Mining Practices & Impacts

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A look at surface and subsurface mining methods as well as their environmental impacts.

A look at surface and subsurface mining methods as well as their environmental impacts.

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  • 1. Mining Practices and Impacts Derrick Willard
  • 2. Why do we mine minerals?
  • 3. Coal Types & Uses
  • 4. Coal Found in 32 States Valued for energy and steel production
  • 5. Identifying Mineral Deposits (costs $$$$$ to find them…)
    • Aerial photos
    • Radiation detectors
    • Magnetometer
    • Gravimeter
    • Deep well drilling
    • Seismic survey
    • Chemical analysis
  • 6. 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
  • 7. Q. Just how much land are we talking about? A. About 270 million acres (or 1/4 of USA)
  • 8. 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
  • 9. Methods of Coal Mining
  • 10. US Mining Trends
  • 11. Pros and Cons Surface Subsurface -disturbs large area -produces large amounts of spoil -relatively safe -cheaper -more efficient -disturbs much smaller surface area -spoil often left in mine -dangerous -expensive -less efficient
  • 12. Surface Mining
    • Strip out overburden (becomes spoils)
    • Four land methods possible
      • Open-pit (quarry)
      • Area strip mining (flat terrain)
      • Contour strip mining (hilly terrain)
      • Mountaintop removal
    • Clean up (reclamation)
  • 13. Overburden Removal
  • 14. A Dragline Shovel
  • 15. 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 ...
  • 16. Open Pit Copper Mine near Silver City, NM
  • 17. Area Strip Mining
  • 18. Area Strip Mine (Coal)
  • 19. Contour (Bench) Strip Mining
  • 20. Contour Mining in KY “ Highwalls”
  • 21. The “New” Technique
  • 22. Mountaintop Removal Mining
  • 23. Mountaintop Removal and Valley Fill (WV) The top of a mountain has been pushed into a valley
  • 24. Mountaintop Removal Coal Mine in Southern WV
  • 25. Mountaintop(s) Removal near Kayford Mountain, WV
  • 26. Mountaintop Removal-Up Close (spoil pile)
  • 27. 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)
  • 28. Subsurface Mine Types
  • 29. Longwall Mining
  • 30. Longwall Mining Machine
  • 31. Room and Pillar Mining
  • 32. Room and Pillar Mining
  • 33. Room and Pillar Mining Machine
  • 34. 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.
  • 35. 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
  • 36. Scarring in Tennessee
  • 37. Subsidence over a Coal Shaft in Colorado
  • 38. Coal Mine Subsidence in Colorado
  • 39. Centralia, Pennsylvania (where a coal vein fire started in 1961)
  • 40. Centralia, Pennsylvania (Helltown, USA)
  • 41. Centralia, Pennsylvania (almost abandoned)
  • 42. Centralia, Pennsylvania (Highway 61)
  • 43. Acid Mine Drainage *results when the mineral pyrite (FeS 2 ) is exposed to air and water, resulting in the formation of sulfuric acid and iron hydroxide
  • 44. Slurry Pond Spill in Kentucky October 2000
  • 45. 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
  • 46. Reclamation Restoration of abandoned surface coal mine in Pennsylvania- now wild game lands
  • 47. Sources for You to Explore
    • http://www.xydexx.com/modernruins/centralia_gallery.htm
    • http://www.mountainjusticesummer.org/facts/steps.php
    • http://www.mii.org/reclcoal.html
    • http://www.blm.gov/education/00_resources/articles/mining/reclaimingminedlandprovidesforthefuture.html
    • http://www.wma-minelife.com/coal/coalhome.html