ON THE VISCOSITY OF MOLTEN SLAGS (I)

Viscosity of Synthetic CaO-SiO2-Al2O3 slags was measured by rotating an innercylinder viscosimeter. Iso-viscosity lines at 1, 500 and 1, 600°C were plotted on the diagram. Viscosity of CaO-SiO2 slags at 1, 600°C increased with SiO2 content; and anomaly was not found at the composition corresponding to CaO-SiO2. By a small amount of Al2O3 added to CaO-SiO2 slag the viscosity was almost unaffected, but at more than 20% Al2O3 increase of the viscosity became remarkable. Viscosity of the CaO-Al2O3 side slags which had never been determined were found rather low and comparable to the low viscosity region in the CaO-SiO2 side slags. And some considerations on structures of these molten slags were given from the experimental results.