The viscosities for the selected CaO-MgO-SiO2 and CaO-MgO Al2 O3-SiO2 slags were measured by rota- ting cylinder method in a wide temperature range from 1608 K to 1 823 K. The effects of temperature, slag basicity and Al2 O3 content were studied. The results indicated that the viscosity decreased with increasing the slag basicity at the same temperature. And the viscosities of the slag initially increased linearly with increasing Al2 O3 content in the slags and then decreased as the Al2 O3 content in the slags continued to increase. Al2 O3 addition has a more signifi- cant effect on the viscosity than slag basicity in the selected slags. Based on the experimental data and the fraction of solid phases calculated by the thermodynamic software, the effect of solid phases on slag viscosity was evaluated. The results indicated that the relationship between the relative viscosity and the volume fraction of solid phases esti- mated from the slag composition can be reasonable by allowing the inverse maximum fraction of solid particles to vary.
The densities of the selected quaternary CaO-MgO-Al2O3-SiO2 slag with low silica were measured by the Archimedean method in a wide temperature range from 1773 to 1 873 K. Nine different slag compositions were chosen based on three diffel：ent levels of CaO content and three different levels of SiO2 content. WM,O was equal to 7. 0%. Wcao were varied from 40.04% to 50.64%, for wsO2 =10.25%-20. 70%. The effects of temperature, SiOz content and optical basicity were studied. It is shown that density decreases approximately linearly with an increase in temperature. Under the same CaO content, the density decreases with increasing of SiOz content, and increases with optical basicity increasing. Based on the experimental data as the boundary of the homogenous phase region predicated by FACTSAGE software, the mass triangle model is used to calculate the density of selected limited homogenous phase region. The results showed that the mass triangle model works well.
