Abstract： To simulate the segregation and mixing behavior of binary particle mixtures differing in size and density， a multi-fluid Eulerian model incorporating the kinetic theory of granular flow was developed. The gas-solid and solid-solid drags were respectively determined by the Gidaspow and Syamlal drag model. The results show that jetsam axial and radial concentration distributions obtained by simulation agree well with experimental data. When the segregation occurs at small gas velocities， the motion of jetsam in the jetsam-rich （bottom） layer is slow， while becomes faster for the well-mixed condition at large gas velocities.

Keywords： binary particle mixture; segregation; mixing; bubbling fluidized bed; numerical simulation