3. “Accumulation of organic
residue as sediments”
Carbonaceous deposits are produced during
incomplete hydrocarbon combustion, catalytic
conversion of hydrocarbons and thermal
decomposition of hydrocarbons
4. Coal is a sedimentary deposit composed predominantly of carbon
that is readily combustible. Coal is black or brownish-black, and has
a composition th consists of more than 50 percent by weight and
more than 70 percent by volume of carbonaceous material.
5. • Bituminous coal, or black coal, is a type of coal
containing a tar-like substance called bitumen or
asphalt.
• Its coloration can be black or sometimes dark
brown; often there are well-defined bands of
bright and dull material within the seams. It is
typically hard but friable
• “Common coal”
• Peat is a soft, organic material consisting
of partly decayed plant and mineral matter.
• Under high pressure and heat, it
undergoes physical and chemical changes
(coalification) to become coal.
• Regarded as the first stage in the
evolution of coal from wood
Bituminouscoal
Peat
6. • Lignite is a various colored i.e., black,
brown or earthy variety of coal of lowest
rank.
• The vegetable matter is decomposed more
than in peat.
• Contains Carbon below 70% and O2 below
20%.
• Anthracite coal is the highest rank in which
woody material has been metamorphosed to
it’s extreme condition (92-98%)
• It shows semi metalic luster and conchoidal
fracture.
• These coal contain richest in carbon and
lowest in volatile materials
Lignite Anthracite
7. • Cannel coal is a dull black, compact Varity
of coal with conchoidal fracture
• It burns with a bright smoky flame like a
candle.
• cannel coal is considered to be coal but by
its texture and composition of the organic
matter it is considered to be oil shale