Thermodynamic analysis of reduction of ferrous oxide in gaseous mixture (CO-H2) in the presence of carbon

The features of the processes of reduction of iron oxides Fe3O4 to FeO and FeO to Fe in gas mixtures H2 (ao) - CO (co) in contact with carbon are discussed when heated to temperatures of 850-955 K at a pressure of 1 atm. The total amount of gases in the initial mixture was set (ao + co) = 1 mol, and the ratio ao/co varied from 1/0 to 0/1. The parameters of the resulting equilibrium systems: Fe3O4 - FeО - Н2 (a) - Н2О (b) - СО (c) - СО2(d) - С, FeO - Fe - Н2 (a) - Н2О (b) - СО (c) - СО2 (d) - С are calculated. The conditions for the separation of black carbon and its amount are determined. The parameters of gasification reactions of carbon with water vapor H2O and dioxide CO2 are calculated. The total and specific costs of carbon are calculated. The amounts of reduced oxides Fe3O4 and FeO are calculated. Based on the results of these calculations, the reduction ratios of H2 and CO of γ = b/d are determined. For the reduction of Fe3O4 to FeO and FeO to Fe, this ratio varies from 0 to 5.76 depending on the temperature and the value of ao/co. It is shown that the reduction of Fe3O4 to FeO at a temperature of ~ 917 K is characterized by a value of γ = 1.71 and large amounts of the reduced oxide. The reduction of FeO to Fe at ~955 K is characterized by a value of γ = 2.30 and a large amount of the reduced oxide.