From Collection to Furnace: A Critical Review of Aluminum Can Recycling Routes, Technologies, and Sustainability Challenges

Abstract

Aluminum beverage cans are among the most successful examples of metal recycling in a circular economy, with global collection rates exceeding 70% and surpassing 95% in some regions. However, the pathway from post-consumer collection to remelting is technically complex, involving cumulative material losses, energy penalties, and quality constraints often overlooked in simplified sustainability narratives. This critical review examines the entire recycling chain of used beverage cans (UBCs), including collection systems and reverse logistics, sorting and physical preparation, decoating technologies, melting furnace configurations, dross formation, alloy control, and environmental performance. Emphasis is placed on the metallurgical and thermodynamic mechanisms governing oxidation losses, coating removal efficiency, impurity accumulation, and metal yield during remelting in reverberatory, rotary, and induction furnaces. The influence of contamination, scrap variability, furnace atmosphere, and operational practices on energy consumption, emissions, and final alloy quality is systematically assessed, along with the limitations of life-cycle assessment (LCA) data and of industrial transparency. Although aluminum can recycling is often described as nearly lossless and infinitely recyclable, industrial evidence indicates measurable yield losses, alloy downgrading risks, and process-related emissions that challenge the idealized closed-loop paradigm. Emerging solutions—including advanced sensor-based sorting, controlled-atmosphere melting, digital process optimization, and improved dross valorization routes—are discussed as pathways to enhance material efficiency and reduce environmental impact. The review identifies key technological bottlenecks and research gaps necessary to improve the metallurgical robustness and sustainability performance of aluminum can recycling systems.