Mining Methods Flashcards
1
Q
Sub-level stoping
A
- Extraction of large massive or tabular steeply dipping orebodies
- Ore is extracted by longhole drilling from sublevels. The blasted ore fall to the bottom of the stopes where it is loaded at the haulage levels
- Main haulage drive is at the bottom of the stoping level
- Ring or fan filling is the main form of rock breakage
- Stability is maintained typically by pillars and backfill
- Top down or bottom up using upholes or down hole drilling
- Multiple stopes and drawpoints for extraction
- Haulage drifts is in the wall along the FW/HW outside the mining area
- Low to moderate costs, non-entry production, high
2
Q
Open stoping
A
- Naturally supported mining method
- Tabular in lenticular orebody shape
- Up to 2400m depth
- Dip > 50
- Bulk mining method
- Competent footwall
- Grade should be moderate to high
- Use of pillars for support to aid with mining sequence
- Objective is 100% recovery
3
Q
Overhand cut and fill
A
- Cut and fill is a mining method in which a single excavation is possible
- Overhand cut starts at the bottom that cuts a horizontal slice of 1.8m-4.6m
- Advancing from an access point
- Ore fall and rests on the backfill placed during last cycle. Advancing upwards
- Back needs little support
- Roof is less stable therefore have to use rockbolts
4
Q
Bench and Fill Open Stope
A
- Uphole/downdip method
- Flexible, low grade/sub-economic zones can be left
- High recovery, low dilution
- Pillars need to be left in the orebody to maintain integrity
- Operator exposed during drilling and charging
5
Q
Underhand cut and fill
A
- Direction of stope advances downwards
- Cement is used to provide the roof or back
- Weak narrow vein orebodies
- Require cemented backfill
6
Q
Mechanised cut and fill
A
- Selective mining method for highgrade irregular deposits
- Used for pillar recovery as well as primary stoping
- High cost of labour and materials
- Fill is required
