Life cycle assessment of secondary aluminium refining

Abstract

This paper presents a life cycle assessment (LCA) of various technologies for refining of post-consumer aluminum scrap. The goal is to identify the environmental performance of relevant refining technologies compared to the production of primary aluminum. The assessment is based on a given scrap composition and given purity limits to meet the technical requirements of a certain aluminum product which is currently produced from primary aluminum. From an environmental perspective low- Temperature electrolysis and fractional crystallization are the preferred refining methods. This is due to the low energy use in these methods, and that the environmental impact is mainly caused by the energy used during refining. Since the assessment is based on a specific scrap composition and specific purity requirements, it is suggested that other possibilities to reduce environmental impacts are investigated, for example better sorting processes or production of wrought alloys more suitable for recycling. Such methods are likely to be more relevant when the use of aluminum has increased even further and more stable sources of scrap are established. Copyright © 2014 by The Minerals, Metals & Materials Society.