Image Credits: Alf Manciagli/shutterstock.com
By Sydney Luntz
More often than not, mining sites are formed around their natural foundations. In order to optimize each pit’s efficiency, the mining space tends to merge the land’s natural characteristics and man-made features.
Although many metal deposits arise through surface mining, there is an economical desire to mine the large number of valuable resources and metals below ground. Today, with goals of performing more underground missions, some mining practices operate both underground and open-pit methods.
Open-pit mining can also be identified as open-cast or open cut mining. The practice operates above ground, always at the surface, extracting minerals and rocks from the surface. Open-pit mining presents less dangers in comparison to underground mining - these surface mines do not need to tackle issues such as air loss and cave-ins, nor do workers have to worry about regulating heavy machinery.
As this method of mining is less intrusive and does not require tunneling into the ground, it is most productivel when a large number of rocks and minerals are found near the earth’s surface. If the desired material is found amongst sand or cinder, open-pit mining is required because the material is insufficient and usually too brittle for tunneling.
Once an open-pit mine expands and the mineral source is exhausted, it can be transfigured into a landfill of solid waste. When this process occurs, an extensive amount of water control is needed in order to prevent the mine pit from becoming a body of water. Open-pit mines are found globally and they are responsible for surfacing resources like clay and coal, as well as metals like uranium and gold.
For rocks and minerals that are below the mining area, a different mining practice is required. Unlike open-pit mining, underground mining methods are used to extract materials beneath the earth’s surface.
Underground mining presents many dangers, including fires, floods, collapses, and toxic containment. Fires can be caused by unexpected coal heating, short circuits, or friction from defective bearings; collapses can result from induced seismicity or explosives; and toxic containment is the product of poor ventilation. Despite the increased amount of difficulties and dangers that occur in underground mining, there is still a series of danger surrounding open-pit mining too. Either type of mine can be dangerous for its miners, but there are more external forces to consider with underground mining. Nonetheless, its extraction success is seen as worth the extra care and caution.
What Changed and Why it is Changing
While both underground and open-pit mining are widely accepted mining processes, there is a greater inclination to further expand underground mining. This transition from open-pit to underground begins when open-pit mines are exhausted or inaccessible; meaning, they have either been depleted of minerals, rocks, and resources, or they are unfeasible to build upon.
Once the decision is made to change from open-pit to underground mining, there are several approaches: miners can build spiral tunnels around the desired resources, descend shafts in the ground, or form adits that rest in the side of elevated land, such as hills.
The upfront costs for open-pit mining are much more economical than that of underground mining, however, these initial costs are usually offset by the revenue from extracted minerals, rocks, and resources. There is a limit to the success of surface mining, in which going underground proves to be necessary in order to continue mining for earthly valuables. Thus, underground mining’s higher production rate results in an alleviation of initial costs, making underground mining an inevitable and ultimately, cost-effective practice.
As mining remains one of the leading ways to extract valuable resources and geological fragments from earth, its popular open-pit and underground techniques will change with surface mineral exhaustion. Both mining practices, whether above or underground, are often in isolated areas that demand miners to live at the sites for a significantly long and labrious time.
Granted that open-pit provides lower costs at the start, mechanical and electrical advantages, and safer surroundings, there comes a point when underground mining is unavoidable. This transition is becoming more and more current, as more deposits are emptied and land is unsuitable to create open mines.
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