Abstract： To investigate the fractal dimension of ground calcium carbonate particles and the relationship between multifractal characteristics with grinding time, the particle size distribution at different grinding time was studied in the wet ultrafine ball-stirring grinding system. The fractal dimension of samples was computed by the methods of single fractal and multifractal, and fitted curves of fractal dimension and grinding time were established. The results show that the particle size distribution can be described more accurately by the multifractal method comparing with the single fractal method. The best grinding time can be determined by the peak value of the fitted curves of fractal dimension and grinding time, which is consistent with the best grinding time of 60 min about the ground calcium carbonate sample in the experiment. The parameter of grinding time in the process of particle ultrafine can thus be optimized and grinding energy consumption be reduced.

Keywords: ground calcium carbonate; ultrafine grinding process; fractal dimension; single fractal; multifractal