Chemical Sciences

The present invention is directed to a novel integrated process for the recovery of sulphate of potash (SOP) from sulphate rich bittern. The process requires bittern and lime as raw materials. Kainite type mixed salt is obtained by fractional crystallization of the bittern, and is converted to schoenite which is subsequently reacted with muriate of potash (MOP) for its conversion to SOP. End liquor from kainite to schoenite conversion (SEL) is desulphated and supplemented with MgCl2 using end bittern generated in the process of making carnallite. Decomposed carnallite liquor produced is reacted with hydrated lime for preparing CaCl2 solution and high purity Mg(OH)2 having low boron content. It is shown that the liquid streams containing potash are recycled in the process, and the recovery of potash in the form of SOP is quantitative