Patent ID: 6479025
Filing Date: 2002-11-12
Classification: C01D

Abstract:
A process for producing sodium carbonate from a feedstream containing trona and insoluble impurities, comprising the steps of:(a) heating said feedstream in a calcining apparatus to a temperature of less than about 350Â° C. to form anhydrous sodium carbonate, wherein a heat source in said calcining apparatus is not in direct fluid communication with said feedstream; (b) contacting said anhydrous sodium carbonate with a saturated sodium carbonate brine solution for a residence time to form sodium carbonate monohydrate crystals; (c) separating at least a portion of said sodium carbonate monohydrate crystals from at least a portion of said insoluble impurities to form an impurity stream; and (d) allowing insoluble impurities to settle from said impurity stream to form a recycle stream.