In gas stirred steelmaking ladles, entrainment of liquid slag into liquid steel and vice versa takes place. Qualitatively, slag entrainment is known to increase slag-metal interfacial reaction rates. However, it is unknown how the entrainment is quantitatively affected by gas stirring rate and the properties of the slag and metal. In this paper the modelling of slag entrainment is resolved into several sub-models to determine the interfacial reaction rates between slag and metal for the droplets and other interfaces. The model predictions are in line with literature values for refining rates and also rationalize the effects of ladle size and number of gas injection plugs.