Process for production of rhombic shaped precipitated calcium carbonate
AssigneeECC International Limited
InventorsVasant D. Chapnerkar, Mohan N. Badgujar
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Abstract
A process for producing rhombic or barrel shaped precipitated calcium carbonate. Quicklime is slaked in an aqueous solution containing about 0.1% to about 2% by weight of a sugar, based upon the weight of the CaCO.sub.3 to be produced. Carbon dioxide is added to the slaked lime slurry at a preferred temperature of about 50.degree. F.-70.degree. F. until the pH drops from about 11-12 to about 7-8.
Claims14
An improved process for producing rhombic shaped precipitated calcium carbonate comprising:
- (a) slaking quicklime to form slaked lime in an aqueous solution containing about 0.01% to about 2% by weight of sugar, based on the weight of the calcium carbonate to be produced, to form a slaked lime slurry;
- and
- (b) adding carbon dioxide to the slaked lime slurry at an initial temperature in the range of about 40.degree. F.-80.degree. F. until the pH drops from about 11-12 to about 7-8 to precipitate the rhombic shaped calcium carbonate having a surface area of 2-20 m.sup.2 /g.
A process in accordance with claim 2, wherein the said initial temperature at which said carbon dioxide is added is in the range of 50.degree. F. to 70.degree. F.
Dependencies are inferred from the claim text.