A polymeric approach to the sulfide capacity of silicate slags and melts

Abstract

A thermochemical model for calculating the sulfide capacity of simple and complex silicate melts in the framework of the Toop-Samis polymeric model combined with a Flood-Grjotheim treatment of partial reactions is proposed. “Electrically equivalent ion fractions” are computed, in a fused salt Temkin notation, over the appropriate matrixes, whose relative extensions are assigned by solving the mass balances of the Toop-Samis model. The polymerization constant between quasi-chemical species of oxygen is related to the contrast of acid-base properties of the slag-constituent oxides, depending on their role of either network former or modifier and on their optical basicity value. Model activities follow the Raoultian behavior implicit in the ion matrix solution of the Temkin notation and the adopted parameters bring a clear energetic significance. The model displays a high heuristic capability with virtually no compositional limits as long as the structural role assigned to each oxide holds.