Viscosity and desulphurisation behaviour of CaO–SiO 2 –MgO–Al 2 O 3 –BaO–MnO slag

Abstract

The influence of BaO on the structure, viscosity and sulfide capacity at 1500°C of CaO-SiO2-MgO-Al2O3-BaO-MnO slag was investigated comprehensively. The activity of O2− and activity coefficient of S2− were discussed, and the sulfur distribution ratio was deduced and analyzed from sulfide capacity. The results revealed that the viscosity increased slightly owing to an increase of BaO content, and the complexity of [SiO4]-tetrahedra and the connection between [SiO4]- and [AlO4]-tetrahedra structure were tighter. The sulfide capacity was lager due to the increased sum of basic component, but the increased range was weakened when BaO was more than 3wt-%. The activity of CaO increased and activity coefficient of CaS descended firstly and then enhanced, but the difference between logaCaO and logγCaS tended to be bigger as a function of BaO. The sulfur distribution ratio was in range of 40–50, similar to the variations of sulfide capacity.