Experimental Evaluation of Chemical Composition and Viscosity of Melts during Iron Ore Sintering

Abstract

The viscosity of the melts formed in the sintering reaction was measured for evaluating the fluidity of the melts, which play a crucial role in the sintering process. Using the sphere draw-up method carried out the measurements of high temperature viscosity. With low-melting point compositions of the Fe₂O₃-CaO-SiO₂ system, the viscosity of high SiO₂ content melts (Fe₂O₃/CaO/SiO₂=38.5/34.5/27.0 weight basis) was 5 times higher than that of low SiO₂ content melts (Fe₂O₃/CaO=80/20). The viscosity of low SiO₂ content increased with addition of Al₂O₃ and SiO₂. Similarly, with melt compositions generated from actual ores, viscosity depended on the contents of Al₂O₃ and SiO₂.
Based on the results, the viscosity of the melted liquid was estimated from the chemical composition, and the viscosity of the solid-liquid coexistence phase was also evaluated using a viscosity calculating equation for suspensions. The viscosity distribution of the solid-liquid coexistence phase at 1 300°C in the ternary composition system Fe₂O₃-CaO-SiO₂ was obtained.