Effect of ore types on high temperature sintering characteristics of iron ore fines and concentrate

Sinter quality (strength and reducibility) plays an important role in reducing the GHG emissions from the blast furnace ironmaking process and is significantly influenced by the reactions occurring in the sintering bed. Formation and fluidity of the initial sinter melt from adhering fines and its interactions with coarse nucleus particles are the key sintering reactions. Hence understanding of these high temperature characteristics of iron ore is urgently needed in order to produce strong and reducible sinter and optimise resource utilisation. In the present study, laboratory scale sintering tests were carried out to examine the effect of adhering fines and nucleus particles from various ores on the characteristics of initial sinter melt formation, fluidity, as well as penetration and assimilation. The formation ability and fluidity of the initial melts from various adhering fines were quite different, and various iron ore fines required distinct CaO contents to form the melt and spread out. The ore type of adhering fines and substrates affected the penetration and assimilation ability of the initial melt, but a good formation ability and fluidity of initial melt was the basis of good penetration and assimilation ability. Based on the micro and macro sinter structure, the high temperature characteristics were further related to the sinter quality and sintering performance. This information is expected to provide excellent tools in formulating and optimising future low cost and low emission sinter blends.