LAUSR

The understanding of the thermodynamics of slags has become extremely important due to the higher demands on steel qualities in terms of the presence of impurities such as sulphur.1–3) The sulphide capacity (CS) of liquid slag systems has been extensively studied, and many models related to this have been developed. Zhang et al.4) developed an empirical model based on optical basicity to calculate the CS of metallurgical molten slags. Thermodynamic models were also proposed by Reddy and Blander5) and Pelton et al.,6) where CS is calculated solely from the knowledge of thermodynamic activity. Derin et al.7) proposed a neural network approach to estimate the CS in binary and multicomponent melts. Choi and Min8) studied the cationic effect of ferrous ions on the CS of CaO–FetO–Al2O3–SiO2 slags from the point of view of the ionic structure within them using micro-Raman spectroscopy. Moosavi-Khoonsari and Jung9) studied the dissolution behaviour of sulphur in silicate melts using the modified quasi-chemical model in the quadruplet approximation. Reddy and Blander10) proposed that the sulphide ions (S2−) in the dilute solution in silicate melts substitute O2− ions. The equilibration reaction may be written as follows: Thermodynamic Modelling of Sulphide Capacity of Ternary Silicate Slags