The application of rock mechanics parameters to the prediction of comminution behaviour

A wide range of test methods are available to the rock mechanics engineer in order to assess rock strength. The application of these test techniques to the prediction of comminution behaviour is investigated. Previously test methods that rely on inducing tensile failure have been found to correlate well with power consumption and product grading from crushing machinery. Building on this previous work the point load, fracture toughness and Hopkinson Pressure Bar core based tests are examined in relation to breakage. The application of these testing techniques to the prediction of comminution behaviour has tremendous potential if the rock strength parameters can be linked to a measure of breakage. The measure of breakage used in this study is the drop weight apparatus developed at the Julius Kruttschnitt Mineral Research Centre. The A, b and t10 parameters provided by the drop weight test describe the ore-specific rock breakage in the context of comminution. This approach has been successfully used in the simulation and optimisation of numerous crushing and grinding circuits. As such this paper seeks to investigate the relationship between the parameters of tensile based tests and those of the drop weight test. Given the expense of obtaining drill core samples it is essential that the samples yield the maximum amount of information. Early indications suggest that this technique will enable data required for comminution plant design to be obtained from core samples. (C) 1997 Elsevier Science Ltd.