APES: Mining What is it? Why do we do it? What does it do to the Earth? How can we be more sustainable?

Mineral Resources Naturally occurring in earth’s crust Must be extracted, processed Examples Fossil fuels Metallic minerals (aluminum, iron, copper) Nonmetallic minerals (sand, gravel, limestone) Nonrenewable!

Ores A rock that contains a mineral Must contain profitable amount High grade = large amt of desired mineral Low grade = smaller amount of desired mineral

How do we use minerals? Aluminum Steel (alloy containing iron) Sand Packaging, cars, airplanes Steel (alloy containing iron) Buildings, vehicles) Sand Glass, bricks, concrete Limestone Cement, concrete, road rock

The life cycle of a metal resource Key terms: gangue: worthless material that surrounds ore Smelting: using heat and chemicals to turn ore into useable mineral

Mining: the good and the bad Advantages Disadvantages Income! Revenues for cities, states and countries employment Uses lots of energy Disturbs land Erodes soil Produces a lot of waste Pollutes air, water, soil

Mining Methods Surface mining Subsurface mining Removal of shallow deposits Overburden removed Rock/soil on top of deposit Discarded as “spoils” Used in 90% of nonfuel mineral/rock resources Used in 60% of coal used in U.S. Removal of deep deposits Often used for coal and metal ores Deep vertical shaft is dug Tunnels must be blasted Machinery used to reach deposits

Specific kinds of surface mining Open-pit mining Strip mining Holes are dug Ores are removed Iron, copper, gold, sand, gravel, stone Used for horizontal beds of minerals Area strip mining: flat land Contour strip mining: hills

Surface mining method: mountain-top removal Mountain top removed Exposes deposits Prominent in Appalachian mountains

Harmful environmental effects of mining Scarring/disruption of land Spoils left behind, vegetation can’t grow well Streams polluted with waste material Flooding Creates toxic waste during processing Often stored in valleys Can collapse and get into ecosystem Forests removed Subsidence, cave-ins, explosions, disease (subsurface)

Harmful effects, cont’d Processing involves many chemicals (sulfuric acid, mercury, arsenic, cyanide) Air pollution from processing Highest industrial air polluter of toxic emissions! Tailings left behind, pollute

How do we fix this? Clean up and restore mining sites 500,000 surface sites in U.S. $70 billion to clean up Subsurface disturbs <1/10 the land that surface mining disturbs Produces less waste But…causes cave ins, explosions, fires, diseases

How long will our supplies of minerals last? Abundant deposits of iron, aluminum Scarce deposits of chromium, manganese, cobalt, platinum Deposits are not distributed equally around the world! U.S., Canada, Russia, S. Africa, Australia supply most of modern world with nonrenewable minerals Sharp rise in per capita use of minerals since 1950’s U.S. depends on imports of 50% + of 24 most important nonrenewable mineral resources Strategic resources: manganese, cobalt, chromium, platinum Essential for economy and military Most of these are imported!

Future supply depends on… Actual/potential supply of mineral Rate at which we use them Never completely run out, they just become “economically depleted”! Market prices Increased prices mean increased supplies (encourages exploration) Encourages more efficient use

Subsidies for mining Keep minerals prices low! Given to help promote economic growth/national security Your tax $ pay for these! 1982-2007 $6 billion +

1872 U.S. General Mining Law Designed to encourage mineral exploration on U.S. public lands and populate the West Individuals could “claim” land Must spend $500 to improve land Could pay $6-12 for land owned by all U.S. citizens Could build, sell, lease, use it for whatever Frozen in 1995 Some land still being transferred at 1872 prices! 1992 modification: must post bonds to cover clean up cost in case of bankruptcy Mining companies trying to weaken

SURFACE MINING CONTROL AND RECLAMATION ACT OF 1977  establishes a program for regulating surface coal mining and reclamation activities establishes mandatory uniform standards for these activities on state and federal lands, including a requirement that adverse impacts on fish, wildlife and related environmental values be minimized. creates an Abandoned Mine Reclamation Fund for use in reclaiming and restoring land and water resources adversely affected by coal mining practices.

Making mining more sustainable Replace with substitutes! “materials revolution” Silicon, ceramics, plastics replace metals Recycle and reuse metals Recycling aluminum can produces 95% less air pollution, 97% less water pollution, and uses 95% less energy than mining and processing aluminum ore

Making mining more sustainable Decrease use and waste of nonrenewable minerals