MINING: The process of obtaining
mineral resources from the Earth
Warm-Up
• What are examples of resources we extract
from the earth?
• How do we get those resources out of the
earth so we can use them?
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What do we mine?
Coal!!!
Salt
Sulfur
Granite
Marble
Sand
Gravel
Gold
Copper
Iron
Diamonds
Gemstones, other minerals
Why?
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Energy- coal, oil, natural gas, uranium
Technology- metals for electronics
Infrastructure- rocks, gravel, metals
Agriculture- minerals for fertilizers
Luxury- diamonds, gold, sapphires, rubies, etc.
Mining Methods
Surface Mining
• Digging down from the
surface
Sub-Surface
• Cut small “shafts” into
earth and excavate from
within
Surface Mining: Open Pit Mining
• Used when minerals are
close to the surface
• Mined from top
downward in layers
• Ore hauled (pulled) out
via trucks and then
minerals are extracted
• Gold and Copper can be
mined this way
The El Chino mine located near Silver City,
New Mexico is an open-pit copper mine.
Surface Mining: Strip Mining
• A long strip of overlying soil and rock is removed and the
mineral seam is exposed
• This layer of removed soil and rock is called the
overburden
• Used for coal and other minerals that come in horizontal
(layer) deposits
• Overburden materials can be replaced once the mineral
has been taken out of the ground
Surface Mining: Quarrying
An abandoned construction aggregate
quarry near Adelaide, South Australia
• Rocks such as marble
and granite can be
excavated this way
• Construction Materials
such as sand, gravel
and crushed stone can
also be obtained this
way
Surface Mining: Solar Evaporation
• Salty Sea water is placed
into very shallow
artificial ponds.
• The water slowly
evaporates and salt
crystals form
• 30% of our Salt comes
from this process
• Most common in dry
climates…why???
A salt pan worker in a salt evaporation
pond in Tamil Nadu, India
Subsurface Mining: Room-and-Pillar Mining
• “Rooms” are cut into seams of coal (or salt or iron)
• Pillars of ore are left standing to support the ceiling
• When all possible ore is extracted from the rooms – often the
pillars are then removed and the land above collapses
Subsurface Mining: Longwall Mining
• A machine (a shearer) cuts
and scrapes coal from the
wall of a coal seam
• The machine moves back
and forth and the coal drops
onto a conveyor belt
• The ceiling next to the
machine is held up by roof
supports and as the
machine advances into the
coal seam the roof collapses
Subsurface Mining: Solution Mining
• Hot water is injected into the mineral deposit
through a well
• The mineral water mixture is then pumped to
the surface
Mining Regulations &
Mine Reclamation
Environmental Impacts of
Mining
What are some environmental impacts
associated with mining?
Be ready to explain your answers or provide examples.
Environmental Impacts of
Mining
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Air and noise pollution
Water pollution
Displacement of wildlife
Erosion and sedimentation
Soil degradation
Subsidence
Because the environmental impacts are so great, mining
is one of the most heavily regulated industries in the US!
Air and Noise Pollution
• Dust is produced by removing,
loading, hauling, and dumping
soil and overburden (stuff on
top of ore)
• Dust is also produced from ore
blasting
• Noise is created by equipment
and blasting
Air and Noise Pollution
Regulation
• Most surface mines are NOT
located near urban
populations
• Regulations in US forbid
mining operations to allow
dust or noise to exit the area
being mined
Water Contamination
• Water that seeps into mines or through piles of
rock can pick up or dissolve toxic substances
• Containments can then wash into streams where
they can harm or kill aquatic life
Think!
What do you think happens when water is contaminated with a
mineral like sulfur?
What regulations do you think exist to combat water
contamination?
Water Contamination &
Regulation
• Minerals that contain a lot of sulfur
and react with oxygen and water to
produce dilute sulfuric acid
• Contaminated water from this
process is called Acid Mine Drainage
(AMD)
• Regulations in the US require
companies to dispose of acidproducing rock in landfill or in ways
that prevent water contamination
Displacement of wildlife
• Removing soil from a surface mine site strips away all
plant life.
• Without plants, animals will leave the area.
• Dredging disturbs river bottoms and destroys aquatic
plant life. (Example: gold and silver)
Think!
What do you think happens when soil is returned to a surface
mine site?
Displacement of wildlife
When the soil is
returned to the site
different plants and
animals may
establish themselves,
creating a new
ecosystem.
Think!- Would this be primary
or secondary succession?
Erosion and Sedimentation
• Excess rock from mines
is dumped into large
piles called dumps.
• Running water erodes
unprotected dumps
and may harm water
quality and aquatic life
Soil Degradation
• Soil at a mine is removed from the uppermost
layer downward.
• Soil must be stored in layers with the upper
layers stored above lower layers.
Think!
What do you think happens if the soil is not removed and
stored properly?
Soil Degradation
• Soil must be removed and stored properly
or it can be depleted of nutrients when it is
reclaimed.
• Deeper soil layers may also contain sulfur.
Think!
 What might happens to sulfur compounds in the soil?
 How might this affect plant growth?
Subsidence
• The sinking of regions
of ground with little or
no horizontal
movement.
• Caused when pillars in
a mine collapse or the
mine roof or floor fails
Think!
What are some hazards that may result from subsidence?
Subsidence
• Buildings, houses,
roads, bridges,
underground pipelines
and utilities may be
damaged
- Explosions, fires
• Loss of wildlife or
human life
Underground Mine Fires
• Fires in underground coal seams are one
of the most serious environmental
consequences of coal mining
• Lightning, forest fires and burning trash
can cause coal-seam fires.
• Centralia, PA. – still burning since 1962
Think!
 What are some of the problems with underground mine fires?
Underground Mine Fires
• These fires are hard to
put out and often left to
burn out (which may take
decades).
• They release smoke and
gasses that can cause
respiratory problems.
Mining Regulations
• Mining is the most heavily regulated industry in
the US.
• Mines on land in the US are regulated by federal
and state laws.
• States must issue permits for mining, run
inspections, and address noncompliance.
Think!
 What federal regulations exist to control negative impacts
mining has on the environment?
Mining Regulations
• The Clean Water Act &The Safe
Drinking Water Act
• The Comprehensive Response
Compensation and Liability Act
– regulates the release of hazardous
substances into air, soil, & water
• The Endangered Species Act
– protects threatened & endangered
species and their habitats
Reclamation
• Reclaiming the land or returning it to its original or
better condition after mining.
• Billions of dollars are spent to clean up abandoned
mines.
• The Surface Mining control and Reclamation Act of
1977 (SMCRA)
– Set standards to minimize the effects of coal mining on
environment
– Established funds used to reclaim land and water resources
adversely affected by mining
Mine Reclamation
Before
After
Before
After
After
Before
Lessening impact: The 3 R’s of Mining
• Reduce the amount of waste you
produce (use less stuff)
• Reuse materials in the waste
stream as much as possible
• Maximize Recycling opportunities
Mining Video Clips
• https://www.youtube.com/watch?v=4WbaON
JEbRE - Surface Mining: Open pit Mining
• https://www.youtube.com/watch?v=4_tDoTvQ6A -Underground Mining