Coal fire types
Several approaches for the classification of coal fires exist.
The first one relies upon the position of the coal. Fires can be classified into two types: coal seam fires (coal is in-situ)
and coal heap fires (coal is not in-situ).
In the next step, coal seam fires can be classified into mine coal fires (mining related) and natural coal fires (not related
to mining activities), while coal heap fires include coal waste and stockpile fires.
Secondly, each coal fire type can be divided into the following classes according to its attributes: surface fire (fire is
burning on the surface of the earth) and underground or subsurface fire (fire is burning in the ground); paleo fire (fire
was burning in the paleo time) and recent fire (fire was burning in recent time); extinct fire (now fire is extinct, incapable
of further burning), dormant fire (fire is not spreading, but probably capable of re-ignition) and active fire (fire is burning