Mines and quarries

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Temps de lecture : 4 minutes  

Carrière
No matter how huge they seem, the Earth’s resources are not limitless. Certain metals are even starting to lack due to sharp increases in demands. The mining industry generates a lot of money and jobs but at a heavy social and environmental cost.

Mankind uses about 32 billion tons of mineral and energy resources every year. There are 5 main categories: building materials, industrial materials, metals, energy minerals and precious substances.

These resources are spread very unequally throughout the world. Some minerals are relatively common, like iron – the most mined mineral in the world. Its production reached 1.6 billion tons in 2006 and is currently increasing by 10 % a year. The three largest producers are, in order, China, Brazil and Australia. Other minerals are rarer, like hafnium, which is used to make filaments and electrodes. The world stocks are estimated at 1 million tons in total (most of this is in South Africa).

Open air or underground mines

There are different types of mines. An open air mine is a huge basin with rows that are dug by layers of rock being successively scraped. A recent technique which causes many problems is called Mountain top removal: it consists in blowing up the top of the hills with dynamite to directly access the fibres.

The most common underground mine looks like a huge ant hill on a human scale. The liquid substances or gasses are extracted through wells.

Seas contain hydrocarbons as well as gold, diamonds, cobalt, etc. These substances are however, often hard to extract. Today, materials extracted from the sea are essentially sand for the building sector. Certain marine grains (limestone slow growing algae squeletons for example) can also be used to restore farmland, like in Japan.

The distinction between mines and quarries is legal. It depends on the substances that are extracted from these sites and not on the type of mine (there are underground quarries and open-air mines)

The mining industry

The mining industry is very concentrated: 40 companies represent 80 % of the sector’s market capitalisation. The largest mining company in the world is the Anglo Australian BHP Billiton (with a share value of 165 billion dollars in 2007); the second is the Brazilian Companhia Vale do Rio Doce. However, a lot of the production comes from small mines, of which most are illegal. According to the International Labour Organisation (ILO), 13 million people in the world work in these small structures, and this helps about a hundred million people to live.

Companies in the mining sector share an 820 billion Euros market a year (energy resources included). This is mainly due to China’s demand. In 2006, the sector’s results were fifteen times higher than in 2002.

Between 2000 and 2004, minerals represented over 50 % of five countries’ exports (Botswana, Guinea, Jamaica, Surinam, and Zambia), and between 30 % and 50 % of 10 other countries (the highest first: Niger, Chilli, Papua, Congo, Ghana, Cuba, Peru, Rwanda, and Uzbekistan). [Debate]

Social conditions

Working conditions are often very tough. Pulmonary diseases like silicosis and black lungs are widespread as are pains due to heat in the mines. In certain gold mines, large reservoirs of stagnant water are kept close to mines and encourage malaria. Collapses, explosions, floods and fires cause a lot of deaths. In China alone, there are officially about 5000 deaths a year in coal mines; this figure is an underestimate.

Effects on the environment

Mining often causes a lot of pollution. Extracting millions of tons of rock can lead the land to collapse or to gully erosions. The debris can also obstruct watercourses. Slag heaps disfigure landscapes. [Debate]

During the extraction process, a lot of water is used and this can cause problems where it is lacking.

Highly toxic products are used to separate precious metals from the rock that is extracted: cyanide, mercury and arsenic are mixed with mud and are stocked in basins. But history can show many examples where mine dykes gave way and spilt their contents. In Guyana, in 1996, 3.4 million m3 of contaminated water were spilt; in 1998 in Andalusia, 5 million tons of toxic mud was spilt; in 2000, in Romania, 100 000 tons of mud spilt into the Danube’s tributaries and killed almost everything in it (5).

Radioactive residues are also dangerous and can contaminate soil or water.

Closing and rehabilitating sites

When a mine shuts, the local communities are the first to be affected, sometimes, heavily. But the environmental problems do not stop when activity ceases. The site then needs to be rehabilitated. This is considered to be the responsibility of the outgoing mine owners. However, it is hard to ensure that this is respected. They have sometimes gone bankrupt or have ceased all activity in the country. On old sites, the previous owner is often unknown. [Debate]

Once the site is rehabilitated it can be used for other activities. This is the case of the tourist spot, the Eden Project, built in 2001 in an old kaolin quarry in the United Kingdom. It contains several greenhouses which bring together an exceptional amount of biodiversity.

Recycling: an alternative to mining

It is inevitable that in the long term mining resources will run out or become rare. When it is possible, reusing and recycling transformed material can reduce extraction. Recycling aluminium, for example, saves four times its weight in bauxite and up to 95 % of the energy necessary to make primary metal (recycled aluminium has the same properties as the first fusion metal).

Dirty gold

The illegal trade of certain raw materials like gold (« dirty gold ») or diamonds (« blood diamonds ») is used to pay for conflicts, civil wars and local mafias. Various processes now aim to control this illegal trade better.

In 1998, the United Nations Security Council placed restrictions on the sale and import of rough diamonds from Angola. At the time the country was being torn apart by a terrible civil war funded by diamond smuggling. These restrictions were then placed on Sierra Leone and Liberia. In 2000, they culminated in an international certification scheme which is called the Kimberley process – the South African town where the negotiations were held. The process now brings together 44 exporting and importing countries.

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