APES Mining What is it Why do we

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 � 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: 1. gangue: worthless material that surrounds ore 2. Smelting: using heat and chemicals to turn ore into useable mineral

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

Mining Methods Surface mining Subsurface mining �Removal of shallow �Removal of deep 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. 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 � Used for horizontal beds of �Ores are removed �Iron, copper, gold, sand, gravel, stone 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 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