Download Mining and Mineral Resources

Mining and
Mineral
Resources
Minerals: solids with characteristic chemical composition,
orderly internal structure, and a characteristic set of
physical properties
-Made up of compounds: atoms of two or more elements
chemically bonded together
Native element: elements considered to be minerals, eg:
gold, silver, copper
Ore Minerals
• Ore minerals are those that are valuable and
economical to extract, such as aluminum,
copper, iron, lead, or tin
• Gangue minerals are the other minerals that
are extracted from rock, and have no
commercial value
(M)Ore Minerals
• Metallic minerals conduct electricity, have
shiny surfaces, and are opaque
• Nonmetallic minerals are good insulators, may
have shiny or dull surfaces, and may allow
light to pass through them
How do they form?
• Hydrothermal solutions are hot, subsurface
waters that contain dissolved minerals from
the rocks they flow through. New minerals
crystallize out of the solutions and fill cracks in
the rocks, creating veins
• Evaporites form when water contained
dissolved salts evaporate, leaving the crystals
behind
Mineral Resource Uses
• Alloys are combinations of two or more
metals, like steel or bronze
• Other metals can be used without being
alloyed
• Nonmetals are among the most widely used
minerals in the world, such as gypsum, which
makes up Sheetrock, or sand and gravel
• Gemstones are nonmetallic minerals valued
for their beauty, rarity, or durability
How to Open a Mine
1. Find a mineral deposit.
Use a plane with special instruments on it to find
areas with high concentrations of minerals
2. Take samples of rocks from the area
3. Analyze the samples to see what the ore
grade, or metal content, is.
4. See if the ore deposit is big enough.
5. Open a mine!
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Types of Mining
Subsurface mining is used for ore deposits that
are 50 m or more below the Earth’s surface
• Room-and-pillar mining is a common method
of mining salt and coal
• Longwall mining is a more efficient method for
mining coal
• Solution mining is good for getting soluble
minerals like salt or sulfur
More Types of Mining
Surface mining is used when ore deposits are close
to the Earth’s surface
• Open-pit mining uses explosives to break up ore,
then it is loaded into trucks and taken to
processing plants to be removed from the rock
• Surface coal mining removes layers of rock called
overburden from the top of coal deposits.
Loaders remove the coal, then the overburden
and soil is replaced.
• Quarries are types of open-pit mining where
granite and marble are mined
Even More Types of Mining
• Solar evaporation uses the sun to produce salt
– Saltwater is placed in shallow ponds and allowed
to evaporate
– The salt remaining is harvested and processed for
use
• Minerals can be concentrated by wind and
water into deposits called placer deposits. These
can be mined by dredging.
He Who Smelt It…
• Smelting is the process of removing ore from
rock
Ore is crushed, then melted
Impurities bond with a material called
“flux”, and float to the top of the furnace,
forming a layer called “slag,” which is removed
The purified ore can now be formed into
products for use.