Recycling of iron-rich basic oxygen furnace dust using hydrogen-based direct reduction

The reduction of iron oxide-bearing ores necessitates the exploration of alternatives. Recycling iron oxide-enriched metallurgical dust could serve as secondary raw material for metallurgical processes. Implementing environmentally friendly technologies utilizing hydrogen has prompted the concept of hydrogen reduction of metallurgical dust to recycle secondary steel production products. The present study investigates the characteristics of hydrogen reduction of briquettes and pellets produced from basic oxygen furnace dust and reduced at the temperature of 850 °C. Experimental results revealed that the reduction degree for pellets was approximately 1.5 times higher compared to briquettes. The reduction swelling index of pellets was noticeable lower compared to literature data of reduction swelling index for iron ore pellets. Scanning electron microscopy/energy-dispersive X-ray spectroscopy was carried out to detect changes in the microstructure and chemical composition of the samples. Subsequent melting of the reduced samples unveiled non-metallic inclusions within the iron alloy and the impact of slag on their distribution between the alloy and slag.