General Mining Law, 1872

Concrete – sand,

gravel, crushed

limestoneSalt

Copper

Minerals – Elements or compounds that occur naturally in

Earth’s crust

Rocks – mixtures of minerals

Ore – rock that contains enough of a mineral for it be be profitable to mine High-grade – contain large amounts of minerals

Low-grade – contain smaller amounts of minerals

Metals – minerals that are malleable, lustrous, & good conductors

Mineral Distribution and Formation

• Abundant (e.g., Al, Fe)

• Scarce (e.g., Cu, Mo)

• Must be accessible & profitable to mine

• Unequal global distribution

Concentration of Minerals are the result of:

Magmatic concentration Layering of magma by density is assoc. w/certain minerals

Hydrothermal processes Heated water dissolves minerals in rocks & carried in

solution

Sedimentation Weathered particles are transported & deposited in as

sediments

Evaporation Minerals are left behind; may be covered with sediments

Discovering Mineral Deposits

– aerial photos / satellite images geologic formations

– examine magnetic field

– Seismographs

– Drill for samples & analyze composition– http://www.grist.org/article/2010-01-19-stephen-colbert-on-mountaintop-removal-mining-video

– http://understory.ran.org/2010/01/19/mountaintop-removal-on-colbert-nation/

– http://www.ilovemountains.org/

– http://www.hippocampus.org/hippocampus.php/course_locator.php?course=Environmental%20Science&lesson=47&topic=1&width=800&height=550&topicTitle=Area%20Strip%20Mining&skinPath=http://www.hippocampus.org/hippocampus.skins/default

• Extracting Minerals• Subsurface Mining

• Shaft mine

• Direct vertical shaft to vein; ore is broken up & removed in buckets

• Slope mine

• Slanting passage for ore to be removed in cars

• Surface mining• Open-pit mining quarries are dug

• Strip mining

• trench is dug to extract minerals

• parallel new trench for overburden (spoil bank – loose rock)

• Overburden – soil & rock overlying useful deposits

• Processing Minerals• Smelting – ore is melted at high temperatures to

separate impurities from molten metal

• Blast furnace• Slag –molten mixture of impurities that is disposed

of

• Requires air pollution control devices

• http://www.hippocampus.org/hippocampus.php/course_locator.php?skinPath=http://www.hippocampus.org/hippocampus.skins/default&course=Environmental%20Science&lesson=48&topic=1&topicTitle=Ore%20Processing

Began in 1947; 2.5 million jobs globally as of 2012.

Rock is broken by injecting a pressurized mix of water, sand and chemicals Solutuion is injected into wellbore

Cracks are formed in rock formations.

Natural gas, petroleum and brine flow more freely

Costs Ground water contamination

Deption of fresh water.

Air pollution

Earthquakes

Noise pollution

Associated human and environmental health risks

Benefits More access to fossil fuels.

Domestic fuel source.

Economical (?)

Disturbs large areas of land Destroys vegetation, increases erosion, increases water & air

pollution

Uses huge quantities of water Pump out water to keep mine dry

Affects water quality Contain high levels of heavy metals (As & Pb)

Dissolved toxins, ACID MINE DRAINAGE, toxic pulses

Cost-benefit Analysis of Mine Development Benefits of mining ($) vs. benefits of preservation

Costs of damage

Benefits decline as resources decline

Environmental Impacts of Refining Minerals

Problems from Refining: Tailings – impurities left over after processing

Left in piles on ground or ponds

Contain toxins contaminate soil, water, air

Smelting plants Release many air pollutants (ex. S, Pb, As, Zn, Cd)

Pollution-control devices

Release dangerous liquid & solid wastes

Energy Intensive

The problem of tailings

Case-in-Point: Copper Basin, TN

Surface Mining Control and Reclamation Act

Reclamation Goals Prevent further degradation & erosion

Eliminating sources of toxic pollutants

Making land productive for non-mining purposes

Derelict lands Lands degraded from mining

Reclamation Process Filling in & grading derelict land

Planting vegetation Need plants that tolerate toxins & little/no topsoil.

Funding limitations

Surface Mining Control and Reclamation Act Requires reclamation of areas that were surface mined

for COAL

Creative Approaches to Cleaning Up Mining Areas Conversion to wetlands

Series of wetlands to trap sediments & remove toxins

Bacteria consume S, Zn & Cu percipitate

Manure increase pH

Phytoremediation Use of plants to absorb and store toxins (ex. Ni)

Plants are disposed of or burned http://www.hippocampus.org/hippocampus.php/course_locator.php?course=Environmental%20Science&lesson=47&

topic=2&width=800&height=550&topicTitle=Mining%20for%20Borax&skinPath=http://www.hippocampus.org/hippocampus.skins/default

• Developed• Use minerals to make products

• Rely on developing countries for resources

• Significant environmental damage due to mining

• Developing• Need more minerals as become industrialized

• Little env reg & clean up efforts great environmental damage

• Industrialization increases demand for minerals

U.S. and World Use North American consumption of selected metals

Distribution Versus Consumption Some minerals needed for many industrial processes,

but only found in abundance in few places Ex. chromium

Results in dependence Stockpiling common

Strategic minerals – critically important metals

Reserves / annual production

Mineral reserves Identified mineral deposits that are presently profitable

to mine

Mineral resources Undiscovered mineral deposits or low-grade deposits

that are unprofitable to mine

Total resources (world reserve base) Reserves + Resources

Changes with economy, politics, & technology

Many deposits have NOT been exploited because:• accessibility problems (ex. Indonesia & malaria)

• technology issues (ex. Poles)

• too deep

• Potential for unknown deposits in developing countries (ex. Andes, Amazon Basin)

Minerals in Antarctica Negotiations for which countries have access to

resources

Antarctic Treaty (1961) limits activities to peaceful uses

Madrid Protocol (Environmental Protection Protocol to the Antarctic Treaty), 1990 Prohibits exploration & development for 50 years

Valuable in regulating global environment

Mineral reserves in ocean may increase supplies Minerals from seawater

Mine sea floor

Affect seabed organisms & land where ore is processed

Manganese nodules on ocean floor with several minerals

Minerals from the Ocean

U.N. Convention on the Law of the Sea International treaty for international waters

Constitution of the ocean

Protects ocean’s mineral resources from being mined off seabed

Advanced Mining and Processing Technologies Ability to exploit low-grade ores

Better technology

Increased energy efficiency

Environmental costs may be too high

Biomining Microorganisms are used to extract minerals from low-grade

ores (ex. Bacterium + sulfuric acid Cu

Finding Mineral Substitutes Substituting inexpensive / abundant resources for

expensive / scarce resources

E.g., Glass, plastics, and aluminum have substituted for tin

Mineral Conservation Reuse same product used over and over

Recycling - product is processed into another product

Changing Our Mineral Requirements

fight the “throw away” mentality