Surface mining

Surface mining

Surface mining recovers a higher proportion of the coal deposit than underground method and is economic only when the coal seam is close to the surface. There are several types of surface mining, but only three of them are the most common: open-pit mining, strip mining, quarrying.

Open-pit mining refers to a method of extracting rock of minerals from the earth by their removal from an open pit or borrow.

Strip mining is the practice of mining a seam of mineral by first removing a strip of overlaying soil and rock (the overburden). After the mineral has been removed, an adjacent strip is uncovered and its waste material is put in the excavation of the first strip. The method is most commonly used to mine coal, especially lignite. A strip to the overburden next to the previously mined strip is usually drilled. The drill holes are filled with explosives and blasted. The overburden is then removed using large earthmoving equipment.

Quarrying is the extraction of stone blocks of specific colour, size, shape and quality- an operation requiring special and expensive production procedures.

Surface mining offers distinct advantages, for example it makes possible the recovery of deposit which for physical reasons cannot be mined underground, provides safety working conditions, and it is generally cheaper.

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