Effect of flow rate and CO2 content on the phase and morphology of CaCO3 prepared by bubbling method

Calcium carbonate particle attracts more and more attention because of its wide application in papermaking, rubbers, plastics and paints. In this paper, the CaCO3 particles were prepared by passing the mixed gas (CO2/N2) into CaCl2 solution. The effect of flow rate and CO2 content on the phase and morphology of precipitated CaCO3 was investigated with the help of SEM and XRD measurements. Both the results of SEM and XRD showed that more vaterite was formed at a high flow rate or high CO2 content, which was attributed to the slowing down of the transformation of vaterite to calcite. The change of pH and reaction time with the flow rate was also studied and the dissolution of carbon dioxide was analyzed.