Kinetics of the chlorination reaction of tantalum pentoxide with carbon tetrachloride gas

Abstract

The chlorination reaction of tantalum pentoxide is one of the important intermediate steps to produce tantalum metal from its oxide. The results of experiments on the kinetics of the reaction between tantalum pentoxide and carbon tetrachloride gas are presented in this paper. The experiments were carried out using a thermogravimetric analysis technique at temperature ranges between 723 and 798 K and carbon tetrachloride partial pressures between 36.5 and 81.1 kPa. Spherical shrinking core model was found to fit well the chlorination reaction rate over the entire temperature range. The chlorination reaction was controlled by surface chemical reaction, and an activation energy of 46.3 kJ/mol (11.1 kcal/mol) was obtained. The reaction order with respect to carbon tetrachloride partial pressure in a gaseous mixture with nitrogen was 2.15. © 2005 The Japan Institute of Metals.