Page 2 - 30. Don't Trash our Future .... Recyle it! - Part 3
P. 2
Extracting and processing raw materials (wood, oil, ore) to make usable
products (paper, plastic, metal) requires a lot of energy. Recycling often
saves energy because the products being recycled usually require much
less processing to turn them into usable materials.
The amount of energy saved is dependent on the material in question. For
instance, glass is made by melting sand and other minerals at very high
temperatures. The molten mixture is then cooled to form glass. The most
energy-intensive part of the glass-making process is the heat necessary to
melt the mineral mixture. As recycled glass still needs to be re-melted to
make new glass products, the energy savings from recycling glass are
relatively small (roughly 10-15%).
However, aluminium is produced from bauxite, which needs to be
extensively processed to isolate the aluminium metal. This processing
requires a huge amount of heat and electricity. None of this processing is
required for the recycling of aluminium metal (e.g. in the form of cans),
which can be simply cleaned and re-melted, saving 94% of the energy that
would be required to produce the aluminium from ore.