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

Precipitated calcium carbonate (PCC) was prepared by bubbling a CO 2 /N 2 mixed gas into a CaCl 2 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 CaCl 2 concentration, flow rate and temperature play an important role on the morphology of PCC. At low initial CaCl 2 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.