Coal forms from the sedimentation and metamorphosis of organic matter like plant material over millions of years. There are two main types of coal: sapropelic and humic. Sapropelic coals like boghead coal and cannel coal contain a high percentage of algae. Humic coals include peat, lignite, bituminous coal, sub-bituminous coal, and anthracite - classified based on the degree of metamorphosis from plant material to a harder, more carbon-rich rock. The different coal types are also distinguished by their color, hardness, heating value, and other physical properties.

1. Coal And Their Types

2. COAL
➢ COAL IS PHYTO-ORGANIC-SEDIMENTO-METAMORPHOSED
ROCK
➢ COAL IS CHARACTERIZED BY ORGANIC OR INORGANIC
SUBSTANCES
➢ ACCORDING TO TO STARC (1982) COAL IS SEDIMENTARY
ROCK FORMED BY MACERALS AND MINERALS AND CONTAIN
MORE ORGANIC THEN MINERAL MATTER
➢ COAL IS A MIXTURE OF COMPLEX ORGANIC COMPOUND WITH
SOME AMOUNT OF MOISTURE AND INORGANIC MINERAL
MATTER.C,H,O ARE THE PRINCIPLE PRESENT IN SMALL AMOUNT

3. contents
1.COAL
2.TYPES OF COAL
(A) SAPROPELIC COALS
1.BOHEADCOAL
2.CANNELCOAL
(B) HUMIC COALS
1.PEAT
2.LIGNITE
3.BITUMINIOUSCOAL
4.SUB-BITUMINIOUS
5.ANTHRACITE

4. Sapropelic Coals
SAPROPELIC COAL CAN BE DIVED INTO TWO TYPES :
BOGHEAD COAL (TORBANITE )
➢ PRESENCE OF YELLOWISH BROWN ALGAE WAS MAXIMUM THAT IS MORE THAN 80%
ALSO CALLED ALGAE BEARING COAL
➢ IN 1850 THIS COAL TYPE WAS FIRST DISCOVERED AT TORBANE HILL,SCOTLAND
DERIVED AFTER TORBANITE FURTHER REFERRED TO BOGHEAD COAL
CANNEL COAL
➢ IT IS USED AS CANDLE SO DERIVED AS CANNEL
➢ ALGAE IS LESS THAN 5% AND MOSTLY MADE UP OF MICROSPORES
➢ IT IS CHARACTERIZED AS DULL, COMPACT, HARD AND VERY FINELY GRAINED WITH
CONCOIDAL FRACTURE AND VERY LITTLE STRATIFICATION OR BANDING HAVING VERY
LOW ASH CONTENT

5. Humic Coal
ON THE BASIS OF PLANTS OR THE BASIS
OF ORIGIN A HUMIC COAL IS OF
DIFFERENT TYPES
1.PEAT
➢ PEAT IS NOT REGUARDED AS COAL, THOUGH IT
REPRESENTS THE FIRST STAGES OF COAL
FORMATION
➢ GENERALLY LIGHT OR DARK BROWN IN COLOUR
➢ USED AS FERTILIZER FOR MAKING FERTILIZERS
➢ HIGH NITROGEN AND LOW IN SULPHUR
➢ FOUND IN NILGIRI HILLS OF SOUTH INDIA ABOUT
2000 METERS
➢ ALSO FOUND IN KASHMIR BUT DEPOSIT IS
PROBABLY TO CLASSED AS LIGNITE

6. 2.LIGNITE(BROWN COAL)
➢ ALSO KNOWN AS BROWN COAL
➢ A WOODY TEXTURE COMPOSED OF FINELY DIVIDED
PLANT TISSUE
➢ LIGNITE SPLITS PARALLEL TO BEDDINGS BUT HAVE
EXCESSIVE MOISTURE ABOUT (12-50%)
➢ DRIES ON EXPOSURE ,SHRINKS AND BREAKS UP
READYLY IN IRREGULAR MANNER
3.BITUMINIOUS COAL
➢BITUMINIOUS COAL CONTAINS BITUMEN AS THE NAME
SUGGESTED AVOBE AND ALSO BURNS LIKE BITUMEN WITH
A YELLOW SMOKY FLAME
➢JET BLACK IN COLOUR BUT DARKER THAN SUB-
BITUMINIOUS COAL
➢ALTERNATE BANDINGS ARE CLEARLY VISIBLE
➢BREAKS INTO CUBES AND MUCH FOR HARDER AND
DENSER THAN SUB-BITUMINIOUS COAL

7.  4.SUB-BITUMINIOUS COAL
➢ BLACK IN COLOUR DARKER THAN LIGNITE
➢ HAVE DULLY WAVY LUSTURE DENSER AND HARDER THAN
LIGNITE
➢ LOW MOISTURE CONTENT ABOUT (12-25%)
➢ MOST LIKELY BANDED LIKE BIYUMINIOUS COAL BUT ARE
POORLY JOINTED PARALLEL TO BEDDING PLANES HENCE
SPLITS INTO SLABS RATHER THAN BREAKING INTO
RECTANGLAR FRAGMENTS
➢ DIFFICULT TO TRANSPORT
5.ANTRACITE
➢ ANTRACITE IS LAST TRANSFORMATION OF COAL
➢ CHARACTERISED BY VISIBLE BANDING
➢ DEEP BLACK IN COLOUR,SHINY AND SILVERY,SEMI METALLIC
LUSTURE, AND BREAKS BY CONCOIDAL FRACTURE
➢ KNOWN AS “STONE COAL” IN THE PAST