This document discusses coal mining practices and their environmental impacts. It begins by explaining that coal and other minerals are mined to produce energy and materials like steel. Several mining techniques are described, including surface mining methods like mountaintop removal and subsurface techniques like longwall mining. The document notes that while mining is important, it can cause issues like water and air pollution, subsidence, and damage to landscapes. Laws like the Surface Mining Control and Reclamation Act were passed to regulate impacts and require cleanup, but mining continues to significantly alter environments.
6. Coal Found in 32 States
Valued for energy and steel production
7. Identifying Mineral Deposits
(costs $$$$$ to find them…)
• Aerial photos
• Radiation detectors
• Magnetometer
• Gravimeter
• Deep well drilling
• Seismic survey
• Chemical analysis
8. Acquiring Land for Mining
• The General Mining Law of 1872 has
served to reduce “start up” costs and
maximize profits for “hardrock” mineral
companies in the U.S.A on public lands
– $2.50/acre fro an open-pit mine
– $5/acre for a “vein”
– No claim limit/claims don’t expire
– No royalties have to be paid out
9. Q. Just how much land are we talking about?
A. About 270 million acres (or 1/4 of USA)
10. Mining Techniques
• Surface Mining
– Extracts 90% of nonfuel mineral and rock
– Extracts 70% of coal
• Subsurface Mining
– Extracts coal and metal ores too deep to
reach by surface mining
13. Pros and Cons
Surface Subsurface
-disturbs large area -disturbs much
smaller surface area
-produces large -spoil often left in
amounts of spoil mine
-relatively safe -dangerous
-cheaper -expensive
-more efficient -less efficient
14. Surface Mining
• Strip out overburden (becomes spoils or
tailings)
• Five land methods possible
– Open-pit (quarry)
– Area strip mining (flat terrain)
– Contour strip mining (hilly terrain)
– Mountaintop removal*
– Placer mining (in riverbeds-usually gold or silver)
• Clean up (reclamation)
17. Mining Trucks
*To the left is a
photograph of a
Liebherr 360 ton
(327 metric ton) haul
truck. This unit is
powered by a 2750
horse power engine
and weighs 443,000
pounds (177 tons)
empty...
29. Subsurface Mining
• Deep vertical shafts used to reach coal
and ores too deep for surface mines
– Blasting
– Drilling and excavating machinery
• Once underground…
– Room-and-Pillar method (coal pillars)
– Longwall method (metal supports)
36. Load Out
Regardless of how it
is mined, coal is
crushed into a
standard size. Then
the coal loaded onto
trains for shipment
across the U.S.A. to
use for making steel
and generating
electricity.
37. Impacts of Mining Coal
• Scarring and disruption of area (ugly)
• Erosion increases if reclamation not
done properly
• Subsidence (sinkholes)
• Toxins released (dust, gas,drainage)--
possible soil, air, water pollution
• Acid mine drainage (esp. sulfur…)
• Slurry (coal waste) pond overflow
45. Acid Mine Drainage
*results when the mineral pyrite (FeS2) is exposed to air and water, resulting in the formation of sulfuric acid and iron hydroxide
47. Surface Mining Control & Reclamation
Act of 1977
• Came about due to concerns
about damage from strip
mining
• Regulates active mines and
drives reclamation
• Requires permits for mining
• Allows for inspection and
punishment
• Requires companies post a
bond before mining to
ensure cleanup is done
• Prohibits strip mines in
National Parks