Segregation flow behavior of polydisperse particle mixture with skewed distribution in a rotating drum

Abstract

Industrial particle mixtures are naturally polydisperse due to the variations in size distribution during mineral processing, which makes it necessary to investigate segregation behaviors of polydisperse particle mixtures. In this work, five groups of polydisperse particle mixtures were defined separately by different skewed distributions. Based on discrete element method, the polydisperse particle segregation behaviors of in rotary drums were simulated. The results indicate that in the polydisperse particle system with normal distribution, larger particles tend to accumulate towards the both sides, while smaller particles tend to be in the middle of the drum. In this case, the medium-sized particles are uniformly distributed throughout the system. However, once the polydisperse particle mixture transitions from the coarse particle to the fine particle system, the size of medium particles exhibiting uniform distribution characteristics decreases with an increase in the skewness coefficient. Moreover, the smaller the skewness coefficient of the polydisperse particles, the slower the initial particle segregation rate, and the lower the steady particle segregation degree. Furthermore, whether the drum length to diameter (L / D) ratio or drum filling rate increases, the particle segregation rate in initial stage and the particle segregation degree in steady stage are subsequently significantly reduced, while the size of medium particles with uniform distribution characteristics remains essentially constant.