What is a mineral?
A naturally occurring solid with:
• Characteristic chemical composition
• orderly internal structure
• Characteristic set of physical properties.
How do I use minerals?
• Aluminum: transportation, packaging, construction, foil
• Copper: electric cables, plumbing, wiring in electronics, roofing
Bauxite – the ore from which Aluminum is extracted
Malachite – the ore from which copper is extracted
Bingham Canyon Copper MineSalt Lake City, Utah
Two and a half miles across and three quarters of a mile deep
How do I use minerals?
• Iron: most iron ore is combined with other minerals to form make steel (used in construction, vehicles, trains and train tracks)
• Lead: batteries for cars, electronics, TV glass, protective covering from x-rays.
Galena – a common ore of lead
Iron ore
Coltan and War• Coltan is the ore of
Tantalum • Used as capacitors in cell
phones, computers, playstation etc.
• 80% of ore is found in the Democratic Republic of Congo
• Cost $400/kg• Money from smuggled
ore fuelled a bloody civil war
• Mining has begun in biodiverse National Parks
http://www.youtube.com/watch?v=3OWj1ZGn4uM
Coal: The most abundant fossil fuel
• The U.S. has the world’s largest coal reserves (enough for the next 225 years)
How do companies know where to mine?
• Planes with instruments that i.d. changes in magnetism and radioactivity fly over the area
• Satellite images and aerial photos are used to create a geological map
• Rock samples are taken to determine the metal content of the ore
• Test holes are drilled• Cost-benefit analysis is conducted
Subsurface mining
• Underground coal mining is one of the world’s most dangerous occupations
• Mine shafts can collapse
• Miners are constantly exposed to coal dust
Subsurface Mining
• Room and Pillar Mining. A room is cut into the side of a mountain. Pillars of mineral are left to support the roof.
Surface Mining• Often used to mine large
quantities of coal and copper.
• Ore is mined downward, layer by layer
• The rock covering coal seams (overburden) is removed by machine
• Overburden is dumped in the valley
Mountain top removal in Appalachia
• More than 1/3 of U.S. coal comes from Appalachian
• The hardwood forests of Appalachia are some of the most productive and biodiverse temperate forests on Earth
• Since 1970, an estimated 1.5 million acres of hardwood forest have been lost.
• Over 470 mountaintops have been blasted
1,200 miles of Appalachian streams have been buried
Surface mining Control and Regulation Act (SMCRA 1977)
• SMCRA requires that "all surface coal mining operations back-fill, compact... and grade in order to restore the approximate original contour of the land.”
• UNLESS…the proposed post mining land use is deemed to constitute an equal or better economic use of the affected land as compared to pre mining use.
Not all coal is the same
• Coal varies in the amount of impurities (sulfur, mercury, arsenic and other trace metals) it contains
• Coal in the Eastern U.S. is higher in sulfur because it formed from marine sediments
• High sulfur coal contributes to industrial smog and acid rain
• Mercury emitted may bioaccumulate in organisms’ tissues, poisoning animals up the food chain