Mining

History of mineral
exploration

➔

Early history, people only
knew a mineral was present
if it was visible

➔

People started to recognize
patterns
◆

Certain minerals were
found in the same type
of rock formations

◆

This led to the first
mines

➔

This was still largely trial and
error

Modern Times

➔ Airplanes and Satellites can detect

◆

Small changes in gravity, magnetism, and radiation

◆

Visual patterns

➔ If an area looks good, test holes are drilled
➔ Still a risk of no mineral but FAR better than previous times

Subsurface mining

➔

Room and Pillar mining
◆

Large pillars are left in a room to hold up the ceiling

➔

Longwall mining
◆

Coal is found in seems

◆

Coal is sheared off a wall and collected on a conveyor belt

➔

Solution mining
◆

Used for some salts and dissolvable minerals

◆

Hot water is injected into a well

◆

The water and dissolved minerals are pumped to the surface

Room and Pillar

Longwall

Surface Mining

➔

Used when the mineral is close to the surface

➔

Open pit mining
◆

Removes OVERBURDEN to expose the mineral

◆

This can cause a large amount of land to be disturbed

➔

Quarrying
◆

Used for minerals used in construction

◆

Sand, gravel, crushed rocks (aggregates)

◆

Granite

➔

Solar evaporation
◆

Extracting minerals from sea water

Open pit Solar evaporation

Placer mining

➔Water can move minerals and
deposit the minerals together

➔Gold panning

➔Dredges

Undersea mining

➔

The ocean floor may have vast mineral deposits

➔

Currently, it is too expensive to mine the ocean floor