Crushing of single irregularly shaped particles by compression: size distribution of progeny particles

Abstract

On the basis of experimental results with quartzite an analytical description is presented for the progeny size distribution of irregularly shaped particles crushed singly by slow compression. For the four initial size ranges investigated the progeny size distributions are composed of four truncated (three-parameter) log-normal distributions for each comminution energy range. The dependence of the parameters of the experimental size distribution upon the comminution energy has been determined. In contrast to the results for single crushed spheres, for irregularly shaped initial particles the ratio of newly formed surface area to comminution energy depends upon the comminution energy. This is caused by the influence of friction during the crushing of the initial particles. On the basis of the central limit theorem of statistics an attempt is made to explain the origin of the mathematical form of the progeny size distribution produced by the crushing of spheres. The genesis of the progeny size distribution is also qualitatively established for irregularly shaped initial particles. On the same theoretical basis one may reasonably expect that the size distribution of progeny particles is truncated log-normal. In the case of the progeny of irregular parent particles, as distinct from spheres, several such distributions should be superimposed on one another.