METHOD OF PROCESSING SULFATE-CONTAINING SODA-POTASH SOLUTIONS Russian patent published in 2001 - IPC

FIELD: inorganic compounds technology. SUBSTANCE: invention relates to production of soda and potash from soda-potash solutions and likewise to nonferrous metallurgy, in which those solutions are produced as by-product in processing of alkaline aluminosilicate minerals into silica. Method includes multistep evaporation to isolate double sodium-potassium carbonate, separated from mother solution and utilized for processing a part of initial soda-potash solution, and evaporation of processed solution to isolate soda be separating it from mother solution. Mixing mother solution of soda with concentrated rest of initial solution gives solution with molar portion of potassium within a range of 73 to 94.8%. This solution is freed from sulfates on cooling and purified solution is used to isolate double sodium-potassium carbonate. The latter is processed by part of initial solution at 80 to 110 C, content of sulfate ion constituting 0.4-1.4 mol.% of the summary concentration of anions in solution. EFFECT: simplified process flowsheet and improved quality of soda product. 2 cl, 2 dwg, 2 tbl