PUSHING THE DECARBONIZATION OF THE STEELMAKING SECTOR THROUGH THE USE OF CLEAN HYDROGEN FOR THE IRON ORE DIRECT REDUCTION

The majority of global steel is produced via the blast furnace–basic oxygen furnace (BF-BOF) route, which accounts for approximately 8 and 7% of the global value for energy demand and CO2 emissions, respectively. Therefore, it is under severe pressure to push the steelmaking production towards a net-zero emission transition, through the development of an affordable and innovative direct reduction (DR) process. The aim of the study is to examine the kinetics of the DR of iron ores shedding light on the effect of pellets chemical-physical properties (i.e. chemical composition, morphology, sizing, etc.) and of operative conditions on the reduction behavior and the kinetics of the process. Real samples of iron ore pellets, with different chemical composition and chemical-physical properties, were obtained from a steel-making factory. Samples were characterized through N2-physisorption analysis, XRD and XRF measurements. Direct reduction tests were performed in a laboratory micro-plant, equipped with a quadrupole mass spectrometer. The chemical composition of iron-bearing minerals deeply affects the reduction behavior of the materials; the presence of other oxides, for example, modifies the reduction pattern of Fe2O3. Both the increase of temperature and hydrogen flow rate positively affect the reduction kinetic.