Abstract
Physical model of slag foaming was developed by using results of cold and hot model experiments. The bubble size at the slag/metal interface, the void fraction of foam and the film life of a bubble at the top surface of slag were calculated. The governing factors of slag foaming have been clarified with this model. It was confirmed that the bubble size at the slag/metal interface is determined basically by the static balance between the buoyancy force and the adhesive force to the slag/metal interface. It was resulted that the slag/metal interfacial tension and the surface tension of metal also affect the foam height besides the surface tension and the viscosity of slag because they change the bubble size.
