Patent ID: 6399038
Filing Date: 2002-06-04
Classification: C01D

Abstract:
A process for producing sodium carbonate, comprising the steps of:successively calcining a sodium sesquicarbonate ore to form a calcined ore comprising anhydrous sodium carbonate substantially free of sodium sesquicarbonate; dispersing said calcined ore in an aqueous solution substantially saturated with hydrated sodium carbonate to form an aqueous suspension; aging said aqueous suspension to crystallize hydrated sodium carbonate having an average diameter greater than an average diameter of said calcined ore, the aging step further comprising extracting a fraction of said suspension, processing said fraction in a particle size classifier to divide a solid part of said fraction into a fine particle size class and a coarse particle size class, said fine particle size class having a particle diameter less than said average diameter of said hydrated sodium carbonate, discarding said fine particle size class, and recycling said coarse particle size class into said aqueous suspension; collecting an aqueous slurry of a powder comprising crystals of hydrated sodium carbonate; and subjecting said powder to a particle size classification.