A modified carbonation process for the synthesis of super-fine calcium carbonate particles from Ca(OH)2 slurry at room temperature using a CO2-air gas mixture was investigated, The adaptation of a radial-shaped sparger and the addition of chemicals such as ZnCl2 and EDTA accelerated the carbonation process, thus reducing the diameter of the precipitated calcium carbonate particles. Thermodynamic calculation results showed that the role of EDTA in the carbonation process was mainly through the complex interaction between EDTA and Ca2+.