Coal (or thermal coal) is a fuel mainly composed of carbon. It is extracted from underground or open mines. It contains traces of hydrocarbons in addition to other mineral elements and sulphur. Coal comes through the gradual elimination of elements like hydrogen and oxygen with a consequent indirect carbon enhancement.
Coal is employed in the power generation (steam coal). From coal, it’s possible to obtain other kinds of fuels through the gasification and liquefaction process.
Metallurgical coke is a carbonaceous solid residue of bituminous coal with low ashes and sulphur content, which volatile matters have been removed to through the drying in oven without oxygen, this process allows to melt the fix carbon with the ashes. Metcoke is grey , hard and porous and it is used as fuel and as a reducing agent in the blast fournaces and in siderurgic industry. Coal cannot be employed in metallurgy as it is compact, crumbly, plenty of sulphur and volatile matters.
| Typical Specifications as Received Basis | Russia standard | U.S.A. | Republic South Africa | Colombia standard | Colombia premium | Venezuela premium | |
| Moisture | % | 8 – 10 | 8-10 | 8-10 | 11-13 | 6 – 10 | 7-8 |
| Ash Content | % | 10 – 14 | 11 – 14 | 10 – 12 | 7 – 8 | 6 – 10 | 5 – 7 |
| Volatile Matters | % | 18 – 30 | 31 – 34 | 20 – 26 | 34 – 36 | 33 – 38 | 32 – 36 |
| Sulphur Content | % | 0,4 – 0,9 | 0,5 – 3 | 0,5 – 0,8 | < 1 | 0,5 – 0,8 | 0,5 – 0,8 |
| NCV | Kcal/Kg | 6000 – 6300 | 6000 – 6250 | 6000 | 6000 | 6500 | 6700 |