2. COAL
Coal is a flammable black hard rock used as a
fossil fuel.
It is mainly made up of 65-95% carbon and also
contains hydrogen, sulphur, oxygen and nitrogen.
It is a sedimentary rock formed from peat, by the
pressure of rock laid down later on top.
The harder forms of coal, such as Anthracite,
Metamorphic rock because they were change by
higher temperature and pressure.
3. Peat, and therefore coal, is a formed from the
remains of the plant which lived millions of year ago
in tropical wetlands, such as those of the late
carboniferous period (the Pennsylvanian).
A similar substance made from wood by heating it
in an airless space is called Charcoal.
4. CHEMICAL, PHYSICAL & MECHANICAL
PROPERTIES OF COAL-
Moisture
Volatile matter
Ash
Fixed Carbon
Relative density
Particle size distribution
Float-sink test
Abrasion testing
5. TYPES OF COAL
Category Attributes Flame
Brown coal/lignite Brown colour woody
structure
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Bituminous coal Black and banded Smoky yellow flame
Anthracite Black and lustrous Burns without flame
6. Anthracite is a hard, black, shiny form of coal that
contains virtually no moisture and very low volatile
content. Because of this, it burns with little or no
smoke and is sold as “smokeless fuel”.
Anthracites can have energy contents up to about
32mj/kg, depending on the ash content.
Lower rank coals may have lower energy contents,
but they tend to be more reactive (they burn faster)
because of their porosity and resultant higher
surface area.
ANTHRACITE COAL-
7. PEAT-
Peat is the layer of vegetable material directly
underlying the growing zone of a coal forming
environment. The vegetable material shows very
little alteration and contains the root of living plants.
Peat is widely used as a domestic fuel in rural parts
of Scotland and Ireland.
8. LIGNITE
Lignite is geologically very young (upwards of
around 40,000 years).
It is brown and can be fibrous, containing
discernible plant material. It also contains large
amount of moisture (around 70 %) and so has a low
energy content: around 8 to 10 mj/kg.
As the coal develops it loses its fibrous character
and darken in color.
9. BLACK COAL
In Australia, black coal ranges from cretaceous age (65
to 105 million years ago) to mid permian age (upto 260
million years ago).
They are all black; some are sooty and still quite high in
moisture (sub-bituminous coal).
Coals that get more deeply buried by other rocks lose
more moisture and start to lose their oxygen and
hydrogen.
These coals are harder and shinier (Bituminous coal)
These are typically the most coal mined in NSW and
Queensland, which have energy content around 24 to
28 mj/kg.
These coals have generally less than 3% of moisture.
10. USES OF COAL
Mainly used in power generation.
Used in steel production.
Paper manufacturing.
Alumina refineries.
Chemical and Pharmaceutical industries.
Refined coal tar is used in the manufacture of
chemicals, such as creosote oil, naphthalene,
phenol, and benzene.
11. HAZARDS OF USING COAL
Reduction in life expectancy.
Respiratory hospital admissions.
Black lung from coal dust.
Congestive heart failure
Non-fatal cancer, osteroporosia, ataxia, renal dysfnction.
Chronic bronchitis, asthma attacks, etc.
Loss of IQ from air and water pollution and nervous
system damage.
Degradation and soiling of buildings that can effect
human health.
Global warming.
Ecosystem loss.