Minerals

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Minerals the Environment
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Uses Of Minerals
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Minerals

• A solid homogenous (crystalline) element or
  compound naturally occurring

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Types of Minerals

• Metallic
• IRON, main component of steel
• COPPER, used in electrical wiring

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Types of Minerals

• Non-metallic
• PHOSPHOROUS, medicines
  and detergents
• SULFUR,
  used to make
  tires, paints,
  paper, etc.

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High-Grade Ores

• Rocks that contain large enough quantities of
  minerals to be profitably mined

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Mineral Distribution Abundance
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Forming Mineral Deposits

• Magma Chambers
• Hydrothermal Processes
• Sedimentary Weathering Processes
• Evaporative Processes
• Biological processes

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• Ores are deposited at convergent and divergent
  plate boundaries

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Divergent Boundaries

• Water is heated by molten rock in MAGMA CHAMBERS
• Heated water
  rises through
  rocks, leaches
  minerals
  deposited
  when water
  cools

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Convergent Boundaries

• Heat causes rocks to melt, minerals are separated
  by density.
  
• Different
  minerals
  form at diff.
  temp
• Ex.
  Mercury

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Igneous Processes

• As magma cools, the heavier minerals crystallize
  first, causing them to fall, and the lighter
  minerals rise above them.

Sills form when magma intrudes between the rock
layers, forming a horizontal or gently-dipping
sheet of igneous rock. Dykes form as magma
pushes up towards the surface through cracks in
the rock. Batholiths are large, deep-seated
intrusions (sometimes called Plutons) that form
as thick, viscous magma slowly makes its way
toward the surface, but seldom gets there!
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Igneous Processes

• When deposits of carbon are buried and
  subjected to pressure

DIAMONDS
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Kimberly Diamond Mine
Anyone know where this is?
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Hydrothermal Processes

• Chemical reaction occurs between metal salts
  carried in super-heated ground water and sulfur
  in earths crust forming metal sulfides

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Hydrothermal Processes

• Metal sulfides are not soluble in water and are
  deposited (Gold
  Silver
  deposits)

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Sedimentary Processes

• Water and wind can separate materials by their
  size, shape and density
• Phosphorus Sulfur
  deposits

Toroweap Formation in the Grand Canyon, Arizona
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Palos Verdes Cliffs
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Sedimentary Processes

• Water can also concentrate minerals found in
  stream bedrock
• Minerals collect in fissures and pits in slow
  parts of the river--Placer Deposits

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Weathering Processes

• Weathering of soils can cause deposits to form.

Erosion in the Himalayas. Where are the
Himalayas?
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Weathering Processes

• Aluminum deposits are formed by the weathering of
  aluminum rich bedrock

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Weathering Processes

• Metal sulfides in the soil react with oxygen and
  water. The fluid carries the minerals down
  toward the water table where they are
  concentrated
• ex. copper deposits

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Evaporation

• Water can also concentrate minerals when it
  dries/ evaporates
• ex. salt,
  K salts
  CaCO3

Calcium carbonate deposits in Mono Lake, Ca
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Biological Processes

• Ore deposits can be affected by biological
  processes. There are 31 biologically produced
  minerals
• Iron deposits come in two forms
• gray - red

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• The red form (oxidized) was deposited after
  plants had produced O2
• Iron deposits stopped
  forming when
  O2 reached
  current levels

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Biological Processes

• Organisms create calcium (shells)

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How Large Is Our Mineral Supply?

• Mineral deposits that have been identified and
  are currently profitable to extract
• Current copper reserves are estimated to last
  until 2029

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Mineral Reserves

• Deposits of low grade ores that are
  currently
  not
  profitable
  to mine

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World Reserves

• Combination of global mineral reserves and
  resources

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How Minerals Are Found, Extracted Processed

• Vibrator truck

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Discovering Mineral Deposits

• Survey of Earths Crust
• Satellite or Aerial photographs of geological
  features to give general idea
  where mineral
  deposits are located

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Discovering Mineral Deposits

• Drilling For Mineral Samples
• Analyze chemical composition of
  samples to
  identify
  presence of minerals

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Extracting Minerals
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Surface Mining

• Open-pit extraction quarry is dug and mineral is
  extracted
• Copper,
  Iron,
  Sand,
  Gravel,
  Limestone

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Surface Mining

• Bucketsscrape surface ore

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Strip Mining

• Trench is dug and minerals are extracted
• New trench is dug parallel to old trench

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Strip Mining

• Overburden from new trench is deposited in old
  producing a spoil bank

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Strip Mining

• Spoil is replaced in rows
• Spoil is susceptible to erosion (sediment
  pollution)

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Strip Mining

• Rainwater leaches chemicals into ground water
  (acid drainage)

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Placer Mining

• Huge amounts of water are used to separate gold
  ore (by density) that has been weathered and
  deposited in streams
• Mercury often used to
  bind gold

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Placer Mining
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Placer Mining

• Amazon gold miners are using mercury and have
  dumped 100 tons of mercury into the Amazon river

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Subsurface Mining
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Subsurface Mining

• Shaft mine dug vertically to mineral deposit
• Less environmental impact, but more
  dangerous
  to workers

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Gold Mining
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Heap-leach Extraction

• Separates gold from low grade ores
• Sprays rock with CYANIDE to dissolve gold
• Mining sites
  are often left
  unaltered
  high toxin
  levels

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Dredging

• Buckets and draglines scrape underwater deposits

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Dredging

• Mineral-containing ocean ooze is deposited in
  settling
  container for
  later
  extraction