I. Mining Law of 1872 - Bennatti

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I. Mining Law of 1872 - Bennatti
Minerals and the
Environment
I.
Mining Law of 1872 –
encouraged mineral exploration and
mining.
• 1. First declare your belief that mineral deposits
are on the land. Then spend $500 in
improvements, pay $100 per year and the land
is yours
• 2. Domestic and foreign companies take out
$2-$3 billion/ year
• 3. Allows corporations and individuals to claim
ownership of U.S. public lands.
• 4. Leads to exploitation of land and mineral
resources.
http://seattlepi.nwsource.com/specials/mining/26875_mine11.shtml
•
•
"This archaic, 132-year-old law
permits mining companies to
gouge billions of dollars worth
of minerals from public lands,
without paying one red cent to
the real owners, the American
people.
And, these same companies
often leave the unsuspecting
taxpayers with the bill for the
billions of dollars required to
clean up the environmental
mess left behind."
-- Senator Dale Bumpers (DAR, retired)
Nature and Formation of Mineral
Resources
A. Ore – a concentration of naturally
occurring material in or on the earth’s
crust that can be extracted and
processed at an affordable cost. Mineral
and energy resources such as coal, oil,
gold, and copper are nonrenewable
resources.
Nature and Formation of Mineral
Resources
• 1. Metallic Mineral Resources – iron,
copper, aluminum
• 2. Nonmetallic Mineral Resources –
salt, gypsum, clay, sand, phosphates,
water and soil.
• 3. Energy resource: coal, oil, natural gas
and uranium
Ore Formation
1. Magmatic Concentration – magma cools and
crystallizes into various layers with denser Fe
and Mg containing magma sinking while lighter
Si containing magma forming upper layers
Ore Formation
• Hydrothermal Processes: most common way of mineral
formation
• A. Gaps in sea floor are formed by movement of tectonic plates
• B. Water enters gaps and comes in contact with magma
• C. Superheated water dissolves minerals from rock or magma
• D. Metal bearing solutions cool to form hydrothermal ore
deposits.
E. Black Smokers – upwelling magma solidifies. Miniature
volcanoes shoot hot, black, mineral rich water through vents of
solidified magma on the seafloor. Support chemosynthetic
organisms.
Ore Formation
• Manganese Nodules (pacific ocean)–
ore nodules crystallized from hot
solutions arising from volcanic activity.
Contain manganese, iron copper and
nickel.
Methods For Finding
Mineral Deposits
•
•
•
•
•
•
A. Photos and Satellite Images
B. Airplanes fly with radiation equipment
and magnetometers
C. Gravimeter (measures local difference in
gravitational forces)
D. Drilling
E. Electric Resistance (measure resistance
of the Earth to the passage of an electric
current)
F. Seismic Surveys
G. Chemical analysis of water and plants
Methods of Mining
• Surface mining
– open-pit mining
• copper, iron, sand, gravel, limestone
– dredging
• buckets and draglines scrape underwater deposits
Methods of Mining
• Surface mining
– open-pit mining
• copper, iron, sand, gravel, limestone
– dredging
• buckets and draglines scrape underwater deposits
https://www.youtube.com/watch?v=U0odIwj
RpAk
Strip mining
•
•
•
•
•
overburden (and all vegetation) is removed in strips
resource is removed
spoil is replaced in rows
spoil is susceptible to erosion (sediment pollution)
rainwater leaches chemicals into ground water (acid
drainage)
Mine tailings
• Mine tailings often include sulfide
compounds
• When these react with water, sulfuric acid
and toxic minerals can be washed into local
water
Subsurface mining




coal mining
disturbs less than 1/10 as much land
produces less waste
more dangerous to miners than surface mining
Heap-leach Extraction
• heap-leach
extraction separating gold
from low grade
ores - spraying rock
with a cyanide
solution which
dissolves the gold mining sites are
often left with high
toxin levels
Placer Mining
• placer mining – mining streambed deposits
for gold and other minerals
– Destroys riverbanks and vegetation along
banks
– Increases sediment in rivers
– Uses heavy metals like Mercury that
contaminate waters
• in the Amazon, gold miners are using
mercury and have dumped 100 tons of
mercury into the Amazon river
• Minerals are extracted from ores by heating
or chemical reactions
– Smelting - heating the ore - produces huge
amount of air pollution (SOx)
– In the US, the mining industry produces
more toxic emissions than any other
industry
Steps
Mining
exploration, extraction
Processing
transportation, purification,
manufacturing
Use
transportation or transmission
to individual user,
eventual use, and discarding
Environmental Effects
Disturbed land; mining accidents;
health hazards; mine waste dumping;
oil spills and blowouts; noise;
ugliness; heat
Solid wastes; radioactive material;
air, water, and soil pollution;
noise; safety and health
hazards; ugliness; heat
Noise; ugliness
thermal water pollution;
pollution of air, water, and soil;
solid and radioactive wastes;
safety and health hazards; heat
Fig. 14.6, p. 326
Subsurface
Mine Opening
Surface Mine
Runoff of
sediment
Acid drainage from
reaction of mineral
or ore with water
Spoil banks
Percolation to groundwater
Leaching of toxic metals
and other compounds
from mine spoil
Leaching
may carry
acids into
soil and
ground
water
supplies
Fig. 14.7, p. 326
Smelting
Separation
of ore from
gangue
Melting
metal
Metal ore
Conversion
to product
Recycling
Discarding
of product
Surface
mining
Scattered in environment
Fig. 14.8, p. 327
A. Life Cycle of Metal
Resources (fig. 14-8)
• Mining Ore
• A. Ore has two components: gangue(waste)
and desired metal
• B. Separation of ore and gangue which
leaves tailings
• C. Smelting (air and water pollution and
hazardous waste which
contaminates the soil around the smelter for
decades)
• D. Melting Metal
• E. Conversion to product and discarding
product
A
Mine, use, throw away;
no new discoveries;
rising prices
Recycle; increase reserves
by improved mining
technology, higher prices,
and new discoveries
Production
B
Recycle, reuse, reduce
consumption; increase
reserves by improved
mining technology,
higher prices, and
new discoveries
C
Present
Depletion
time A
Depletion
time B
Time
Depletion
time C
Fig. 14.9, p. 329

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