NATURAL FORMATION OF MINERAL NATURAL FORMATION OF MINERAL RESOURCESRESOURCES

Mineral Resource – is a concentration of naturally occurring material in or on the earth’s crust that is extracted & used at a reasonable cost to consumers.

Commercially valuable minerals and rocks are referred to as

industrial minerals. Rocks from which minerals are mined for

economic purposes are referred to as ores.

Minerals form over geologic time (millions of years) and are therefore

classified as non-renewable resources.Common minerals: calcite, quartz, mica

ORES (ROCKS)

1) Metallic – iron, copper, aluminum

2) Non-metallic – salt, sand

3) Energy – coal, oil, natural gas, uranium

Mineral Resources

Hydrothermal Vents Create ORES

USGS defines mineral resources into two categories 1) identified

& 2) undiscovered

Reserves are identified as resources from which a usable nonrenewable mineral can be

extracted for profit.

HOW DO WE FIND MINERAL DEPOS ITS?

1) Drilling deep wells and extracting core samples

2) Aerial photos & satellite images to reveal protruding rock formations (outcrops)

3) Radiation measure – detect uranium ore

ORES from WEATHERING

Sedimentary Sorting (gold)

Evaporite Deposits (salt)

Residual Deposits (bauxite)

Overburden – layers of soil & rock overlying a mineral deposit & is removed during surface mining.

SPOILSSPOILS

SubsidenceSubsidence – – slow or rapid sinking of part of the ground

that is not slope related..

SmeltingSmelting – process in which a desired metal is separated from the other elements in an ore.

Gangue Tailings

Waste material

Piles of Gangue

WORDS

TO

KNOW

STRIP MINING &

MOUNTAIN TOP REMOVAL

Exposure of toxic materials that will leach into ground and surface waters

Wildlife is exposed to toxins

Sediment runoff

Land Erosion (sediment runoff) Acid Mine Drainage

Habitat Loss

Land Collapse

Fires - fumes

Black Lung Disease

Acid Mine Drainage

Emits - SO2, NOx, CO2

Inorganic Mercury in Atmosphere - methylmecury in aquatics

Ground-level ozone – smog

Respiratory Disease

STRIP MINING

Subsurface MINING

COMBUSTION (electrical production)

• Open Pit Mines (coal, copper, Open Pit Mines (coal, copper, uranium, lead, gold, silver)uranium, lead, gold, silver)

• Exposes waste rock like pyrite Exposes waste rock like pyrite (FeS(FeS22) which can react with water ) which can react with water to form sulfuric acid.to form sulfuric acid.

• Releases ferric ions (Fe++)Releases ferric ions (Fe++)

• Leaches toxic heavy metals (AlLeaches toxic heavy metals (Al33++, ,

ZnZn22++))

• Red Staining - “Yellow Boy”Red Staining - “Yellow Boy”• Changes pH (can be higher or Changes pH (can be higher or

lower as it degrades natural lower as it degrades natural buffers)buffers)

• Increases conductivity and Increases conductivity and hardnesshardness

TYPICAL COAL BURNING POWER TYPICAL COAL BURNING POWER PLANTSPLANTS

High CO2 emissions (greenhouse gas)

Other emission: SO2 (acid rain); NOx; & Mercury

Human health impact – respiratory diseases

Large disruption to land

Acid Rain

Global Climate Change

ENVIRONMENTAL IMPACTSENVIRONMENTAL IMPACTS

Coal Supplies 50% of our electrical needs in the

United States

China largest global consumer of coal

reserves

High land impactHigh land impact

Increased Surface Increased Surface MiningMining

High COHigh CO22 emissions emissions

Higher cost Higher cost

Lower net yieldLower net yield

COAL GASIFICATION

Disadvantages

Advantages

Large supplyLarge supply

Vehicle FuelVehicle Fuel

Produces synthetic natural gas by coal

liquefaction

1)1)Removes most of the sulfur Removes most of the sulfur dioxidedioxide

2)2)Reduces emissions of NOxReduces emissions of NOx

3)3)Burns coal more efficiently Burns coal more efficiently and cheaply than and cheaply than conventional methodsconventional methods

Fluidized-Bed Coal Combustion

Cleaning - Chemical/Physical cleaning of coal prior to combustion

Scrubbing - injection of limestone into gases, reaction of carbonate with sulfur dioxide produces calcium sulfate (sludge)

.

CLEANING UP COAL!

Disturbed land; mining accidents;health hazards; mine wastedumping; oil spills and blowouts;noise; scarring; heat; subsidence

Solid waste; radioactive waste;air, water, & soil pollution;

noise; safety & healthhazards; heat

Noise; uglinessthermal water pollution;

pollution of air, water, and soil;solid and radioactive wastes;

safety and health hazards; heat

Use

transportation or transmissionto individual user,

eventual use, and discarding

Mining

Exploration; Extraction

Processing

Transportation; purification,

manufacturing

ENVIRONMENTAL IMPACT TO MINING PRACTICES & USE

Percolation toPercolation togroundwatergroundwater

Leaching of toxic metalsLeaching of toxic metalsand other compoundsand other compounds

from mine spoilfrom mine spoil

Acid drainage fromAcid drainage fromreaction of mineralreaction of mineralor ore with wateror ore with water Spoil banksSpoil banks

Runoff ofRunoff ofsedimentsediment

Surface MineSubsurfaceMine Opening

Leaching may carryLeaching may carryacids into soil andacids into soil and

groundgroundwater supplieswater supplies

Fig. 14.7, p. 326

ENVIRONMENTAL DAMAGE FROM MINING PRACTICES

The ruins of Centralia Pennsylvania no longer exists on some maps.

The story began sometime in 1961 along the outskirts of town when trash was burned in an old open pit mine. The fire in the open pit caught an exposed vein of coal on fire. The coal then began to burn underground. That was in 1961. Over 40 years and 40 million dollars later the fire still burns through old coal mines and veins following the coal under the town and the surrounding hillsides. The fire, smoke, fumes and toxic gases that came up though the back yards, basements and streets of Centralia practically ripped the town apart. Attempts to put the fires out were unsuccessful.

IMPACT:

1962: Pop. Of 1,100 – 2,000

545 Families & Businesses

1996: Pop. Of 46

20 Families - NO businesses