METHOD OF EXTRACTION OF SODIUM SULFATE AND CHLORIDE FROM MINERALIZED WATER Russian patent published in 2006 - IPC C02F9/10 C02F103/08 

FIELD: treatment of mineralized water containing admixtures in form of sodium sulfate and chloride.

SUBSTANCE: proposed method consists in preliminary softening of water, concentration of salts for obtaining pure water and brine, partial alkalizing and additional saturation of brine, cooling of brine at separation of sodium sulfate crystals, boiling-down of mother solution and cooling at extraction of remaining sodium chloride; brine is additionally saturated with sodium chloride to the following ratio: Na₂SO₄:1: (1.6-2.0); then, mirabilite is subjected to crystallization at temperature of from (-8) to (-10)°C; extracted mirabilite crystals are washed with saturated sodium sulfate solution at temperature of 40°C at ratio of washing solution to mirabilite of 1:1 returning it to mirabilite crystallization process; after mirabilite has been freed from mother solution, part of sodium chloride is extracted, washed with sodium chloride solution saturated at temperature of 20°C at ratio of flushing solution to sodium chloride of (0.5-1.0): 1 and boiled-down solution with remaining part of sodium chloride and flushing solution is divided into three flows. At stage of extraction of sodium chloride, no more than 60% of sodium chloride is subjected to crystallization.

EFFECT: improved grade of sodium sulfate and chloride due to increased concentration of main agent; reduced content of admixtures in commercial products.

2 cl, 1 dwg, 1 tbl, 16 ex