Production of calcium carbonate
AssigneeImperial Chemical Industries PLC
InventorRichard Derek Anthony Woode
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Abstract
Calcium carbonate is manufactured by the carbonation of an aqueous suspension of calcium hydroxide in the presence of a complex-forming agent for calcium ions which is added subsequently to the primary nucleation stage, and preferably during a first carbonation stage. Optionally there is also added a long-chain fatty acid or long-chain fatty acid salt, preferably after a final carbonation stage.
Claims9
In a process for the manufacture of calcium carbonate by carbonating an aqueous suspension of calcium hydroxide to produce calcium carbonate and separating the thus formed calcium carbonate, the improvement which comprises adding to the suspension, subsequently to a calcium carbonate primary nucleation stage of the carbonation step and before completion of the carbonation step, a complex-forming agent for calcium ions.
Dependencies are inferred from the claim text.