Effect of MnO on high-alumina slag viscosity and corrosion behavior of refractory in slags

Abstract

The influence of MnO on viscosities of CaO-SiO2-MgO-Al2O3-Cr2O3-based slags and the corrosion mechanism of carbon composite brick used in blast furnace hearth by slags was investigated in this work. From the viscosity experimental results, it was indicated that the viscosity decreased with the addition of MnO. The break point temperature decreases from 1 655 to 1 632 K and the apparent activation energy decreases from 217.54 to 185.90 kJ mol-1 with the increasing MnO content from 0 to 3 wt.%. The FTIR spectra analyses revealed that MnO exists as a network modifier and the polymerization degree of the slag decreases with the rising content of MnO. The corrosion of carbon composite brick by molten slag could be a consequence of dissolution, slag penetration and slag-refractory reaction, and the degradation of the brick becomes intenser with the addition of MnO.