Optimisation of Steel Desulphurisation by Lime Powder Injection by Numerical Simulations

Abstract

This paper focuses on the simulation of steel desulphurisation by lime powder injection. Thereby, the particle laden plume as well as additional gas stirring plumes are modelled by an multifluid Eulerian method. In addition, a transitional heterogeneous reaction is assumed to happen between the rising lime particles and the dissolved sulphur. Furthermore, a permanent reaction mechanism is defined at the metal-slag interface. With help of these macroscopic simulations the desulphurisation performance of a given ladle-lance-stirrer configuration can be estimated. Once the simulations are calibrated by steel plant experiments, these simulations should be able to hint to possible geometrical or operational improvements. Nevertheless, since a sound validation of the macroscopic simulation tool is not feasible many modelling uncertainties remain. Therefore, in a second part this paper focuses on the detailed modelling of the initial momentum of the injected powder which is critical for the powder penetration depth. In this context dedicated experiments are performed in order to substantiate the boundary conditions of the macroscopic simulations.