Coal breakage characterisation - Part 1: Breakage testing with the JKFBC

An improved method for coal breakage characterisation has been developed at the Julius Kruttschnitt Mineral Research Centre (JKMRC). Part 1 of this paper presents the breakage testing method and results, Part 2 gives a breakage model that determines the energy-size reduction relationship for multi-components of particle size and coal density, and Part 3 demonstrates the applications of the model for HGI predictions and coal breakage simulations. The new method incorporates hardware for a fine particle breakage characterisation test, the JKFBC(JK Fine particle Breakage Characteriser), a device modified from the standard HGI mill, which has a precision torque meter installed to record energy utilisation during the experiments. Distinguished from the traditional HGI test, which is based on a single particle size with a single energy, the new characterisation test offers the flexibility to grind coal particles at various sizes, or various densities, or indeed (various components) with a range of energy levels. Energy consumption during the grinding was recorded. Using an Australian and a Chinese coal sample collected from power stations, this paper demonstrates the effects of particle size and density on coal breakage, and elucidates the deficiencies associated with the traditional HGI test. (C) 2013 Elsevier Ltd. All rights reserved.