The Anatomy of a Mine - Mining and the Environment: From Ore to Metal - page 189

FIGURE 4.11
Transition from Surface to
Underground Mining

Production
Plant

Headframe

Settling Pond

Tailings

Surface mining is more common, since
it is less expensive than underground
mining. Only high ore grades normally
warrant underground mining.
Source:
Adapted from Atlas Copco 2002

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Ventilation
Shaft

Open Pit
(Mined Out)

Decline

Abandoned

Mined Out
and
Blackfilled

Level

Cage

Sublevel

Ore Pass

Producing
Stopes

Main Level

Skip

Haulage Level

Water Basin

Development
of Stopes

Crusher

Pump Station

Ore Bin

Internal Ramp

Ore

Conveyor Belt

Measuring
Pocket Skip Filling

Station

Exploration

Sump

Drilling

Future Reserves?

Ore benei ciation conventionally separates ore minerals from gangue minerals to the
degree of concentration required for downstream mineral processing industries. Under
regulations pursuant to the US. Resource Conservation and Recovery Act (40 CFR §261.4),
benei ciation is restricted to the following activities: crushing; grinding; washing; dissolu-
tion; crystallization; i ltration; sorting; sizing; drying; sintering; pelletizing, briquetting;
calcining to remove water and/or carbon dioxide; roasting, autoclaving, and/or chlorina-
tion in preparation for leaching; gravity concentration; magnetic separation; electrostatic
separation; l otation; ion exchange; solvent extraction; electrowinning; precipitation; amal-
gamation; and heap, dump, vat, tank, and in situ leaching (USEPA 1995a,b).