Over burden stripped off to expose resources using drag line excavation (surface mining)
Open Cast mining
1 of 6
Where topography intercepts bed, ... deposits are stripped away. Follows ore down into mine (shallow - surface mining)
Adit/Drift mine
2 of 6
Pillar is put in each time coal is removed to stop overburden falling in. Subsidence is caused when pillars fall (deep mining)
Pillar and Stall Mining
3 of 6
Two access tunnels are set up and joined at the back by a third which is at 90 degrees. Mechanical shearer is used to mine coal and hydraulic rams hold up roof over coal. Roof collapses after coal is removed (deep mining)
Long Wall Retreat
4 of 6
Pillars collapse causing earth above to fall into mine. Earth falls between pillars and takes on a bowl shape at the surface.
Sag Subsidence
5 of 6
Pillars aren't strong enough to hold up earth so weight of roof falls in. Takes on a pit shape at the surface.
Pit Subsidence
6 of 6
Other cards in this set
Card 2
Front
Adit/Drift mine
Back
Where topography intercepts bed, ... deposits are stripped away. Follows ore down into mine (shallow - surface mining)
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