A Ball Mill grinds stone or mineral material by rotating a cylinder with steel grinding balls, causing the balls to fall back into the cylinder and onto the material to be ground. The rotation is usually between 4 to 20 revolutions per minute, depending upon the diameter of the ball mill.
The operating principle of the ball grinding mill consists of the following steps. In a continuously operating ball mill, feeding material fed through the central hole of one of the caps into the drum and moves therealong, being exposed by grinding media. The stone material grinding occurs during impact falling grinding balls and abrasion the particles between the balls. Then, discharge of ground materials performed through the central hole in the discharge cap or through the grid.
In filling mineral ball mill by grinding balls on 40 — 50% and non-smooth liner, the outer layers slip is virtually absent, but the sliding of the inner layers one on another observed in various modes of operation grinding mill. In a monolayer filling mill by grinding media, they rotate around their axis parallel to the drum axis of rotation. Grinding media are not subjected to a circular motion by a smooth lining, even at high speeds.
