ТЕРМОДИНАМИЧЕСКИЙ АНАЛИЗ ВОССТАНОВЛЕНИЯ ОКСИДОВ ЖЕЛЕЗА В ГАЗОВЫХ СМЕСЯХ (CO–H2) В ПРИСУТСТВИИ УГЛЕРОДА

Abstract

The features of the processes of reduction of iron oxides Fe 3 O 4 to FeO and FeO to Fe in gas mixtures H 2 ( 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: Fe 3 O 4 – FeO – H 2 ( a ) – H 2 O ( b ) – CO ( c ) – C0 2 ( d ) – C, FeO – Fe – H 2 ( a ) – H 2 O ( b ) – CO ( c ) – C0 2 ( 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 H 2 O and dioxide CO 2 are calculated. The total and specific costs of carbon are calculated. The amounts of reduced oxides Fe 3 O 4 and FeO are calculated. Based on the results of these calculations, the reduction ratios of H 2 and CO of γ = b / d are determined. For the reduction of Fe 3 O 4 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 Fe 3 O 4 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.