A binary and multicomponent quasi-chemical model for chemical equilibrium calculations in HSC Chemistry software platform

Abstract

HSC Chemistry SIM is a thermodynamical calculation and process simulation software platform developed by Metso. HSC Chemistry contains models to conduct metals processing communication and separation simulations as well as hydro- and pyrometallurgical modeling. These metallurgical processes are simulated using the models of the machines that Metso produces as its primary products, such as crushers, conditioners, furnaces, etc. By simulating the input and output flows of species into the different models, it allows for the estimation of possible outcomes, including the output material flow, emissions, or energy consumption.

One of the most important processes that are crucial for thermodynamic modeling in metallurgy is chemical equilibrium, which is implemented in HSC software relying on solving Gibbs energy minimization problem for a solution. The platform calculates the final amounts of species at equilibrium dynamically for each assigned time step. Previously, the ideal solution model was used in calculations, but to increase the accuracy for complex designs, such as copper smelting, it requires a more sophisticated theoretical framework. The quasi-chemical solution model is studied in the current work to enable a non-ideal solution model in HSC and provide more accurate calculations for complex heterogeneous process designs. It takes into account possible interactions between species within the solution that leads to more precise calculation results for output amounts and activity coefficients of species.

The goal of the current thesis is to implement the first version of the quasi-chemical model calculation engine as well as the user interface in HSC Chemistry software platform and make as many existing tools in HSC available for a new modeling approach as possible.