A New Methodological Approach on the Characterization of Optimal Charging Rates at the Hydrogen Plasma Smelting Reduction Process Part 2: Results

Daniel Ernst, Michael Andreas Zarl, Julian Cejka, Johannes Schenk

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To meet the target for anthropogenic greenhouse gas (GHG) reduction, the European steel industry is obliged to reduce its emissions. A possible pathway to reach this requirement is through developments of new technologies for a GHG-free steel production. One of these processes is the hydrogen plasma smelting reduction (HPSR) developed since 1992 at the Chair of Ferrous Metallurgy at the Montanuniversitaet Leoben in Austria. Based on the already available publication of the methodology in this work, potential process parameters were investigated that influence the reduction kinetics during continuous charging to improve the process further. Preliminary tests with different charging rates and plasma gas compositions were carried out to investigate the impacts on the individual steps of the reduction process. In the main experiments, the obtained parameters were used to determine the effect of the pre-reduction degree on the kinetics and the hydrogen conversion. Finally, the preliminary and main trials were statistically evaluated using the program MODDE® 13 Pro to identify the significant influences on reduction time, oxygen removal rate, and hydrogen conversion. High hydrogen utilization degrees could be achieved with high iron ore feeding rates and low hydrogen concentrations in the plasma gas composition. The subsequent low reduction degree and thus a high proportion of oxide melt leads to a high oxygen removal rate in the post-reduction phase and, consequently, short process times. Calculations of the reduction constant showed an average value of 1.13 × 10−5 kg oxygen/m2 s Pa, which is seven times higher than the value given in literature.
Original languageEnglish
Article number4065
Number of pages22
Journal Materials
Issue number12
Publication statusPublished - 8 Jun 2022

Bibliographical note

Funding Information:
Acknowledgments: The authors gratefully acknowledge the SuSteel project’s funding by The Austrian Research Promotion Agency (FFG) and the funding support of K1-MET GmbH metallurgical competence center. The K1-MET competence center’s research program is supported by COMET (Competence Center for Excellent Technologies), the Austrian program for competence centers. The Federal Ministry funds COMET for Climate Action, Environment, Energy, Mobility, Innovation and Technology, the Federal Ministry for Digital and Economic Affairs, the provinces of Upper Austria, Tyrol, and Styria, and the Styrian Business Promotion Agency (SFG).

Funding Information:
Funding: This research was funded by the COMET program Fundamentals of hydrogen reduction, K1-MET project number 12204396. In addition, this research work is partially financed by the industrial partners voestalpine Stahl GmbH and voestalpine Stahl Donawitz GmbH and the scientific partner Montanuniversität Leoben.

Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.


  • HPSR
  • hydrogen reduction
  • iron ore
  • kinetic
  • plasma reduction
  • smelting reduction

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