A treatment of impact breakage of particles

Particles of a given size and material have a distribution of strengths so that some fractions break at low specific strain energies, more at higher strain energies, and all break at sufficient strain energy. Those fragments from breakage at a low specific strain energy produced during a higher specific energy impact will have relaxed their stored strain energy but will be recompressed and rebroken by the remaining impact energy. Thus, a size/mass/energy balance must be performed where the remaining specific impact energy of fragments is their original specific impact energy minus that required for fracture. An algorithm for this balance is presented and a computed example given. It is shown that the apparent primary breakage distribution from impact at a given specific impact energy will become finer as the energy is higher. These so-called “energy-dependent” primary breakage distributions (B values) can be computed using a known distribution of strengths as a function of particle size and specific energy and a true primary breakage distribution.