What is highwall mining?
Highwall mining is a hybrid of surface and underground mining technologies. Surface mines typically continue to remove overburden to gain access to the coal until they reach an economical limit where the cost of overburden removal exceeds the value of the coal. This point in the life of a surface mine is referred to as the final highwall. A highwall mining system is set up at the face of the final highwall. A continuous miner which is typically used in underground mines begins mining its way under the mountain. The coal is transported from the back of the miner to the surface on conveyance system that is incrementally increased in length as the miner advances into the mountain. The mining machinery is operated remotely from an operators cab that is located on the surface. The tunnel is mined the maximum distance allowed by equipment design and geological conditions. At that point, the equipment retracts from the hole and moves down the highwall and drives another entry parallel to the
