Mining and Mineral Resources

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Mining and Mineral Resources
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What is a mineral?

• Naturally occurring
• Inorganic solid
• Characteristic chemical composition
• Orderly internal structure
• Set of physical properties

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Minerals Around You

• Almost every solid object you see is made of
  minerals. We depend on the use of mineral
  resources in many aspects of our daily lives.
• http//www.oum.ox.ac.uk/thezone/minerals/usage/gam
  es/memory.htm

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Ore Minerals

• Minerals that are valuable and economical to
  extract are known as ore minerals.
• Metallic Minerals conduct electricity and have
  shiny surfaces. Ex silver
• Nonmetallic Minerals tend to be good insulators
  and have dull surfaces. Ex quartz

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How Minerals Form

• Cooling Magma
• Hydrothermal Solutions
• Evaporites

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Mineral Uses
Chapter 16
Metals can be pressed into various shape,
conduct heat electricity, are prized for their
durability, and resist corrosion. Nonmetals
construction, concrete, glassmaking, computer
chips, jewelry/gemstones.
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Mining Exploration

• Exploring rocks for ore deposits
• -planes fly over an area creating images of an
  area and identify patterns in gravity, magnetism,
  or radioactivity.
• - samples are analyzed to determine how much
  metal is in the ore.
• If the metal content is high then a mining
  company can justify the cost of mining the area.

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Subsurface Mining

• Mining of ore deposits found at least 50m beneath
  Earths surface
• room-and-pillar mining rooms are created that
  are held up with pillars
• longwall mining uses a machine to shear the ore
  from a wall it falls onto a conveyor belt
• solution mining uses hot water to dissolve the
  ore compressed air to bring the ore to the
  surface

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Subsurface Mining
Room-and-Pillar Mining
Longwall Mining
Solution Mining ?
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Surface Mining

• Mining of ore deposits close to Earths surface.
• Open-pit mining used for mining coal metals
• Strip mining used for mining coal metals
• Quarrying used for mining granite, marble,
  clay, gypsum, talc

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Smelting

• Crushed ore is melted at high temperatures in
  furnaces to separate impurities from molten metal.

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Environmental Impacts of Mining

• Mining dust and machinery exhaust
• Mining equipment is loud
• Water that seeps into mines or through piles of
  excess rock picks up dissolved toxic substances
  that can wash into streams
• Coal contains lots of sulfur can form acid mine
  drainage

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Environmental Impacts of Mining

• Water Contamination
• Air Noise Pollution
• Displacement of Wildlife
• Erosion
• Soil Degradation
• Subsidence (sinking ground)
• Underground Mine Fires

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Underground Mine Fire in PA

• Centralia - Columbia County, Pennsylvania - The
  fire was started in a garbage dump over an open
  coal seam in May of 1962.  The fire was reported
  and seemed to be quenched at the time, but
  actually continued underground.  There are many
  additional versions of the original cause but the
  garbage pit and the date are probably right.  In
  1983, there was fire under about 350 surface
  acres.  By 1991, this area had been increased by
  about three-quarters.  Worst case scenario would
  be about 3700 acres and possibly a hundred
  years.  Finally 26 homes along Route 61 west of
  town were bought in April of 1991.  There were no
  further plans to fight the fire.   The population
  of Centralia as of 4/18/97 was 44 people and has
  dwindled since.   There are just a few scattered
  homes today remaining in the town along with the
  borough hall.  The Commonwealth of Pennsylvania
  owns the remaining homes. 

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Think About It

• Should mining continue? Why/why not?

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Mining Regulations Reclamation

• Mining companies are now required to consider the
  environment.
• Reclamation the process of returning land to
  its original condition after mining is completed.