On the Kinetics of Carbon-and Oxygen-Transfer between CO-CO₂, Mixture and Molten Iron

Abstract

Measurements have been done on the rates of carbon and oxygen transfer between CO-CO₂ mixtures and levitated iron droplet. Supposing that the mass transfers between two phases determine the total reaction rate, the kinetics of this reaction has been considered. Results obtained here are as follows: Type of reaction at the initial period is different from that at the later period. At the initial, a simple absorption of gas takes place independently of the composition of gas mixture. The rate is controlled by the mass transfer at the melt side. At the later period, decarburization or carburization proceeds and the countercurrent flow of CO and CO₂ in gas phase controls the total rate. It is concluded that whether iron is melted by the levitation technique or in usual crucibles, there is no essential differences in the mechanism of reaction, and that one or both of the mass transfers at gas and melt determines the total rate of reaction according to the experimental conditions such as the flow rate and composition of gas, mass and violency of stirring of melt. Re-examinations have been done for the previous investigations which proposed the interfacial chemical reaction mechanism as the rate determining step.