INVESTIGATION OF PARTICLE BREAKAGE MECHANISMS IN A BATCH BALL MILL USING BACK-CALCULATION

Simultaneous estimation of breakage rate and distribution function parameters has been carried out for two industrial ore samples and three types of cement clinker using dry batch ball mill data. Unique parameter estimates were obtained through a back-calculation approach using non-linear least squares fitting. The batch mill operating conditions were chosen to resemble industrial grinding situations. Investigation showed that breakage distribution and rate parameters did not conform to the commonly used functional forms. The analysis demonstrates that the breakage distribution function correlates to material property and particle size, and the breakage rate function also changes with material type and with mill content size distribution. The mechanisms of particle breakage in a ball mill inferred from the fitted breakage rate and distribution functions are also discussed in this paper.