Empty Field Mining
Empty field mining is a surface mining technique used to selectively mine thick, flat, horizontal geologic deposits. This method is typically used to extract coal from large deposits found in an area such as the Powder River Basin in Wyoming and Montana. Empty field mining utilizes machinery that does not disturb the soil, making it ideal for surface mining in regions with sandy soil.
The process of empty field mining begins by clearing the topsoil and other debris from the surface above the coal deposit. This leaves behind a field of soil which is referred to as the empty field. The next step is to construct a network of long, narrow, metal strips known as ribbons. These ribbons are connected to each other and placed in a pattern around the deposit of coal. Each ribbon consists of two parallel metal strips and a meshing that lies between the two strips.
Once the ribbons are in place, the empty field is loaded as the strip-mining machines move along the ribbons. The machines dig a trench between the connected ribbons and carefully scrape the coal from the surface. The coal is then loaded onto trucks, which take it to a processing plant for separation and sale. The empty field is then filled with the earth that was scattered by the machines during the mining process.
The advantages of empty field mining are its low cost and minimal environmental impact. In comparison to underground mining, empty filed mining does not involve the use of explosives or cause any disruption to the surrounding ecosystems. Furthermore, it is often more economical than other forms of surface mining because it does not require the excavation and removal of large quantities of material. It is also preferred in areas with sandy soils due to its ability to quickly and cheaply remove large amounts of coal.
Overall, empty field mining is a relatively safe and inexpensive method of extracting coal from the Earths surface. It reduces the amount of disruption to the environment and is often more economical than other forms of surface mining. Furthermore, it is an ideal technique for regions with sandy soils. As such, empty field mining continues to be a popular method of coal extraction in many countries around the world.