This volume covers a retrospective and an outlook for the future steelmaking processes. The first part examines the frame in which the future evolution of the steel industry will take place, the trends in steel consumption, the steel production, and its geographical repartition. Requirements and availabilities of raw materials are discussed and partial attention is devoted to the recycling of scrap. Similarly, energy sources are reviewed especially in view of the necessity to reduce CO2 emission. Another important factor for the evolution of the steel industry is the necessity to comply with stricter ecological constraints. The second part examines the future evolution of iron- and steelmaking technologies. In the past, steel properties have been continuously improved; the future trends indicate that closer relations will be established with the steel users and this will include technical guidance and solving manufacturing problems. With volume 12a, b the Gmelin-Durrer series is complete.