Open-pit Mining By 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

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