* Anthracite: 1.4 - 1.8
* Bituminous: 1.2 - 1.5
* Subbituminous: 1.1 - 1.3
* Lignite: 0.8 - 1.1
Important Note: These are just general ranges. The specific gravity of a specific coal sample will depend on factors like:
* Moisture content: Wetter coal will have a lower specific gravity.
* Ash content: Higher ash content generally means lower specific gravity.
* Density of the minerals present: Coal is a complex mixture, and the density of the minerals within it will impact the overall specific gravity.
Specific gravity is a crucial property in the coal industry, influencing:
* Transportation and handling: It affects how much coal can be moved in a truck or train car.
* Combustion: It impacts how much air is needed for burning and how much energy is released.
* Coal preparation: It helps determine the efficiency of processes like washing and crushing.
If you need the specific gravity of a particular coal sample, it's best to consult with a professional or laboratory specializing in coal analysis.
