Surface Mining

In contrast to underground mining, the terrain layer - soil and rock above deposit - is removed to extract minerals and ores in the surface mining technique. Surface mining is a commonly used technique by the miners globally.

Types of Surface Mining

Surface mining is used to extract minerals like iron, stone, gravel, sand, and other non-precious metals. It is further subdivided into five major categories, depending on the mineral extraction process and the type of mineral being extracted.

Strip Mining

As the name says, the process of strip mining includes removal of the surface layer to retrieve the minerals. With the help of machinery like bucket-wheel excavators, soil, rock, and other vegetation are removed to reach the mineral deposits.

Strip mining is generally used when the mineral deposits are close to the surface of the earth. Miners must constraint from using this method for deeper deposits as it would unnecessarily damage the terrain.

Strip mining is a technique most commonly used to extract minerals like coal and ignite.

Open-pit Mining

Open-pit mining is very similar to strip mining, however, the ore is retrieved through an open-pit here. These pits are enlarged to the point where no ore is left in the area to extract. Once done, the pits are not filled back in, rather they are commonly used as a garbage dumping ground.

Open-pit mining is generally used in areas where ore is close to the surface and large quantities of it are scattered in a wide area. Also, the method is slightly economical as the process of removing the overburden is eliminated for good. But, such mines sites are dangerous to work in and can cause extravagant damage to the nearby area.

Open-pit mining is generally used to extract minerals like salt, marble, and granite.

Mountaintop Removal

Mountaintop removal is the most complex and controversial method of mining. Such mining methods are generally used to extract large coal deposits from the mountain top. Besides, it is only undertaken when the depth of the mineral deposit is 400 feet or more.

The mountain top is removed by using techniques like blasting to remove the overburden above the deposit. However, a huge controversy surrounds this method as it is believed to damage the ecosystem and the entire landscape.

Highwall Mining

Highwall mining is very similar to augur mining technique, instead of augur holes high wall mining depends on expensive machinery. Such mining techniques are used to extract additional mineral deposits through a high wall.

Why Surface Mine?

Surface mining is a preferred method by many mining companies. This happens for a variety of reasons, one of them being its cost-effectiveness. The removal of terrain surface to retrieve minerals is less costly than building tunnels for operations.

Besides, surface mining is considered a safer mining method than any other. It also requires low electricity and water piping, which makes it environmentally sustainable.