The present work aims the calculation of the mass transfer coefficient in the slag bath area of a gas-stirred steel ladle. The mass transfer in dependence on influencing factors like flow rate and velocity of purging gas was investigated. For this purpose computational fluid dynamics calculations were performed. Due to the fact that during refractory corrosion diffusion-controlled mechanisms take place simulations considering diffusion were performed. From the resultant concentration of the diffusive component in the slag in dependence on time the mass flux is known. With the help of Fick´s 1st law that describes the diffusive mass flux the mass transfer coefficient may be calculated. From a dimensional analysis followed by a parameter study conducted with the help of computational fluid dynamics calculations a relation for the mass transfer in the slag bath area of the gas-stirred steel ladle was deduced.