Glossary
Secondary aluminium — definition
Aluminium produced by remelting scrap, re-alloyed to standardised casting alloys.
The raw material comes from aluminium products that have already lived a life — car parts, drink cans, road signs, facade products. The scrap is sorted, remelted and re-alloyed so that it meets an international standard.
That last step is the point. What determines the properties of your part is the alloy designation, not whether the atoms have been used before. If the metal is supplied to the standard, it behaves as the standard says.
Remelting takes a fraction of the energy of primary production. That is by far the largest climate effect in the value chain — and with rising metal and carbon prices it is increasingly a cost argument as well.