In beneficiation plant, quality grading effect was evaluated by classifying efficiency. The classification efficiency is the percentage of the fine fraction in the overflow product obtained after the material is classified and the content of the fine fraction (same level) in the material fed into the classifier. There are usually two ways to represent grading efficiency. In the formula, α, β, θ - respectively represent the weight percentage of a certain grade in the ore feeding, overflow and returning sand of the classifier, % . When the content of the fine fraction in the raw material is not large, the formula of the effective amount is used; when the content of the fine fraction in the raw material is large, the formula is calculated by the mass efficiency formula. In actual production, the classification efficiency is mostly calculated by mass efficiency. Obviously, the higher the classification efficiency, the less the amount of qualified material in the sand returning, the lighter the over-grinding phenomenon in the grinding process, and the higher the grinding efficiency. At present, the mechanical grading equipment used in production has low classification efficiency, generally only 30 to 60% . Therefore, the formation of sand returning is fine, and the overflow is rough, which affects the grinding efficiency and affects the selection index. Therefore, the development and improvement of grading equipment and the improvement of grading efficiency are one of the important directions for improving the grinding operation index. Sewage Suction Truck,Fecal Suction Truck,Cleaning Sewage Suction Truck,Chassis Sewage Suction Truck ChengLi Special Automobile Co.,LTD , https://www.chenglispecialautomobile.com.cn