Estimation of TiO₂-FeO-Na₂O slag viscosity through molecular dynamics simulations for an energy efficient ilmenite...

Along with the increasing demand for the TiO₂ pigment, the ilmenite smelting process has also become significant because it can utilize both rock- and sand-type ilmenite. However, due to the high liquidus temperature of the TiO₂ slag system, the smelting process is highly energy consuming. In the present study, the viscosity of molten ilmenite slag was estimated using molecular dynamic simulations at a high temperature to achieve an appropriate and efficient slag design. To verify the validity of the simulation technique, experimental measurements were performed in parallel and their results were compared. The effects of FeO and Na₂O addition on viscosity of TiO₂ slag were also investigated. The addition of Na₂O as a flux enhanced the ilmenite smelting process by not only lowering the liquidus temperature but also slowing the drastic viscosity increase. Statistical information obtained from the molecular dynamic simulations revealed a three-dimensional TiO₆ octahedral network structure. The relationship between viscosity and structural change with varying FeO and Na₂O concentrations was explored considering the coordination number of Ti and various bonding types.