Green Technology-Based Utilization of Refractory Siderite Ores to Prepare Electric Arc Furnace Burden

Siderite ore is a typical and widely available refractory iron ore. In consideration of the growing demand for iron ores and the increasing pressure to reduce emissions in the steel industry, a green technology-based utilization of siderite ore as an electric arc furnace (EAF) burden by applying carburization roasting and magnetic separation processes is proposed. Under optimized conditions, an electric furnace burden (Fe3C) assaying 81.62% Fe and 6.48% C, with a corresponding iron recovery rate of 91.33%, is prepared. Moreover, when compared with the traditional blast furnace (BF)-basic oxygen furnace (BOF) long process, the CO2 and NOx reductions amount to 17.60% and 35.07%, respectively. Furthermore, the carburization behavior and separation mechanism are revealed using X-ray powder diffraction, scanning electron microscopy, and optical microscopy. The results show that siderite can be carburized to Fe3C; however, the separation efficiency of iron carbide and gangue is very low. Furthermore, Na2SO4 is a necessary additive to enhance the separation efficiency as it improves the carburized efficiency, increases the iron carbide particle size, and improves the embedded relationship of gangue and iron carbide. The proposed technology is promising for the utilization of siderite ores in terms of product value and environmental friendliness.

Automated summary

By utilizing carburization roasting and magnetic separation techniques, siderite ore can be used as an electric arc furnace burden to produce high-grade furnace burden and achieve efficient separation. This technology not only improves product value, but also effectively reduces CO2 and NOx emissions.