A unique laboratory-scale electric arc furnace simulator (EAF-SIM) was constructed at the Process Metallurgy Research Unit of the University of Oulu during the FFS1 and FFS2 projects. The system has enabled the study and real-time monitoring of the melting behaviour of new steel industry raw materials—such as hydrogen-reduced pellets and briquettes—during the FFS2 project. The primary architect and operator of the furnace is Laboratory Engineer Tommi Kokkonen, the development of measurement instrumentation is led by Postdoctoral Researcher Henri Pauna, and the main experimental user of the furnace is Doctoral Researcher Matias Hauru.
The EAF-SIM is operated in an argon atmosphere at 50–125 A current and 20–40 V voltage. A single graphite electrode is used as the cathode, while a graphite plate at the bottom of the furnace serves as the anode; the material to be melted is placed on this plate either in a crucible or using a steel holder. The furnace roof contains three ports, allowing additional materials—such as slag—to be added into the crucible during melting. The most interesting feature of the furnace is the durable quartz window, which enables real-time monitoring of the arc and melting process by means of a video camera and optical emission spectroscopy.
System development has continued during the FFS2 project, during which the device has been used to study:
- Melting of individual reduced pellets using steel holders
- Crucible melts (100–300g of material) for scrap, DRI, and HBI
- Slag, scrap, DRI, HBI, and briquette additions onto the melt surface during experiments while the arc is present
Figure 2 compiles example images of single-pellet melts from June 2025, crucible melts of scrap from December 2025, and technical drawings of the electric arc furnace (drawings modified from the peer-reviewed FFS2 article [1] under the CC BY 4.0 licence). Short videos attached to this release allow the viewer to observe the melting of scrap.
The next step in the research is to publish the results obtained during 2025, deepen the analysis of differences in melting behaviour among various materials, and to investigate the utilisation of industrial by-products in electric arc furnace melting. The EAF-SIM enables the use of a wide range of raw materials, which can be charged directly into the crucible or added onto the melt surface during the process.
Attachments and references
[1] H. Pauna et al., Hydrogen Direct Reduced Iron Melting in an Electric Arc Furnace: Benefits of In Situ Monitoring (2025), Volume 11, pages 4655–4667, https://doi.org/10.1007/s40831-025-01261-6
The FFS2 project has received funding from Business Finland.