Surface mining involves the removal of soil, rock, and plant life that are covering mineral deposits. It is the opposite of underground mining, as shafts and tunnels are not required to extract resources.
Also, it is considered to be the safer option because water piping and electricity rigging are not necessary. Mining companies prefer surface mining methods as it is more cost effective to remove the terrain surface instead of developing shafts and tunnels.
Surface Mining Extraction
Most of the world’s solid minerals are accounted for through surface mining methods, such as coal, iron, copper, aluminum and more. Surface mining soared in popularity for mining companies since the 20th century began, particularly in North America – where most surface mining takes place.
Surface mining methods require heavy equipment and earthmovers to remove overburdens, from there the excavators will extract the minerals. KJ’s has the capacity to supply all kinds of operators and excavators across North Queensland – along with appropriate training for each type.
Surface Mining Methods
There are 5 main types of surface mining, which have specific uses:
The most frequent surface mining method – Open-pit mining involves forming open pits from digging in the ground using drilling, explosives and other methods to extract desired materials.
Open-pit mines operate until the targeted mineral is depleted or becomes profitable no more, often resulting in mine sites being modified to become landfill. Water management systems are mandatory in order to alleviate risks of collapse and flooding of active mines.
Commonly used to extract shallow deposits, when mineral layers are covered by layers of soft topsoil and weathered rocks. These layers of earth are then stripped by industrial shovels or a dragline to extract the deposits – these mostly being clays, coal, tar, and phosphates.
Mountaintop Removal Mining
Mountaintop mining is a recent, alternative method of strip mining that involves the removal of coal seams from the top of steep mountains in order to expose the target deposits below.
This method is most commonly used for the more confined coal mining projects in the Appalachian regions of the United States. Non-targeted deposits excavated from the mountaintop are deposited in nearby low valley areas known as “valley fills”.
Dredging is a surface mining method that mines materials underwater. The purpose is to use small dredges to collect mined materials to then be disposed of at a different location. This surface mining method is also undertaken for environmental remediation, navigation, flood control and much more.
High Wall Mining
Combining subsurface and surface mining techniques, Highwall mining is done to recoup additional minerals that are adjacent to a surface mining area. It starts by creating an open-pit mine – then drilling deeper into the walls to extract a higher volume of the targeted resources.
To perform this method safely, continuous mining machines are operated remotely by workers on the surface or in a nearby cabin, who transport cut coal back out to the surface.