METHOD FOR PREPARING POTASSIUM SULFATE Russian patent published in 2003 - IPC

FIELD: inorganic chemistry, chemical technology. SUBSTANCE: invention relates to method for preparing potassium sulfate from potassium chloride and ammonium sulfate in an aqueous medium. Method involves interaction of ammonium sulfate with potassium chloride in an aqueous medium, isolation of binary salt of potassium-ammonium sulfate, its treatment, separation of formed potassium sulfate from mother liquor and feeding mother liquor to the stage for preparing binary salt of potassium-ammonium sulfate, its washing out and potassium sulfate washing out. Potassium sulfate is washed out at value L:H 1.0 with alkaline reagent an aqueous solution in reagent consumption 15-100% of necessary stoichiometric amount for formation of ammonium hydroxide from ammonium ions in solid phase of potassium sulfate. Suspension is separated by filtration to isolate potassium sulfate of enhanced purity and liquid phase is fed to the stage of treatment of binary potassium- -ammonium sulfate salt. Alkaline reagent an aqueous solution is prepared as 1-3% concentration mainly using potassium hydroxide, sodium hydroxide, potassium carbonate as an alkaline reagent. For preparing alkaline reagent an aqueous solution water and depleted waters from the stage of potassium sulfate filtration are used. Method provides preparing chloride ions-free potassium sulfate of enhanced purity. EFFECT: improved preparing method, enhanced purity. 4 cl, 4 ex