IN SUMMARY
Aluminium is a soft, silvery-white metal renowned for its strength-to-weight ratio: three times lighter than copper, yet stronger than steel when alloyed. As the third most abundant element in the Earth's crust, it is found almost entirely in bauxite ore, and turning that ore into metal takes substantial electricity, which is the source of its large carbon footprint. At the same time, aluminium is highly recyclable, and remarkably, nearly 75% of all the aluminium ever produced is still in use today. This guide, part of Minviro's "Explore the Elements" series, introduces aluminium's geology, production routes, market and the sustainability challenges and opportunities that define it.
A material built for the energy transition. Aluminium's light weight, conductivity, corrosion resistance and versatility make it essential to solar panels, wind turbines and EVs, so production is expected to rise across all transition pathways.
Primary production is highly emitting. The aluminium industry accounts for around 2% of global greenhouse gas emissions, driven by coal-heavy electricity, direct CO₂ from carbon anodes, and the challenge of toxic red mud byproduct.
Recycling is the decarbonisation lever. Producing secondary aluminium from scrap takes only about 5% of the energy of primary production, which is why circularity is central to cutting the industry's footprint.
What makes aluminium so useful
Aluminium (symbol Al, atomic number 13) is a soft, silvery-white metal with an exceptional strength-to-weight ratio, three times lighter than copper but capable of being stronger than steel when alloyed, and its malleability and ductility suit everything from beverage cans to aircraft parts. It is an excellent conductor of heat and electricity, and is rust-resistant, non-toxic, non-magnetic and non-sparking, a combination of properties that makes it sought after across many industries. Crucially, it is indispensable to the renewable energy transition: solar panels, wind turbines and EVs all rely on it, so its production is expected to increase significantly under any decarbonisation pathway. As the third most abundant element in the crust after oxygen and silicon, the raw material is plentiful, but converting it to metal is where the environmental challenge lies.
Geology and production routes
The only commercially exploited ore for aluminium is bauxite, which is enriched with aluminium hydroxides (gibbsite, boehmite and diaspore) and typically contains 15–20% aluminium. Bauxite forms through intense surface weathering and occurs in two forms: lateritic bauxites, which form in humid tropical climates, and karst bauxites, "fossil" deposits formed over ancient carbonate bedrock and found mainly in the northern hemisphere. Production is a complex, electricity-intensive two-stage process. First, the Bayer Process extracts alumina from bauxite through crushing, purifying, leaching, precipitation and calcination. Then the Hall-Héroult Process smelts the alumina: it is dissolved in a molten cryolite bath and an electric current is passed through it, so aluminium ions migrate to the cathode and are removed by electrolysis. The resulting metal can be cast, extruded and rolled into a wide range of products.