Correlations for the Grindability of the Ball Mill as a measure of its Performance

Abstract

Ball mill is vital equipment in industries viz. mineral dressing, ore processing, fertilizers, food and diary, pharmaceuticals and many others. The present work involves a meticulous study of the effect of the various parameters on the performance of a ball mill. The parameters studied in this work are particle size, number of balls, time of grinding, particle density, and speed of the ball mill (rpm). An attempt has been made to develop correlation for the performance of the ball mill by correlating these variables with the grindability on the basis of dimensional analysis approach as well as fractional factorial design method. It is observed that these parameters influence the performance of the ball mill significantly. The performance of a ball mill is measured with reference to the quantity of undersize or fines (amount of grounded material passing through120 mesh screen) per revolution of the mill, collected for variation of each of the individual parameters. Finally the calculated values of the fines in terms of the grindability of the mill obtained through the correlations by both the above-mentioned methods are compared with the experimental values thereby justifying the analysis with reasonable deviations. Thus the developed correlations can be applied to know the grindability of the Ball Mill over a wide range of parameters.