Evaluation of viscosity of molten SiO2-CaO-MgO-Al2O3 slags in blast furnace operation

The viscosity of molten SiO2-CaO-MgO-Al2O3 Slag was measured using a rotating cylinder method at high CaO and Al2O3 concentration regions to search for a slag with low melting temperature and low viscosity. The experimental results showed that the viscosity of molten 35mass% Al2O3-43.1 mass% CaO-7.5mass% MgO-14.4mass% SiO2 slag at 1673K was lower than 0.6 Pa.s that satisfies the fluidity in blast furnace operation. The experimental results were compared with the calculated results of the viscosity model derived by the authors. The viscosity of molten SiO2-CaO-MgO-Al2O3 system can be evaluated from our model in wide Al2O3 concentration range.