Morphology of impact fragmentation distribution of single spherical and ellipsoidal particles in drop weight experiments

Abstract

Particle shape is an important factor affecting the fragmentation distribution of the ore particles. To investigate the influence of particle shape on the morphological fragmentation distribution characteristics, the crushable ore particles are defined as prolate, oblate ellipsoid and spherical particles, which have different aspect ratios (AR) and sphericity (S). Based on the drop weight experiment, the influence of the net drop height on the macroscopic mechanical behavior and crushing distribution characteristics of the single spherical and ellipsoidal particles is studied. The results show that different peak-shifting characteristics exist during particle fragmentation. The fragmentation distribution peak shifts left when the increased impact energy is eventually only enough to break medium-sized sub-particles. Conversely, it shifts right when impact energy is increased enough to break largest-sized sub-particles. Besides, regardless of whether the net drop height changes, the maximum continuous fragmentation degree presents “M”-shaped characteristic with the increased AR. Compared with the ellipsoid particles, the single spherical particle is more difficult to be broken by impact, with wider equivalent particle fragmentation distribution. With the increase of particle sphericity, the maximum continuous fragmentation degree of a single ellipsoid particle has an overall trend of initial increase and subsequent decrease. Especially when particle sphericity is 0.9 < S < 0.95, the maximum continuous fragmentation degree of both prolate and oblate ellipsoid particles is much higher.