Kinetic modelling of carbothermal reduction of TiO2-Fe2O3 composite with natural gas using matlab
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Date
2016-06
Authors
Nur Atiqqah Mohd. Moslim
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Abstract
An alternative way to obtain titanium metal in low cost was proposed via carbothermal reduction by yielding titanium oxycarbonitride (TiOxCyNz) as product. Synthetic anatase and hematite was mixed together with carbon to study the reduction kinetics when using synthetic materials. The reduction process was planned by using Design of Experiment (DOE) and executed at 1150°C and 1250°C for 1 to 4 hours in hydrogen, nitrogen and natural gas atmosphere. The carbon to reducible oxygen molar ratio (C:Ored) was varied in this experiment too. Highest extent of reduction with 92.68% was obtained at 1150°C for 4 hours using sample with molar ratio of 1:1. The extent of reduction, extent of nitridation and amount of carbon deposited was studied using 23 factorial design to define the optimum parameters in producing TiOxCyNz. From DOE analysis, the most influential factor contributing to the extent of reduction was reduction time, followed by carbon to reducible oxygen molar ratio and reduction temperature subsequently. Shrinking core model was developed to determine the extent of reduction at different time and temperature. This model was developed by applying physical and thermodynamics properties of elements/compounds involved in the reaction. The model was then compared to the experimental extent of reduction. the extent of reduction predicted by model was deviated from experimental but still having the same reduction trend which is high reduction concomitant with high temperature and time.