CHLORIDE-SULFATE SEWAGE OR NATURAL WATERS TREATMENT METHOD Russian patent published in 1996 - IPC

FIELD: chemical, power and other industries, water preparation and purification of sewage and natural waters. SUBSTANCE: method provides for initial water multistage concentration by evaporation with production at last stage of calcium sulfate, after separation of which liquid phase is cooled to temperature of beginning of solid phase formation. Then mirabilite is crystalized from it under temperature of no higher than minus 10 C. Formed crystals are separated from liquid phase and the latter is sent for crystallization of sodium chloride, that is exercised due to dewatering with increase of concentration of magnesium salts up to 25 - 29 %. Sodium chloride crystals are separated fro magnesium salts solution. EFFECT: improved process. 1 dwg, 2 tbl