Assimilation and Mineral Formation during Sintering for Blends Containing Magnetite Concentrate and Hematite/Pisolite Sintering Fines.

Abstract

Blends for sintering in China commonly contain domestic magnetite concentrate and imported hematite or/and pisolite sintering fines. Interactions between these ores will, no doubt, have an important impact on sintering performance and sinter quality of these blends. Studies have been carried out to look at assimilation of sintering fines and mineral formation during sintering of such blends. The results show that at given mix composition, pisolite ores are easier to be assimilated than hematite and magnetite ores while magnetite shows the least assimilation. For the same ore, the assimilation depends on melt level and ore porosity. For this reason, higher assimilation was observed for porous ores or ores with high gangue content or when an easy-fusing ore was present in the blend. Studies on mineral phase formation of blends containing magnetite, hematite and pisolite indicate that good sinter mineralogy with increasing SFCA (silico-ferrite of calcium and aluminium) content is obtained with increasing Ore E (hematite). Substitution of Ore J (pisolite) for various hematite ores did not lead to significant changes in sinter mineralogy. The only change was the reduced level of primary hematite owing to the high reactivity of Ore J.