Transcript Where Minerals Are Found

Mineral Resources
Where Minerals Are Found
 The Earth’s crust is made up of mostly
common rock forming minerals combined in
various types of rock.
 Less common and rare minerals are not evenly
spread throughout the crust.
The Uses of Minerals
 Minerals are the sources of metals,
gemstones, and other materials used
make many products.
Gemstones
 Gemstones are highly prized minerals
because they are rare, beautiful and
durable.
 Usually a gemstone is a hard, colorful
mineral that has a brilliant or glassy luster.
 Once a gemstone is cut and polished, it is
called a gem.
 Uses: jewelry, decoration, mechanical parts
Metals
 Some minerals are the sources of metals such
as aluminum, iron, copper and silver.
 Metals can be stretched into wire, flattened into
sheets, molded and hammered without
breaking.
 Think of all the things made of metal in your
life.
 All these began as minerals inside the Earth’s
crust.
Other Uses of Minerals
 People use materials from minerals in
food, medicines, fertilizers, and
building materials.
Ores
 Ore is a rock that contains a metal or
economically useful mineral that can be
mined at a profit (Give example).
 Not all metals occur in pure form.
 Iron which is used in everything from
frying pans to ships, is obtained from its
ore hematite. Magnetite is another mineral
that contains iron.
Prospecting
 Searching for an ore deposit.
 Some ores can be found near certain features
on the Earth’s surface.
 Test plants growing in an area for the
presence of certain chemicals.
 Geologist also set off explosions below
ground to create shock waves. The echoes of
these shock waves can be used to map the
size, shape and location of the ore deposit.
Mining
 Geologist help determine how the ore
should be mined from the ground.
 There are 3 types of mines:
 Strip Mines
 Open Pit Mines
 Shaft Mines
Strip Mine (Surface Mining)
Strip Mining: Soil or dirt is moved to expose ore.
Open-pit Mine (Surface Mining)
Open-pit Mining:
 Miners dig an open pit mine to remove ore deposits that
start at the surface and may extend down deep into the
Earth. Some open-pit mines are a kilometer wide and
nearly as deep.
Shaft Mining
Shaft Mining:
 Is used for deposits that occur in veins. Shaft
mines can consist of a network of shafts that
follow the ore.
Harmful Effects of Mining
 Strip mining and pit mining leave
scars on the land.
 Waste materials from mining can
pollute rivers (Examples: acid mine
runoff and sediment in streams).
 Often in strip mining the soil is
replaced and vegetation planted.
This called reclamation.
Smelting
 Ores must be processed before the
metals they contain can be useful.
 During smelting, a substance is
melted to separate it from any
unwanted materials that may remain.
 So smelting is necessary to remove
the metal from the ore.
Smelting continued…
 After smelting the iron has to be
further processed to remove
impurities from the iron.
 The result is steel, which is much
stronger.
Steel
 Steel is stronger than iron.
 Steel is an alloy: a solid mixture of two or more
metals.
 Steelmakers mix iron with other elements to create
alloys with special properties.
 Stronger steel: mix with manganese and carbon
 Rust resistant steel: mix with chromium and nickel