Single and Multiple Breakage Events in Fine Particle Breakage Testing with a Rigidly-Mounted Roll Mill

For the prediction of breakage in fine grinding processes (<200 mu m), simulation based on population balance models and/or discrete element method is often applied. Both numerical techniques require a deep understanding of the breakage mechanisms within the grinding process. Depending on the breakage mechanism, different devices are available to characterize the breakage behaviour of the feed material, such as the breakage function or breakage rate. For characterizing breakage specific parameters of particles in fine grinding, a new breakage tester based on a rigidly-mounted roll mill was presented in a previous study. The present work focuses on the investigation of progressive stress events in fine particle breakage testing. For this, the effect of weakening and breakage history is analysed. As a result, the shape of the resulting particle size distribution and the particle strength are influenced by previous stressing. Therefore, a new approach considering the history of particle breakage is introduced.