Segregation dynamics of complex mixed granules when subject to simple-harmonic vibration

QIAO Jinpeng; YANG Jinshuo; XUE Dong; HU Keyu; DONG Liang; DUAN Chenlong; JIANG Haishen; ZHAO Yuemin; YU Wenpeng

doi:10.13225/j.cnki.jccs.2023.0033

Abstract：The segregation of granules under vibration is the premise of minerals screening,and particle shape and size are important factors affecting the segregation rate and results.Based on the Discrete Element Method simulation,the dynam-ics of a single(non-)spherical large particle segregation in the sea of small particles were investigated,the influence of particle shape on its segregation rate was studied.The interaction effect between the shape and the size in a binary uni-form mixed particle bed was analyzed,and the distributions of segregation rates as well as the orientations in a multi-com-ponent particle group were revealed.The results show that under a strong vibration,the segregation rate of spherical large particles showed a non-monotonic trend of first increasing and then decreasing with the increase of particle size ratio.And the segregation rate of non-spherical large particles is significantly higher than that of spherical large particles,mainly be-cause the particle's bottom end extends to a deeper bed where large porosity fluctuation occurs.In addition,the segrega-tion rate difference between non-spherical large particles and spherical large particles also shows a trend of first increas-ing and then decreasing with the increase of amplitude.When there is convection in the binary mixed particle group,the segregation rate is significantly higher than that of the non-convective particle group.The segregation rates and rotation orientations of non-spherical particles in the binary bed show a"Gaussian-like"distribution,and there is a competition ef-fect between shape and size,which leads to the abnormal"Reverse-Brazil nut"phenomenon when a small size ratio and low sphericity are given.In addition,the influence of particle shape on the segregation rate is significantly higher than that of particle size structure.Adding intermediate-size particles slows down the segregation process while widening the size distribution range also reduces the segregation rate.