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Rutqvist, Anders
Publications (2 of 2) Show all publications
Semberg, P., Rutqvist, A., Andersson, C. & Björkman, B. (2011). Interaction between iron oxides and olivine in magnetite based pellets during reduction at temperatures below 1000°C (ed.). Paper presented at . Ironmaking & steelmaking, 38(5), 321-328
Open this publication in new window or tab >>Interaction between iron oxides and olivine in magnetite based pellets during reduction at temperatures below 1000°C
2011 (English)In: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 38, no 5, p. 321-328Article in journal (Refereed) Published
Abstract [en]

In this work, the solid state diffusion of magnesium was studied in magnetite based pellets at temperatures between 500 and 1000°C. The samples were laboratory produced pellets with a largely exaggerated addition of olivine. The results showed that the olivine particles after oxidation had decomposed along the particle boundary and turned into magnesioferrite crystals and pyroxene/vitreous silica. Large patches of magnesioferrite rich in magnesium oxide were spread out among the haematites in the interior of the pellet. In the subsequent reduction, the haematite was converted to magnetite at 500°C. At temperatures of 800°C and above, the magnesium in the magnesioferrite diffused out to the secondarily formed magnetite and wü stite. During reduction at 600-700°C, cracks appeared along this boundary as the haematite transferred into secondary magnetite. Comparison to a commercial olivine pellet showed that the diffusion of magnesium followed the same pattern as in the laboratory pellets

National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-13213 (URN)10.1179/1743281210Y.0000000012 (DOI)000292592100001 ()2-s2.0-79960161967 (Scopus ID)c669da73-6a70-4a3c-9784-29f1c56964f4 (Local ID)c669da73-6a70-4a3c-9784-29f1c56964f4 (Archive number)c669da73-6a70-4a3c-9784-29f1c56964f4 (OAI)
Note
Validerad; 2011; 20110808 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Semberg, P., Rutqvist, A., Andersson, C. & Björkman, B. (2011). Interactions between iron oxides and the additives quartzite, calcite and olivine in magnetite based pellets (ed.). Paper presented at . ISIJ International, 51(2), 173-180
Open this publication in new window or tab >>Interactions between iron oxides and the additives quartzite, calcite and olivine in magnetite based pellets
2011 (English)In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 51, no 2, p. 173-180Article in journal (Refereed) Published
Abstract [en]

Magnetite-based pellets with large amounts of the additives olivine, calcite and quartzite were isothermally reduced in a tubular furnace to study and describe the reaction behaviour of the additive minerals in the pellets. The reduction was thermodynamically set to yield wustite at three different temperatures: 900, 1000 and 1150 degrees C. The mineralogical phases that had formed before and after reduction were studied by Scanning electron microscope and X-ray diffraction. The pellets with the different additives were different already before reduction due to different reaction behaviour during induration: The results showed that it was possible to identify the main reactions during reduction for pellets with all three additives. All but the very small quartzite particles remained unreactive in reducing atmosphere until they began to form a fayalitic melt at 1000 degrees C. The calcium ferrites of the pellets with calcite reacted to form a porous calciowustite already at 900 degrees C. In the pellets with olivine, the magnesium, which had constrained into magnesioferrite pockets after induration, redistributed into the entire iron oxide structure at 900 degrees C and also reacted with silica at 1000 degrees C. The olivine core which had not reacted during induration did not appear to react in reducing conditions at temperatures of 1150 degrees C and below. These reaction mechanisms have indicated a potential to reduce the required amounts of additives in the pellets.

National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-13191 (URN)10.2355/isijinternational.51.173 (DOI)000288183900001 ()2-s2.0-79959939265 (Scopus ID)c615ea8e-1f43-4ae4-b28e-6703d2ddff7f (Local ID)c615ea8e-1f43-4ae4-b28e-6703d2ddff7f (Archive number)c615ea8e-1f43-4ae4-b28e-6703d2ddff7f (OAI)
Note
Validerad; 2011; 20110325 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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