Physicochemical Properties of High Alumina Blast Furnace Slag

摘要

As a result of the consumption and the rising cost of raw materials for ironmaking, steel producers have increased their utilization of low-cost, low-grade raw materials such as high alumina iron ore. The effect of Al_2O_3 and the Al_2O_3/SiO_2 ratio on the viscosity, surface tension and sulfide capacity of the CaO-SiO_2-Al_2O_3-MgO-TiO_2 blast furnace slag system were studied in the present work. At a fixed CaO/SiO_2 ratio of 1.20, 9 mass pct MgO, and 1 mass pct TiO_2, the viscosity increases with an increase in Al_2O_3 content at a range of 16-24 mass pct, and decreases when the Al_2O_3 is higher than 24 mass pct. Increasing Al_2O_3/SiO_2 from 0.47 to 0.92 causes a slight decrease in viscosity of the slags and has an opposite effect when Al_2O_3/SiO_2 is more than 0.92. The surface tension increases with increasing Al_2O_3 content at a fixed Al_2O_3 content and Al_2O_3/SiO_2 at a fixed CaO content. The desulfurizing capacity decreases with increasing of Al_2O_3 content, while increases with increasing Al_2O_3/SiO_2 at a fixed CaO content.