abstract |
The calcium carbonate is prepared by: (a) slaking quicklime in an aqueous medium; (b) carbonating and neutralising the suspension of slaked lime formed in step (a) using a gas comprising carbon dioxide; and (c) separating the precipitated calcium carbonate formed in step (b) from the aqueous medium in which it is suspended. There is added 0.1% to 2% by weight, based on the weight of dry calcium oxide, of a reagent having one or more active hydrogen atoms (or a salt thereof), to the aqueous medium in which the quicklime is slaked in step (a). |