Sintering Properties of Iron Ore Mixes Containing Titanium

Abstract

Titanium containing compounds are valuable materials for addition to the blast furnace to extend operational campaigns. However, the addition of these materials via the sinter plant has been known to create problems. This study investigates the effect of adding a titanomagnetite to two sintering ore blends, containing 10 and 20% pisolitic limonite respectively. The addition of up to 2% titanomagnetite did not affect the sintering parameters or sinter quality. Increasing the titanomagnetite levels to greater than 3% also had no significant influence on sintering but a significant deterioration in sinter RDI was recorded. Results also showed that the deterioration in RDI was greater for the blend containing more pisolitic limonite. SEM studies carried out on the product sinters found most of the titanium in the glass phase. The mechanical properties of the glass was characterised using indentation fracture mechanics. Although some difficult was experienced, due to the small and disperse nature of the glass, addition studies using artifically manufactured glass indicated that the fracture toughness of the glass decreased with increasing titanium levels. It is postulated that because glass in the weakest phase in sinter and is widely dispersed any reduction in its fracture toughness will increase the vulnerability of the sinter to crack propagation, thereby increasing sinter RDI. It is also postulated that increasing the pisolitic level increased melt formation and the dispersion of the glass phase, resulting in a further deterioration in sinter RDI. © 1992, The Iron and Steel Institute of Japan. All rights reserved.