Room and pillar mining is an example of one such dangerous method. Continuous miner machines remove coal, eventually forming entire open rooms. Large pillars are left in a grid-like pattern to support the roof. The coal is cleared while digging and is taken back to the surface using conveyor belts. Crews then enter the room and insert metal rods into the roof four to six feet apart from each other in order to maintain the integrity of the topsoil and the surface. Around half of the coal in the mined area remains unexcavated in the form of the pillars, so at times, coal companies practice retreat mining. This is the process of removing the pillars with the goal of extracting as much coal as possible. Retreat mining must be conducted very carefully with extreme planning and care. It has accounted for 25% of all mining-related deaths, but only accounts for about 10% of the coal industry in terms of processes
Room and pillar mining is an example of one such dangerous method. Continuous miner machines remove coal, eventually forming entire open rooms. Large pillars are left in a grid-like pattern to support the roof. The coal is cleared while digging and is taken back to the surface using conveyor belts. Crews then enter the room and insert metal rods into the roof four to six feet apart from each other in order to maintain the integrity of the topsoil and the surface. Around half of the coal in the mined area remains unexcavated in the form of the pillars, so at times, coal companies practice retreat mining. This is the process of removing the pillars with the goal of extracting as much coal as possible. Retreat mining must be conducted very carefully with extreme planning and care. It has accounted for 25% of all mining-related deaths, but only accounts for about 10% of the coal industry in terms of processes