Process Characterization of Sustainable Hot Metal Production in the Electric Smelting Furnace

Kurzbeschreibung:

Direct reduction has become one of the principal technological pathways for reducing greenhouse gas emissions in the steel industry. The resulting direct reduced iron (DRI) is typically melted and refined in an electric arc furnace (EAF), which has a limited capacity to process high slag volumes. As a large proportion of the world’s iron ore resources are of lower grade, an alternative melting technology capable of handling the increased slag volumes associated with DRI from these ores is required.

The electric smelting furnace (ESF) aims to fill this gap by processing low-grade, high-gangue DRI into hot metal and slag. The hot metal is compatible with existing basic oxygen furnace (BOF) facilities, while the slag remains suitable as a raw material for the cement industry. The furnace relies on electricity as its primary energy source for melting, requiring only small additions of carbon to maximize iron recovery and achieve the desired carbon content in the hot metal. When biogenic carbon carriers are used, process-related greenhouse gas emissions can be further reduced, making the ESF a promising route for producing hot metal from a wide range of iron ores.

The technology is currently under development, with several projects of varying scale ongoing worldwide. The multi-cathode furnace at the Chair of Ferrous Metallurgy enables the investigation of key process parameters on a laboratory scale using varying input materials. In addition, partitioning behavior of key elements in ironmaking and refractory interactions are being studied. In this context, the HyPAT (Hydrogen Plasma and Arc-based Technologies) research group contributes to the industry’s transition toward reduced emissions.