improved method for the extraction of salt by evaporation crystallization essentially from a solution with hochsuspension under recovery of abwaesser for evaporation

摘要

A salt, esp. sodium chloride, is obtd. by evaporation-crystallisation from a soln. contg. a high suspension of calcium sulphate; to prevent a deposition of scale in the equipment from the undersired constituents in the soln. the water from one or more evaporators, after clarification, is subjected to cooling to cause the suspended micro crystals of calcium sulphate to become dissolved; the water treated in this way is then returned to one of the evaporators. Pref. the clarification stage consists of heating the effluent from the evaporator, causing pptn. of the supersatd. calcium sulphate.