When it comes to underground mining, there are different ways to approach removing coal, depending its structure and location. At the current Carlisle Mine and developing Bulldog Mine, Sunrise Coal is using the room and pillar mining method. At the developing mine in Clay City, Indiana, coal is close to the surface and will require surface mining.
Room and pillar mining is a non-subsidence plan for a mine, preserving the precious farmland above. It is among the safest and one of the most ecologically-friendly approaches to mining coal today, creating a non-subsidence environment (no movement of land) and maintaining clean water standards.
As the name indicates, large pillars of coal (40 feet wide) are left standing to help support the roof of the mine—more than half of the coal remains intact as supporting pillars to maintain the integrity of the surface land. The end result is a grid of open space (rooms) cleared by a continuous miner machine and separated by pillars.
Once the coal is cleared and placed on a conveyor belt to our state-of-the art surface wash plant, roof bolters enter the new area to secure the roof, inserting fully grouted 6-foot metal rods every four feet. At the wash plant, rock and debris are separated from the coal so that it can be cleansed of sulfur and other minerals in preparation for our customers.