Optimisation of self-reducing mill scale briquettes for sustainable iron recovery in induction furnaces

Primary mill scale generated during steelmaking and hot deformation processes contains substantial iron oxides and can be directly recycled by converting it into self-reducing briquettes for induction furnaces. In this work, the roles of calcined petroleum coke as the reductant and molasses as the binder were examined to identify a balanced formulation offering both good reduction behaviour and adequate mechanical strength. Stoichiometric calculations suggested that 10−12 wt.% CPC is required to fully reduce Fe 2 O 3 present in mill scale. Thermogravimetric analysis on briquettes with 6−14 wt.% CPC showed that the 12 wt.% briquette exhibited the highest mass-loss in the 600−900°C window, indicating the most active reduction stage. After reduction, SEM-EDS revealed iron-rich phases, and a metallic iron content of 96.8% was confirmed by wet analysis. Briquettes containing 10–12 wt.% CPC and 4–5 wt.% molasses provided mechanical strength of 48 N and a bulk density of 4.6 g/cm 3 , allowing stable charging into the melt.