The kinetics and mechanism of selective iron chlorination of an ilmenite ore

Abstract

The kinetics of the ilmenite chlorination was studied between 600 and 850°C. The ilmenite chlorination rate was determined by monitoring the mass changes using a thermogravimetric system of high resolution. Non-isothermal and isothermal runs were performed. The influence of temperature, chlorine flow and sample mass in the reaction rate was established. The thermal decomposition of ilmenite previous to the chlorination was taken into account. The formation of intermediate titanates during the chlorination reactions was found. The dependence of the reaction rate with temperature was analysed, and apparent activation energy of 186 kJ mol−1 was obtained for the chlorination process. A global mechanism was proposed involving: rupture of the ilmenite structure, formation and subsequent decomposition of pseudorutile and chlorination of hematite.