酸化鉄および酸化亜鉛ペレットのCO-CO2混合ガスによる還元反応速度
鉄還元揮発法による亜鉛製錬の基礎研究 (第6報)
1989 年 105 巻 12 号 p. 951-957
詳細
1989 年 105 巻 12 号 p. 951-957
In order to analyze the reduction rate for the mixture of iron oxide and zinc oxide with CO-CO2 gas mixtures, reduction experiments were carried out in pure hematite pellet and pure zinc oxide pellet in the temperature range from 973 to 1173 K. Experimental data for each reduction were analyzed in terms of the mixedcontrol kinetics based on the isothermal unreacted core model and the isothermal shrinking model, respectively. Then the rate parameters were determined. The results are summarized as follows:
(1) For hematite pellets the reaction rate constant kC2 and the effective diffusivity De1 are expressed, respectively, by following equations: kc2/10-2m·s-1=exp 16.65-120.0×103/(RT) Del/10-4m2·s-1=exp (8.553-9.646×103/T).
The activation energy of the reaction was 120 kJ·mol-1. The calculated reduction curves by using the rate parameters based on the unreacted core model are in satisfactory agreement with the experimental data.
(2) For zinc oxide pellets the reaction rate constant kc1 are expressed by the following equation and the activation energy was 240 kJ·Emol-1. kc1/10-2m·s-1=exp 23.33-240.3×103/(RT)
The calculated reduction curves finely reproduced the experimental data. Finally, it was found that the overall rate is controlled by chemical reaction under the experimental conditions.
