calcium carbonate | chemical compound | Britannica
Calcium carbonate (CaCO 3 ), also used as a filler, is prepared by precipitation by the reaction of milk of lime with either carbon dioxide (CO 2) or soda ash (sodium carbonate, Na 2 CO 3 ). Calcium carbonate as a paper filler is used mainly to impart improved brightness, opacity, and.. Read More. biological pump of carbon dioxide.