Raw material is feeding into ball mill through the hollow body of feed device, in ball mill body there are various diameter steel ball grinding media. When ball mill rotation around the horizontal axis  to a certain speed and hight, the steel balls grinding media and materials in the role of centrifugal force and friction, when the centrifugal force is greater than their own gravity, they rotary projectile from falling or rolling the body wall, due to impact force to crushing raw materials. Meanwhile,the sliding movement between grinding of raw materials also have abrasive. Due to the constant to the feeding raw materials, the pressure for turning material from the feed side to the discharge end.