Dispersive calcium carbonate (CaCO3) particles were synthesized at 40 degrees C via the modified carbonation route developed in this paper. The influence of M9Cl2 on the dispersion behavior of the slaking slurry and the carbonation product were investigated using a laser particle size analyzer and a zeta potential analyzer, the corresponding changes of the morphology and the structure were identified by the field scanning electron microscopy (FSEM) and X-ray diffractometry (XRD), respectively. The experimental results indicated that the addition of MgCl2 in the Ca(OH)(2) slurry converted the Ca(OH)(2) agglomerates to the dispersive Mg(OH)2 particles, the carbonation of the slaking slurry containing Mg(OH)(2) and CaCl2 led to the formation of the dispersive CaCO3 (calcite) cubic particles with a particle size of 0.3-0.8 mu m and a mean agglomerate size of 1.3 mu m. (c) 2005 Elsevier B.V. All rights reserved.