A quasi-chemical viscosity model for fully liquid slags in the Al2O3-CaO-‘FeO’-SiO2 system

Abstract

A structurally based viscosity model for fully liquid silicate slags has been proposed and applied to the Al 2 O 3 -CaO-'FeO'-SiO 2 system at metallic iron saturation. The model links the slag viscosity to the internal structure of melts through the concentrations of various anion/cation structural units (SUs). The concentrations of structural units are equivalent to the second nearest neighbor bond concentrations calculated by the quasi-chemical thermodynamic model. This viscosity model describes experimental data over the entire temperature and composition range within the Al 2 O 3 -CaO-'FeO'-SiO 2 system at metallic iron saturation and can be extended to other industrial slag systems.

Quasi-Chemical Viscosity Model for Fully Liquid Slag in the Al2O3-CaO-MgO-SiO2 System—Part I: Revision of the Model

“…The following Eyring Eq. [1] for liquid viscosity was derived [16][17][18] using the above principles [13] :…”

“…Development of a structurally based viscosity model for predictions in the multi-component slag systems valid over wide ranges of compositions and temperatures has been the focus of previous studies [1][2][3][4][5][6][7] ; the present paper describes recent developments of the model formalism and its application for fully liquid silicate slags in the Al 2 O 3 -CaO-MgO-SiO 2 system. Similar to other structurally based viscosity slag models, [8][9][10][11][12] the link of viscosities to the complex internal slag structure at the atomic level improves the predictive capability of slag viscosities.…”

Development of a Quasi-chemical Viscosity Model for Fully Liquid Slags in the Al2O3–CaO–‘FeO’–MgO–SiO2 System. The Experimental Data for the ‘FeO’–MgO–SiO2, CaO–‘FeO’–MgO–SiO2 and Al2O3–CaO–‘FeO’–MgO–SiO2 Systems at Iron Saturation

“…[1][2][3]19) A brief description of the essential features of the model is given below for the benefit of the reader.…”

“…Based on the postulates of liquid state and liquid viscosity initially formulated by Frenkel,19) the Eyring viscosity equation was developed, 21) which was used for the present where R and k are the gas (J K Ϫ1 mol Ϫ1 ) and Boltzmann (J K Ϫ1 ) constants, respectively, pϷ3.1416, T is the absolute temperature (K), DE v and E a are the vaporisation and activation energies (J mol Ϫ1 ), respectively, m SU and v SU are the weight and volume of a particular structural unit of viscous flow (kg and m 3 , respectively).…”

“…The shape of the symbol indicates the first author of the previously published data. Experimental data on the pseudo-binary "FeO"-SiO 2 that has been previously evaluated 19) has been included in the optimisation; these data are not marked on the Figures.…”