Kinetics of grinding ceramic bulk considering grinding media contact points

Results of experiments carried out in a pilot-plant ball mill are discussed in the paper. The objective of the experiments was to determine the effect of the number of contact points between grinding media on the rate of grinding. The experimental material was ceramic body used in the production of floor and wall tiles. Main component of the feed was a mixture of feldspar and clay with antiemulsifiers. The feed was subjected to wet grinding. During grinding the rate of comminution of particular size fractions was determined. Changes in particle size distribution of ground material in time were analysed and the effect of ball size, mill filling with the feed and the number of grinding media on the process rate was described. Main objective of the study was to define the effect of changes in the number of grinding media contact points on the grinding rate. Additionally, the effect of mill filling with the feed on changing specific rate of grinding of particle fractions was determined. The change in time of the particle size composition enabled to calculate the grinding rate of particular fractions. In the calculations Gardner and Austin differential equation was used for discrete values of fractions.