Aluminium can be recycled endlessly
Aluminium is like an energy bank. Only 5 percent of the energy required to produce primary aluminium is needed to remelt aluminium for new uses, with no loss in the quality of the metal. This makes sense environmentally and financially. We recognise that if we all did our bit, the world would be a much better place. At Mode-AL, we are doing our bit by recycling all the aluminium scrap from our machining processes back to our extrusion suppliers so it can be melted and used again. Below is an extract from Sapa Profiles Ltd showing the benefits of recycling aluminium – from the humble fizzy drink can to our bespoke integrated furniture.
From Bauxite to Recyclable Aluminium
There is plenty of raw material for the production of aluminium. No less than 8% of the crust of the earth consists of aluminium compounds in many different forms. The most important raw material in the process of making aluminium is Bauxite. If we continue mining bauxite at the same rate as the present one, the deposits of bauxite will last 200-400 years of production (this does not include an increase in recycling).
Bauxite, which is created when certain aluminium bearing rocks decompose, consists of oxides of aluminium, iron and silicon. The most important deposits of bauxite are situated near the Equator. Brazil, Australia, Jamaica and Surinam are all big producers.
At first, the bauxite is purified into Alumina (AL²O³). The process of making bauxite into alumina is often performed near a bauxite mine. The aluminium is produced by an electrolysis of molten aloxite, as often as possible this is done in countries with good access to power supplies, often from hydro-electric power plants. The production of 1kg of aluminium requires approximately 2kg of alumina. The production of 2kg of alumina requires 4kg of bauxite.
In the melting process, 1kg of metal requires approximately 47 MJ (app. 13kWh). This is an investment. The use of energy will be justified many times over when Aluminium is converted into many forms e.g. When used in automotive application it results in reduced consumption of fossil fuels.
Used aluminium products have great importance as a raw material for production. In principle, all available aluminium can be recycled. By sensible sorting, aluminium scrap can be turned into new products over and over again. Even though aluminium is used over and over again, its characteristics never change which is unique in comparison to most other materials. The recycling process uses 5% of the energy that was used when producing the primary aluminium. The re-melting and recycling of aluminium is becoming more and more important in today’s society of recycling. Aluminium is the ideal metal. In the re-melting process, only a few percent is lost. A better sorting of scrap results in an increasing recycling percentage. Small quantities end up in refuse disposal units. The metal is just as valuable as black coal and carbonised coal regarding the process of making energy. What is left over, becomes alumina.
All industrial activity uses up natural resources and has an impact on the environment. This also happens when producing aluminium. However, production of aluminium often imposes a positive impact on the environment compared with the use of alternative materials. Life cycle analysis is the only method which can be used to determine the comparative impact on the environment.
Aluminium that is gathered for recycling can circulate in an almost never-ending cycle of operation. The loss of metal die to oxidation in the melting process is small. The quantity of the re-melted material is so high that it can be used for the same product over and over again. Repeatable recycling is possible without lowering the quality and with high yield absolute recycling.