Controlling Morphology and Specific Surface Area of Calcium Carbonate Particles with Humic Acid
利用腐植酸调控碳酸钙微晶形貌及比表面积

Humic acid (HA) was utilized as additive to prepare calcium carbonate particles via the carbonizing reaction between Ca(OH)2 and CO2. The powder with high specific surface area over 50 m2/g was prepared. BET method was used to analyze the BET specific surface area and pore-size distribution of the as-made products. XRD and SEM analysis was employed to investigate the morphology and composition of the calcium carbonate particles in the reaction process. The results show that humic acid could increase the specific surface area and change the crystal morphology at the same time. Morphology of the calcium carbonate fine particles graduated from sphere-like into rod-like, and then into cubic-like shape. A proposed mechanism based on the results of SEM and XRD analysis was developed to explain the phenomena.