Patent ID: 6890509

Claim:
A process for recovery of low sodium salt from bittern, comprising the steps of: a) treating the bittern with calcium chloride solution to produce insoluble calcium sulfate, b) separating calcium sulfate of step (a) to obtain desulphated bittern, c) evaporating the desulphated bittern of step (b) in solar pans until a density ranging from 30 to 33° Bé is reached, with deposition of salt in pans, d) removing the salt deposit in step (c) to obtain concentrated desulphated bittern, e) feeding the concentrated desulphated bittern of step (d) to carnallite pans and continuing the evaporation to cause the deposition of a solid mixture, f) separating the solid mixture of step (e) constituting a mixture of sodium chloride and carnallite (KCl.MgCl 2 .6H 2 O) from carnallite pans for obtaining liquid bittern, g) treating with stirring the solid mixture of step (f) with water for a period of 20-60 minutes to produce low sodium salt solid and a liquid bittern in equilibrium with low sodium salt, containing mainly magnesium chloride with dissolved sodium chloride and potassium chloride, h) separating the solid from the liquid bittern of step (g) by centrifugation, and obtaining supernatant liquor, i) drying the solid of step (h) at a temperature ranging from 90-130° C. to obtain low sodium salt, j) recycling the supernatant liquor of step (h) to the carnallite pans for recovery of sodium and potassium salt in the presence of an additive, and k) treating the dried product of step (i) with an alkali salt and an additive to obtain an iodised low sodium salt.