Contribution Oral Presentation
Bahavior of magnetite based ores during hydrogen-induced fluidized bed reduction
Hydrogen based direct reduction by the means of fluidized bed technology is one possibility for sustainable ironmaking in the future. On the one hand, the exclusive use of hydrogen as a reducing agent allows an almost CO2 free reduction procedure; on the other hand, iron ore fines can be used directly without a prior agglomeration step. Because of the endothermal character of hydrogen-based reduction reactions, the iron ore has to be preheated to demanded reduction temperature in advance. Thus, a use of magnetite based ores would be beneficial because the heat provided by the exothermic oxidation reaction of Fe3O4 to Fe2O3 could be used during preheating and would lower therefore the primary energy demand. During fluidized bed reduction, magnetite based ores show a high sticking tendency. In this study, a concept is presented to avoid the sticking of the particles during the reduction procedure at reduction temperatures up to 800°C. Therefore the effects of prior oxidation, as well as the role of additives on the fluidization behavior and reducibility, are discussed.