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MINING. What Are Minerals?. A MINERAL is any naturally occurring, pure, non-living substance found in the rocks of the earth. Minerals can be divided into 3 categories Metallic Minerals Fossil Fuels Industrial Minerals. Metallic Minerals.
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What Are Minerals? • A MINERAL is any naturally occurring, pure, non-living substance found in the rocks of the earth. • Minerals can be divided into 3 categories • Metallic Minerals • Fossil Fuels • Industrial Minerals
Metallic Minerals • When metallic minerals are purified, they are the metals we use everyday. • Metallic minerals need to have some quality that we value to be considered valuable • Beauty (gold, silver) • Strength (iron) • Conducts electricity (copper) • Light and strong (aluminum, tin)
Fossil Fuels • Fossil fuel is the remnant of biotic material. • Coal was one of the first important fossil fuels • Coal, put under sufficient pressure for sufficient time, morphs into diamonds • Oil and natural gas are now the most popular forms of fossil fuels • Fossil fuel mining requires oil rigs, or other pumping mechanisms
Industrial Minerals • Industrial minerals are any mined minerals that are not metallic or fossil in nature • As the name implies, these are minerals primarily used in industry • Asbestos – protects from fire and heat • Potash – used to make fertilizer • Gypsum – makes drywall • Diamond – not just for jewellery; used as a cutting tool as well
Where Do We Find the Minerals? • Saskatchewan – world’s largest potash deposits • Quebec – major asbestos mines • Northwest Territories – diamonds
Importance of Mining • Canada is the third largest producer of minerals in the world • United States, Russia are larger • Largest EXPORTER or minerals • 80% of what we mine we export • $83 Billion dollars (2001) • Helped to develop road and rail systems • Needed to reach the far-flung deposits
How Do We Find Minerals? • Mineral deposits that are economical to develop are called MINERAL RESERVES • Metallic minerals are found in IGNEOUS and METAMORPHIC rocks (like on the Canadian Shield) • In the earth the minerals we want are mixed with other compounds (like rock, other minerals, etc). This mixture is called ORE.
A MAGNETOMETER generates a magnetic field which ore such as nickel, iron and copper respond to. • Satellite images and aerial photos give geologists geomorphologic clues. • Satellites can also be used to create thermal images, infra-red images, and other imaging which various minerals respond to. • Once a likely spot has been located, geologists will drill CORE SAMPLES • Using this method, they can locate the edges of the reserve
Mining Methods • Most mines are located in remote areas • If the ORE BODY is relatively near the surface, the mining company may choose to STRIP or PIT mine. • If the ore body is deep inside the earth, UNDERGROUND or SHAFT mining will be used • This method is more difficult, more dangerous and more expensive
Strip Mining • Used to mine minerals like coal and oil sands that develop in horizontal layers. • OVERBURDEN is removed • Ore is shovelled onto trucks or conveyor belts • The ore is removed for processing
Pit Mining • Similar to Strip mining, but used when the ore body extends downward rather than outward • Overburden is removed • Explosives blast apart the ore • The ore is put onto trucks and trucked out of the mine for processing
Underground/ Shaft Mining • Used to get at ore deep in the earth • A SHAFT is sunk into the earth at the edge of the ore body • Horizontal tunnels, called ADITS or DRIFTS are dug into the body • This is where the ore is removed from • The chamber at the end of the adit is the STOPE
The rock in the stope is blasted apart with explosives • The rubble is called MUCK • The muck is transported to an ORE PASS where it falls into a CRUSHER • As the name implies, the crusher crushes the ore into smaller pieces • It is funnelled down another ore pass into a SKIP where it is hoisted to the surface and sent for processing
Processing Minerals • Metallic mineral ore need to be purified before it is useful • MILLING separates the mineral from the majority of the waste • Usually a physical proceedure • SMELTING involves heating the remainder until the compounds separate. The metal will generally sink to the bottom of the furnace, where a tap will drain it off
Leftovers • The waste material produced by mills and smelters is called TAILINGS • Tailings are often toxic, ugly or otherwise difficult to deal with • A HUGE issue facing the mining industry today is how to safely get rid of the tailings • What are some of the other issues the mining industry must face?