Patent ID: 6776972
Filing Date: 2004-08-17
Classification: C01D,C02F,Y02A,Y02W

Abstract:
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 29-32Â° Beâ€² 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 35.5Â° Beâ€² 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).