INFLUENCE OF DISTRIBUTOR PLATE DESIGN AND PARTICLE PROPERTIES ON THE FLUIDIZATION BEHAVIOR OF IRON ORE CONCENTRATES AND THEIR BLENDS

To comply with the European Green Deal and Austria¿s national decarbonization roadmap, the steelmaking sector is currently transitioning from blast furnace production toward processes with a lower carbon footprint. Among the available alternatives, the reduction of iron using hydrogen as the reducing agent (DRI) is considered a promising and sustainable approach. Implementation of this sustainable approach requires uniform gas-solid contact between the iron concentrate and the reducing gas. Fluidized bed technology offers a means for achieving this contact. However, they are not without challenges, particularly when operated with blended feeds that vary in density, particle size, and mineralogy. This study, therefore, investigated the fluidization behavior of six different iron ore concentrates of varying density, shape, particle size, and mineralogy. The test rig was a laboratory-scale fluidized bed that was driven by a suction system. The experimental program involved fluidizing each sample individually, followed by binary and ternary mixtures. Two distributor plate designs were also compared. One distributor plate proved unsuitable for stable fluidization, mainly due to its insufficient pressure drop relative to that of the bed. Finally, the experimental umf were compared to theoretical calculations. Segregation was observed in the binary and ternary mixtures. In most cases, density was the driving force for segregation, whereas in one case, particle size was the driving force.