Aluminium is an incredibly popular and versatile modern metal. From the roll of foil that every kitchen can't live without to the super-modern components of fighter jets and sports cars; aluminium is widely used around the globe.
Naturally, it's the most commonly occurring metal which makes up almost 10% of the entire earth's crust. Bauxite ore is what aluminium is eventually extracted from, with almost all bauxite mines being found in the tropical belt across Australia, Brazil and India. Bauxite ore is carried from the mine to a processing plant, where it will be crushed into finer material. Crushing and grinding mills are filled with bauxite ore and sodium hydroxide to make produce a finer consistency, which is then filtered into an autoclave. Non-soluble residue is removed whilst the rest is passed through a precipitator and a calciner. The resultant fine white powder that emerges is called alumina, or aluminium oxide.
Through the process of electrolytic reduction, pure aluminium is extracted and kept in a holding furnace until it can be smelted and moulded into the desire shape; normally ingots. For every 2 tons of alumina, 1 ton of aluminium can be produced.
To make the ever-present aluminium foil that's in every kitchen in the UK, it's a surprisingly simple process. Whilst the machinery is heavy-duty, expensive and complicated; it's manufactured exactly in the way you would expect. Molten aluminium is smelted into thin rod or ingots and put through a number of presses and rollers which used heat and incredible pressure to provide the ultra-thin sheeting on huge rolls.
Aluminium oxide itself has uses beyond converting it into aluminium, including making up laundry powder, toothpaste and even light bulbs. Often used as a component in ceramics including fake teeth and military windshields, alumina is also used as an abrasive finishing compound on metal. The unfortunate by-product of aluminium production is what those in the industry call red mud. Made up of the ore refuse, the amount of wastage equals the amount of actual alumina production itself. Although it contains a number of useful materials, it's incredibly difficult and expensive to separate the components and has largely no use.
The process of electrolytic reduction and smelting is a big contributor to climate change, with more than 5,000,000 tons of carbon dioxide being given off every year in the US. With a number of other dangerous materials being produced in the process, aluminium production has its potholes to overcome. Being fully recyclable without the loss of any properties, aluminium can at least benefit from re-usage for hundreds of years and the production costs can be one-off.
