Particle-wall collision and particle-gas interaction have significant influence on the separation performance of the impact separators. The experiments were carried out to study the particle-wall collision behaviors. A particle-wall collision model with average restitution coefficient was proposed. The restitution coefficient and friction coefficient were described as a function of collision angle

and this function varies for different particles. The shape of particles was measured by microscope. The glass beads are very close to sphere

while the coal particles are quite irregular. Thus spherical particle drag force model was adopted for glass beads

and non-spherical particle drag force model was adopted for coal particles. The numerical investigations on the separation performance and gas-solid flow in the plate-type impact separators were conducted with the particle-wall collision model and non-spherical drag force model. The simulation results show good agreements of both overall and grade separation efficiency with the experimental results. The separation prediction of particles with large Stokes number is sensitive to the particle-wall collision model

while that of particles with small Stokes number is sensitive to the particle-gas drag force model.