University of Oulu

Vuolio, T., Visuri, VV., Paananen, T. et al. Metall and Materi Trans B (2019) 50: 1791.

Identification of rate, extent, and mechanisms of hot metal resulfurization with CaO-SiO₂-Na₂O slag systems

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Author: Vuolio, Tero1; Visuri, Ville-Valtteri1; Paananen, Timo2;
Organizations: 1Process Metallurgy Research Unit, University of Oulu, P.O. Box 4300, FI-90014, Finland
2SSAB Europe Oy, Rautaruukintie 155, P.O. Box 93, FI-92101, Raahe, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.3 MB)
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Language: English
Published: Springer Nature, 2019
Publish Date: 2019-08-05


The resulfurization of hot metal has not been comprehensively studied in literature. This study presents an experimental and mathematical modeling study of resulfurization in thermodynamic and kinetic point of view. The rate, extent, and mechanisms of resulfurization were evaluated by analyzing concurrently the physical properties and sulfur-extracting ability of the slag. Experiments were conducted in a chamber furnace in an argon atmosphere, and the hot metal was sampled with pre-defined basis. The experiments were continued until the metal–slag system reached an apparent thermodynamic equilibrium. To obtain a quantitative measure on the effect of system properties on the rate and extent of resulfurization, the results of this study were combined with previous studies handling the sulfide capacities of Na₂O-SiO₂ and CaO-SiO₂-Na₂O slag systems. The sulfide capacities of the slag and corresponding metal–slag sulfur partition ratios were mathematically modeled with data-driven techniques such as multiple linear and non-linear regression and artificial neural networks. Finally, with the help of these, to study the kinetics of resulfurization, a simple mechanistic reaction model was derived. The results suggest that resulfurization of hot metal follows 1st-order kinetics and that the rate and extent can be regulated through the control of the associated thermodynamic driving force and by modifying the physical properties of the slag. The rate-limiting factor was found to be determined by the morphology of the slag phase.

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Series: Metallurgical and materials transactions. B, Process metallurgy and materials processing science
ISSN: 1073-5615
ISSN-E: 1543-1916
ISSN-L: 1073-5615
Volume: 50
Issue: 4
Pages: 1791 - 1807
DOI: 10.1007/s11663-019-01600-5
Type of Publication: A1 Journal article – refereed
Field of Science: 215 Chemical engineering
216 Materials engineering
Funding: Open access funding provided by University of Oulu including Oulu University Hospital. This work was conducted within the Symbiosis of Metal Production and Nature (SYMMET) research program, which is funded by Business Finland. The financial support from Technology Industries of Finland Centennial Foundation as well as Finnish Cultural Foundation is also acknowledged.
Copyright information: © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.