A COST-EFFECTIVE PROCESS FOR THE PREPARATION OF SOLAR SALT HAVING HIGH PURITY WHITENESS

摘要

The process of the invention deals with significant improvements in saltpurity and whiteness brought about through treatment of brine with alum priorto charging into crystallizers for solar salt production. The improvementsrealized are partly on account of elimination of suspended impurities likegypsum and clayey matter in the brine, which may otherwise be carried alongwith the brine in the crystallizer and finally end up in the salt, and partlydue to the improved crystal size and morphology that minimizes embeddedimpurities in the salt. Rain washing of the heaped salt has resulted in a saltwith greatly reduced calcium and sulphate impurity levels hitherto notachieved in solar salt production. Alum treatment by the process of theinvention requires no additional time or infrastructure and the cost of thetreatment works out to 3 U.S. cents per ton of salt. The process can beimplemented in any solar salt works.