Effect of BaO/Al2O3 molar ratio on the viscosity and structure of CaO SiO2MgO Al2O3BaO slag
Yong Hou, Shuo Zhang, Jia Guo, Hanghang Zhou, Xuewei Lv
Abstract
In this study, the effect of BaO/Al 2 O 3 molar ratio on the viscosity and structure of CaO SiO 2 MgO Al 2 O 3 BaO slag was investigated. The results revealed that the viscosity first increased and then decreased with increasing the BaO/Al 2 O 3 ratio, and the transition point occurred at the ratio of 0.36. Deconvolution of Raman spectra showed that the Q 3 unit first increased and then decreased with increasing the BaO/Al 2 O 3 ratio, while the Q 0 , Q 1 and Q 2 units presented the opposite trend. FTIR and XPS analyses indicated that the [SiO 4 ] and [AlO 4 ] tetrahedra polymerized due to the charge compensation of Al 3+ by Ba 2+ and the increase in bridging oxygen prior to increasing the BaO/Al 2 O 3 ratio to 0.36. However, once the BaO/Al 2 O 3 ratio further increased, the tetrahedra gradually depolymerized owing to the interrupting effect of BaO and the increase in non-bridging oxygen. Spectral analysis demonstrated that the degree of polymerization of slag was the main factor affecting viscosity.