Interfacial Tensions between Mutual Interfaces of Liquid Iron, SiO₂-Al₂O₃-MnO-MnS Slags and MnS Based Sulfide

Abstract

Interfacial tensions between liquid MnO-SiO₂-Al₂O₃(sat)slag/liquid iron of varying sulfur content, MnS based sulfide/liquid iron, and MnO-SiO₂-Al₂O₃(sat) slag/MnS based sulfide were studied at 1550°C using Sessile Drop Method. The interfacial tensions, σ, between liquid MnO-SiO₂-Al₂O₃ slag/liquid iron were found to be 0.164 to 1.10 N/m, depending on sulfur and oxygen contents in liquid iron and they were expressed by the following equation as a function of sulfur and oxygen activities :
1.07-σ = 0.235 ln(1+10a_s+120a_s)
Precipitation of MnS based sulfide under the condition of adding more than 20mass% MnS to the slag was observed to occur at the slag-metal interface. The interfacial tensions between MnS based sulfide/liquid iron as well as MnO -SiO₂-Al₂O₃(sat) slag/MnS based sulfide were found to be 0.114 and 0.077 N/m, respectively.