We’re pleased to share the HELIOS project first peer reviewed article publication by Yuhan Sun (Doctoral Researcher at the University of OULU) in the Journal of Sustainable Metallurgy! The full article is available here: https://doi.org/10.1007/s40831-025-01200-5.
Ilmenite is a critical resource in the titanium and steel industries. To reach climate neutrality, hydrogen is being explored as an alternative energy source and reductant to replace traditional carbon-based materials. In this context, hydrogen plasma smelting reduction has emerged as a potential method for reducing even chemically very stable oxides. This study presents five ilmenite reduction experiments performed using hydrogen plasma smelting reduction at varying reduction times. Optical emission spectroscopy and video recording were employed as in-situ analytical monitoring and reductant species probing methods for each experiment. The hydrogen plasma reactor was operated with a gas mixture of 10% H₂ and 90% Ar.
Samples were reduced under this plasma environment for durations ranging from 150 to 750 s, with spectral analysis covering the wavelength range of 200–700 nm. Plasma composition was determined by identifying characteristic emission lines, and the time evolution of elemental intensities was examined. Plasma images were used to assess the temporal behavior of the plasma arc, complementing the optical emission spectroscopy analysis. Titanium oxide was successfully extracted from FeTiO3 as TiO2 and became the enriched component in the slag. Metal recovery exceeded 70 wt.% after 750 s of reduction, while the iron content in the metallic droplet reached 92.31 wt.%, and O and Si decreased to 6.84wt.% and 0.37wt.%, respectively, after 600 s.
The global steel industry contributes over 7% of global greenhouse gas emissions and over 11% of global CO2 emissions, as highlighted in the latest report by Green Steel Economics. To align the steel sector with carbon neutrality targets and to meet the objectives of the Paris Climate Agreement targets by 2050, hydrogen is being considered as a promising alternative to conventional carbon-based energy sources and reductants. In this widely recognized context, the extraction of metallic titanium from ilmenite minerals, a key process in the iron and steel industry, offers significant potential for improved environmental performance.
