Chlorination kinetics of zirconia in an RF chlorine plasma tail flame

Abstract

The chlorination kinetics of zirconia were studied in a single stationary particle reactor system. A plasma of pure chlorine generated by an induction torch provided both the high enthalpy field and the reacting gas. The influence on the rate of conversion of such parameters as temperature, chlorine concentration (in the presence of argon) and particle diameter and porosity were investigated. Based on experimental and theoretical studies, rate equations were developed under different rate controlling mechanisms.The chlorination of zirconia in the particle temperature range of 1 540" to 2 480°K obeyed a shrinking core reaction model. The reaction was chemically controlled below 1 950"K, and above this temperature both chemical and mass transfer resistances were important. The experimental results confirmed the theoretical analysis.

The chlorination kinetics of zirconium dioxide in the presence of carbon

“…The fractional order of the reaction found in this study agrees with the order of metal oxide chlorinations reported in the original work by Biceroglu (1978). An order of 0.64 and 1.0 was reported by O'Reilly et a1 (1972) and Landsberg et a1 (1972), respectively, for the chlorination of zirconium dioxide.…”

“…The kinetic data of these runs are presented in Biceroglu's (1978) previous work. The kinetic data of these runs are presented in Biceroglu's (1978) previous work.…”

“…A typical plot is shown in Figure 7. The experimental data for each of these cases plus the results of another smaller number of runs with pellets of 18.0 and 20.0 wt % of carbon are presented in Biceroglu's (1978) original work. When more than one set of conversion-time data a t a constant temperature were available, the overall rate constant used in the Arrhenius plots was obtained from the slopes of the straight lines by least-squares fit.…”

“…In order to confirm that the value of the activation energy reported in the previous section was an intrinsic one, a number of kinetic runs were carried out with pellets of 1.000 and 0.671 cm in diameters, in addition to that of 0.826 cm used in the previous experiments. The kinetic data of these runs are presented in Biceroglu's (1978) previous work. Figure 8 includes Arrhenius plots for the three pellet diameters.…”

Treatment of pitch in argon/hydrogen plasmas

“…The reactor was fabricated from a single piece of Monel (Biceroglu, 1978) and housed a reaction chamber with the crucible containing the residue. Optical pyrometry and spectroscopy measurements were performed through a window in the upper section of the reaction chamber.…”