Kinetics of Cementite Formation from Reduced Iron in CO-H2-H2S Mixtures under Pressurized Conditions

In the present authors' previous study, the rate of iron carbide formation from completely reduced iron ore was gravimetrically measured in CO-H2-H2S mixtures of sulfur activity 0.035 to 0.6 at the total pressure of 0.1 to 0.6 MPa and at the temperature of 773 to 1 023 K. From the experimental results under the wide conditions, it was derived that the rate of iron carbide formation was controlled by the carburization reaction on the pore surface of reduced iron. In this study, the integrated rate equation for the first order reaction, −ln(1−fθ)=g(pi, T)t, was applicable to cementite formation curves, fθ versus t relation, in the range of iron carbide formation, i.e. fθ