Studies on the kinetics of carbon tetrachloride chlorination of tantalum pentoxide

Studies on the kinetics of chlorination of tantalum pentoxide powder by carbon tetrachloride vapor in dilution with nitrogen have been carried out by weight-loss measurements in two temperature ranges, i.e., 698 to 773 K and 793 to 853 K. The effect of time, temperature, and partial pressure of CCl sub 4 (P sub CCl4 ) on the kinetics of chlorination of the powder Ta sub 2 O sub 5 , (-105 + 74 mu m) has been investigated. In both the temperature ranges, the chlorination results have been found to fit the following relationship during the 'initial periods:' In the 'latter periods' of the chlorination of Ta sub 2 O sub 5 , the following relationship was found to be applicable in both the temperature ranges. Based on these kinetics results, two different mechanisms for the Chlorination of Ta sub 2 O sub 5 by CCl sub 4 vapor have been suggested for the two temperature ranges studied. It was possible to chlorinate > 92 pct of Ta sub 2 O sub 5 (-105 + 74 mu m) at 833 K in 210 minutes, by using CCl sub 4 at a partial pressure of 0.6 atm.