There are various types of coal, with some better than others.
Types of coal, based on progression of coalification:
(1) peat
(2) lignite
(3) sub-bituminous
(4) bituminous
(5) anthracite
|
Type
|
Color and Consistency
|
Carbon Content (when dry)
|
Moisture Content (before drying)
|
Heat Content in MJ/kg
|
|
peat
|
soft, dark brown
|
LT 60%
|
75%
|
15
|
|
lignite
|
brown
|
65-70%
|
35 to 55%
|
17 to 18
|
|
sub-bituminous
|
grey-black or dark brown
|
70-76%
|
18 to 38%
|
18 to 23
|
|
bituminous
|
black
|
76-86%
|
8 to 18%
|
23 to 33
|
|
anthracite
|
dark black
|
86-92%
|
7 to 10%
|
32 to 33
|
Coal may also be categorized by its contaminants, such as sulfur.
