Nonequilibrium Thermodynamics of Oxidative Recovery Reactions Vanadium Containing Titanomagnetite Concentrates

Abstract

Non-equilibrium and equilibrium thermodynamic conditions of direct reduction of magnetite to free iron and oxidation of vanadium (3) to vanadium (5) in granules fluxed by soda vanadist titanomagnetite concentrates using a mixture of natural gas and hydrogen were determined. To determine temperature dependences of Gibbs free energy of redox reactions, the Temkin-Schwartsman equation was modified with due regard for the Gibbs free energy of formation of magnetite-based substitution solid solutions and the vapor pressure of the components in the flow system where the mixture of methane and hydrogen is continuously fed while gaseous reaction products are removed. 3D modeling of the Gibbs free energy difference of reactions proceeding under equilibrium and non-equilibrium conditions was carried out. On the basis of the free energy of the system deviation from the equilibrium state, it revealed that the greatest effect of reducing the temperature of redox reactions is observed in terms of low values of the reaction products pressure As a result of the thermodynamic analysis, the temperature range of 950-970K was chosen to produce metallic iron and sodium vanadate.