Kinetic Studies on the Chlorination of Zircon

Abstract

This paper reports on an investigation on the zircon chlorination process. The chlorination was conducted (i) with static zircon-coke powder mixtures in horizontal and vertical reactors, (ii) with zircon-coke mixed powder compacts in the two reactors, and (iii) with a sintered zircon disc and a grooved carbon disc. Experiments with the zircon and carbon discs clearly revealed that physical contact between zircon and coke was mandatory for the chlorination to occur. It was also observed that a faster chlorination rate and a higher extent of chlorination with static charge were achieved if the charge was compacted prior to chlorination. This was explained as being due to the formation of fine zircon and coke particles in intimate contact with each other. Due to the complexity of zircon carbo-chlorination, system specific rate expressions have been proposed. For a loose charge in a horizontal static bed reactor, the rate expression was linear, while for a compacted (and crumbled) zircon-coke mixture held in a vertical pipe reactor the reduced time plots technique was used to arrive at the rate expression, which turned out to be the Ginstling-Brounshtein expression.