Aluminum and steel recycling

Solo disponible en BuenasTareas
  • Páginas : 8 (1806 palabras )
  • Descarga(s) : 4
  • Publicado : 23 de noviembre de 2009
Leer documento completo
Vista previa del texto
Steel and aluminium are common metals in the UK and are produced and exist in large quantities. Their uses and usefulness were discovered thousands of years ago. Longevity, malleability, strength and conductivity -their properties have been used over the ages to provide us with the many goods we see today. They may be found in items as varied as cars, computers,buildings and packaging. Although UK per capita consumption of steel has dropped since the 1970s, aluminium use is still growing. Metals may remain for many years as viable products and so the environmental effects of their production will be lessened relative to using less durable materials.
World primary production of aluminium is around 24 million tonnes on average a year. The largest producer ofaluminium is Australia, although other producer countries include Jamaica, Brazil, Guinea, China and parts of Europe.
World crude steel production stood at 1.05 billion tonnes in 2004. This represented a worldwide increase in production of 8.8% compared to 2003. Excluding China, world production rose by 4.5% in 2004.
Why bother?
top of page
Metals can be recycled indefinitely without loosing any oftheir properties. They make up around 8% of the average household dustbin yet in 2003 the recycling rates for aluminium and ferrous metals as a percentage of their consumption were only 33% and 26% respectively.

Aluminium is produced from bauxite, a clay-like ore that is rich in aluminium compounds. The aluminium is only found as a compound called alumina, which is a hard materialconsisting of aluminium combined with oxygen. This alumina has to be stripped of its oxygen in order to free the aluminium. The alumina is dissolved in a molten salt at a reduction plant and a powerful electric current is run though the liquid to separate the aluminium from the oxygen. This process uses large quantities of energy.
Recycling 1kg of aluminium saves up to 6kg of bauxite, 4kg of chemicalproducts and 14 kWh of electricity.
Recycling aluminium requires only 5% of the energy and produces only 5% of the CO2 emissions as compared with primary production and reduces the waste going to landfill. Aluminium can be recycled indefinitely, as reprocessing does not damage its structure. Aluminium is also the most cost-effective material to recycle. 
A recycled aluminium can saves enoughenergy to run a television for three hours
If all the aluminium cans in the UK were recycled there would be 14 million fewer full dustbins each year.
Steel is also mined from an ore. Iron ore is plentiful but it too is usually combined with oxygen or sometimes carbon or sulphur. The iron ore is stripped in a blast furnace to reduce it to pig iron that can then be used in steel production.
Thereare currently about 11Mt per year of iron and steel scrap arisings. About 70% of this scrap is recovered. Of the remainder - 2/3 is landfilled.
Steel Facts and Figures
• Each household uses approximately 600 steel cans per year
• There are over 300million cans used per week over the xmas period
• The thinnest part of the can wall measures only 0.07mm thick - that's thinner than a human hair
• Itwould take 1087 steel drinks cans stacked end to end to reach the top of the London Eye or 2818 to reach the top of the Eiffel Tower
• The value of used steel cans in the waste stream is £28 milllion per annum which is available to collectors.
• Don't forget that 1.8 billion drinks cans are made of steel
• Millions of steel cans are collected every day by using huge magnets to pull them out ofdustbin waste
• The recycling rate of all steel packaging is 46%; aluminum has a 23.4% packaging recycle rate .
• Steel cans are becoming lighter with the average weight of a soft drinks can in 2004 expected to be only 21.4g .In 1980 it was 31.2g
• There are over 2.5 billion cans recycled in the UK each year - [That's a saving of 125,000tonnes of solid waste every year] that's equivalent to the...
tracking img