Investigation of a possible route for oxygen transport via the metal droplets in top-blown steel converters

The action of a top-blown compressible oxygen jet forms a deep cavity onto the molten steel bath surface. Oxygen chemically dissolved into the liquid metal droplets that have detached at the cavity edge by shear returns to the bath when each droplet descends through the slag layer and rejoins the bath. The remaining oxygen needed to sustain the part of the decarburization taking place in the bath (or at its surface) is assumed to be supplied by liquid iron oxide emulsified with the liquid metal. In a numerical model of the fluid flow in the converter vessel (gas in the top space and liquid metal in the bath) the concentration of this emulsion is traced as the oxide is carried by the strong, turbulent flow around the cavity lip to mix inside the bath. Highest concentrations are observed near the free surface suggesting that the interface layer is the main site of the bath reaction