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Mining's Problem With Waste
Safe disposal of mine waste, including tailings, is generally recognized as the single largest environmental challenge facing the mining industry worldwide and a major expense for mining companies.
Modern open-pit mining has a very high waste-to-product ratio (roughly 99 tonnes of waste to each tonne of copper, and even far more waste in gold mining), making waste the major product of mining. The Canadian mineral industry generates about 650 million tonnes of waste per year.1 The storage of this waste poses significant engineering challenges. All over the world, tailingsdams are leaking, or breaking, and seeping toxins on a daily basis; but recent environmental and social disasters in Romania, Guyana, Spain, and the Philippines—caused by tailings-dams that burst—have served to focus public attention on this problem.
Mine waste poses an environmental threat not only through its volume but also because of its toxicity. Mine tailings commonly contain sulfides as well as metals—such as cadmium, copper, iron, lead, manganese, mercury, silver, and zinc—that occur naturally in the ore body. When sulfides in the tailings are exposed to air they oxidize. If oxidized tailings come into contact with water, environmentally toxic sulfuric acid is produced. This process is known as Acid Mine Drainage (AMD). The sulfuric acid also accelerates metal leaching in tailings. Acid Mine Drainage can have a toxic impact on ground and surface water around mines. According to the United States Environmental Protection Agency, water contamination from mining poses one of the top three ecological security threats in the world.
For more information, please contact:
Igor O'Neill
Workphone: +62 21 794 1672
Mobile: +62 81 286 12 286
Created: 01 Jan 1970 | Last updated: 08 Dec 2004
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