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US 8,202,659 B2Granted
Method for obtaining sodium carbonate monohydrate crystals
AssigneeSolvay (Societe Anonyme)
InventorsFrancis Coustry, Michel Hanse
Life of this patent
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Abstract
A method for producing sodium carbonate monohydrate, according to which an aqueous sodium chloride solution (5) is electrolyzed in a membrane-type cell (1) from which an aqueous sodium hydroxide solution (9) is collected, and carbonated by direct contact with carbon dioxide (15) to form a slurry of crystals of a sodium carbonate monohydrate (16), and the slurry or its mother liquor is evaporated (3) to collect sodium carbonate monohydrate (18).
Claims16
A method for producing sodium carbonate monohydrate, comprising:
- electrolyzing an aqueous sodium chloride solution comprising 25 to 40% by weight of sodium hydroxide in a cell with an ion permselective membrane in order to produce chlorine and an aqueous solution comprising sodium hydroxide, and
- carbonating the aqueous solution comprising sodium hydroxide wherein the carbonation is carried out by directly contacting carbon dioxide with the aqueous solution comprising sodium hydroxide under conditions that cause the initial conversion of the aqueous solution into an aqueous slurry comprising sodium carbonate monohydrate crystals without evaporation.
Dependencies are inferred from the claim text.