Kinetics of Carbidization of Reduced Iron in CO-H_2-H_2S Mixtures

摘要

Particles of a hematite were first completely reduced in H_2-H_2S mixtures and then carbidized in CO-CO_2-COS-N_2 and CO-H_2-CO_2-H_2O-H_2S-Ar mixtures. The following conclusions were obtained. The kinetics of carbidization of reduced iron is controlled by the carburization reaction on the surface of pores of reduced iron. The kinetics were represented as the product of g(p_i,T) and h(f_θ). From the plot for -ln(l-f_θ) vs t, we evaluated the value of g(p_i,T). The rate controlling elementary reactions are the reaction of CO+H(ad)→[C]+OH(ad) and O(ad)+CO→CO_2. The former becomes drastically rapid by the catalytic effect of H(ad). By substituting the equilibrium relation, a rate equation (24) has been obtained.