Investigation of the Viscosity and Structural Properties of CaO-SiO₂-TiO₂ Slags

The viscosity of CaO-SiO₂-TiO₂ slags was measured via the rotating cylinder method to reveal the effect of TiO₂ on viscous flow of the slags. Furthermore, the structure of the ternary slags and the role of Ti⁴⁺ were investigated by Fourier transform infrared and Raman spectroscopy techniques. The results are beneficial for a better understanding of the behaviors of Ti-bearing silicate slags. The TiO₂ additions lowered the viscosity and apparent activation energy of the slags. However, the degree of polymerization (DOP) of silicate network was found to be enhanced with increasing the TiO₂ content, which is suggested by the increase in mole fraction of Q ³ ([SiO₄]-tetrahedra with three bridging oxygens) and the decrease in Q ⁰. The Eq. [2] Q ² ↔ Q ¹ + Q ³ was appropriate to express the relationship of different Q ⁿ species. The introduction of Ti⁴⁺ into the silicate network as network formers increased the DOP but weakened the strength of slag structure at the same time. Besides, a large proportion of Ti⁴⁺ exists in the slag in the form of \( TiO_{4}^{4 - } \) monomers, resulting in a decrease of viscosity with increasing TiO₂ content.