Chapters 14, 15, 16

Net energy: usable amount of high quality energy
available from a given energy source, minus the cost
from extraction and processing
The more energy used in the extracting and refining
process, the less energy will be available (decreased net
energy)
 Improved by decreasing waste

 Fuel efficiency
 Building insulation
 Efficient coal/nuclear plants

Takes high quality energy to get high quality energy

As energy is used it is wasted or degraded
 Laws of thermodynamics (Chapter 2)

Nonrenewable Sources





Exist in fixed quantities
Most commercial energy comes from the burning of
fossil fuels
Oil, Natural Gas, Coal (fossilized organisms)
Nuclear
Renewable Sources


Replenished through natural processes
Solar, Hydropower, Wind, Biomass, Geothermal,
Hydrogen

Low net energy sources subsidized by
governments

Nonrenewable vs. Renewable


5 times greater than the rest of the world
Developed countries used 70% of the worlds
energy, and have 20% of the worlds population

Mineral


naturally occurring, inorganic, solid element or
compound with a definite chemical composition and
a regular internal crystal structure
We can extract and process at a reasonable cost
 Gold, sulfur, diamond, silver; salt, mica, quartz

Rock
solid, cohesive, aggregate of one or more minerals
 Each rock type has a characteristic mixture of
minerals

 Limestone, quartzite

Metallic
 Iron (steel) , copper (wiring), gold (jewelry), and aluminum
(packaging and cans)

Nonmetallic
 Phosphate Salts (fertilizer), limestone (concrete), and sand
(glass, bricks, concrete)

Ore
 Rock containing one or more metallic mineral
 High and low-grade ore
 Copper and gold mined together

Types of Mining

Surface Mining
 Shallow deposits;
remove all soil, vegetation
and rock to expose mineral
 Used in 90% of US mineral extraction and 60% of coal
mining
 Ex. Open pit mining, strip mining, contour strip mining,
mountaintop removal

Subsurface Mining
 Underground deposits removed through tunnels and
shafts
 Deep coal and metal ore deposits


Machine digs
holes to
remove ore,
sand, gravel
and stone
Iron, copper,
gold,
limestone and
marble
Open-Pit Copper
Mine, UT
Diamond Mine, Russia
Diamond
Mine, Canada




Use on flat terrain
Strip away
overburden, dig out
mineral deposit
Trench filled back
with overburden and
new trench dug
parallel to previous
Leaves behind wavy
highly erodible hills




Used on hilly,
mountainous terrain
Cut terraces into
sides of hill
Overburden dumped
onto terrace below
Wall of dirt in front of
highly erodible rock
and soil

Use explosives, massive
shovels to remove top of
mountain to expose coal
seams

Waste dirt pushed down
into streams and valleys

Causes considerable
environment damage

More than 500
mountaintops have been
removed in West
Virginia and other
Appalachian States
Mountaintop
Removal, WV
Mountaintop Removal
Mountaintop
Removal
Mountaintop Removal, West
Virginia

Room-and-Pillar



Machinery gouges out
coal and load onto cart
Pillars of coal left to
support mine roof
Longwall



Steel props support
mining roof
Coal sheared off onto
mining belt
As supports moved,
roof behind allowed to
fall
 Result in collapse of
land above

Land surface disrupted and scarred
 Left to susceptible to weathering and erosion
 Vegetation re-grow slowly (no topsoil)
 Primary succession

Acidic mine drainage in streams and
groundwater (sulfuric acid and mercury)
 From processing of metals

Toxic chemicals emitted into atmosphere
 By blasting rock..more toxic emissions than any other
industry

Lower grade ores take more money

Human Health hazards
 Black lung

Harmful effects often exceed value of minerals
extracted
 Costly cleanup efforts for years after mining stops





Overburden—soil and rock removed from
mineral deposit
Spoils—piles of waste material
Tailings—piles of waste from extracting metal
from ore (smelting)
Gangue-waste material mixed with mineral in
ore
Subsidence- collapse of land above subsurface
mines

Most mineral
resources are
supplied by the US,
Canada, Russia,
South Africa and
Australia


90% of minerals
needed by US are
imported
Economic
depletion: not cost
effective to mine,
process, and
transport mineral
Metal
Global Reserves
Remaining (years)
US Reserves
Remaining (years)
Iron
120
40
Aluminum
330
2
Copper
65
40
Lead
20
40
Zinc
30
25
Gold
30
20
Nickel
75
0
Cobalt
50
0
Manganese
70
0
Chromium
75
0
Type of
Mining
Operation
Effects on
Air
Effects on
Water
Effects on Effects on
Soil
Biodiversity
Effects on
Humans
Surface
Mining
Significant
dust from
earth
moving
equipment
Contamination
of water
percolates
through tailings
Soil
removed
from site,
replaced if
reclaimed
Habitat
alteration and
destruction
Minimal in
mining
process, but air
quality and
water quality
adversely
affected
Subsurface
Mining
Minimal
dust, but
emissions
from fossil
fuels from
equipment
Acid mine
drainage plus
contamination
that percolates
through tailings
Subsidence
of land
above
Road
construction
fragments
habitat
Occupational
hazards in
mine; chronic
respiratory
diseases

1977 Surface Mining and
Reclamation Act (SMRCA)



Requires mining companies to
restore surface-mined land so that it
can be used for the same purpose as
before
Taxes on mining companies to
restore sites pre-1977
Funding weakened due to
lobbying, limits enforcement

Reclamation includes


maintaining water and air
quality, minimizing
flooding, erosion and
damage to wildlife and
aquatic habitats caused by
surface mining.
Why do you think
reclamation is such a
huge issue for mining
companies?

