A Model Description of the Thermochemical Properties of Multicomponent Slags and Its Application to Slag Viscosities~1

摘要

In view of the urgent need for an extrapolation of the thermochemical and thermophysical properties of multicomponent metallurgical slags, a semiempirical slag model has been developed at the Department of metallurgy, Royal Institute of Technology, Stockholm. In this model, Temkin's description of ionic melts is coupled with Lumsden's total dissociation of polymerized silicate and aluminate species. The excess Gibbs energies are described by means of Redlich-Kister polynomials. The model parameters that correspond to binary silicate systems are generated from available experimental data and used consequently to describe systems of higher order. The model is successful in extrapolating the thermodynamic data for a number of ternary and higher-order silicate systems. In view of the uncertainties in the literature data in the case of the Al_2O_3-SiO_2 system, Knudsen cell mass spectrometric measureemnts are conducted and the model parameters are assigned on the basis of these results. This enables reasonable predictions of the thermodynamic properties of multicomponent aluminosilicate slags. The model description is also used in liking thermodynamic data with slag viscosities. The viscosities of ternary silicates could be predicted from the binary viscosities and the thermodynamic data.