| Abstrakt: |
The influence of solid carbon on the chlorination of TiO with Cl and CO-CO-Cl gas mixtures was investigated gravimetrically using rutile and graphite tablets. In the experiments, the temperature, composition and total pressure of the gas phase as well as the TiO-C separation were varied. The chlorination rate of TiO was found to be 40 to 50 times faster with TiO-C contact than in the absence of carbon. The acceleration of the chlorination rate is due to the kinetic influence of solid carbon and takes place even when TiO and C are separated by the gas phase. In the latter case the C influence decreases with increasing TiO-C separation. In the case of flowing Cl-Ar mixtures at 10 Pa total pressure this influence exists within a critical TiO-C separation, L, which is approximately 40 μm at 1273 K and PCl = 2.7 × 10 Pa. L increases linearly with increasing temperature and decreases approximately linearly with increasing total gas pressure in the case of a closed reaction vessel. The ratio of the reacted amounts of TiO and C is also dependent on the TiO-C separation. From the experimental results a kinetic reaction model is proposed to provide a quantitative description of the influence of solid carbon. The dependence of the chlorination rate, i, of TiO on the TiO-C separation, l, is given by i ∼ (l + Β) where Β is a constant. [ABSTRACT FROM AUTHOR] |
