Mixing in the industrial oxygen steel converter was studied using a water-vaseline-air cold model reactor, equipped with top and bottom pneumatic agitation. The effect of a number of different parameters were studied: the relative effect of top and bottom blowing rates, the variation in surface tension, the effect of the organic phase, the variation in the relative position of the lance With respect to the quiescent bath level, and the direction of the streamlines. The results are analyzed in terms of the parameters of a previously tested compartments model.