Effect of Al2O3 Addition on the Precipitated Phase Transformation in Ti-Bearing Blast Furnace Slags
2016 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 47, no 2, 1390-1399 p.Article in journal (Refereed) PublishedText
The present paper aims to provide a fundamental understanding on phase change of Ti-enriched crystalline phase induced by Al2O3 addition in Ti-bearing blast furnace slags with different basicities using Single Hot Thermocouple Technique and X-ray Diffraction. The results showed that an increase in the Al2O3 content led to phase change from rutile or perovskite to Mg3Al4Ti8O25 and prompted crystallization of the slags with basicity of 0.60 and 0.75, whereas only CaTiO3 was precipitated at a basicity of 0.95. Both thermodynamic and kinetic analyses were conducted to study the slag crystallization, which would throw light on phase change and enhanced crystallization. To further reveal the relationship with Al2O3 addition on slag structure and crystallization, Fourier transform infrared spectroscopy and magic angle spinning-nuclear magnetic resonance were adopted, with AlO4 tetrahedra and AlO6 octahedra observed in the slag. For slags with the basicity of 0.60 and 0.75, AlO6 octahedron, which was suggested to induce the phase change from TiO2 or CaTiO3 to Mg3Al4Ti8O25, was detected at high Al2O3 content. On the other hand, in slags with the basicity of 0.95, abundant Ca2+ may be connected to TiO6 octahedra, resulting in CaTiO3 formation.
Place, publisher, year, edition, pages
Springer, 2016. Vol. 47, no 2, 1390-1399 p.
Alkalinity, Blast furnaces, Fourier transform infrared spectroscopy, Magic angle spinning, Nuclear magnetic resonance spectroscopy, Oxide minerals, Phase transitions, Slags, Thermocouples, X ray diffraction, Crystalline phase, Hot thermocouple, Magic angle spinning nuclear magnetic resonance, Phase Change, Slag crystallization, Slag structure, Thermodynamic and kinetic analysis, Ti-bearing blast furnace slag
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-187097DOI: 10.1007/s11663-015-0576-7ISI: 000375454700057ScopusID: 2-s2.0-84959917977OAI: oai:DiVA.org:kth-187097DiVA: diva2:928914
QC 201605172016-05-172016-05-172016-05-30Bibliographically approved