Abstract: In the preparation of bismuth oxychloride（BiOCl） by hydrolysis method and with bismuth salt as raw material， the morphology，particle size，and dispersibility of BiOCl crystals would be influenced by the crystal nucleation and growth rate of BiOCl.In allusion to the problems，the crystal nucleation and growth kinetics of BiOCl were investigated by intermittent dynamic method，the dynamic model of crystallization process was established by moment transformation method and the kinetic parameters were obtained by least square method for the multivariate linear regression.Results showed that the growth of BiOCl obeyed the size-independent growth model when the particle size was larger than 3 μm；and that both of the suspension density and supersaturation had significant effect on the nucleation rate；and the supersaturation had a greater effect on nucleation rate than on the growth rate.

Key words: bismuth oxychloride, reaction crystallization, kinetics, intermittent dynamic method