窒素気流下における酸化亜鉛の金属鉄による還元揮発反応速度

鉄還元揮発法による亜鉛製錬の基礎研究 (第12報)

抄録

In order to clarify the reduction rate of zinc oxide with metallic iron under nitrogen stream, kinetic experiments were carried out in the temperature range between 1, 223 and 1, 373 K. Experimental data were an alyzed in terms of the mixed-control kinetics based on the isothermal shrinking unreacted-core model, in which activities of ZnO and FeO were taken into account. The rate parameters were then determined.
The reaction rate constant k_c and the effective diffusivity D_e are represented by the follwing equations: kc/mol·m^-2·s^-1=exp {-185.2×10³/(RT)+13.72}D_e/m²·S^-1=exp (-3433/T-8.620)
The activation energy of the reaction was 185kJ·mol^-1. The calculated reduction curves by using the rate parameters based on the shrinking unreacted-core model finely reproduced the experimental data.
At temperature of only 50K higher, the reaction rates of zinc oxide with metallic iron under nitrogen stream was comparable with that under vacuum.