THERMODYNAMIC ANALYSIS OF REDUCTION OF FERROUS OXIDE IN GASEOUS MIXTURE (CO–H2) IN THE PRESENCE OF CARBON

Abstract

The features of the processes of reduction of iron oxides Fe₃O₄ to FeO and FeO to Fe in
gas mixtures H₂ (a_o) – CO (c_o) 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
(a_o + c_o) = 1 mol, and the ratio a_o/c_o varied from 1/0 to 0/1. The parameters of the resulting equilib­rium systems:

Fe₃O₄ – FeO – H₂ (a) – H₂O (b) – CO (c) – C0₂ (d) – C,

FeO – Fe – H₂ (a) – H₂O (b) – CO (c) – C0₂ (d) – C

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 a_o/c_o. 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.