Factors affecting the phase and morphology of CaCO3 prepared by a bubbling method

Precipitated calcium carbonate (PCC) was prepared by bubbling a CO2/N2 mixed gas into a CaCl2 solution. The influence of preparation conditions on the phase and morphology of PCC was discussed with the help of XRD and SEM measurements. The results showed that the initial CaCl2 concentration, flow rate and temperature play an important role on the morphology of PCC. At low initial CaCl2 concentration or high flow rate, spherical vaterite was preferably formed. Otherwise, the rhombic calcite was ready to form. Temperature is a determining factor on the formation of aragonite. Needle-like aragonite was precipitated at 60 °C. The results also indicated that both the bubbling time and stirring rate have a minor effect on the phase and morphology of PCC.