Intrinsic kinetics and mechanism of rutile chlorination by CO+Cl-2 mixtures

Abstract

The intrinsic kinetics for the chlorination of natural rutile in CO-Cl-2 gas mixtures were studied in a shallow fluidized bed. The effects of particle size, temperature, and partial pressures of chlorine and carbon monoxide were determined. The chlorination of rutile was found to follow a topochemical reaction scheme, the rate of which can be expressed as eq 7, in the ranges 950 degrees C less than or equal to T less than or equal to 1150 degrees C and 0.9 kPa less than or equal to (p(Cl2), p(CO)) less than or equal to 57 kPa, where T is in K, d is in mu m, p is in kPa, and t is in min. A reaction mechanism involving lower-valence titanium oxides produced near the surface during chlorination is proposed.