DEVELOPMENT OF THE L. B. E. -PROCESS.

The LBE (Lance-Bubbling-Equilibrium) process enlarges the possibilities of the BOP converters by combining the advantages of top and bottom blowing refining processes. In the LBE process inert gas is injected through gas-permeable media in the converter bottom so that intensive stirring of the liquid metal and slag and commensurate approximation to the thermodynamic equilibrium between liquid metal and slag are achieved. Tests, which were performed in France and Luxembourg on a 6-t and a 65-t converter with hematite pig iron and also on two 150-t LD-AC converters with Thomas pig iron revealed for the two pig iron types of greater flexibility in the scrap/pig iron ratio, better control of the blowing process and shorter blowing period, better Fe yield, better steel quality (lower P and S values), and lower additions of ferroalloying elements. The LBE process is fully developed for industrial operation and has been adopted since mid-1981 in nearly all steelworks provided with top blown converters in France, Luxemburg and Australia and also in some plants in Germany, Sweden and North America.