University of Oulu

Kemppainen, A., Ohno, K., Iljana, M., Mattila, O., Paananen, T., Heikkinen, E., Maeda, T., Kunitomo, K., Fabritius, T. (2017) 高炉内融着帯における酸性ペレットおよびオリビンペレットの軟化挙動, Softening Behaviors of Acid and Olivine Fluxed Iron Ore Pellets in the Cohesive Zone of a Blast Furnace. Tetsu-to-Hagane, 103 (4), 175-183.


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Author: Kemppainen, Antti1; Ohno, Ko-ichiro2; Iljana, Mikko1;
Organizations: 1Process Metallurgy Research Unit, University of Oulu, PO Box 4300, FI-90014 Finland
2Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University
3SSAB Europe
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.2 MB)
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Language: Japanese
Published: Iron and Steel Institute of Japan, 2017
Publish Date: 2021-01-25


Softening behaviors of acid and olivine fluxed iron ore pellets in the cohesive zone of a blast furnace

A ferrous burden loses its permeability in the cohesive zone of a Blast Furnace (BF) which has an effect on the flow of reducing gases. Iron ore pellets with various chemical compositions have different softening properties. Due to the occurrence of numerous simultaneous phenomena the clarification of different variables is difficult. In this study the effect of Reduction Degree (RD) on the softening behavior of individual acid and olivine fluxed iron ore pellets was experimentally tested under inert conditions. The acid pellet softened rapidly at 1150°C and reached about 40% contraction at 1200°C. The olivine fluxed pellet softened gradually in the range of 1150 and 1350°C and reached 30–35% contraction. The RDs of 50–70% for acid and 50–65% for olivine fluxed pellet had no significant effect on the softening behavior. However, the highest contraction-% was reached with the lowest RD. The results indicate that softening of the pellets is caused by the softening of the pellet core. The early softening of the acid pellet was attributed to high SiO₂ content and formation of fayalite slag with high wüstite solubility. The superior properties of the olivine fluxed pellet were attributed to the low SiO₂ content and favorable effects of fluxes to prevent wüstite dissolution. FactSage V6.4 -software and its FToxid-database was used to compute the phase equilibrium of a pre-reduced pellet with a quaternary FeO-SiO₂-CaO-MgO system in the core region. The computed phase equilibrium provided additional information about the effects of different components in the phase equilibrium.

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Series: Tetsu-to-Hagane
ISSN: 0021-1575
ISSN-E: 1883-2954
ISSN-L: 0021-1575
Volume: 103
Issue: 4
Pages: 175 - 183
DOI: 10.2355/tetsutohagane.TETSU-2016-097
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Funding: 本研究は Finnish Metals and Engineering Competence Cluster(FIMECC)のSystems Integrated Metal Processes(SIMP)研究プログラムの一部として遂行された。本研究はSSAB EuropeとFinnish Funding Agency for Technology and Innovation(TEKES)によって資金援助がなされたことを付記する.
Copyright information: © 2017 The Iron and Steel Institute of Japan, 一般社団法人 日本鉄鋼協会.