Competitive Dissolution Mechanism of Sulfur in CaMnSilicate Melts: Structural View

Abstract

The sulfide capacities of the CaOSiO2MnO(Al2O3MgO) slags were measured at 1873K over a wide composition range using a gas-slag equilibration method. The effects of MnO content and the MnOCaO substitution on the sulfide capacity of molten slag were also investigated based on the structural view of silicate melts. In the multicomponent silicate melts containing high MnO (up to about 50wt%), the sulfide capacity mainly increased with increasing MnO content. Also, the sulfide capacity and the activity of MnO showed a linear relationship with a slope of unity, indicating that MnO is dominant component controlling the sulfur dissolution behavior into CaMnsilicate melts. The sulfide capacity increased as MnO substituted for CaO in the high silica melts (>30 (+/- 5) wt% SiO2), whereas it decreased by increasing the MnO/CaO ratio in the low silica melts (<30(+/- 5) wt% SiO2). This tendency of sulfide capacity resulted in the clock-wisely rotating iso-capacity contours from MnO-free side to MnO-rich corner in CaMnsilicate melts. The dissolution mechanism of sulfur in CaMnsilicate melts can be explained by the Competitive dissolution mechanism.