Grinding is the last operation process of ore material preparation before beneficiation. The preparing work of ore material beneficiation includes two works with crushing and grinding, in which grinding is more important, it is not only with high energy consumption and high material consumption, but also the product quality directly affect the operation indicators. Moreover, the rate of grinding determines the capacity of mill plant actually. Therefore, the grinding operation is most important work before beneficiation
The grinding has its special requirements before mines. Crushing ore is the purpose of grinding in the cement industry, the fine the crushing size, the higher the quality of the cement, called crush grinding. The main purpose of construction sand grinding and pelletizing raw material grinding is not for crushing material, but for washing materials and show out the fresh surface for adhesive of the material, which is called scrub grinding. However, all kinds of grinding before beneficiation, including grinding before hydrometallurgy, they are for the purpose of the dissociative mineral, or for exposed mineral, which called dissociative grinding. The grinding before beneficiation not only make dissociation mineral as the first purpose, also make the particle size of mine selection conform to the requirements, as well as make the crushed graded reduce as much as possible. Usually the grinding is closed-circuit work and controlled the grinding granularity by the classification equipment outside mill, then discharging qualified by classification machine, and unqualified returned to grind again.