MAGNESIUM PRODUCTION WASTE PROCESSING METHOD Russian patent published in 2005 - IPC

FIELD: nonferrous metallurgy.

SUBSTANCE: invention relates to processing of solid salts waste produced in production of magnesium via electrolysis of magnesium chloride stock, said processing leading to manufacture of commercial products, in particular mineral fertilizers. Process comprises crushing salt waste, leaching washed solid phase with concentrated potassium chloride solution, separating mother liquor from solid potassium chloride, and drying the latter. According to invention, mother liquor is treated with sodium carbonate solution to form suspension of magnesium hydrocarbonate, which suspension is then separated into solid magnesium hydrocarbonate and filtrate. Solid magnesium hydrocarbonate is additionally washed and calcined to give magnesium oxide, while filtrate is heated until sodium chloride-saturated solution is formed, which is allowed to crystallize producing sodium chloride. Solid potassium chloride is leached with water in the second step at temperature up to 25°C. Mother liquor, prior to be treated with sodium carbonate solution, is settled, after which clarified part thereof is passed to treatment stage and suspension is returned to leaching stage. Magnesium hydrocarbonate is washed with water, solid potassium chloride and sodium chloride are dried in fluidized-bed furnace.

EFFECT: enabled production of commercial magnesium and sodium compounds.

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