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Open-pit MiningBy Jessica Paddy
What Is open-pit mining?
•The process of extracting rocks and minerals through an open pit or hole in surface of the ground
•Type of strip mining, removes layers of ore that go deep into the ground
•Mining is done through extraction, which removes the ore from the ground, and beneficiation, the separation ore and metals from non-metals
History of Open-Pit Mining
•Aloud the expansion of mining production to be coast-to-coast in 1960s
•Developed after the Second World War•Developed because of ore grades and new
mining technologies•Took off after the 1960’s
How Is It important in BC?
•B.C. has been one Canada's major mining industries since the mid-1800s
•B.C.’s mining industry values at $9.2 billion
•Mining in B.C. provides 29,000 jobs
The Problem•Leaves open rock and tailings (left over
material after separating the ore and metals)
•When rock is openly exposed, acid rock drainage can occur
•Forms sulphuric acid when rock come in contact with air or water
•The aquatic ecosystem is damage once contaminated water enters streams, lakes, and rivers
The Problem cont. •Mine drainage is a main chemical threats
to ground water quality•Mine waste is increasing •The problems are avoidable, with careful companies, new technology and good planning•How can open-pit mines become more sustainable?
National and Global
• It destroys forests, and habitats, where the mines are being developed – destructing agricultural land and leads to soil erosion• Rain washes contaminated top soil into streams,
polluting waterways – Hurting fish and other plants and animals, can cause river channels and streams becoming disfigured, leading to flooding
•The risk of chemical contamination to ground water, when the minerals in the earth seep into water is rising
•For the Canadian mining industry, one million tones of waste rock, and 950,000 tones of tailings every day, and 650 million tonnes of tailings every year
•Every tonne of copper, 99 tones of waste material is removed
How can open-pit mining become more sustainable?
•Mine waste can be used for landform reconstruction, vegetation covers, and road construction
•Water protection should remain the highest goal
•Water can be removed from tailings, leaving it as a paste, that reduces its environmental impact
•Some mines collect the toxic water and clean it, by adding lime. This raises the pH and removes the metals
•Other mines collect tailings, pump it to the treatment plant and add ferric sulphate. This lowers the pH to 4.5, then it reacts with the iron and makes sludge
•Mine have acid plants that convert sulphur dioxide to sulphuric acid, a useful chemical
•Overburden, from the mining, can be used for landscape contouring and revegetation while the mine is closed
Bibliography• Cranny, Michael William. Horizons: Canada Moves West.
Scarborough, Ont.: Prentice Hall Ginn Canada, 1999. Print.• "Greenpeace | Greenpeace." Web. 21 May 2015.• "InfoMine - Technology Reviews." Web. 21 May 2015.• "MIT - Massachusetts Institute of Technology." Web. 21 May
2015.• "Mining & Exploration." Web. 21 May 2015.• "Protect Ecuador - Southern Ecuador | Open-pit Mining ..."
Web. 21 May 2015.• "Protect Fish Lake, British Columbia, Canada." Web. 21 May
2015.• "The Canadian Encyclopedia." Web. 21 May 2015.• "EHow | How to - Discover the Expert in You!" Web. 21 May
2015.