Influence of unburned pulverized coal on the viscosity of blast furnace slag

Abstract

In order to explore the influence of unburned pulverized coal in ironmaking on the viscosity of blast furnace slag, the impact of temperature, volume fraction of solid particles and the rotating speed on the viscosity of CaO-MgO-Al 2 O 3 -SiO 2 heterogeneous slag were studied by experiment. The calculation model of relative viscosity of heterogeneous slag containing unburned pulverized coal is corrected. The results showed that the viscosity of heterogeneous slag increased with the increase of the volume fraction of the solid particles, and decreased with the increase of the rotating speed. For the heterogeneous slag with the same composition, the relative viscosity is not affected by the temperature and decreases with the increase in the rotating speed. The impact of unburned pulverized coal solid particles on the viscosity of the slag was much larger than the predicted value of the Einstein-Roscoe equation.

Viscosity and desulphurisation behaviour of CaO–SiO 2 –MgO–Al 2 O 3 –BaO–MnO slag

“…The desulphurization reaction occurred when mixes gases contacted with molten slag, as shown in Equation (1).…”

“…From Equation (2), it is clear that sulphide capacity is determined by the activity of basic oxides (a O 2− ), the activity coefficient of sulphides (g S 2− ) in slag and the equilibrium constant K (1) which is a function of temperature. Figure 3 shows the effect of BaO on the sulphide capacity of the slag at 1500°C.…”

“…The changes in viscosity of blast furnace slag are mainly attributed to network structure evolution behaviour, which had considerable influence on the blast furnace operation and the quality of molten iron, including the gas flow distribution, charge column permeability, desulphurisation behaviour, slag-iron separation, etc. [1,2]. Furthermore, the physicochemical properties of the slag were determined by its chemical composition except temperature, mainly related to type and proportion of the iron ore and other raw materials [3,4].…”