The treatment of liquid metal in gas-stirred ladles has long been identified as the main process responsible for the inclusion cleanness in special steels. Four university teams and three steels developers have combined their efforts through a project, supported by French National Research Agency, in order to improve the understanding of the complex mechanisms involved during the ladle treatment. In this paper, the contribution of the Institut Jean Lamour to this program, that bears the acronym CIREM, is presented. Using a commercial CFD code as a basis, a three-dimensional simulation model is developed that includes the geometry and industrial operating conditions. The hydrodynamics of the turbulent metal/bubbles mixture is well represented along with the coupled mechanisms of transport, aggregation and surface entrapment of inclusions.