METHOD OF RECOVERING MAGNESIUM OXIDE FROM NATURAL BRINES Russian patent published in 2003 - IPC

FIELD: inorganic compounds technology. SUBSTANCE: high-mineralized brine is cooled to temperature between +18 and -25 C to separated crystals CaCl₂•6H₂O. Remaining brine is then diluted, aerated, and precipitated iron hydroxide is separated. Brine is further treated with lime milk prepared by firing dolomite limestone and resulting pulp is thickened in presence of polyacrylamide to give calcium chloride solution and magnesium hydroxide precipitate. The latter is filtered off and washed. Pulp is carbonized to give magnesium bicarbonate solution and solid precipitate. The former is heated to boil during which time magnesium carbonate precipitates and is then subjected to calcination. Calcium chloride solution is processed to dissolve crystals CaCl₂•6H₂O to produce heavy salt solutions. EFFECT: extended resource for production of magnesium oxide. 3 cl, 5 dwg, 3 tbl, 7 ex