Abstract

Rock fragment size is a key variable in several mining stages such as underground mine design, equipment selection, and mineral processing. In Block Caving, rock fragment sizes are affected by fragmentation during gravity flow in the ore column while ore is being extracted from drawpoints. Additionally, smaller fragments can percolate between large fragments during gravity flow. These two phenomena — rock fragmentation and particle percolation — are not easy to simulate at a large scale in Block Caving. In this paper, a fragmentation model in a cellular automata gravity flow simulator is proposed to model rock fragmentation during flow at large scales. The fragmentation model uses the rock strength, vertical stresses, and travel distance as inputs to estimate the rock breakage and was calibrated with experimental and mine data. The mine scale results show an error of 9% and 7% of the fragmentation in the zones evaluated. This error rate is considered low due to the variability of the phenomena involved. Then, integrating a fragmentation model into a gravity flow simulator can more realistically represent ore fragmentation in caving-mine to generate flow simulations.