Thermodynamic Simulation of Complex Metallurgical and Chemical Systems with the Method of Chemical Dynamics

Current understanding of chemical equilibrium is based exclusively on the probabilistic considerations that are correct for isolated systems with only one chemical reaction to take place. For the systems with multiple chemical interactions, current paradigm of chemical thermodynamics promotes the idea of openness, artificially flavored with coefficients of thermodynamic activity. Recently introduced thermodynamics of chemical systems and the Method of Chemical Dynamics (MCD) offer explicit accounting for the multiple chemical interactions within the system. In the new theory, thermodynamic equilibrium of the j-subsystem obeys the logistic equation ΔG_j/RT - τ _jΔ_j(1-Δ_j)=0, (1) derived exclusively from the currently recognized concepts of thermodynamics. Having the only one new parameter - the subsystem's reduced chaotic temperature τ_j to describe external interactions, and reaction extent Δ_j as independent variable, this equation covers the whole domain of the system's possible states - from true thermodynamic equilibrium through the open equilibrium to bifurcations and chaos depending on the τ_j value. The MCD brings new opportunities to thermodynamic simulation of complex metallurgical and chemical systems, allowing for the analysis of their domains of states and the area limits, and for more accurate calculation of the equilibrium compositions. Its usage is exemplified in this paper by several applications.