Comparison between measured CaO and Al2O3 normalised to CaO–Al2O3 in top slag, calcium aluminate inclusions and results of theoretical calculations

Abstract

This study sets out to compare the wt-% CaOslag and Al2Oslag3 in the binary system of CaO–Al2O3 that were measured in the top slag before teeming, the CaOincl and Al2Oincl3 in calcium aluminates that were analysed by scanning electron microscopy of the steel samples and the CaOcalc and Al2Ocalc3 that were achieved from theoretical calculations using the total measured elements in the top slag and steel before teeming. The CaOincl and Al2Oincl3 in all of the calcium aluminate inclusions of this study did not have the same ratio; in the opposite, they covered a large range. The average CaOincl and Al2Oincl3 in all samples had nearly similar compositions that were close to the border of the phase Ca12Al14O33 in the binary phase diagram of CaO–Al2O3. The CaOslag and Al2Oslag3 in all samples had almost similar compositions that were close to the border of the phase Ca3Al2O6 in the binary phase diagram of CaO–Al2O3. The results of theoretical calculations were close to the CaOslag and Al2Oslag3, but they did not follow the same maximum and minimum tendencies of CaOslag and Al2Oslag3.