Phase Change of Calcium Carbonate by Adding Polymers

Phase change of calcium carbontae crystals in crystallization of precipitated calcium carbonate was researched by adding additives such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), citric acid (CIT) and pyromellitic amid (PMA). At low temperature , calcite crystal was made. At high temperature , aragonite crystal was made without additives. At middle temperature and , Aragonite crystal also made by adding EDTA, DTPA. The crystal growth of Aragonite was retarded by the presence of CIT, PMA and the single phase of calcite was made. It was found that additives were important factors to make the single phase of calcium carbonate.