Thermodynamic analysis of chemical reactions conditions of iron carbonization by CO gas during reduction from wustite

The article presents the results of a thermodynamic assessment of the possibility of chemical reactions of indirect reduction of iron from wustite and its carburization using the reducing gas CO. The purpose of this work is to obtain expressions for calculating the numerical values of the Gibbs free energy depending on the temperature for the specified chemical reactions and finding with their help the numerical values of the boundary (equilibrium) temperatures, allowing us to determine the range of numerical values of temperatures in which the chemical reactions of the process of carburization of reduced iron with carbon monoxide are thermodynamically possible. The results of the thermodynamic analysis performed using the expressions derived by the author for calculating the numerical values of the Gibbs free energy for chemical reactions of indirect reduction of iron from wustite and carburization of iron by CO gas made it possible to establish that the process of carburization of iron is thermodynamically possible by the chemical reaction of carburization of iron during its indirect reduction from wustite by CO gas, consisting of two separate stages described by chemical reactions of indirect reduction of iron from wustite and carburization of reduced iron by CO gas, only at numerical values of temperatures up to 662°C or in the range of negative temperature values. Taking into account the fact that the Bell-Boudoir chemical reaction can theoretically proceed at temperatures above 557°C or above 697°C, or above 699°C, or above 706°C, or above 748°C, or above 750°C (according to literature data), or above 709°C (according to the author), as well as high numerical values of temperatures of the working space of metallurgical reduction furnaces, it can be concluded that carburization of reduced iron by CO gas (along with the impossibility of reducing iron from wustite by CO gas above 765°C, which was established by the author of the work earlier) practically does not occur or the degree of carburization of iron is very small, which corresponds well with the data of some literary sources. A conclusion is made about the carburization of reduced iron due to solid carbon