Accurate Density Calculation for Molten Slags in SiO2-Al2O3-CaO-MgO-'FeO'-'Fe2O3' Systems

A simple and accurate density calculation model for molten slags containing iron oxides in SiO2-Al2O3-CaO-MgO-'FeO'-'Fe2O3' systems is established in the present study, by extending a previous model developed for SiO2-Al2O3-CaO-MgO systems. To quantitate the iron oxides in slags, a new method is proposed to recalculate all the iron oxides as 'FeO' and 'Fe2O3,' which represent the iron oxides in equilibrium with metallic iron and the air atmosphere, respectively. This method is essentially different from most of the other models that dealt with ferrous (FeO) and ferric (Fe2O3) iron oxides. A total of 860 experimental data points for iron oxide-containing melts are critically collected for the optimization of the model parameters. The model achieves an excellent agreement with literature values with an average error of 1.96 pct and an overall absolute error of 0.092 g/cm(3). The compositional dependences from unary to multicomponent systems are discussed using the present model. The results show that the densities always increase with the increasing 'FeO' or 'Fe2O3,' and the substitution of 'FeO' by 'Fe2O3' will cause a decrease in density. In the multicomponent systems, SiO2 tends to have a larger impact on the density of 'Fe2O3'-containing systems compared with 'FeO'-containing systems. (C) The Minerals, Metals & Materials Society and ASM International 2019.