Study On Particle Segregation And Its Impact On Crushing Effect Of Ball Mill

Particle material is a kind of material that exists extensively in nature.Segregation is one of the important phenomenon during the motion.Particle material is widely used in modern industry.The ball mill is a common construction machinery using particle material,which is widely used in mining,metallurgy,pharmaceutical preparation and other fields.But the ball mill working efficiency is low.The existing optimizations of the ball mill do not consider the phenomenon of segregation during the milling process.Therefore,the segregation of particle material and its effect on ball mill working efficiency is studied in this paper to provide a new idea for ball mill optimization from the view of segregation of particle material.Firstly,based on Newtonian mechanics,the motion of the particles in the drum was deduced.It is pointed out that the friction between the end wall and the particles will lift the particles higher and produce a slope near the end wall,causing the small particles to gather towards the middle of the drum.Secondly,based on the discrete element method,the particle motion in the drum was studied.The particle motion was probed from the aspects of aspect ratio,rotation speed,filling rate and coefficient of friction.It was pointed out that the friction of the end wall was the determinant of particle segregation.The experiment results verified the theoretical derivation and numerical simulation results.Thirdly,the concept of total energy in the region was put forward to evaluate the crushing effect of each region in the ball mill.It was pointed out that the crushing effect of each part in the drum is inconsistent.Finally,the method of particle replacement was used to simulate the crushing process,and the whole crushing process was divided into several stages.The proportion of particles in different positions in the drum is different and the effect of each crushing stage is different,the conclusion of the evaluation of the crushing effect of each position in the drum based on the total energy of the area is confirmed.Through the study of particle segregation,it shows that the particle segregation will make the actual crushing effect of ball mill deviate from the expected design effect,which provides a new idea for ball mill optimization.