Grinding Efficiency of an Agitation-Beads Mill (II)

Relationship between the Media Flow Pattern and the Grinding Efficiency

Abstract

The relationship between the media flow pattern and the particle size distribution of CaCO₃ ground by an agitation-beads mill was examined. Fractionated alumina beads between 1.7 and 2.0mm were used as grinding media. Longitudinal and cross-sectional flow patterns of the grinding media in a grinding vessel of an agitation-beads mill were observed. The mill was equipped with perforated, non-perforated or pin-discs. Several types of inhomogeneously distributed flow patterns were observed under certain operating conditions. Appearance of each pattern was determined by the media filling degree or viscosity of the fluid. The fraction of the larger particle, F_L, did not depend on the energy consumption. F_L, decreased with decreasing irregular segregated flow of the grinding media and increasing residence time of the specimen.