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) a dagger" 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 monomers, resulting in a decrease of viscosity with increasing TiO2 content. (C) The Minerals, Metals & Materials Society and ASM International 2014