Underground mining involves opening one or more portals or shafts into the earth that follow or intercept coal seams that are too deep for surface mining methods.
Method of Work is Bord & Pillar method & longwall method for extraction of coal.
There are two stages of board & pillar mining i.e Development & Depillaring?.
Development: It is method of making drivage of gallery by drilling and blasting for establishing & extending ventilation, traveling roadway, haulage roadway for material flow, making sump area, panel making (sectionalisation) etc.?
Depillaring: Final extraction of coal from pillars, ?
Depillaring is Two Method: 1. Caving 2. Stowing?
Caving: Allowed roof to cave in after final extraction of coal pillar in slices in a sequence manner, Permitted when no surface feature. In caving process development of crack/subsidence up to surface thus danger of fire- Air flowing through cracks developing conditions of Spontaneous heating of coal, inrush of water from upper seam-inundation, release of gas. It required land filling & degradation, reclamation and plantation/vegetation.?
Stowing: Filling of Sand, Other Incombustible Material- Flyash, LD Slag in de-coaled area, Sand on Lease- Collection of sand at river.
Followed the all legal requirement subjected to method of working.
In this course you will learn about underground mine planning process & coal winning process.All methods for extraction of coal from underground. Formation of coal & their rank, types & grade of coal. All statutory requirement of Working Under Railway, Public Road etc. Working near Mine Boundary, Working under water body &.Multi Seam or Section Working.