INTEGRATED PROCESS FOR THE SIMULTANEOUS RECOVERY OF INDUSTRIAL GRADE POTASSIUM CHLORIDE AND LOW SODIUM EDIBLE SALT FROM BITTERN

摘要

Process for simultaneous recovery of KCl and KCl-enriched edible salt comprises: (i) desulphatation of bittern with CaCl2; (ii) subjecting desulphated bittern to evaporation; (iii) mixing desulphated bittern of step (ii) with concentrated MgCl2-solution to obtain carnallite; (iv) decomposing carnallite with water to obtain KCl and residual bittern; (v) concentrating residual bittern to obtain NaCl and KCl in bittern as crude carnallite and carnallite decomposed liquor; (vi) decomposing crude carnallite of step (v) with water to produce KCl-enriched low sodium salt, as well as carnallite decomposed liquor; (vii) collecting carnallite decomposed liquor of steps (v) and (vi) and treating with lime to generate Mg(OH)2 and filtrate containing CaCl2 and KCl; (viii) recycling the filtrate of step (vii) to step (i), while recovering KCl lost in carnallite decomposed liquor; (ix) recycling end bittern of step (iii) for production of carnallite and CaCl2; (x) utilizing excess MgCl2 to recover bromine and obtain MgCl2.6H2O.