Slag-Metal- Refractory Interactions During Dissolution of Hydrogen-Based Directly Reduced Iron (H-DRI) in Liquid Iron Melt

Abstract

The steel industry is regarded as the most critical industry in the nation and is crucial to economic prosperity; however, its high energy use and carbon emissions significantly impact climate change and global warming. In view of achieving carbon neutrality, one of the most promising technologies is using green hydrogen gas as a reductant for producing carbon emission-free direct reduced iron (H-DRI) from iron ores/pellets. Moreover, the produced H-DRI is subsequently used for steel making in the induction furnace/electric arc furnace. However, the study on the melting behavior of H-DRI, interaction among slag and metal produced from H-DRI with refractory during the steel making in induction furnace/electric arc furnace has yet to be thoroughly studied. Therefore, in this study, DRI’s dissolution/melting behavior in the liquid iron at 1600 ± 10 °C has been studied. Then, interactions among slag generated during the melting/dissolution of DRI, refractory of the induction furnace, and metal produced from H-DRI have been studied using the SEM backscatter electron method. The thermodynamics modelling for the slag formation and interactions among slag-metal-refractory systems have been studied using FactSage 8.2. The penetration of iron from a liquid melt into porous refractory and the formation of complexes like mullite, spinal, and olivine has been observed. The boundaries between the slag-metal-refractory system and the dissolution of Mg and Fe have been identified using backscattered electron mode. Thermodynamics modelling has been validated with experimental observations.

Graphical Abstract