Ball
Mill-A ball mill consists of a hollow cylinder
mounted such that it can be rotated on its horizontal longitudinal axis.


Grinding Parameters in Ball Mill: The most
important grinding parameters are:


  1. Feeding arrangement.

  2. Particle size of the feed

  3. Grinding media-material, size, and quality.

  4. Mill size, its speed and power consumption.

  5. Solid-liquid ratio and circulating load in a closed circuit
    operation.



If mill rotate very fast centrifugal force
keeps the balls in contact with wall and with each other during the upward
movement. While in contact with the wall, the balls do some grinding by
slipping and rolling over each other, but most of the grinding occurs at the
zone of impact, where the free-falling balls strike the bottom of the mill. If
the speed is too high, however, the balls are carried over and the mill is said
to be centrifuging. The speed at which centrifuging occurs is called the
critical speed. Little or no grinding is done when a mill is centrifuging, and
operating speeds must be less than the critical