However ‘green fingered’ or not, most of us would probably acknowledge a basic understanding of the way living plants progress through a life cycle, changing their forms as part of the process. Remarkably, for an inanimate material, aluminium also has the sustainable and environmentally friendly capability of changes in form, passing through potentially numerous life cycles by being recycled from one product into another. No wonder aluminium is called the greenest of metals!
For another ‘natural’ analogy you can also consider comparing aluminium with secondary clay. Both materials, originating from the earth’s crust, are in abundant supply; both are solids and yet lend themselves to changes in form through cold working and/or various forms of heat treatment. Interestingly there are clay building products that can be recycled by composting, while aluminium is recycled through re-melting and manufacturing into new shapes and products.
The worldwide annual recycling of aluminium is very much expanding with a three fold increase from 5 million tonnes in the early 1980’s to something in the region of 15 million or more tonnes in the mid naughties. It is currently estimated the construction industry is recovering over 90% of the aluminium used in redundant buildings (96% of the aluminium from the old Wembley Stadium was recycled).