Nobuya Shinozaki, Yoshiroh Takahashi and Kusuhiro Mukai
Department of Materials Science & Engineering, Faculty of Engineering, Kyushu Institute of Technology, Kita-kyushu
In order to obtain fundamental information for clarifying the reason why spinel-alumina refractory has strong resistance against slag corrosion, interfacial reactions between Al2O3-MgO substrate and liquid iron were investigated by the use of X-ray diffractometer and X-ray micro analyzer.
When the substrate contains non-stoichiometric MgAl2O4 spinel and the oxygen content of iron is sufficient, iron diffuses easily with oxygen into the substrate, which leads to the formation of (Fe, Mg)Al2O4 spinels in the vicinity of substrate-liquid iron interface. The formation of (Fe, Mg)Al2O4 spinels containing a large amount of iron occures when α-alumina coexists with MgAl2O4 spinel in the substrate. (Fe, Mg)Al2O4 spinels have larger lattice constants than MgAl2O4 spinel. Decrease in porosity of substrate after the reaction can be interpreted to be caused by the formation of (Fe, Mg)Al2O4 spinels.
It is speculated from the estimated activity coefficients of FeO in (Fe, Mg)Al2O4 spinels that non-stoichiometric MgAl2O4 spinel enriched by Al2O3 has a prominent ability to trap FeO.
(Received May 17, 1995)
interfacial reaction, Al2O3-MgO substrate, liquid iron, spinel, α-alumina, refractory, X-ray diffraction, X-ray micro analyzer
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