Quasi-Chemical Viscosity Model for Fully Liquid Slag in the Al2O3-CaO-MgO-SiO2 System. Part II: Evaluation of Slag Viscosities

A model is presented that enables viscosities to be predicted reliably over the whole range of compositions and temperatures in the Al2O3-CaO-MgO-SiO2 slag system above liquidus in the temperature range from 1543 K to 2643 K (1270 A degrees C to 2370 A degrees C). Experimental procedures and data from the studies reported in the literature have been collected and critically reviewed with particular attention to the viscometry methods and possible contamination of slag samples to select reliable data points for further model development. Relevant revised formalism to describe the complex viscosity trends including charge-compensation effect of the Ca2+ and Mg2+ cations on the formation of tetrahedrally coordinated Al3+ was introduced. Parameters of the quasi-chemical viscosity model have been optimized to reproduce within experimental uncertainties most of the selected experimental data in the Al2O3-CaO-MgO-SiO2 system and all subsystems. This study is part of the overall development of the self-consistent viscosity model of the Al2O3-CaO-FeO-Fe2O3- MgO-Na2O-SiO2 multicomponent slag system.