E-Weekly-5/17
Green Earth Movement
An E-Newsletter for the cause of Environment, Peace, Harmony and Justice
Remember - “you and I can decide the future”
COAL
MINING
AND
ECOLOGY
Coal is a black or brownish-black shiny rock and
most of it is buried deep underground so we
must "mine" or dig it out. Finding coal used to
be done by people called prospectors. Today it is
done by geologists.
Coal forms from organic
material that decays and
experiences pressure and
heat for millions of years.
Since they take so long to
form, fossil fuels like coal
and oil are nonrenewable. The process to generate
energy from coal involves mining the coal, then
transporting, cleaning and burning it. Water heated
by burning coal converts into steam and generates
electricity. Each stage of this process generates
pollution. However, plans to reduce its pollution
output may improve coal's standing as an energy
source.
Advantages of Coal Energy
• It's easily transported to many areas in the world
• Inexpensive to buy on open market due to large reserves
and easy access ability
• Coal is the least expensive fossil
fuel because it is rather simple
to mine
• Coal powered generation scales
well, which makes it possible to
build a variety of sizes of generation
plants
• Since coal is a fossil fuel, it can be used to build power
stations almost anywhere as long as there are large amounts
of it
COAL MINING METHODS
Coal is mined by two methods:
surface or 'opencast' mining
underground or 'deep' mining
The choice of mining method is largely determined by
the geology of the coal deposit. Underground mining
currently accounts for a
bigger share of world coal
production than opencast;
although in several
important coal producing
countries surface mining
is more common. For example, surface mining
accounts for around 80% of production in Australia;
while in the USA it is used for about 67% of
production.
1] STRIP MINING
Strip mining (also known as open cast, mountaintop
or surface mining) involves scraping away earth and
rocks to get to coal buried near the surface. In many
cases, mountains are literally blasted apart to reach
thin coal seams within, leaving permanent scars on
the landscape as a result.
Strip mining accounts for about 40 percent of the
world’s coal mines but in some countries, such as
Australia, open cast mines make up 80 percent of
mines. Even though it's highly destructive, industry
often prefers strip mining as it requires less labour
and yields more coal than underground mining.
Impacts of strip mining:
→ Strip mining destroys
landscapes, forests and
wildlife habitats at the site
of the mine when trees,
plants, and topsoil are
cleared from the mining
area. This in turn leads to
soil erosion and destruction of agricultural land.
→ When rain washes the loosened top soil into streams,
sediments pollute waterways. This can hurt fish and smother
plant life downstream, and cause disfiguration of river
channels and streams, which leads to flooding.
→ There is an increased risk of chemical
contamination of ground water when minerals in
upturned earth seep
into the water table,
and watersheds are
destroyed when
disfigured land loses
the water it once held.
→ Strip mining causes dust and noise pollution when
top soil is disrupted with heavy machinery and coal
dust is created in mines.
The result of all this is barren land that stays contaminated
long after a coal mine shuts down.
Although many countries require reclamation plans for coal
mining sites, undoing all the environmental damages to water
supplies, destroyed habitats, and poor air quality is a long and
problematic task. This land disturbance is on a vast scale. In
the US, between 1930 and 2000, coal mining altered about
2.4 million hectares [5.9 million acres] of natural landscape,
most of it originally forest.
Attempts to re-seed
land destroyed by
coal mining is
difficult because the
mining process has
so thoroughly
damaged the soil. For example, in Montana,
replanting projects had a success rate of only
20-30 percent, while in some places in Colorado
only 10 percent of oak aspen seedlings that
were planted survived.
In China, coal mining has degraded the quality
of land of an estimated
3.2 million hectares,
according to a 2004
estimate. The overall
restoration rate
(the ratio of reclaimed
land area to the total
degraded land area) of mine wasteland was
only about 10–12 percent.
2] UNDERGROUND MINING
The majority of the world’s coal is obtained through
underground mines. While underground mining, which
allows coal companies to extract deeper deposits of coal, is
viewed as less destructive than strip mining, it still causes
widespread damage to the environment. In room-and-pillar
mines, columns of coal are left to support the ground above
during the initial mining process,
then they are often taken out and
the mine is left to collapse, which
is known as subsidence. In longwall
mines, mechanical shearers strip
the coal from the mines. Support
structures that enable the shearers’ access to the mine are
eventually removed, and the mine collapses.
Impacts of underground mining
Underground mining causes huge amounts of waste earth and rock to
be brought to the surface – waste that
often becomes toxic when it comes into
contact with air and water.
It causes subsidence as mines collapse
and the land above it starts to sink. This
causes serious damage to buildings.
It lowers the water table, changing the
flow of groundwater and streams. In Germany for example, over 500
million cubic metres of water are pumped out of the ground every year.
Only a small percentage of this is used by industry or local towns – the
rest is wasted. What’s worse is that removing so much water creates a
kind of funnel that drains water from an area much larger than the
immediate coal-mining environment. Coal mining produces also
greenhouse gas emissions.
Coal mine methane
Coal mine methane, less prevalent in the atmosphere than CO2, but 20
times as powerful as a greenhouse gas, forms during the geological
formation of coal, and is released during the coal mining process. Most
coal mine methane come from underground mines. While this methane
is often captured and used as town fuel, industrial fuel, chemical
feedstock and vehicle fuel, it’s very rare that it all gets used.
Methane is also used in power generation projects. However, despite
big investment in research, only
about 50 such projects exist worldwide.
In China, which mines more than 95
percent of its coal underground, about
300 of the state-owned mines are
classified as methane-outburst prone.
Worldwide emissions are expected
to increase by 20 percent in the next 12 years.
