Three Methods Of Coal Mining
1- Contour Mining: Contour Mining is most commonly used in areas that have steep or rolling terrain. It involves digging the earth above the coal line, or coal seam, alongside the contours of the hilly terrain. This methodology can be dangerous because it may cause landslides and erosion problems.
2- Strip Mining: Strip Mining often occurs on flat terrain. The earth is dug up in lengthy cuts or strips till the Buying & Selling Coal Mining Permit seam is exposed. After the strip has been drilled and blasted and all the coal has been eliminated, a new strip is created proper next to it and the process continues.
3- Mountaintop Removal Mining: Mountaintop Removal Mining involves using a combination of Contour Mining and Strip Mining. The mountaintops are removed to expose the coal beneath and the coal is extracted.
Underground Mining Strategies
If the coal seams are too deep belowground, then deep beneathground mining is necessary. Deep beneathground mining strategies embrace Continuous, Longwall, Blast, Retreat Mining and Shortwall Mining.
o Steady Mining: A machine that has a large rotating metal drum with tungsten carbide teeth scrapes coal from the seam. Conveyors are used to transport the removed coal. About 5 tons of coal will be mined per minute. Accounts for about 45% of belowground coal production.
o Longwall Mining: A sophisticated machine that has a rotating drum that mechanically strikes back and forth alongside the seam. Loosened coal falls on the pan line which takes the coal to the conveyor belt. Accounts for about 50% of coal production.
o Blast: An older mining method that makes use of dynamite and explosives to interrupt away the coal seam. Accounts for less than 5% of coal production.
o Retreat Mining: One of the most harmful coal mining methods. Pillars are used to hold up the mine roof as coal is extracted. The pillars collapse as miners retreat.
o Shortwall Mining: Much like longwall mining. Uses a steady mining machine with moveable roof supports. The machine shears coal panels about 200 toes wide and half a mile long.