Surface mining is a type of mining in which the soil and rock covering the mineral deposits are removed to extract the desired resources. It is the opposite of underground mining, where the overlying rock is left behind, and the required mineral deposits are removed through shafts or tunnels. There are five main types of surface mining, which are used in various degrees and for different resources:
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Strip mining: This involves removing a long strip of overlying soil and rock (the overburden) to mine a seam of mineral. It is most commonly used to mine coal and lignite (brown coal) and is practical only when the ore body to be excavated is relatively near the surface and/or is mostly horizontal.
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Open-pit mining: This involves creating a large open pit or hole in the ground to extract minerals. It is used for minerals that are found near the surface and is commonly used for copper, gold, iron, and other metals.
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Mountaintop removal mining: This is a type of strip mining that involves removing the top of a mountain to expose the coal seams underneath. It is used to extract coal in the Appalachian coalfields.
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Dredging: This involves removing sediment from the bottom of bodies of water to extract minerals such as gold, tin, and diamonds.
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Highwall mining: This is a form of mining sometimes conducted to recover additional coal adjacent to a surface-mined area. It evolved from auger mining but does not meet the definition of surface mining since it does not involve the removal of overburden to expose the coal seam.
Surface mining can have negative effects on the local environment, including soil, water, air, and noise pollution, as well as landscape alteration. However, new technology and proper management can make it easier to properly treat the local water supply and restore the local ecology, which helps rebuild the environment. Surface mining is often preferred to underground mining by mining companies because it is less expensive, there are fewer complications in terms of electricity and water, and it is safer.
