Effects of mill speed and filling on the behaviour of the load in a rotary grinding mill: Liddell, K S; Moys, M H J S Afr Inst Min MetallV88, N2, Feb 1988, P49–57

Abstract

The dynamics of the ball load within a wet-grinding mill are examined, using measurements of torque and load position, The test equipment provided an accurate torque measurement, and the toe and shoulder positions of the load were measured by the use of a conductivity probe mounted in the mill shell. Both the variables tested-mill filling and rotational speed-influence the position of the load, and hence the torque, and have interactive effects on both the torque and the load position, An increase in mill speed and filling causes the torque to increase to a maximum value, after which further increases in speed or filling cause the torque to decrease. The position of the load toe is influenced only by the filling up to speeds of approximately 80 per cent of critical, whereas the speed and filling both cause the load shoulder to rise as their magnitudes are increased, The power drawn by the mill is predicted by the use of published equations, and these values are compared with the measured power draw.