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 decomposition reaction of sodium carbonate and calcium hydroxide in aqueous reaction medium th e improvement of producing calcium carbonate having a scalenohedral particle shape and a rosette aggregate structure comprising adding said sodium carbonate in more th an one stream to said calcium hydroxide over a period of 1 to 8 hours and maintaining s aid reaction medium in the range of 80 to 140 F.