Aluminium Recycling - Raw material supply from a volume and quality constraint system
The limited availability of energy and raw materials as well as the ambitious emission reduction targets are of big concern in the metallurgical industry as in other base materials industries. Consequently resource efficiency targets are set under EU's Raw Material Initiative, measures are taken to reduce GHG-emissions and there is a focus on carbon footprint of products and companies. For example legislators and stakeholders request a high recycled content in downstream products. Due to missing knowledge about the relative availability of secondary raw materials in growing markets the debate of recycling content vs. end-of-life recycling is still ongoing. In case of the European aluminium industry the remaining primary smelters suffer from high costs of energy and the emission trading system. A survival is depending on acceptable power contracts and their role as active player in the electricity grid modulation. Furthermore restructuring and consolidation of the recycling industry is not finalized. On the other hand collected aluminium scrap volumes are expected to increase significantly and therefore, remelters and integrated cast houses prepare themselves to remelt different kinds of scrap to minimize the use of primary ingots. But depending on the final product properties the chemical composition of aluminium alloys has to fulfil strict specifications. Consequently the usability of secondary raw materials can be limited or would require costly up-grading and sorting processes. In order to analyse and forecast the scrap availability the use of Material Flow Analysis gains increasing importance. A high accuracy is requested from MFA calculations when quantity and quality of particular material flows are of major concern. Applying existing models, two major issues become obvious, which are discussed in this paper on a global scale: The limited availability of end-of-life scrap and possible quality constraints of the current recycling system.