Simulating large-diameter industrial ball mills from batch-grinding tests

Abstract

Phenomenological models of ball milling are routinely used to optimize size reduction operations. A usual method adopted in the minerals industry relies on batch-grinding tests to calibrate models in a population balance model formulation describing the breakage behaviour and then scale-up the breakage parameters using an energy-based relationship. Despite the important advances and application of these methods, their application in describing grinding in large-diameter (>7.5 m) mills has not been widely demonstrated. The work demonstrates the calibration of industrial-scale ball mill model parameters from laboratory milling tests on Platinum Group Metals (PGM) and Itabirite iron ores. Minor fine-tunning of a single model parameter was required to simulate the large-diameter industrial mills, demonstrating the validity of the approach for ores as distinct as PGM and Itabirite iron ores. Estimation of the Arbiter Flow Number below 4.1 showed a regular slurry transport for all mills studied. This model can then be used in optimization of the ball mill performance.