The paper presents results of studies whose aim was to determine the effect of the number of contact points of grinding balls on the rate of grinding in a ball mill. Experiments were carried out in a pilot-plant batch mill. The process was performed in a water suspension with the addition of antiemulsifiers, using raw materials that are typically applied in a commercial-scale production of ceramic tiles. The grinding process was analysed for three compositions of grinding balls and two values of mill filling. Grinding rates were determined for particular size grades. Changes in the size distribution of ground material in time were analysed and the effect of ball size, degree of filling the mill with feed and the number of grinding balls on the process rate was reported. This rate varies during grinding, and the effect of the above listed factors is different on subsequent stages of the process.