University of Oulu

Pauna, H., Aula, M., Seehausen, J., Klung, J.-S., Huttula, M., & Fabritius, T. (2020). Industrial Ladle Furnace Slag Composition Analysis with Optical Emissions from the Arc. ISIJ International, 60(9), 1985–1992.

Industrial ladle furnace slag composition analysis with optical emissions from the arc

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Author: Pauna, Henri1; Aula, Matti1; Seehausen, Jonas2;
Organizations: 1Process Metallurgy Research Group, University of Oulu
2Deutsche Edelstahlwerke
3Nano and Molecular Systems Research Unit, University of Oulu
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.1 MB)
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Language: English
Published: Iron and Steel Institute of Japan, 2020
Publish Date: 2020-09-15


With the strict standards for steel quality and high production rates, the demand for faster and more convenient slag composition analysis for both electric arc and ladle furnaces has become a major issue in industrial steel plants. To overcome the time-delay between slag sampling and results of the slag composition analysis, an on-line slag composition analysis is required. Such a method that can be used in on-line analysis and is also chemically sensitive to the slag composition is optical emission spectroscopy. In this work, the optical emissions from the arc have been measured in an industrial ladle furnace and used for slag composition analysis. This article focuses on CaF₂ and MgO, since the CaF₂ is a common additive material in the ladle treatment and high MgO content means that the ladle refractory lining is dissolving into the slag. The analysis has been carried out by comparing emission line ratios to the XRF analyzed ratios of CaF₂/MgO and MnO/MgO, respectively. The results show that several atomic emissions lines of calcium, magnesium, and manganese can be used to evaluate the CaF₂/MgO and MnO/MgO ratios in the slag. It was found out that the plasma temperature derived from Ca I emission lines has a non-linear relation with the CaF₂ content of the slag. Additionally, the dissociation pathways of molecular slag components were determined and studied in different plasma temperatures with equilibrium composition computation in order to determine the relations between the slag and plasma compositions.

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Series: ISIJ international
ISSN: 0915-1559
ISSN-E: 1347-5460
ISSN-L: 0915-1559
Volume: 60
Issue: 9
Pages: 1985 - 1992
DOI: 10.2355/isijinternational.ISIJINT-2019-676
Type of Publication: A1 Journal article – refereed
Field of Science: 114 Physical sciences
215 Chemical engineering
Funding: This work was conducted within the Symbiosis of Metal Production and Nature (SYMMET) research program funded by Business Finland. We acknowledge the support of Research Fund for Coal and Steel under grant agreement No. 709923, Academy of Finland for Genome of Steel grant No. 311934, and Steel and Metal Producers’ Fund for a 2019 postgraduate grant.
Copyright information: © 2020 by The Iron and Steel Institute of Japan. Published in this repository with the kind permission of the publisher.