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Theoretical Prediction of Energy Consumption and Particle Size Distribution in grinding and drilling of brittle materials
Author(s) -
Weichert Reiner
Publication year - 1991
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/ppsc.19910080111
Subject(s) - comminution , breakage , weibull distribution , brittleness , mechanics , materials science , particle (ecology) , grinding , distribution function , spheres , particle size , specific energy , particle size distribution , physics , composite material , thermodynamics , geology , mathematics , metallurgy , statistics , oceanography , paleontology , astronomy
Based on physical assumptions, simple equations have been derived for the probability of breakage of particles, for the dependence of fragmentation energy on particle size and for the fragment size distributions as a function of mass‐specific energy. The particles were considered as spheres, and Hertz theory of the stress distribution at the contact between a sphere of brittle material and a flat surface was applied in combination with Weibull statistics of failure. The predicted dependence of the probability of breakage on particle size and mass‐specific energy agrees well with experimentally obtained data for single‐particle experiments, even if the particles were not spherical. The resulting fragment size distribution could be predicted by the application of fracture mechanics. The theory can also be applied to rock drilling, where the breaking material is considered as a flat surface and the drilling tool as being of spherical shape. In both comminution and drilling, the experimental results agree fairly well with the theory.