Introduction
The discrete element method (DEM) was first proposed by Cundall and Strack to model the behaviour of soil particles subject to dynamic loading conditions . Mishra and Rajamani pioneered the application of DEM to grinding mills and demonstrated that despite the fact that the DEM simulations are based on two dimensions (2D), the technique is able to predict the power draw of mills with reasonable accuracy over a wide range of mill diameters . More than 10 years since then, the DEM technique has been successfully applied to ball mills , SAG mills and centrifugal mills.
Introduction
DEM has also been applied to study impact-induced particle breakage. Using DEM simulation of impact breakage of agglomerates and aggregates that are hardened by cement, different parameters that influence the impact fracture have been analysed. In some studies, the finite element method (FEM) is usually adopted to determine stress patterns, and DEM has been used to show crack distributions in rocks under loading. Also, using DEM modeling of the compressive strength and drop weight test, the relationship between strain rate, impact energy and the degree of fragmentation has been determined.
Nine rocks with different mechanical properties were modelled as granular assemblies in the shape of a sphere and/or a cube. Each rock as a single particle was modelled while it was crushed in a laboratory