METHOD FOR TREATING WASTES RESULTING FROM PROCESSING CRUDE POTASSIUM SALTS AND CONSTITUTED, PREDOMINANTLY, BY SODIUM SULFATES Russian patent published in 1998 - IPC

FIELD: inorganic chemistry; production of potash fertilizers; environmental control. SUBSTANCE: method is based on treating wastes constituted by sodium SULFATES by subjecting them to exchange reaction with potassium chloride to ultimately produce potassium sulfate and water. Exchange reaction is carried out in single stage at temperature 5-50 C, preferably 20-30 C, to obtain slurry consisting of potassium sulfate $$$ and mother liquor, composition of which based on 1000 kmole water, corresponds to the following: 11.5-15.0 kmole of $$$, 2.4-3.0 kmole of sodium sulfate and 23.0-43.6 kmole of $$$. Potassium sulfate is mother liquor saturated with potassium sulfate, followed by drying it. Potassium sulfate mother liquor is mixed with KCl-NaCl mixture taken, predominantly, in the form of KCl-NaCl crystallizate, in such weight ratio as to form pure potassium chloride crystallizate, saturated KCl and substantially saturated NaCl solution. If necessary, KCl crystallizate is fully or partially, as starting material, recycled to process step of producing potassium sulfate, and/or saturated KCl and substantially saturated NaCl solution are recycled back to circulating system of chemical plant for processing crude potassium salts. EFFECT: higher efficiency. 5 cl, 1 dwg