Download Mineral Resources and Mining

Mineral - a solid, naturally occurring
element or inorganic compound with a
crystalline structure
 Rock - a solid combination of various
minerals

› Igneous - formed from molten rock which has
cooled and hardened
› Sedimentary - formed from sediment that has
accumulated in layers over a period of years
and is cemented together
› Metamorphic - when a previously existing
rock through pressure, temperature, or
chemical reaction is changed

Rock Cycle - the natural recycling of
rocks from one type into another
Igneous Rocks
Examples: granite, lava rock
Sedimentary Rocks
limestone
Sedimentary Rocks
Sandstone
Metamorphic Rocks
Marble
Metamorphic Rocks
Slate
The Rock Cycle
Non-renewable mineral resources - a
concentration of a naturally occurring mineral
that can be extracted for use at a reasonable
price
 Ore - rock which can be profitably mined to
extract minerals
 An ore is high grade or low grade depending
on the amounts of desired materials in the ore.
 Examples: Metallic Minerals - Aluminum,
manganese, iron, copper, gold, etc. Nonmetallic minerals: sand, gravel, limestone
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Aluminum
› Most commonly mined element in earth’s
crust.
› Bauxite is aluminum ore
› Used in packaging, transportation, and
building

Coal
› Not really a mineral: a rock
› Formed from carbonized plants in
swampy areas millions of years ago
› Low S coal from fresh water swamps and
high S coal from salt water swamps
› This is the most mined substance in the
U.S.
 Wyoming, Kentucky, West Virginia,
Pennsylvania
› Four types are mined:
 Anthracite, lignite, bituminous, and subbituminous

Iron
› Main metal in steel
› Used in tools and machinery
› Silvery, metallic element

Copper
› Used in electric cables, wires, plumbing,
switches, heating, construction,
machinery, alloys, pennies
› Alloys include brass and bronze

Manganese
› Used in various alloys such as steel
because of its corrosion resistant
properties
› Also found in batteries and lightbulbs
Through aerial photos
 Radiation detecting equipment
 Magnetic detecting equipment
 Measuring differences in gravity
 Seismic surveys
 Chemical analysis of water and plants
 Drilling and extracting samples


Surface mining – mining just below the
surface of earth for shallow deposits of
minerals.
› Overburden - soil and rock
› Spoils - waste material
Open Pit
Holes are dug and minerals removed along with sand, gravel, and
stone
Dredging
For underwater deposits
Area Strip Mining
Large amounts of overburden are removed; a shovel digs out
deposit; the trench is filled with overburden and a new, parallel
trench is cut; spoil banks are left behind.
Contour Strip Mining
Used on mountain areas; terraces are cut into the hill; a shovel digs
out deposits and overburden is dumped onto terrrace below;
highwall is left
Mountain Top Removal
Top of mountain is removed; waste pushed into valleys and streams
below; causes significant environmental damage
Strip Mining
Mountaintop Mining
Mountaintop Removal

Mining companies must return land to
the conditions before mining so the land
can be used for the same purposes as
before.
Do any forms of mining
occur underground?

Subsurface mining - for deep mineral
deposits which cannot be reached by
surface methods.
› A vertical shaft is dug and tunnels are blasted
out.
› Disturbs less land and produces less waste.
› Leaves more of the mineral in the ground and
is more hazardous to miners as well as more
expensive.
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Scars and disrupts the land’s surface
Causes subsidence (collapse of ground)
Wastes are often toxic and can moved by
wind or water to other areas
Acid mine drainage (wastes often contain
H2SO4 which can be removed by rainwater)
Toxic emissions released into air
Toxic mining wastes stored in pits can harm
wildlilfe

Ore
› Ore Mineral (portion that contains the desired
metal)
› Gangue (waste material in ore)
› Tailings (when gangue is removed, these are the
piles of waste remaining)

Smelting is the process which separates the
useful metal from other components of the
ore
› Releases air and water pollutants as well as solid
hazardous wastes
Many environmentalists believe that
more damage is done by extracting
the metals and creating products than
by using up supplies.
 The lower the grade of the ore, the
more resources that must be
expended to extract it.
 The price of the environmental
damage is not passed on to
consumers

Economic depletion occurs when it
costs more to utilize the mineral than it
is worth.
 When depletion occurs: recycle or
reuse materials, waste less, use less,
find substitutes, or do without
 Depletion time - how long before
roughly 80% of the mineral reserves
are used up at a given rate of use.

Prices of most minerals are often low due
to government subsidies to the mining
industry
 Companies are also able to get tax
breaks by deducting their costs
 Companies are also able to buy public
land at 1872 prices or use public lands
without paying royalties

Use of microorganisms to help extract
metal from ore
 Uses natural or genetically engineered
bacteria.
 Slow process
 More than 30% of copper produced
worldwide is collected by this process

South Africa - gold, uranium
 Russia – cobalt, iron
 Australia – nickel, bauxite, gold
 Ukraine - iron
 Guinea - bauxite
 Visual.ly/top-five-mining countries-world
 Top five mining countries in the world
and their GDP

Uses atoms and molecules to build
materials
 Creation of buckyballs which could store
information, deliver medicines, create
appliances that never need cleaning
 These extremely small particles are
potentially more reactive and toxic than
larger particles

Remove important chemicals from
seawater.
 Mineral deposits along continental
shelf
 Deposits found at hydrothermal vents
(black smokers)
 Manganese nodules on the ocean
floor
 Problems: costs and disagreements
over who owns what

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Ceramics
› Harder, stronger, lighter, and longer lasting,
can withstand high heat and corrosives

Plastics and composites
› Important to automobile and aerospace
industries
› Often much cheaper than traditional
materials
› Are light in weight and high in strength