The paper presents the results of studies on quartzite milling in a ball mill. The milling was conducted in a batch system, for diversified compositions of balls. The milling product was subjected to granulometrical, morphological and strength analyses. On the basis of the developed Reid's theory and using the Austin-Gardner equation, a form of the function circumscribing the specific rate of comminution of selected size fractions was determined. The values of the breakage rate function bi, j for the mill's apparatus conditions were determined. The impact was investigated for a variable number of grinding media contact points on the values of specific rate S and the values of the breakage rate function bi, j. Furthermore, the values of coefficients occurring in the equations circumscribing the specific rate of milling S and breakage parameter bi, j were determined.

This paper presents the results of experimental drum granulation of silica flour with the use of wetting liquids with different values of surface tension. Additionally, different liquid jet breakup and different residual moisture of the bed were applied in the tests. The process was conducted periodically in two stages: wetting and proper granulation, during which no liquid was supplied to the bed. The condition of the granulated material after the period of wetting (particle size distribution and moisture of separate fractions) and a change in the particle size distribution during the further conduct of the process (granulation kinetics) were determined.