Development and application of a novel fluxing compound for improving sintering performance of high alumina iron ore

Abstract

Blast furnaces (BF) ferrous burden consist of sinter (>50%) with rest being pellets and lump ore. Good sinter quality is necessary for efficient BF operation which depends on iron ore quality and its gangue. In gangue, alumina has a strong influence that adversely affects product quality and productivity. To address those effects this study presents a two-stage method. It involves the development of a novel low temperature melting synthetic flux i.e. Iron Rich Calcium Ferrite (IRCF) at Stage-1 and its addition in high alumina sinter feed at stage-II. Microstructural and dilatometry studies show that IRCF encourages the formation of silico-ferrite of calcium and aluminum (SFCA-1). The IRCF addition (6% max) in the high alumina (3.1%) sinter feed improves the Tumble index by 4.7 points, lowers the Abrasion index by 2.7 points, and decreases the return fines by 4.4%. Moreover, the Reduction degradation index (RDI) was also improved by 7.9 points.