Predicting effect of media size in ball milling using the mechanistic grinding model.

In spite of the growing use of other size reduction technologies, such as high-pressure grinding rolls and stirred media mills, ball mills are retaining their importance in the minerals industry as the machines responsible for the greatest capital expenditure and installed power inside most mineral processing plants. Mathematical models and formulae have been important tools to assist the engineer in these tasks, having evolved significantly since the middle of the 20th century. Arguably, one of the variables that has presented the greatest challenge when the performance of full-scale mills is to be predicted from data collected in small-scale laboratory mills is the ball size distribution. This paper demonstrates the use of the mechanistic model of the ball mill, which is based on the discrete element method and the population balance model, to predict breakage rates in mills operating with balls of different size. The limitations of investigating ball size effects in small lab mills are discussed on the basis of simulation results.
In spite of the growing use of other size reduction technologies, such as high-pressure grinding rolls and stirred media mills, ball mills are retaining their importance in the minerals industry as the machines responsible for the greatest capital expenditure and installed power inside most mineral processing plants. Mathematical models and formulae have been important tools to assist the engineer in these tasks, having evolved significantly since the middle of the 20th century. Arguably, one of the variables that has presented the greatest challenge when the performance of full-scale mills is to be predicted from data collected in small-scale laboratory mills is the ball size distribution. This paper demonstrates the use of the mechanistic model of the ball mill, which is based on the discrete element method and the population balance model, to predict breakage rates in mills operating with balls of different size. The limitations of investigating ball size effects in small lab mills are discussed on the basis of simulation results.