PRECIPITATION OF CALCIUM-CARBONATE IN A CALCIUM NITRATE AND MONOETHANOLAMINE SOLUTION

High-purity precipitated calcium carbonate has been produced in the la boratory by carbonation of a solution of calcium nitrate and monoethan olamine. The process was traced by measurements of the change in Ca co ncentration and in electrical conductivity of the solution. The kappa- t and c(Ca)-t curves were analyzed to determine the effect of temperat ure and concentration of carbon(IV) oxide on the process of carbonatio n. The samples obtained were mainly of aragonite and vaterite crystal modifications with traces of calcite. The relationship between the min eralogical composition and particle size (morphology) and operating co nditions was examined as well.