University of Oulu

Iljana, M., Mattila, O., Alatarvas, T., Kurikkala, J., Paananen, T., Fabritius, T. (2013) Effect of Circulating Elements on the Dynamic Reduction Swelling Behaviour of Olivine and Acid Iron Ore Pellets under Simulated Blast Furnace Shaft Conditions. ISIJ International, 53 (3), 419-426.

Effect of circulating elements on the dynamic reduction swelling behaviour of olivine and acid Iron ore pellets under simulated blast furnace shaft conditions

Saved in:
Author: Iljana, Mikko1; Mattila, Olli2; Alatarvas, Tuomas1;
Organizations: 1University of Oulu, Laboratory of Process Metallurgy, PO Box 4300, University of Oulu, FI-90014 Finland
2Ruukki Metals Oy, Rautaruukintie 155, Raahe, FI-92100 Finland
3Boliden Harjavalta Oy, Teollisuuskatu 1, Harjavalta, FI-29200 Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.6 MB)
Persistent link:
Language: English
Published: Iron and Steel Institute of Japan, 2013
Publish Date: 2021-01-20


Sulphur and alkalis in the blast furnace gas have been associated affecting the reduction swelling behaviour of iron ore pellets. A tube furnace was used in this study to examine the dynamic reduction swelling behaviour of olivine and acid pellets in CO–CO₂–N₂ atmosphere with sulphur and potassium in gaseous phases up to 1100°C simulating the conditions in the blast furnace shaft.

No abnormal swelling was detected in sulphur or potassium containing CO–CO₂–N₂ atmospheres during dynamic reduction. Instead, sulphur in the reducing atmosphere was associated with pellet contraction and FeO–FeS melt formation which became more dominant with increasing sulphur partial pressures. In the extreme case, having a maximum of 1.0 vol-% S₂ gas in the reducing atmosphere, the reduction reaction of wüstite to metallic iron was hindered. The formation of FeO–FeS liquid phase extends the cohesive zone towards the blast furnace top and lower temperatures and decreases the gas permeability. Furthermore, large amounts of potassium in the reducing atmosphere (max. 0.03 vol-%) led to swelling and cracking in the olivine pellets still remaining in the range of normal swelling.

see all

Series: ISIJ international
ISSN: 0915-1559
ISSN-E: 1347-5460
ISSN-L: 0915-1559
Volume: 53
Issue: 3
Pages: 419 - 426
DOI: 10.2355/isijinternational.53.419
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Funding: Ruukki Metals Oy and the Finnish Funding Agency for Technology and Innovation (TEKES) are acknowledged for funding this work.
Copyright information: © 2013 by The Iron and Steel Institute of Japan.