ABSORPTION-COEFFICIENTS AND REFRACTIVE-INDEXES OF SYNTHETIC GLASSY SLAGS CONTAINING TRANSITION-METAL OXIDES

The absorption coefficients and refractive indices of Na2O-SiO2 and Ca O-SiO2-Al2O3 slags doped with transition metal oxides have been measur ed. Additions of Fe2O3, Cr2O3, and NiO were found to cause marked incr eases of absorption coefficient, in contrast to MnO, which produced on ly a small increase. The refractive indices of the slags were found to increase with increasing concentrations of Fe2O3, MnO, NiO, and Cr2O3 . Simple empirical rules have been developed to predict the absorption coefficients and refractive indices of slags containing these oxides. Estimated values of the extinction coefficient and refractive index o f slag films formed between the steel strand and the mould in continuo us casting have been used to calculate the magnitude of the radiation conduction contribution to heat extraction from the mould. These calcu lations indicate that radiation conduction is unlikely to exceed 20% o f the total heat flux. IS/1078