Assimilation Behavior of Quasi-particle Comprising High Alumina Pisolitic Ore

Abstract

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.

Improvement of sintering characteristics by selective granulation of high Al2O3iron ores and ultrafine iron ores

“…As shown in Table 3, the use of ultrafine magnetite ore (PF-J) as adhering fines showed approximately 55°C higher maximum temperature of exhausted gas compared with that of ultrafine haematite ore (PF-N) due to the oxidation of magnetite ores during sintering. Recently, Jeon et al 12 reported that the formation of a high viscosity interfacial layer on the boundary between high Al 2 O 3 iron ores used as nuclei and ultrafine magnetite iron ores used as the adhering fines effectively localised Al 2 O 3 in the centre of granules, which lead to the improvement of sinter strength.…”

“…From a microscopic viewpoint, the gangue components such as Al and Si contained in high Al 2 O 3 iron ores could be localised by coating the surface of high Al 2 O 3 iron ores (G) with ultrafine iron ores containing low Al 2 O 3 , which limits the dissolution and diffusion of the gangue components into primary sinter melts, leading to the minimisation of the adverse impact on sinter quality. 12 The selective granulation of high Al 2 O 3 iron ores and ultrafine iron ores would increase the relative amount of flux (limestone) and fuels in sinter blends, which consequently leads to the promotion of primary melt formation. 18 As a result, the proper selective granulation of high Al 2 O 3 ores and ultrafine iron ores would make great contribution to the improvement of sintering productivity as well as sinter quality such as strength and RDI.…”

“…The design technology of quasi-particles is receiving great attention as one method of utilising low grade iron ores in the sintering process to counter the situation where iron ores are being degraded and is expected to improve the sinter quality by the proper designing of quasi-particles. 11 Jeon et al 12 reported that the designing conditions of quasi-particles have great influence on the assimilation behaviour and sinter quality when using high Al 2 O 3 iron ore and ultrafine ore as nuclei and adhering fines, respectively.…”

The Mechanism of the Effect of Al2O3 Content on the Liquid Phase Fluidity of Iron Ore Fines

“…Jeon et al, studied the assimilation behavior of quasi-particle-comprised, high alumina pisolitic ore. The results showed that the quasi-particle comprised high Al 2 O 3 pisolitic ore and ultra-fine magnetite ore obtained high sinter quality [17]. Umadevi et al, revealed that with increasing alumina content in the sinter of both the conventional and selective granulation processes, the fractions of hematite and of SFCA, and the pore phase increased, whereas the magnetite and silicate phases decreased [18].…”

Ore Assimilation and Secondary Phases by Sintering of Rich and High-Gangue Iron Ores

“…There is a history of efforts to understand the roles of ore fines and coarse particles in assimilation and matrix formation in the scientific literature [20][21][22][23][24]. However, most of it is based on experiments conducted in laboratory-scale electric furnaces.…”