2014 Volume 54 Issue 12 Pages 2713-2720
This study aims to utilize the high Al2O3 pisolitic ore in sintering process by designing the quasi-particle where the pisolitic ore is used as nuclei and ultra-fine hematite and magnetite ores are employed as adhering fines. The assimilation behavior between nuclei and adhering fines was investigated through microstructure analysis and it was correlated to sinter quality. When ultra-fine hematite ore was used as adhering fines, the low viscous melt of CaO·Fe2O3 was formed in the assimilation. Since this results in the low extent of Al2O3 localization and the porous structure, the detrimental effect of Al2O3 on the strength was not fully controlled. On the other hand, for the ultra-fine magnetite ore, 3CaO·Fe2O3·3SiO2 melt with high viscosity was predominantly participated in the assimilation. The assimilation was suppressed by the formation of ‘interfacial layer’. Due to the dense structure and high extent of Al2O3 localization, the detrimental effect of Al2O3 on strength was reasonably controlled. The quasi-particle comprising high Al2O3 pisolitic ore and ultra-fine magnetite ore showed the equivalent sinter quality to the quasi-particle sample consisting of nuclei of dense hematite and adhering fines of ultra-fine hematite resulting in the high sinter quality.