A study on slag dispersion in a model bottom blown bath smelting converter was undertaken. The aim was to investigate the behavior of the dispersed slag phase at very high gas flow rates in low slag volume (10%) systems. For simulation purposes water, paraffin-oil and air were used to represent the bulk steel, molten slag and gases respectively in a one-fifth model of the commercial 100 ton creusot loire uddeholm (CLU) converter used in the manufacture of stainless steel in South Africa. Emulsified samples were collected by means of the specially made syringe. The experimental results revealed that the dispersed slag phase decreased with the vertical distance from the original interface between the liquid phases. The dispersed phase also decreased with the radial distance in the water plume zone toward the wall side. The hold-up was apparently much higher on the left half side of the reactor where there were no tuyeres at all. The modified Froude number ensured the correlation between the model and the prototype reactor. Dispersion phenomena were analyzed mathematically through the use of four dimensionless groups including the modified Froude number which has permitted the modeling of the dispersion and drawing of slag phase hold-up contours in the reactor. (c) 2007 Published by Elsevier Ltd.