This volume contains the papers that will be presented at 'EMC '91 '-the European Metals Conference-to be held in Brussels, Belgium, from 15 to 20 September 1991, and organized by Benelux Metallurgie, GDMB (Gesellschaft Deutscher Metallhutten­ und Bergleute) and IMM (the Institution of Mining and Metallurgy). 'EMC '91' is the first of an intended major series organized at the European level with the aim of bringing together all those who are involved with the extraction and processing of non-ferrous metals-European metallurgists and their international colleagues-to provide them with the opportunity to exchange views on the state and evolution of their industry. The programme covers all the different aspects of the metallurgy of non-ferrous metals from mining to fabricated products. Particular attention is being paid to the European non -ferrous industry with respect to changes in demand, the technology used, pressures on the environment and the competitive position of manufacturers. The contributions of the plenary lecturers (copies of which will appear in the IMM journal Minerals Industry International in 1991-92) and the many authors are gratefully acknowledged. Thanks are also due to the referees of the papers, the sponsors, the companies that have allowed registrants to visit their operations, the chairmen of the technical sessions and the staffs of the organizing bodies for their efficient administrative work. Jean Vereecken Chairman, Organizing Committee July 1991 v Contents Foreword. . . . . . . . . . . . . . . . . . . . .. . . v .