Ball mills are widely used in cement, silicate products, new building materials, refractory materials, fertilizers, ferrous and nonferrous metal beneficiation, glass and ceramics and other production industries to dry or wet grind various ores and other grindable materials. There are many types of grinding machines, but ball mills and rod mills are generally used in metal mines. Pebble mills and autogenous mills have been gradually used in China in recent years. A ball mill is a rotating cylinder with hollow shafts at both ends, and a considerable number of steel rods and steel balls are installed in the cylinder.

　　When ore and water are fed into the cylinder from the hollow shaft at one end and discharged from the hollow shaft at the other end. When the ball mill cylinder rotates at a specified speed, the steel balls and steel rods are together with the ore, and under the action of centrifugal force and friction, they rise to a height with the cylinder, and then fall off the cylinder wall to be thrown and slid down. Then they rise to the same height with the cylinder, and then fall down, and this cycle is carried out, so that the ore is impacted and ground and crushed. The ground ore and water form slurry (wet grinding), which is discharged from the hollow shaft at the discharge end to complete the grinding operation.