Simulation of molten steel refining in a gas-stirred ladle using a coupled CFD and thermodynamic model

In secondary steelmaking, the gas-stirred ladle refining process is enhanced by applying a vacuum. A three phase (steel/gas/slag) mathematical model based on the fundamental transport equations has been reported in the literature. This model was used to study the steelmaking refining process. In this approach, the gas-stirred ladle system fluid flow prediction from Computational Fluid Dynamics (CFD) analysis was linked with thermodynamic analysis, with some thermal simplification. The model predicts the changes in the mass concentration of the elements of concern (Al, O, and S) during the refining process. In the present work we aim to enhance the modeling in the literature. Here we use Fluent as the CFD package to predict the flow pattern of the three phase (steel/gas/slag) system. The thermodynamic package is MTDATA from the National Physical Laboratory (NPL), which has the capability to make thermodynamic predictions for multi-component systems containing up to 30 elements. Therefore, it is possible to solve for the properties of the slag as a function of composition and temperature. The two packages are being linked in a Visual Basic environment. The mass concentration of the different elements at the steel/slag interface is being updated at a pre-defined Δt time step. Comparison of the model calculated results with data from the literature show the potential of this model. Real plant data will be used to validate this multi phase simulation model.