Coal Found in 32 States Valued for energy and steel production
Identifying Mineral Deposits (costs $$$$$ to find them…)• Aerial photos• Radiation detectors• Magnetometer• Gravimeter• Deep well drilling• Seismic survey• Chemical analysis
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
Q. Just how much land are we talking about?A. About 270 million acres (or 1/4 of USA)
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
Pros and Cons Surface Subsurface-disturbs large area -disturbs much smaller surface area-produces large -spoil often left inamounts of spoil mine-relatively safe -dangerous-cheaper -expensive-more efficient -less efficient
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)
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)
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.
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
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
ReclamationRestoration of abandonedsurface coal mine in Pennsylvania-now wild game lands
Sources for You to Explore• http://www.xydexx.com/modernruins/centralia_galle• http://www.mountainjusticesummer.org/facts/steps.• http://www.mii.org/reclcoal.html• http://www.blm.gov/education/00_resources/articles• http://www.wma-minelife.com/coal/coalhome.html
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