No abstract

The viscosities of high alumina blast furnace slags were experimentally determined by the rotating cylinder method using the Brookfield digital viscometer model LVDV-II+ pro. Two different slag systems were considered for the current study, the CaO-SiO 2 -MgO-Al 2 O 3 quaternary and the CaO-SiO 2 -MgO-Al 2 O 3 -TiO 2 quinary system. Experiments were conducted in the temperature range of 1650 to 1873 K. The effects of temperature, basicity, TiO 2 , and silica activity of slags on viscosity were studied. The viscosity decreases with basicity for high alumina blast furnace slags with basicity in the range of 0.46 to 0.8. At high basicity (~0.8), slag viscosity decreases even with a small amount of TiO 2 (~2 pct) addition in the slag. With an increase in silica activity in the range of 0.1 to 0.4, the slag viscosity increases, the increases being steeper below the liquidus temperature.

A viscosity model based on a new definition of basicity has been proposed for blast furnace type slags. Conceptually, this definition of basicity is close to Bell's definition of basicity as used for modelling of sulphide capacity of blast furnace type slags. The model developed in the present work is applicable for wide range of alumina, magnesia and titania containing blast furnace slags, while most of the models available in the literature are mainly applicable for a limited range of slag composition. Viscosity estimation by this model is close to the experimental value for all types of blast furnace slags. This model is based on the chemical composition of slag and is applicable for slags above liquidus temperature. List of symbolsg viscosity of slag g o viscosity of non network forming melts A constant E activation energy of the melt B Ã i modified basicity index

No abstract

No abstract