ABSTRACT
Occurrence of fires in stacks, during storage, are well known in cases of many fuels and porous bodies like coal, charcoal powder, linseed oil, sponge iron, sulphide ores/pyrites, or even hay stacks. Most of these fires originate from spontaneous heating of coal. Such surface fires may be easier to detect and quench at its initial stage than those of underground fires. Stacks of slack coal are more prone to spontaneous heating than those of nut or rubble coals. Highly compact or consolidated stacks are safer than the loosely stacked ones. Stacks of coarse grain-sized coal may allow higher air flow rate in the deeper cores. Higher air velocity always shifts the mantle of heat build-up zone to the deeper layer and at the same time it also shifts the heat-dissipating outermost mantle to a greater depth.
