CFD Study of Roasting Hydrodynamics in Fluidized Bed Roaster of Zinc Sulfide Concentrate

Fluidized bed roasters are widely employed in the zinc extraction process due to their superior roasting performance and high desulfurization efficiency. To examine the hydrodynamics of gas–solid flow and thermal characteristics within a fluidized bed roaster, the multiphase particle-in-cell (MP-PIC) method is utilized. Following validation of the numerical model, this study elucidates the distribution patterns of gas–solid flow and thermal parameters within the system, as well as the influence of various operational conditions. The results demonstrate that the vertical distribution of particle velocity within the roaster is characterized by higher velocities near the bed center and lower velocities near the wall. Elevated particle velocities are predominantly observed around bubble regions and in the wake vortex areas, reaching values of up to approximately 0.2 m/s. Furthermore, bubble dynamics are found to play a critical role in governing the gas–solid flow characteristics within the reactor. The particle Reynolds number and slip velocity increase markedly with higher superficial gas velocity, with peak values occurring at the gas inlet, bubble regions, and freeboard region.