Sunday, 28 June 2009

All that Glitters

I have recently been reading the report Dirty Metals: Mining, Communities and the Environment by Earthworks and Oxfam America (available here http://www.nodirtygold.org/dirty_metals_report.cfm). It is shocking.

Take gold as an example. About 2/3 of the gold in use is new gold and 2/3 of new gold is mined from open pit mines. Over 80% of gold is used for jewellery, such as wedding rings.

Open pit mines are hugely ecologically destructive and generate vast amounts of rock waste. Cyanide is sprayed onto the piles of crushed ore, to trickle through the heap and bond with the gold. The gold-cyanide solution is then pumped to a mill for chemical separation and the cyanide is stored in an artificial pond for re-use. Each bout of leaching may take months, after which the heaps get a fresh load of ore. The piles of cyanide-contaminated waste ore are often abandoned and can continue to contaminate the surrounding area for years.

Another very visible problem is the failure of mine tailings dams. Tailings are a soupy to semi-solid suspension of pulverised rock in water, generally toxin loaded. On-site tailings disposal generally consists of bulldozing some of the dried tailings into a dam which can hold more liquid waste. These dams are constructed and enlarged over the life of the mine, so structural integrity can be a problem. When the tailings dam at Omai gold mine in Guyana failed in 1995, it released some 3 billion litres of cyanide laden waste into the Omai River, which is a tributary of Guyana’s largest river, the Essequibo. The whole 51 km drainage from the mine to the Atlantic Ocean (home to 23,000 people) was subsequently declared an official “Environmental Disaster Zone” by the president of Guyana.

After chemical separation, the extracted gold is transported to a highly energy intensive smelter for processing. There is potential here for a conflict of interests as governments have to choose between supplying energy to smelters or to homes. For example, China’s aluminium smelters use enough energy each week to supply 2 million of its citizens for a year (see Bloomberg on this issue here http://www.bloomberg.com/apps/news?pid=20601103&sid=aCUU6NbjPfmM&refer=us).

The purified gold is sold and made into its final product. According to the report, a typical 18 carat wedding ring produces (at a conservative estimate!) about 20 tons of mine waste (without including “overburden” i.e. the earth which was blasted away to get at the ore)!

This is symptomatic of our lives. Our need for status-objects from stone axe-heads to cars, designer clothes, gold jewellery and wedding rings is having a huge impact on the planet that we live on. As we become more affluent and our model of “success” is spread around the world, the burden we are placing on the planet increases.

We must change our priorities and give serious thought to our “status-objects” if we are to survive.

2 comments:

  1. I always suspected that weddings were little more than an excuse for conspicuous consumption, glad I never bothered with a ring. What I didn't even begin to realise was the impact this kind of mining had, thank you for an informative post.

    Hopefully will follow you to your new blog home, good luck!

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  2. Hi Goo
    Thanks. It was quite shocking to find out myself! I think that it is a huge issue in the deveoped world, that we do not see the impact of our lifestyles first hand.
    I will be posting the same here for a while and see if the GreenPress works out
    Have Fun

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