Utilization of Hydrated Lime as Binder and Fluxing Agent for the Production of High Basicity Magnesium Fluxed Pellets

Abstract

The present work investigates the manufacture of high basicity (CaO/SiO2 = 1.45) magnesium containing fluxed pellets with hydrated lime used as binder and fluxing agent. The fired pellets and lump ores could constitute a binary burden for blast furnace with lower carbon emission. Both of the green and fired pellets with high basicity possessed good physical and chemical properties, and its metallurgical performances were better than the fired pellets in which bentonite and limestone were used as binder and fluxing agent, respectively. The optical microscopy, SEM/EDS and thermodynamic calculation were employed to clarify the difference between limestone fluxed pellets and hydrated lime fluxed pellets. The effect of basicity on the properties of green and indurated pellets was also studied. The results found that basicity and decomposition characteristics of the fluxing agents had great influence on the mineral composition of the fired pellets. Larger amounts of high-melting phases like MgFe2O4, strong bonding phases such as CaFe2O4 and good reducibility phases like SFCA could be generated in the hydrated lime fluxed pellets with high basicity during induration process, thus its metallurgical performances being improved.