New approach to evaluating the thermodynamic consistency of melts in the ‘metal-slag’ system based on interatomic interaction parameters

The article presents a new approach to evaluating the thermodynamic state of the ‘metal–slag’ system during metal smelting in oxidizing-reducing conditions. The interaction between the metal and slag is analyzed using the model of the structure of metallurgical melts, which considers cooperative ion exchange processes and interatomic interaction parameters. As a result of analyzing experimental data on the compositions of reacting melts during pig iron and steel smelting, criteria were developed for assessing the degree of achieving the equilibrium in the system regarding sulfur. The charge state parameters of the metallic system ZY and the slag system Δe, the slag stoichiometry index ρ, and the charge state parameter of the melt components Zi were used. The regularity of a consistent formation of metallic and slag melts has been established, which is evidenced by a significant correlation between the chemical equivalent of the metal composition ZY and the slag Δe. Analytical dependences were obtained in the form of ZY = f (Δe, ρ). The identified patterns and criteria can be integrated into automated process control systems for regulating the slag regime and producing high-quality pig iron and steel.