Minimum fluidization velocity of three mineralogically different iron ore tailing samples: Comparison of empirical correlations and hydrodynamic study

The importance of utilizing various low and lean-grade iron ore samples in the form of tailings, slimes, and mine wastes is the need for researchers and the iron and steelmaking industries. These ultrafine wastes can be reduced by developing commercial technology for fluidized bed reduction roasting systems, which require fundamental research. The minimum fluidization velocity significantly affects the reduction roasting process during fluidization. The minimum fluidization velocity of three mineralogically different iron ore tailing samples was experimentally investigated in a cold fluidized bed setup with an internal diameter of 45 mm and a height of 1200 mm. The hydrodynamics of the fluidized bed, channeling, and elutriation were observed during the cold fluidization study. Additionally, the experimental values were compared with the predicted values obtained from various empirical correlations on minimum fluidization velocity (U_mf). The study also reported that the Coltters and Rivas 12 and 14 correlations predicted the most accurate minimum fluidization velocity for iron ore tailing samples with an error percentage of less than 16%. A new correlation was developed from the experimental U_mf of each size fraction of iron ore tailing samples, which predicted U_mf with an R² of 0.99. Overall, the study highlighted the hydrodynamics of fine particles during fluidization, elucidating the fluidization phenomena of fine particles.