Recovery of common salt and marine chemicals from brine

A process for recovery of common salt and marine chemicals from brine in an integrated manner, said process comprising the sequential steps of:

• (i) treating brine with a composition comprising calcium chloride to produce a calcium sulphate precipitate;
• (ii) seperating the precipitated calcium sulphate from the brine to obtain partly desulpahted brine;
• (iii) treating the partly desulpahated brine obtained in step (ii) with barium chloride to obtain substantially desulphatated brine;
• (iv) evaporating the substantially desulphated brine thus obtained in step (iii) to a density of 29-32° Be′ to obtain crystals of common salt having a negligible amount of sulphate salts, and a bittern;
• (v) washing the common salt thus obtained in step (iv) with water or dilute brine to remove adhering chlorides of calcium and magnesium;
• (vi) evaporating the bittern obtained in step (iv) up to a density of about 35.5° Be′ to obtain crude carnallite and a concentrated end bittern comprising magnesium chloride and enriched bromide;
• (vii) solidifying a part of the end bittern and calcining the solidifed part to produce solid magnesium oxide and hydrochloric acid;
• and
• (viii) reacting the hydrochloric acid produced in step (vii) with a calcerous material comprising limestone to provide calcium chloride, and recycling the calcium chloride to step (i).