Per: Maximilian Köpf (Metso Outotec Gmbh & Co. KG, Oberursel, Hessen, Germany.), Parizat Pandey (Outotec GmbH & Co. KG), Sebastian Lang (Metso Outotec Gmbh & Co. KG), Timo Haimi (Metso Outotec Metals Oy, Espoo, Finland)
Abstract:
The hydrogen-based direct reduction of iron ore combined with EAF smelting is being widely discussed as a possible replacement for the commonly used BF/BOF route in steelmaking when targeting carbon footprint reduction. An alternative to shaft furnaces is Metso Outotec’s Circored process, which uses fine ore as feed for fluidized bed reactors, eliminating the cost and energy-intensive pelletizing step. As a direct reduction process for high-grade (DR quality) fine ores using 100% hydrogen as the reducing agent, producing HBI, Circored has already proven its functionality in an industrial-scale demonstration plant.
However, it is foreseeable that there is globally insufficient high-grade iron ore available for the transition of the steel industry to the DR-EAF-route. It is predicted that in 10 years a tremendous gap between supply and demand will exist, even considering the already planned and announced direct reduction and beneficiation projects. It is obvious that solutions for utilization of low-grade iron ores as alternative to the predominant, carbon-intense BF route are urgently required. Metso Outotec’s solution to such predicament is combination of a simplified Circored process, in which low-grade (BF quality) fine ores are pre-reduced to approximately 80% metallization, and a DRI smelter is coupled for the melting, final reduction, carburization and gangue removal. Metso Outotec’s rectangular six-in-line smelting furnace combines a flash smelter body and Söderberg electrodes. This combination can be a solution to replace small/medium sized BFs and produce hot metal with the desired carbon content, for greenfield projects or in existing steel plants with BOF converters.
