Optimisation of the secondary ball mill using an on-line ball and pulp load sensor – The Sensomag

The ball load and pulp load have a significant influence on the ball mill product size and production capacity. To improve the circuit performance at industrial scale these variables must be tweaked to levels where the plant can get grind and capacity benefits. In most grinding circuits the influence of these variables are not quantified because it is difficult to obtain precise measurements of the pulp load for an industrial scale mill and the conventional method of obtaining ball load measurements that involves crash stops is not attractive. A comprehensive investigation was performed on an industrial scale mill to quantify the effects of both ball and pulp load. A wide range of ball and pulp loads were tested and the findings are reported in this paper. The Sensomag, a sensor developed by Magotteaux, was used to obtain ball and pulp load measurements during the experimental work.

Research highlights
► Industrial scale test work on an overflow discharge ball mill.
► Ball filling and % solids were varied, and mill performance compared.
► On-line pulp and ball angles measured with Sensomag unit.
► Mill performance linked to quantity and quality of ball/pulp interactions.