Thermodynamic Modelling of Sulphide Capacity of Ternary Silicate Slags

Evaluation of the sulphide capacity of Na 2 O-containing silicate slags using a structural model

“…The present model for ternary SiO 2 -AO-BO systems plus sulphur, where sulphide ions (S 2− ) can again substitute for free oxygen ions (O 2− ), has been recently proposed [14]. In the present work, this model was applied to ternary SiO 2 -Na 2 O-MO (M = Ca, Mn, Mg, Fe) systems plus sulphur, which can be represented as a square pyramid with SiO 2 at the apex level, and as shown in Figure 1, the base represents a reciprocal ternary subsystem Na 2 , M // O, S. The mixing Gibbs free energy of this system includes seven terms that can be used to estimate the activities of each component (SiO 2 , Na 2 O, MO, Na 2 S, MS):…”

“…This model has been used to estimate the thermodynamic properties and the phase diagrams of binary and ternary silicate systems [13]. It has also been used to estimate the sulphide capacity of binary and ternary systems [12,14]. In this work, we use the structural model to determine whether the slag sulphide capacity can be calculated only in terms of temperature and composition, independently of each partial pressure of oxygen and sulphur.…”