The conventional mining techniques described above made up of the cyclic operations of cutting drilling blasting and loading developed in association with room and pillar mining the oldest of the basic underground methods room and pillar mining grew naturally out of the need to recover more coal as mining operations became deeper and more expensive.
Room and pillar coal mining.
The oldest of the basic underground methods room and pillar mining grew naturally out of the need to recover more coal as mining operations became deeper and more expensive.
The coal pillar and the mining width are designed using the room and pillar mining method and the optimum panel size is determined by the longwall panel layout longwall panel layout with local shortwall mining it can reduce the waste of coal resources and also protect the surface structures.
To do this rooms of ore are dug out while pillars of untouched material are left to support the roof overburden calculating the size shape and position of pillars is a complicated procedure and is an area of.
Retreat mining is the last phase of a general kind of coal mining technique referred to as room and pillar mining.
In room and pillar mining a mining machine called as continuous miner bores a network of chambers or rooms into a coal seam leaving at the back an unexcavated pillar of coal in every room to support the roof of the mine.
Room and pillar variant of breast stoping is a mining system in which the mined material is extracted across a horizontal plane creating horizontal arrays of rooms and pillars.