METHOD OF PROCESSING SODA-POTASH SOLUTION Russian patent published in 2002 - IPC

FIELD: nonferrous metallurgy, particularly, processing of soda-potash solutions obtained in processing of nepheline raw materials into alumina and soda-potash products. SUBSTANCE: method includes polythermal evaporation of soda-potash solution with separating successively from it productive soda, circulating soda-potash salt, productive potash and return of potash mother liquor to process cycle of alumina production. Reduced in potash mother liquor directed to process cycle of alumina production is molar potassium index to 55 ± 5% with concentration of titrated alkali in solution of 260-300 g/l in terms of Na₂O and solution temperature of 40-60 C, and it is purified from salts of chromium, iron and other associated impurities by hydrochemical conversion of potash mother liquor of sodium sulfate salt or its mixture with soda with precipitation of productive potassium sulfate. Invention ensures reduction of losses of potassium alkali and consumption of lime in process cycle of alumina production, reduction of specific flow of solutions, circulating double salt and steam consumption in process cycle of soda-potash production. EFFECT: improved quality of produced potash. 2 dwg, 1 tbl