Saturday, 1 September 2012

Environmental Impact of extraction of aluminium from bauxite


Bauxite is generally mined by open cast or strip mining.  Rather than tunneling into the earth, these methods include extracting minerals from an open pit.  Heavy machinery is used to remove all the earth covering the mineral.  This will cause an immediate impact on the environment.



The exact effects of bauxite mining are related to the site.  It almost always involves some habitat destruction, soil erosion, loss of biodiversity, or water pollution.  These effects can be short term, and followed by regrowth, or severe and permanent.

Habitat destruction, especially of rainforests, may be the most noticeable impact of bauxite mining but it is not the only one. 

Open cast mining involves removing the top layer of soil in order to get at the ores underneath.  The resultant soil erosion results in the difficultly for vegetation, be it natural or crops, to re-establish itself.  This is especially true if the removed soil is not replaced soon after the mining operation is finished.  Some mining companies have a better record of reducing soil erosion than others.

The deforestation and soil erosion can lead to problems linked to flooding, including wastewater being swept into the drinking supply.  Associated aluminium refineries, which produce the end product, can cause the drinking water supply to be hazardous.  Sometimes, usually in colder regions such as Hungary, the mining may be deep enough to hinder with the water table. It also causes land pollution as some of the by products such as scrap metals are unrecyclable and thus they will be dumped in the dump sites.
 



In addition, the extraction results in air pollution and worsening of greenhouse effect. Carbon dioxide is produced as a by-product from the burning of anodes and carbon monoxide and fluorine compounds that have toxicity are left as remnant gases after electrolysis from the molten croylite, polluting the atmosphere.





How destructive bauxite mining will be, depends a lot on the location and how responsible the company is.  In the worst cases it can harm the environment and affect the lives of the local people.  In the best cases the land can recover quite well afterwards. 



http://1800recycling.com/2010/11/aluminum-extraction-recycling-environment/
http://www.worldal.com/news/others/2010-07-03/127812172829282.shtml
http://www.chemguide.co.uk/inorganic/extraction/aluminium.html



- Yuanlin

2 comments:

  1. Its nice to see related article in one place. Add more post. extraction of aluminium
    gud luck

    ReplyDelete
  2. i think you can also talk about the product produced during the refining process which will have impacts on the environment. for example, it may produce some gas that will worsen the global warming, or some poisonous gas during the refining process.

    ReplyDelete