Kinetics of solid titania reduction by carbon in liquid iron

To clarify the mechanism of TiO2 reduction by Fe-C melt, effects of carbon and sulfur contents in liquid iron and temperature on the reduction rate of solid TiO2 were examined at temperatures of 1 350 to 1 550°C under argon atmosphere.The reduction rate of solid TiO2 was proportional to the activity of carbon in liquid iron, while it decreased by the addition of a small amount of sulfur to the liquid iron. An apparent activation energy for TiO2 reduction by carbon was calculated to be about 400 kJ mol-1.It was concluded from these experimental results that the overall rate of TiO2 reduction was controlled by the rate of chemical reaction step at the solid TiO2-liquid iron interface. The decrease in reduction rate of TiO2 by the addition of sulfur to the liquid iron was attributed to the decrease in effective reaction area by the adsorption of sulfur to the interface.