crystallization. Hydrogen chloride and ammonium chloride-containing gases released during dehydration of carnallite are treated with condensate collected in the course of evaporation of magnesium chloride and ammonium chloride solution to give hydrochloric acid and ammonium chloride solution containing less than 18 wt % of HCl suitable for leaching initial raw material. EFFECT: reduced power consumption and improved environmental condition. 5 cl, 1 dwg