Chapter 07 · Materials & footprintsCircular Economy & Materials
Aluminum
Definition
A silvery lightweight metal (chemical symbol Al) produced primarily from bauxite ore via energy-intensive electrolysis (the Hall–Héroult process). It is widely used in transport, packaging, construction and energy infrastructure, and can be recycled repeatedly without loss of quality.
References
15.1 t CO₂e/t primary (2022) vs 0.52 t CO₂e/t recycled; regional savings percentages; methodology caveats.
186 GJ/t primary energy (2019) vs ~8.3 GJ/t recycled; Hall–Héroult electricity intensity.
95% energy saving; 9 t CO₂ and 4 t bauxite saved per tonne recycled; 60-day can loop; permanent recyclability.
Overview
What it means
Primary aluminium production emitted about 15. 1 tonnes of CO₂e per tonne of metal in 2022 (global average, cradle-to-gate), driven largely by electricity sources — coal-based production in some regions is far more carbon-intensive than hydro-based. Producing metal from scrap required about 0.
52 tonnes CO₂e per tonne (gate-to-gate): recycling saves about 95% of the energy and a similar share of emissions of primary production.
How it is used
Industry and policymakers push higher recycled content, closed-loop scrap systems and decarbonised smelting (renewable electricity, inert anodes). Beverage-can recycling loops can return a can to shelf in about 60 days; around 75% of all aluminium ever produced is estimated to remain in use.
Why it matters
Aluminium demand is growing with the energy transition (vehicles, solar, grids), so the split between primary and recycled production materially affects global emissions. Its value and recyclability make it a model material for circular economy policy — but collection and sorting losses still leak metal to landfill.