Difference in moisture effect on low temperature oxidation of hydrophobic and hydrophilic coal types

摘要

Sixty coal samples were calorimctrically examined with respect to moisture content influence on evolution of oxidation heat (q). Differences in behaviour of hydrophobic and hydrophilic coals were observed. For hydrophobic samples, drying process was found to result in a rise in the oxidation heat q Contrary, drying of hydrophilic coal types caused a decrease in the q values. New reaction sites opened in drying arc most likely responsible for rise in q values for hydrophobic coals, the nature of which being seen in free radicals. For hydrophilic coal types, however, Ihe action of these newly opened free radicals is probably overshadowed by the change in the oxidation mechanism occurring from the lack of water molecules.