PROCESS FOR PREPARATION OF HIGH OPACITY PRECIPITATED CALCIUM CARBONATE BY REACTING SODIUM CARBONATE WITH CALCIUM HYDROXIDE

摘要

In the process for making calcium carbonate by the double decompositionreaction of sodium carbonate and calcium hydroxide in aqueous reaction medium theimprovement of producing calcium carbonate having a scalenohedral particle shape anda rosette aggregate structure comprising adding said sodium carbonate in more than onestream to said calcium hydroxide over a period of 1 to 8 hours and maintaining saidreaction medium in the range of 80 to 140 F.