Numerical simulations have the potential to be effective tools to interpret and investigate comminution mechanisms of mineral particles. Numerical techniques have been mostly used for single particle analysis or for the simulation of pilot-scale mineral processing equipment, within a steady-state processing environment. Due to insufficient fundamental understanding and computational limitations, it is a challenge to use these tools in downstream processing of particles. This article highlights the use of numerical tools in understanding comminution mechanisms of particles in industrial applications. Such understandings may assist in designing energy efficient comminution circuits. This article also considers the issues related to efficient comminution of particles. At present, there are three significant issues: representation of fine particle sizes (down to dust), heterogeneity of ores and the limitations of commonly accepted breakage models that need to be more fully understood in order to numerically simulate crushing and grinding circuits for industrial applications.