Spiral separator is a gravity concentration device. It wasinvented by Humphreys in 1941.It is firstly designed anddeveloped based on experience and through many testingof prototypes and modifications. The main objective of thepresent study is simulation of the particulate-flow of morerealistic solids concentration (15% solids by weight) in spiralseparator. The study is based on Eulerian approach and RING K-E turbulence modelin. The results focus on particulate-flow characteristics such as velocity, and distribution and concentration of particulates on the spiral trough.The predicted results are compared with the experimentalin case LD9 coal spiral. Comparisons between numericaland measured data show good agreement