Coal

Lower Kittanning Coal Seam,

Clarion University Campus

Varieties of Coal

• Anthracite: "hard coal," anthracite is formed from bituminous coal

when great pressures developed in folded rock strata during the

creation of mountain ranges. Anthracite has the highest energy

content of all coals and is used for space heating and generating

electricity.

• Bituminous: Bituminous coal the type most commonly used for

electric power generation in the U.S.

• Subbituminous: Subbituminous coal formed from the remains of

trees, ferns and other plants that existed and died during the time of

the dinosaurs. A dull black coal

• Lignite: Increased pressures and heat from overlying strata caused

buried peat to dry and harden into lignite. Lignite is a brownish-black

coal with generally high moisture and ash content and lower heating

value.

Where is coal mined?

(millions of tons, 2004)

1980:

Appalachia 438

Western 210

Coal 1994

Petroleum liquids 31.2

Petroleum Coke 14.2

Natural gas 876.9

Other gases 11.6

Nuclear 806

Other 10.4

Hydro 248.1

Biomass 55.9

Geothermal 14.9

Solar/PV 0.8

Wind 52

Units in table are billion

kilowatt hours.

Coal Facts

• Total demand for U.S. coal reached 1.05 billion tons in

2010.

• Nearly half of U.S. electricity is generated from coal.

• 9 out of every 10 tons of coal mined each year in the

U.S. is used for domestic electricity generation.

• Each person in the U.S. uses 3.4 tons of coal annually.

• There are approximately 600 coal generating facilities

(1,470 generating units) and 1,100 manufacturing

facilities using coal in the U.S., according to the U.S.

Energy Information Administration (EIA).

• EIA estimates that 73% of all coal-based generating

capacity was 30 years or older at the end of 2010.

More Coal Facts

• The U.S. has 261 billion tons of recoverable coal

reserves

• That is a 235-year supply at current rate of use

• Coal accounts for approximately 94 percent of the

nation's fossil energy reserve

• Coal is found in 38 states, under 458,600 square miles-

or about 13 percent of the nation's land area

A historic shift in electric generation

• 331 recently announced closings of old coal

fired power plants, mostly in 2015, and including

6 in Pennsylvania

• 258 new natural gas fired power plants currently

under construction

• Coal market share has fallen from 52% in 2000

to 39% in 2011

Who to Thank for Healthier and

Cleaner Air and Water?

• Interstate Toxics Rule (EPA)

– Interstate Toxins Rule (2012)

– Cross-state Air Pollution Rule (in progress)

• Marcellus Shale Industry

(various corporations that people love

to hate (while buying fuel from them))

Environmental Effects of Coal Use

• Water pollution

• Subsidence

• Loss of farmland and forests

• Air Pollution

• Waste Disposal

• Carbon flux

Methods of Mining Coal

• Deep Mines

• Longwall Mining

• Surface Mining

Formation of acid mine drainage

• Fracturing of overburden allows groundwater

to percolate through bedrock strata that were

formerly impermeable

• These strata often contain high

concentrations of pyrite (FeS2)

• Groundwater leaches pyrite from the bedrock,

carries it to the surface where it reacts with

oxygen

• 4FeS2+15O2+14H2O > 4Fe(OH3) + 8(SO4) 2 + 16H+

Aluminum floc

from AMD -

Scope of Problem: Pennsylvania

• Over 3,000 miles of stream have been

degraded in PA

• Daily influx of more than 1 billion gallons

of acid-mine drainage

• Economic cost associated with loss of

recreational fisheries alone exceeds 67

million / yr

• Cleanup costs for PA estimated to

exceed 15 billion

SMCRA: Surface Mine Control and

Reclamation Act of 1977

• Regulates current mining practices

– Permitting: A reclamation plan is developed for

each mine at the time of permitting

– Bonding: Coal mining companies must post a

bond to guarantee reclamation of land

– Regulatory: Created OSM, Office of Surface

Mining

– Performance standards: regulations pertaining

to operations and reclamation (restore natural

vegetation)

– Land restrictions, no mining in parks, etc.

SMCRA: Surface Mine Control

and Reclamation Act of 1977

• Created the abandoned mine lands (AML)

fund for reclamation work

– Taxes coal sales (35 cents/ ton) to fund

reclamation work (AML fund)

– Reauthorized in 2006 for 15 years

– Current expenditures about 500 million per year

– PA DEP commits to spending 30% of the 1.4 B it

will receive for water quality restoration

– PA has spent some 650 M on restoration, total

price is as high as 15 B

Methods of Remediating AMD

• Diversion of surface and ground water

• Chemical (Active) Treatment

• Passive Treatment

Water Diversion

• Groundwater diversions drains

• Revegetation,

• Restoration of soil profiles

• Surface contouring

• Surface caps

Chemical Treatment – addition of:

– Calcium cabonate (lime)

– Calcium hydroxide

– Sodium carbonate (quicklime)

– Sodium hydroxide (caustic soda)

to mine effluent

• Calcium compounds cost less, but are

less soluble and require mixing aid

Precipitates Formed

Through Chemical

Reaction

• The goal of

chemical

treatment systems

is to allow alkaline

material to

combine with the

mineral acidity to

precipitate the

metals out of the

AMD. This

neutralizes the

effluent so it can

be released

without causing

harm to the

environment.

