Block size distribution of in situ rock masses using digital image processing of drill core

An empirical approach to the analysis of in-situ block size distribution in closely jointed rocks from drill core is presented. At each step in the mine cycle, the fragment size distribution become finer due to breakage of particles, and the final size distributions of rock becomes different from that of the undisturbed rock. Rock fragmentation analysis for mining and ore preparation must include an analysis of the additional breakage to be expected from the mechanical interaction between the rock and mining equipment. Adequate prediction of the in situ block size distribution and convenient measurement of the post-blast size distribution eventually allows for prediction of the size distribution and the runoff mine product.