Sustainable steel through hydrogen plasma reduction of iron ore: process, kinetics, microstructure, chemistry

摘要: Abstract Iron- and steelmaking is the largest single industrial CO2 emitter, accounting for 6.5% of all emissions on planet. This fact challenges current technologies to achieve carbon-lean steel production align with requirement a drastic reduction 80% in by around 2050. Thus, alternative have be implemented extracting iron from its ores. The hydrogen-based direct has been explored as sustainable route mitigate emissions, where kinetics intermediate oxide product FexO (wustite) into rate-limiting step process. total reaction an endothermic net energy balance. Reduction based hydrogen plasma may offer attractive alternative. Here, we present study about hematite using plasma. evolution both, chemical composition phase transformations was investigated several states. We found that depends balance between initial input mass arc power. For optimized mass-arc power ratio, complete obtained within 15 min exposure In such process, wustite also towards reduction. Nonetheless, exothermic, rates are comparable those Micro- nanoscale microstructure analysis revealed gangue elements partition remaining regions, probed dispersive spectroscopy (EDS) atom probe tomography (APT). Si-enrichment observed interdendritic fayalite domains, at wustite/iron hetero-interfaces primarily solidified particles inside iron. With proceeding reduction, however, gradually removed samples so final nearly free gangue-related impurities. Our findings provide microstructural atomic-scale insights occurring during ore plasma, propelling better understanding underlying thermodynamics kinetic barriers this essential