Influence of Al2O3 on viscous behavior and structure characteristic of TiO2-bearing molten slags

The influences of the increasing content of Al 2 O 3 caused by refractory corrosion on the properties and structures of CaO–MgO-(15 wt%-27 wt%)Al 2 O 3 –SiO 2 –TiO 2 –FeO molten slags were studied at high temperature from 1923 K to 1798 K. The viscosity experimental results indicated that the slag viscosity first increased and then reduced with increasing the Al 2 O 3 content in TiO 2 -bearing slags, and the Al 2 O 3 content that reflected the inflection of the viscosity variation was about 21 wt%. From the Raman and NMR spectra analysis, when the Al 2 O 3 content in the TiO 2 -containing slag was lower than 21 wt%, Al 2 O 3 was an acidic oxide which could increase the viscosity, and with the Al 2 O 3 content in slags further increased to 27 wt%, Al 2 O 3 would behave as network modifiers to decrease the slag viscosity. From the XPS results, the amount of O 2− decreased first and then raised, while the ratio of O 0 and O − increased and then decreased with adding Al 2 O 3 to slags. The changing trend of the oxygens had a good accordance with the variation of slag viscosities.