Multiphase Mass Transfer in Iron and Steel Refining Processes

In the present chapter, a computational fluid dynamics (CFD) model for multiphase flow was developed, allowing the simulation of two different processes, the desulfurization of hot metal in a ladle mechanically agitated by an impeller (KR process) and the desulfuri‐ zation of steel in a gas-agitated ladle. The model gives important information to charac‐ terize the fluid flow conditions, to define the velocity profiles of the phases involved, and to predict the evolution of the sulfur content during the desulfurization treatments. An expression for the rate of transfer of sulfur from the metal to the slag was proposed. This expression can be used in processes where sulfur is transferred from the metal to the slag phase. The predictions of the variations of sulfur content of the metal phase with time were validated based on experimental data obtained in a Brazilian industrial plant for steel desulfurization. After the validation, the model was used to simulate the effects of several parameters and to optimize the processes. Based on these simulations, it was pos‐ sible to set up the best operational conditions to improve the productivity of sulfur re‐ moval in the primary and secondary metallurgy.