Mining Is used to extract valuable minerals from the earth Is dependent on crustal abundance Elements and minerals are not equally represented or distributed in the earth’s crust Countries and companies have mineral reserves Known quantity that can be realistically recovered by mining Relative crustal abundance of most common minerals

Mined Materials Sand and gravel Metals Phosphates Salts Sodium Sulfur Gemstones Fuel sources Coal Uranium

Ore Concentrated accumulations of minerals formed from geologic processes Can also contain waste material Must usually be processed to produce a pure form of the mineral Can occur in veins Localized high concentrations of a mineral Can occur in disseminated deposits Large, widely spread lower concentrations of a mineral

Types of Mining Surface Mining Subsurface Mining Ocean Mining* Placer Strip Mountaintop Removal Open Pit Subsurface Mining Shaft Solution* Ocean Mining*

Placer Mining Used when a resource accumulates in riverbed deposits Running water is used to sift lighter materials from the heavier resource materials Also called panning Disturbs large amounts of sediment

Strip Mining Used when a resource exists in layers near the Earth’s surface Rock and soil above the resource (overburden) is removed from a strip of land Mined material is removed and overburden is replaced

Mountaintop Mining Used when a resource occurs in seams near mountain ridges Entire mountaintops are bulldozed and blasted away to reveal the seam Overburden is replaced on the remaining mountain, and may fall or be dumped into adjacent valleys

Open Pit Mining Used when a resource is in an area unsuitable for tunneling, or when it is spread evenly and close to the surface Called a quarry

Subsurface Mining Used when a resource occurs deep underground Vertical shafts are dug into the ground Horizontal tunnels are dug to follow the seam or deposit being mined Material is removed and sent to the surface for processing

Solution Mining* Also called in-situ recovery Used when a resource is buried deep, and can be dissolved in liquid A hole is drilled to the resource, and water or acid is poured into the hole The resource is sucked out and processed to remove it from the fluid

Ocean Mining* Used when resource deposits exist on or under the sea floor, or in seawater Resources are “vacuumed” off the sea floor Research is underway to extract or evaporate resources from seawater

Problems with Mining All mining uses machinery and transportation that produces pollution All mining produces tailings, or mineral waste that can damage ecosystems The processing of ore can produce toxic byproducts Miners are exposed to some of the most hazardous working conditions on the planet

Acid Drainage* Most harmful form of environmental damage from mining Occurs when newly exposed rock that contain sulfur reacts with water and oxygen to form sulfuric acid

Acid Drainage* Sulfuric acid leaches metals from nearby rock and soil Forms toxic acidic liquid called leachate Cleanup involves neutralizing the acid and removing the metals

Brownfields* Abandoned sites polluted with hazardous waste Includes abandoned mines Dangerous and difficult to clean up for reuse Fall under EPA Superfund sites

Mine Restoration or Reclamation Goal is to restore a mined site to as close to its original condition as possible Involves: Filling in shafts and holes Removing mining structures and equipment Replacing overburden Replanting Ecosystems never fully recover from mining disruption

General Mining Act of 1872 Any individual or company can stake an exclusive claim on federal land open for mining Land can be patented, or bought outright, for about $5/acre No payments are made to the government, even if profits are realized Includes gemstones, metals, uranium and minerals

Mineral Leasing Act of 1920* Public lands must be leased for mining, and royalties on profits are to be paid Amounts depend on the resource being mined Covers fossil fuels, sodium, sulfur, and phosphates

Surface Mining Control and Reclamation Act of 1977 Regulates the surface effects of coal mining Mandates reclamation of mined areas

Minerals are Nonrenewable* Minerals regenerate slowly Many mineral deposits are being mined very quickly As they become scarce, they will become more expensive Environmentally friendly alternatives are being sought, including recycling

Sustainable Mineral Use* Recycling is the best way to sustainably use many minerals Uses less energy in production of goods Reduces the amount of mining Recycling e-waste is especially important Reducing the use of products that contain minerals also helps