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.