Back-calculation of particle fracture energies using data from rotary breakage testing devices

Abstract

Breakage probabilities and fracture energy distributions have now found application in several mathematical models that simulate both degradation during handling and comminution devices. Unfortunately, measurement of these at the range of sizes of interest, in particular in the case of fine sizes, is not a straight-forward task. The paper proposes a procedure to estimate breakage probability distributions over a wide range of particle sizes by combining direct measurements of fracture energies at a selected size to back-calculated values estimated on the basis of progeny size distributions from breaking single particles over a wider range. Whereas direct measurements of fracture energies were carried out in a short impact load cell device, energy-dependent progeny size distributions were conducted by propelling particles against a target in rotary breakage testing devices. The work demonstrates how the parameters that characterize the variation of particle fracture energies with size can be fitted in a stage-by-stage process, with successful application to characterizing breakage of a copper ore contained in the range from 37.5 to 0.25 mm.