Clean Air and Water Acts 1970


Limits pollutants emitted into air and water and
requires companies to comply with requirements
Superfund Act (Comprehensive Environmental
Response, Compensation, and Liability Act—
CERCLA)

Site contaminated with hazardous pollutants must be
cleaned up following regulations
 Implemented by the EPA

Used for abandoned mines prior to 1970s

Finding substitutes for metals with silicon,
plastics, ceramics or nanotechnology



Decrease Use and Waste


Fiber optic cables (replace copper/aluminum wires)
Carbon and glass fiber composites (cars/airplanes)
Instead of increasing supplies
Recycle/Reuse

Less polluting, less energy use than mining for new
metals

Bristol Bay, Alaska


Environmental Concerns





Harm to fisheries (pristine salmon run)
Harm to ecosystem
Groundwater contamination
Earthquake hazard?
Economic Benefits



Site is located in a remote and uninhabited area
Jobs for 25+ years in area with low economic opportunities
Reduce reliance on foreign sources of minerals
Recent Developments


January 2014 EPA publishes assessment on impacts of proposed
mine
Allows Clean Water Act to be envoked

Large scale mining would pose risks to salmon and
native Alaskan people who depend on them

24-94 miles of stream potentially affected

1300-1500 acres of wetlands, ponds and lakes destroyed



Pollution and chemical leachate from tailings ponds will
affect streams
Failures in wastewater treatment, transportation,
pipelines or tailings dams would have catastrophic
effects on surrounding ecosystems and fisheries
(Peer reviewed and approved by 12 industry expert
scientists)



Coal is extracted by mining. Either subsurface or
surface mines (strip mining or mountaintop removal)
Once mined the coal is washed to remove excess
materials
The energy comes from burning of the mined coal
Coal is
burned
to
produce
heat
Coal is
ground
to
powder
Steam spins turbine
to produce
electricity
Heat from
coal warms
water to
produce
steam

The burning of coal releases pollutants into the
atmosphere.





Carbon dioxide (global warming)
Sulfur dioxide (acid rain)
Nitrogen oxides (smog)
Particulates (respiratory diseases and hazy skies)
Heavy metals (mecury, lead, arsenic)

Coal is a reliable source of energy!

One coal plant can power up to 800,000 homes!

US Coal Reserves are expected to last for 250 years!
 Coal is also safe to transport. Coal isn’t radioactive and it
won’t explode.
 Coal supplies half the energy in the US!

Coal is cheap!
 Most power plants use coal because its cost-effective and
produces cheap electricity for families
 It is the least expensive way to produce electricity
 The average cost is $.07 per kWh, this would be about $750 per
year for the average family (CHEAP!)
 Coal plants have taken steps to reduce environmental
impact…so the low cost is justified
 “clean coal”

Environmental Cost of Coal

Air pollution minimized by “scrubbers”
 Technology that is working on removing excess
greenhouse gases from emissions from burning coal.
 Yes it is the dirtiest of the fossil fuels…but we’re
working on it.

Mining impacts…
 Reclamation of abandoned mines
 Subsurface mine less impact on land surface
 Subject to Clean Air and Water Act regulations…as well
as CERCLA and SMRCA
DISADVANTAGES
ADVANTAGES

Cheap to produce

Abundant source

Easy to transport




Non-radioactive

Non-explosive

One plant produces a lot of
energy


Large environmental
impact
Mining coal destructive to
environment
Environmental impacts
from mining as well as
burning
Human health hazards
from emissions and
mining
Non-renewable resource

Major Spills in history include…
Gulf War (1991)—240-300 million gallons
 Deepwater Horizon Oil Spill (2010)—210 million
gallons
 Ixtoc 1 Spill (1979)—140 million gallons
 Exxon-Valdez (1989)—11 million gallons

Deepwater Horizon, April 2010

Mechanical Method
Used to contain and then mechanically remove the spilled
oil
 Usually primary line of defense

 Booms, barriers, skimmers, sorbent materials

Physical Removal

Manually cleaning up shorelines or habitats affected
 Shovels, bulldozing, pressure washing, wiping down plants
and animals

Chemical or Biological Methods

Agents used to disperse oil before it reaches shorelines
 Dispersing and gelling agents


Can you remove all of the oil after a spill?
Using the provided materials…see if you can
clean up an oil spill in water.