Carbothermically producing AlSi-alloy Proceedings of EMC 2013 1 Thermodynamic analysis and experimental validation of carbothermically producing AlSi-alloy Christoph Kemper, Bernd Friedrich Efthymios Balomenos, Dimitrios Panias, Ioannis Paspaliaris RWTH Aachen University NTU-Athens IME Process Metallurgy and Metal Recycling School of Mining and Metallurgical Engineering Intzestraße 3 Laboratory of Metallurgy 52056 Aachen, Germany Zografou 15780, Greece Keywords: AlSi-alloy, carbothermic reduction, EAF 1 Introduction Many technological concepts for an alternative aluminium production process have been developed during the last century, because the still utilized Hall-Héroult process is one of the most energy and CO 2 intensive industrial processes. However no basic approach was able to prevail in industrial scale. The most promising alternative process is still the carbothermic reduction of alumina, which has been investigated by several companies and researchers. The greatest challenges are the exten- sive aluminium volatilization occurring at high reaction temperatures, the complicated back- reaction and carbide formation mechanisms as well as critical reactor design issues. To lower the aluminium activity it is helpful to include a “carrier” metal like silicon into the reduc- tion process. Co-reduction of the oxides reduces vaporization of both aluminium and silicon by forming an AlSi master alloy. A successful further development of such a carbothermic reduction process implicates a sustainable improvement in the primary aluminium production with signifi- cantly less energy consumption, reduced GHG emissions and lower investment costs. In previous investigations at IME, RWTH Aachen University, first experiments of creating an AlSi master alloy out of an oxide residue of Al-slag-treatment were conducted. The collaborative re- search project “ENEXAL” has resumed this idea, but with carbothermic reduction of technical pure raw materials. The present work presents the experimental validation in a small scale Lab-EAF (25 kW) of a previous performed theoretical thermodynamic study with Fact Sage 6.2 software. Different modes of operation, initial system compositions and reducing agents were considered as parameter for the investigation. To prove the quality of the AlSi-alloy chemical analysis were done as well as structure analysis. The full paper will be published immediately after the conference in World of Metallurgy as peer reviewed paper.