Activity Calculation in Complex Metallurgical Molten Slag Systems Based on Regular Solution Model Original Research Article

The activity of FetO is very important in ironmaking and steelmaking process. In order to predict the activity of FetO and optimize the operation conditions in ironmaking and steelmaking process, by application of regular solution model in molten slag systems, FeO-Fe2O3-SiO2 ternary system, FeO-Fe2O3-SiO2-CaO and FeO-Fe2O3-SiO2-NiO quaternary systems have been studied by the chemical equilibrium between H2/H2O gas mixture and liquid slag contained in solid iron. The values of interaction energy between cations concerning steelmaking slags have been determined by application of ferric-ferrous iron equilibrium and iron-ferric iron equilibrium. And then the activity of FetO can be calculated. The results show that the relative error is 3. 9% in FeO-Fe2O3-SiO2 system and 18% in FeO-Fe2O3-SiO2-CaO system. The prediction of activities of FetO in the systems are in good agreement with the measurements and the regular solution model is valid for predicting the activity of FetO in complex molten slags systems. The activity of FetO in FeO-Fe2O3-NiO system have not been tested presently, and the calculated result can not be assessed.