Up-gradation of banded iron ores for pellet grade concentrate

Abstract

As per national steel policy vision 2030, around 500 million tons of quality iron ore is required to produce 300 million tons of steel. In this context, the use of low grade banded iron ores (Fe∼ 30-45%, 40-50% silica) is inevitable. Reduction roasting followed by magnetic separation technique is employed to treat such ore. In this work, banded iron ore with 32% Fe is enriched to a concentrate of ∼53-57% Fe using reduction roasting followed by low-intensity magnetic separation technique. A concentrate of 35% recovery with 53% Fe grade was achieved using Wet High-Intensity Magnetic separator at 12000 Gauss. In case of microwave reduction roasting a concentrate of 57.19% Fe grade and 17.82%wt. recovery is obtained at optimum conditions (540W, 3 minutes and 7% charcoal). Whereas, in muffle furnace reduction roasting 52.95%Fe grade and 47.38%wt. recovery concentrate is obtained at 900°C, 8% charcoal and 30 minutes time.