Research on Medium Filling Rate of Ball Mill

Date:08/29/2012 04:58:33

Medium filling rate and rotation rate are the major two factors affecting medium movement. Scholars both at home and abroad have carried out researches as to relevant influence on medium movement basing on tests and formulas. Detailed study on the influence of the two factors on the ball mill is conducted by the Discrete Element Numerical Simulation Method.

In general, both medium filling rate and rotation rate are at work. Therefore, if the two factors are analyzed separately, the result can be partial, as is proved by the following calculation.

The critical speed of ball mill refers to the instantaneous speed after the process during which the rotation speed of cylinder changes from slow to fast and reaches the maximum height. The medium on the outmost shell rotates together with the inner board of the cylinder liner in uniform circular motion. When the ball mill is at the critical rate, the outmost medium will rotate with the material without impacting, which should be avoided in grinding process.

The critical speed of grinding mill has provided a framework for theoretical and practical rotation rate. Scholars both at home and abroad has carried out extensive research work on it. The formulas calculating the rate are numerous. Since medium can be divided into dynamic and static types, the medium filling rate falls into two accordingly. The medium filling rate tested in production practices is actually static filling rate which is a relative value of filling rate, that is to say, the ratio of the volume of the ball mill and that of the cavity of the ball mill.