Abstract
Phase diagrams of Fe, FeO, Fe3O4, Fe2C and Fe3C in CH4-H2-H2O and CO-CO2 gas mixtures were made by using thermodynamic data at every 50°C in the temperature range from 550 to 850°C. On the basis of these diagrams, experimental conditions were determined. The reaction experiments were carried out by using fluidized bed or fixed bed reactor with the sample of two kinds of ore (dense and porous, 0.4-0.5 mm in diameter). The thermodynamic date used can be recommended because the experimental results under some conditions near the main phase boundary agreed well with the estimated one. It was confirmed that Fe3C was produced via Fe3O4 in CO-CO2, gas mixtures at 550°C. However, the reaction rete was very slow. This Fe3C hardly decomposed to Fe and C. When the steam of 5 vol % or more was included in the CH4-H2-H2O gas mixtures. Fe3C was not generated in 0.1 MPa at all.
