Surface coal mining

Strip mining

Strip mining is a method used when coal is near the surface or when the surface is too unstable to mine under. As the mining progresses, the overburden is placed in previous mining cavities.

Contour mining

Contour mining follows the contour of a hill, leaving terraces in the mountainside.

Mountaintop removal

Mountaintop removal removes the tops of hills to access horizontal coal seams. Overburden is pushed to areas between high elevations and the original contour is not restored. This is the most controversial method of coal mining.

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Underground Coal Mining

Drift mining

 Drift mining is a method of mining where coal seams intersect the surface; the mine enters the seam at a horizontal direction following the coal.

Shaft mining

Shaft mining is one of the most common methods of mining. Elevators provide access to the mines that are deep underground. Most shaft mines in West Virginia are 1000+ feet below the surface.

Room & Pillar mining

Room and pillar mining is a less effective method of mining coal. Half the coal is left behind to create pillars that support the mine roof; pillars can squeeze, thus putting pressure on other pillars and causing the roof to collapse. Roof falls are a constant danger in these mines.

Continuous mining

Continuous mining utilizes machines with drift and room and pillar mines. One miner can operate a continuous machine with a rotating steel drum with tungsten carbide teeth to mine five feet of coal per minute. This method has been used since 1940 and is often combined with a conveyor system.

Longwall mining

Longwall mining is highly efficient. Machines support the roof of the mine with hydraulics as it is mined. Once the coal is removed, the machine retreats, allowing the roof to call behind it. This method mines more coal than the room and pillar method.

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Coal Formation

Coal was formed during the Pennsylvania period in West Virginia. Coal is the remains of swamp plants approximately 300-400 years old. Dead plants are buried in swamp and lack oxygen; this causes the plants to form peat instead of rotting. Sediment covered and compressed the peat. Peat is the precursor to coal, which then becomes lignite, or brown coal, often used to generate electric power. Lignite forms bituminous/black coal, which becomes anthracite coal, also known as hard coal. This then becomes coke, a coal product. The key factors in this process are the lack of oxygen and compression.