Carbide Capacity of CaO–Al₂ O₃–CaF₂ Slag at 1773 K

Abstract

The influence of CaF₂ on the thermodynamic behavior of carbon in the CaO–Al₂O₃ –CaF₂ slag at 1773K was investigated on the basis of carbide capacity concept. The carbide capacity increases with increasing CaF₂ content up to about 25 mol%, followed by nearly constant value in the CaO_satd–Al₂O₃–CaF₂ system. The capacity in the CaO–Al₂O₃–CaF₂ (44–49 mol% CaO) system rapidly increases by increasing the X_.CaF2/X_Al2O3 ratio up to about unity, and then the capacity-increasing rate decreases at X_.CaF2/X_Al2O3≥1. The carbide capacity increases with an increase of CaO/Al₂O₃ ratio at a fixed CaF₂ content; also, the addition of CaF₂ greater than about 14 mol% would have no effect on capacity regardless of CaO/Al₂O₃ ratio. The iso-carbide capacities obtained in the present work are very similar to the iso-sulfide capacities available in the literature.