1994 Volume 34 Issue 3 Pages 241-246
The rate of decarburization of carbon-saturated liquid iron with CO2-H2O gas mixtures has been studied to bettter understand the reaction mechanism between liquid iron containing carbon with post-combusted gas in an iron bath smelting reactor. The measurements were done under conditions in which the effect of mass transfer is negligible. The experimental temperature was 1773–K and the sulfur content in the metal was fixed at 0.2 mass%. The rate was measured for a partial pressure of CO2 in the range of 0.5 to 1 atm for CO2-Ar, 0.7 to 0.9 atm for CO2-H2O and 0 to 0.95 atm for CO2-5%H2O-Ar gas mixtures.
The measured rates agreed well with the predicted rates by assuming an ideal additivity of CO2 and H2O reaction rates individually measured in previous work. It was concluded that there were no special effects retarding or accelerating the reaction rate with liquid iron and the rates were simply additive. It was also found that iron oxide did not form on the surface as long as the surface concentration of carbon did not become very low. The critical carbon content at which FeO forms on the surface was expressed as a function of partial pressure of oxidant, sulfur content in the metal, mass transfer coefficient and temperature and was found to be in agreement with experimental observations.