Coal oxidation; interaction of water; calorimetry

Calorimetric investigation has been applied to study the ?oxygen-coal-water?system at low temperature range. As a result, three different roles for water with respect to spontaneous oxidation of coal have been distinguished. The first role concerns the proportions between the heat of phase transition of water and the heat of coal oxidation. The second role is connected with the actual content of coal moisture during oxidation of the coal. Finally, the third role is related to the previous contact of liquid water with pre-heated coal as a certain analogy with extinguishing the spontaneous combustion site by water. Such a water attack on coal was ascertained to result in chemical changes in coal structure, and, as a consequence, a noteworthy rise in heat evolution of subsequent oxidation of the coal was found.

Calorimetric investigation has been applied to study the ?oxygen-coal-water?system at low temperature range. As a result, three different roles for water with respect to spontaneous oxidation of coal have been distinguished. The first role concerns the proportions between the heat of phase transition of water and the heat of coal oxidation. The second role is connected with the actual content of coal moisture during oxidation of the coal. Finally, the third role is related to the previous contact of liquid water with pre-heated coal as a certain analogy with extinguishing the spontaneous combustion site by water. Such a water attack on coal was ascertained to result in chemical changes in coal structure, and, as a consequence, a noteworthy rise in heat evolution of subsequent oxidation of the coal was found.