METHOD OF PRODUCTION OF POTASSIUM SULFATE Russian patent published in 1999 - IPC

FIELD: production of potassium sulfate from potassium chloride and ammonium sulfate in aqueous medium. SUBSTANCE: method includes interaction of ammonium sulfate solution with potassium chloride suspension followed by separation of double salt of potassium and ammonium sulfates and treatment of it with diluted potassium chloride solution at liquid-to-solid ratio of 0.7 to 1.5. product thus obtained is separated by means of filter, after which it is washed and dried. Filtrate is returned for preparation of potassium chloride suspension. Interaction of ammonium sulfate solution with potassium chloride suspension is effected at return of double salt of potassium and ammonium sulfates which is product of interaction of ammonium sulfate solution with potassium chloride suspension in amount of up to 100% and liquid phase to liquid-to-solid ratio lesser than or equal to 7 in reaction mixture. Ammonium sulfate solution is fed by portions when total consumption of potassium chloride increases by 5 to 15%. EFFECT: reduced content of finely-dispersed fractions (lesser than 0.08) in target product at simultaneous retaining of high quality. 2 tbl, 3 ex