Coal fires
Coal fires - burning or smouldering coal seams, coal storage
piles or coal waste piles –
are a significant environmental
problem in many countries,
including China, Russia, the US,
Indonesia, Australia and South
Africa. Underground coal fires
can burn for centuries, filling
the atmosphere with smoke
laden with carbon-monoxide
(CO), carbon-dioxide (CO2), methane (CH4), sulphur dioxide
(SO2), nitrous oxides (NOx) and other greenhouse or toxic
gases - as well as fly ash from vents and fissures.
Other effects of coal fires include rising surface temperatures
and contamination of groundwater, soil and air.
Although coal fires can be caused by
thunderstorm lightning, and forest or
peat fires, they are often caused by
mining accidents and improper mining
techniques. In Indonesia, the same fires
that are used to clear large tracts of rainforest have ignited
over 300 coal fires since the 1980s.
China has the world’s most coal fires, while India accounts for
the world’s greatest concentration. In China, between 15 and
20 million tons of coal burn uncontrollably each year,
accounting for between 0.1 percent and 1 percent of the
world’s human-induced CO2 emissions, (Although coal fires
are significant, emissions from power plants are far higher.)
Acid mine drainage
Acid mine drainage is created when water mixes with coal
and other rocks unearthed during mining, taking on toxic
levels of minerals and heavy metals. This toxic water leaks out
of abandoned mines to contaminate groundwater, streams,
soil, plants, animals and humans. As a result an orange colour
can blanket the river, estuary
or sea bed killing plants and
making surface water
unusable as drinking water.
Sources of acid mine
drainage can remain
active for decades or centuries after a mine closes.
Common health threats posed by coal mining:
Pneumoconiosis, aka black lung disease or CWP,
is caused when miners breathe in coal dust and
carbon, which harden the lungs. Estimates show
that 1,200 people in the US still die from black
Lung disease annually. The situation in developing
countries is even worse.
Cardiopulmonary disease, chronic obstructive pulmonary disease,
hypertension, lung disease, and kidney disease have been found in
higher-than-normal rates among residents who live near coal mines,
according to a 2001 US study.
Toxic levels of arsenic, fluorine, mercury, and selenium are emitted by
coal fires, entering the air and the food chain of those living nearby.
Mine collapses and accidents kill thousands of workers around the
world every year. Chinese coal mine accidents killed 4,700 people in
2006.
COAL MINING IN INDIA
Coal reserves in India is one of the largest in the world. As on
April 1, 2012, India had 293.5 billion metric tons (323.5 billion
short tons) of the resource.
The production of coal was 532.69
million metric tons (587.19 million short
tons) in 2010-11. The production of
lignite was 37.73 million metric tons
(41.59 million short tons) in 2010-11.
As on 2011, India ranked 3rd in world
coal production. The energy derived from coal in India is
about twice that of energy derived from oil, whereas
worldwide, energy derived from coal is about 30% less than
energy derived from oil.
Right from its genesis, the commercial coal mining in modern times in India
has been dictated by the needs of the domestic consumption. India’s has
abundant domestic reserves of coal. Most of these are in the states
of Jharkhand, Orissa, WestBengal, Bihar,Chhattisgarh, Telangana and Madh
ya Pradesh. On account of the growing needs of the steel industry, a thrust
had to be given on systematic exploitation of coking coal reserves in Jharia
Coalfield. Adequate capital investment to meet the burgeoning energy
needs of the country was not forthcoming from the private coal mine
owners.
Unscientific mining practices adopted by some of
them and poor working conditions of labor in some of
the private coal mines became matters of concern for
the Government. On account
of these reasons, the Central
Government took a decision
to nationalize the private
Coal mines.
The nationalisation was done in two phases, the first
with the coking coal mines in 1971-72 and then with
the non-coking coal mines in 1973.
India is poised to contend with China as the globe's top
consumer of coal, with
455 power plants
preparing to come
online, a prominent
environmental research
group has concluded.
The coal plants in India's
pipeline -- almost 100
more than China is preparing to build -- would deliver
519,396 megawatts of installed generating capacity. That
is only slightly less than pending new capacity in China,
which remains the undisputed king of coal consumption.
Environmentalists called the numbers alarming, but coal
industry leaders said the plants are not enough to meet the
world's energy needs.
"We need more. We need more of everything -- wind power,
renewables, hydro. But we will certainly need more coal," said
Milton Catelin, CEO of the World Coal Association. He argued
that with 1.5 billion people still living without access to
electricity, coal needs to grow.
"The truth is, if you go to India and talk to people
where these are being built, the power is being
exported to the urban centers and the pollution is
staying in the local communities. There is no
correlation between supply and the poor getting
power, and this is the story that nobody talks about.“
This educational PowerPoint Presentation (editable)
is prepared by GEM Team
(courtesy: internet).
For other similar GEM PowerPoint Presentations on
various environmental issues see next slide.
These PPTs may be downloaded from our website
www.stfrancisxavierpanvel.in
Or visit GEM FACEBOOK
http://www.facebook.com/gemenewsletter
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Twenty Tips To Save
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Plastic – a boon or bane?
Green Passion
Soft drink – A Health
Hazard
Waste to energy
Rain Water Harvesting
Eco-friendly Religions
Happy Green Diwali
Climate Change
The future of Biodiversity
Genetically Modified Foods
Waste Water Treatment
Give thanks, Give Life
(Body, Organ, Tissue
Donation)
Organic Farming
Waste to cooking gas
Reduce, Reuse. Recycle
Protect Mangroves
Say NO to Bottled water
Save Lakes and Ponds
Forests are green lungs
Coal Mining and Ecology