Crystallization behavior of calcium carbonate polymorphs and the effect of magnesium ion

The crystallization of calcium carbonate was carried out by mixing the CaCl2 and Na2CO3 solutions, and the crystallization and transformation behavior of the polymorphs, and the effect of additives are investigated. It appeared that at 298 K both calcite and vaterite crystals tend to crystallize, however, the vaterite content is larger at 0.2 mol/l than that at 0.05 mol/l. The transformation rate and the of calcium ion concentration at the stationary value changes with the feed concentration of CaCl2. With magnesium chloride the transformation was retarded and the concentration of calcium ion was also influenced.