Mine Closure - Mining and the Environment: From Ore to Metal - page 806

TABLE 21.3
Environmental Aspects of Mine Closure (based on Khanna 2000)

Issues Objectives Control

Underground mine workings

Physical Stability
● Shafts
● Adits
● Declines
● Subsidence

● Prevent access
● Seal
● Safety
● Stability

● Backfi ll
● Plug openings
● Vent water and gas
● Infi ll underground and surface spaces
● Re-contour surface

Chemical Stability
● Mineral leaching
● Acid drainage
● Contaminants
● Methane

● Clear water
● Meet water
● Quality regulations
● Prevent release

● Flood workings
● Plug openings
● Remove contaminants
● Treat water discharge
● Collect and use gas

Land Use
● Productivity
● Aesthetics
● Drainage

● Restore to original or accepted
alternative use
● Re-establish drainage patterns

● Backfi ll disrupted areas
● Contour surfaces
● Flood workings

Open pit mine workings

Physical Stability
● Steep slopes
● Unstable faces
● Erosion
● Hydrology
● Safety

● Stable surfaces
● Remove hazards
● Control erosion
● Clean water

● Re-contour
● Establish vegetation
● Fence and erect signs
● Install embankments

Chemical Stability
● Metal leaching
● Acid drainage

● Install drainage
● Meet water
● Quality regulations

● Seal surface
● Flood pit
● Control hydrology
● Treat discharge

Land Use
● Productivity
● Aesthetics
● Drainage

● Restore to original or accepted
alternative use
● Re-establish drainage patterns

● Backfi ll disrupted areas
● Re-contour slopes
● Establish vegetation
● Flood

Waste rock and spent ore

Physical Stability
● Steep slopes
● Unstable faces
● Erosion
● Drainage
● Dust

● Stable surfaces
● Avoid failures, slumps and sediment
release

● Site selection
● Internal drains
● Gentle slopes
● Contour surfaces
● Cap
● Water ditches
● Settling ponds
● Establish vegetation
● Monitor