Beneficiation of low-grade, goethite-rich iron ore using microwave-assisted magnetizing roasting

•Microwave-assisted magnetizing roast of a goethite-rich, reject waste stream.•Goethite to magnetite conversion occurred at 600 °C in a 40:60 CO/CO2 gas atmosphere.•A + 62 wt% Fe blast furnace pellet concentrate was produced with > 88 wt% iron recovery.•Higher temperatures caused over-reduction and the generation of reduced Fe phases.