Desulphurization Kinetic Prediction into a Steel Ladle by Coupling Thermodynamic Correlations, Fluidynamics and Heat Transfer

Abstract

In this study, the influence of several operational variables of secondary steelmaking on the desulfurization process in a gas stirred ladle furnace was analyzed by mathematical simulation. The solution of the Navier-Stokes and energy equations were carried out using the multiphasic Eulerian model, while an User Defined Function, UDF, was developed and incorporated to numerical simulation to solve the kinetics of desulfurization. Drag and non-drag forces were also included, as well as interfacial exchange models to solve the interaction among phases. The fluidynamics results were validated by means of an experimental model by employing the Particle Image Velocimetry, PIV, technique. It was found that employed models accurately predicted slag layer behavior and steel velocity field. The results showed that the distribution of the sulfur contained into steel depends on the fluidynamics structure, initial steel temperature and injected argon gas rate. Also, the incorporation of the desulfurization kinetics through UDF’s coupled to the non-isothermal multiphase modeling, is more realistic in the prediction of the sulfur removal rate compared to the use of only kinetic models.