Volume 33 (1993) Issue 1 Pages 12-19
An attempt has been made to estimate the hydroxyl capacities of some molten silicates by the regular solution model of Lumsden, which has been extensively developed to be applied to slag-metal reactions in steelmaking process by the authors. The slag systems discussed were of Na2O-SiO2, K2O-SiO2, Li2O-SiO2, CaO-SiO2 binaries and CaO-SiO2-Al2O3, CaO-SiO2-MgO, CaO-SiO2-MnO and CaO-SiO2-P2O5 ternaries. In the present work, it was assumed that the water vapor is dissolved in the slag as COH'=XHO0.5/(PH2O/P°)1/2, where, PH2O, P° are partial pressure of water vapor in the gas phase and the atmospheric pressure (Pa), respectively.
The interaction energies between hydrogen ion and other cation i, αH-i, have been derived based on the regular solution model in the present work. As the result, it has been confirmed that the model has been applicable to predict the hydroxyl capacities over the wide range of slag composition discussed. It has been found that COH' calculated by the model showed the minimum value at the slag composition of about unit basicity. The hydroxyl capacities calculated by the model have agreed with the measured within ±0.002.