Abstract: The movement law of the grinding balls in planetary ball mill is mainly determined by centrifugal force. Based on the drawing showing the distribution of the centrifugal force acted on the balls at different positions in the mill chamber, the authors analyze the moving trajectory of the balls relative to the chamber and study the effect of the revolution speed, rotation speed and radius of the mill chamber and the size of balls on the ball movement. It is concluded that the improvement of both the revolution and rotation or the adoption of large diameter balls can obviously strengthen the grinding effect, thus providing a theoretical basis for the selection of the operation parameters of planetary bill mill.

Key words: Planetary ball mill, Grinding ball, Movement law, Centrifugal force