MineralsMining

1
Chapter 15

• Minerals/Mining

2
General Mining Law of 1872

• Open up federal land for mining by anyone who
  stakes a claim
• Their way to encourage settlement of the west.
• No provisions for environmental protection of
  reclamation.

3
Minerals

• Mineral- element or compounds of elements that
  occur in the crust
• Minerals found in Rocks gt naturally formed
  aggregates or mixtures of minerals
• Rocks w/ large enough mineral concentration so
  that its economically profitable to extract the
  mineralores
• High grade low grade ores

4
Minerals

• Metals- iron, gold, copper, aluminum
• Nonmetallic- salt, sand, phosphate
• Aluminum iron- abundant in earths crust

5
Minerals formed by 4 methods

• Magmatic concentration- placed by magma
  separates into layers as it cools (e.g. iron,
  copper, nickel, chromium)
• Hydrothermal process- hot gas seeps into fissures
  dissolves certain minerals. These are
  redeposited either by cooling or by chemical
  reaction between metal salts sulfur in Earths
  crust (forms insoluble metal sulfides) e.g. gold,
  silver, copper, lead, zinc

6
Minerals formed by 4 methods

• 3. Sedimentation- weathered particles transported
  by water deposited as sediment (e.g. iron,
  manganese, sulfur, phosphorous, copper
• 4. Evaporation- e.g. salt, borax, potassium salt,
  gypsum

7
Minerals discovered by photos

• Aerial satellite photos instruments that look
  at the earths gravity magnetic fields. Also
  exploration by drilling.

8
Extracting minerals

• Surface mining
• Cheaper
• Safer
• More environmental
• damage
• Overburden- over lying layers of soil rock
• Spoils- waste rock
• Tailing Piles- pile of spoils or spoil bank

• Subsurface mining
• More expensive
• More dangerous to workers
• Less environmental damage

9
Open Pit Mining
10
Open Pit Equipment
11
Subsurface mining
12
Modern Day Subsurface Mining
13
Types of Surface mining

• Open pit/quarries
• Strip photos
• Dragline/Mountaintop removal
• Photos of Dragline Mining

14
Types of Subsurface mining

• Shaft (directly down)
• Coal Mine
• Slope
• Minerals removed from ores via processing
• For metals, use process called smelting (melting
  at high temp.) to produce molten metal
  impurities (slag)
• Use a blast furnace

15
Problems w/ mining

• Habitat destruction/soil erosion
• Water quality degradation- acid mine drainage
• Water supply (mining uses lots of water)
• Air pollution (mineral processing)
• Energy use

16
Problems w/ mining

• Derelict lands- lands degraded by mining
• Reclamation- fixing up/restoring derelict lands
• Surface Mining Control Reclamation Act of 1977-
  regulated reclamation for surface coal mines (not
  regulated for any other kind of mine!)
• Ways to clean up
• Use wetlands for water quality sedimentation
• Phytoremediation

17
Top 5 mineral Producers

• U.S.
• Canada
• Australia
• Russia Federation
• South Africa
• U.S. uses 20 of world metals

18
Definitions

• Mineral reserves- identified deposits that are
  currently profitable
• Mineral resources- deposits of low-grade ores
  that are currently not profitable to extract
• Total resources/World reserve baseresources
  reserves
• Life index of world reservesestimated time to
  use all known reserves
• Hard to predict because
• New discoveries of ore
• Plastics/synthetics replace metals
• consumption/economic changes

19
New Deposits

• Antarctica
• Antarctic Treaty of 1961- limits activities to
  peaceful scientific uses
• Madrid Protocol (Environment Protection Protocol
  to Antarctic Treaty) 1990
• Moratorium on mineral exploration development
  for minimum of 50yrs.
• Ocean
• Sea water (salts) or seafloor (manganese nodules)
• UN Convention on Law of the Sea (1994)
• One focus was on sea mining
• Not binding for territorial waters (12 mi. out)
• Only for international minings

20
How to Extend Reserves

• Conservation
• Reuse
• Recycle
• Find substitute
• Sustainable manufacturing- reducing waste in
  manufacturing
• Dematerialization- decreased in water weight of
  object w/ same or better lifetime