Experimental and CFD simulation study on interphase interaction of the fluidization behavior for spherical and irregular coarse particles

Currently, fluidization techniques have been widely applied to separate and recover coarse particles (>74 μm) in mineral processing. Studies show that the main parameters affecting this regard are hydrodynamic conditions and interphase interactions. The main objective is to investigate the influences of collision coefficient and drag models on the hydrodynamic behavior of liquid-solid fluid beds. Eulerian-Eulerian method was used and spherical and irregular coarse particles were considered in calculations. In this regard, Gibilaro, Gidaspow, Huilin-Gidaspow, and Syamlal-O’ Brien equations were used to obtain the drag force. Moreover, experimental data of particle volume fraction and fluid bed expansion ratio were employed to evaluate the proposed models. The effects of three restitution coefficients (0.85, 0.90 and 0.99) and four specularity coefficients (0.01, 0.10, 0.50 and 0.99) on fluidization characteristics were studied. The results indicate that for spherical and irregular particles, Gidaspow and Hulin-Gidaspow models have good agreement with experimental data in predicting fluid bed expansion ratio and particle volume fraction. Meanwhile, high prediction accuracy can be achieved when the restitution coefficient is 0.9 and the specularity coefficient is 0.1. The results improve the understanding of coarse particle behavior in liquid-solid fluidization and provide useful information for further investigation of three-phase flotation processes.