Patent ID: 6692716
Filing Date: 2004-02-17
Classification: C01D,C05D

Abstract:
A method of formulating food grade sodium bicarbonate and potassium sulfate, comprising the steps of:a) providing a source of liquid sodium sulfate; b) providing a source of ammonium bicarbonate to precipitate sodium bicarbonate; c) contacting said sodium sulfate and said ammonium bicarbonate; d) precipitating sodium bicarbonate and forming a liquor; e) filtering said sodium bicarbonate; f) saturating liquor from step e) with sodium sulfate; g) contacting said liquor with ammonium bicarbonate, ammonia gas or carbon dioxide to precipitate further sodium bicarbonate; h) filtering precipitated sodium bicarbonate from step g); i) combining sodium bicarbonate precipitate from step e) and h) and washing to form food grade sodium bicarbonate; j) treating liquor from step i) with sulfuric acid to convert carbonate minerals to sulfate minerals and release carbon dioxide gas; k) cooling liquor from step j) to 0Â° C. to at least form Glauber's salt precipitate; l) heating liquor from step k) to between 30Â° C. and 40Â° C.; and m) precipitating potassium sulfate by contacting said liquor from step l) with potassium chloride.