Passive Treatment Systems

• Designed to:

– Generate Alkalinity

– Neutralize Acid

– Precipitate Metals

• Resulting in overall improvement in water

quality of discharge before entering

stream.

Components of passive

treatment • Anoxic Limestone Drains (ALD)

• Settling Ponds-aerobic wetlands

• Vertical Flow Wetlands / Successive

Alkalinity Producing Systems (SAPS)

• Function: add alkalinity, allow metals to

settle out of solution

REM Passive Treatment System near Corsica, PA

Strattanville-Reed Treatment

System

Recycling Iron Hydroxide

Issues

• Cost-effectiveness

• Longevity

• Compliance with Clean Water Regs

Mill Creek Watershed

Figure 6: Howe Bridge Discharge pH over Time

Year

92 93 94 95 96 97 98 99 00

Fie

ld p

H

4

5

6

7

8

Right SysDys

Left SysDys

Figure 5. Removal efficiency for acidity, iron, and manganese at

the Howe Bridge passive treatment system over time.

91 92 93 94 95 96 97 98 99 00

% R

emo

val

0

20

40

60

80

100Acidity

Fe

Mn

Additional Environmental Issues

Associated With Coal Mining

• Longwall mining and subsidence

• Loss of farmland for forests

• Mountain Top removal

• Disposal of Fly-ash

Longwall Mining

• 100 Operations in US, mostly in Appalachia

• 31% US Coal production

Types of damage

• Damage to homes

– Cracked masonary

– Damaged foundations

– Cracked plaster

• Lost water supply (wells)

• Damage to roads and railways

• Subsiding streams, loss of surface water • http://www.youtube.com/watch?v=wyyINgzZ8Gw

Mountaintop Removal Up to 1000’ of overburden moved into adjoining valley

Broad extent in Appalachia, with more than

400,000 acres affected

Valley Fill

Websites

http://earthobservatory.nasa.gov/Features/MountaintopRemoval/

Legal protection against

mountaintop removal

• SMCRA 1977 – prohibits surface mining

within 100 ft. of perennial or intermittent

streams

• 2006 – EPA proposed changing this rule

to “minimize the destruction of fish and

wildlife to the extent possible”

• 2010 – EPA changed rule to strictly

regulate water quality – 300 mg/l TDS

Legal protection against mountaintop removal

• Clean Water Act of 1977 - prohibits

industries from dumping waste into

waterways

• EPA 2006 rule change states that debris

from the mountaintop is not waste and

therefore, companies are free to dump

material into valleys

Waste Disposal

• Flyash – the ash captured from Chimney of coal fired

boilers

• Bottom ash – captured from bottom of furnace

• Silicon dioxide, aluminum oxide, iron oxide, calcium oxide

• arsenic, beryllium, boron, cadmium, chromium, chromium

VI, cobalt, lead, manganese, mercury, molybdenum,

selenium, strontium, thallium, and vanadium, along with

dioxins and PAH compounds

• Nearly half is recycled (portland cement, bricks, roadbeds)

• Often stored on site, eventually remainder is placed into

landfills

Flyash – wasteproduct of burning coal

Kingston TN 2008

• 5.4 million

cubic yards

• 1.4 Billion

cleanup

Minerals – Fast Facts

• Every American uses an average of nearly 40,000

pounds of newly mined materials each year

• Telephones are made from as many as 42 different

minerals, including aluminum, beryllium, coal, copper,

gold, iron, limestone, silica, silver, talc and wollastonite.

• A television requires 35 different minerals, and a

computer requires 30 minerals

• The construction industry accounts for approximately 51

percent of US copper demand.

• Silver's largest market use is for industrial applications,

particularly as an electrical connector. Jewelry is the

second largest use of silver.

• The Toyota Prius plug-in-hybrid requires about 50

pounds of rare earth metals for its motor and battery.

Gold Mines (Zortman-Landusky)

Cyanide Heap-Leach Gold Mining

• Began in 1970’s

• Allows the

processing of

low grade ore

• 35 tons of ore

per ounce of

gold

Iron Mines

Copper Mines • Kennecott

Mine,

Utah

Phosphate Mines Bartow, FL