Required Parameters that you must know:

- Area - Usually in square feet or in acres.
- Coal seam height - usually in feet or in meters
- Specific gravity of coal seam - unit-less, usually from lab analysis. (specific gravity - The ratio of the weight of an object in air to the weight of an equal volume of water. The specific gravity1 of bituminous coal ranges between 1.1 5 and 1.5 depending on rank, moisture content, and ash content, and averages 1.32.)

Coal tons per acre feet= (62.4 lbs/cubic feet x 43,560 ft3 natural resource/acre x Specific Gravity)/2000 lbs/ton

2. Equation for the determination of Coal Tons is as below:

Coal tons = Acres * Coal thickness* (coal tons per acre feet)

Conversion factors:

- Specific gravity of bituminous coal = 1.32
- 1 ft3 of water = 62.6 lbs
- 1 acre = 43,560 ft2
- 1 ton = 2,000 lbs

Because specific gravity varies with rank, different ranks of coal have different conversion factors.

- Anthracite: specific gravity = 1.47, so the conversion factor is 2,000 tons/acre foot
- Bituminous: specific gravity = 1.32, which is 1,800 tons/acre foot
- Subbituminous: specific gravity = 1.30, which is 1,770 tons/acre foot
- Lignite: specific gravity = 1.29, which is 1,750 tons/acre foot

- Limestone = 3600 acre-lt.
- Sandstone = 3300 acre-ft.
- ClayIShale = 3250 acre-ft.
- Sand~Gravel = 2400 acre-ft.
- Salt = 2950 acre-fi.

Please contact Ankan Basu, P.G; at admin@coalgeology.com if you have any questions.