Estimation of TiO(2)-FeO-Na(2)O slag viscosity through molecular dynamics simulations for an energy efficient ilmenite smelting process

Along with the increasing demand for the TiO(2) 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 TiO(2) 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 Na(2)O addition on viscosity of TiO(2) slag were also investigated. The addition of Na(2)O 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 TiO(6) octahedral network structure. The relationship between viscosity and structural change with varying FeO and Na(2)O concentrations was explored considering the coordination number of Ti and various bonding types.