Ball mill is the key equipment of beneficiation equipment for grinding after the crushing process, which is composed by feeding part, discharging part, turning part and driving part (reducer, small driving gear, electric motor and electric control) and widely used in the manufacture industries, such as cement, silicate, refractory material, new building material, fertilizer, ferrous metal, nonferrous metal and glass ceramics, moreover, according to different materials and discharging methods, there are dry ball mills and wet ball mills for choice.