A PROCESS FOR CONVERTING NATURAL CALCIUM CARBONATE INTO PRECIPITATED CALCIUM CARBONATE

摘要

A process for converting natural calcium carbonate into precipitated calcium carbonate, involving treating the natural calcium carbonate with a sulfate to produce a gypsum and reacting the gypsum with at least one carbonate source to produce precipitated calcium carbonate. The crystalline polymorph, particle size, and various other characteristics of the precipitated calcium carbonate are controlled by varying conditions during the reacting. Since the natural calcium carbonate is not calcined, the process relates to a low energy method of producing precipitated calcium carbonate of controlled polymorph and particle size with limestone, marble, or chalk as the calcium source.