POTASSIUM SULFATE PRODUCTION PROCESS Russian patent published in 2003 - IPC

FIELD: industrial organic synthesis. SUBSTANCE: process comprises potassium chloride-mediated conversion of sodium sulfate followed by separation of resulting suspension into glaserite solution and glaserite, which is brought into the second potassium chloride-mediated conversion stage, after which resulting suspension is separated returning solution into the first conversion stage and low-grade potassium sulfate obtained in the second conversion stage is processed. In particular, low-grade potassium sulfate is treated with water and resulting suspension is subjected to hydraulic classification. Thus obtained sands are filtered off to recover potassium sulfate. Filtrate and hydraulic classification outflow are introduced into the second conversion stage simultaneously with potassium chloride contained in the portion of solution from the second conversion stage. According to invention, hydraulic classification is preferably conducted according to class 10 mcm and potassium chloride contained in the portion of solution from the second conversion stage, which is added portionwise or continuously, is preferably prepared observing liquid-to-solids ratio 2 to 5. Level of chloride ion in final product is below 0.1%. EFFECT: increased purity of product. 3 cl, 2 ex