underground mining

Underground Mining

1.      Drift mining- is possible where the coal steam intersects with the surface; mine enters the seam in a horizontal direction following the coal.

 

2.       Shaft mining- is a common method; accessing coal seam in which elevators provide access to the mines; commonly deeper than 1000 feet below the surface.

 

 

3.      Room and pillar mining- nearly half of the coal is left behind to support the roof; pillars “squeeze” putting pressure of adjacent pillars leading to roofs collapse.

 

 

4.       Continuous mining- continuous mining machines can be used with drift or room and pillar mines.; one miner can operate a continuous miner to a rotating steel drum with tungsten carbide teeth to mine 5 tons of coal per minute; some varieties of continuous mining machines have been in use since the 1940s.

 

 

 

 

 

 

5.      Long wall mining- highly efficient; huge mining machines support the roof as it also removes coal; when coal is fully removed, the machine is removed and the roof collapses; highly productive underground coal mining technique

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