An experimental approach to selecting chemical inhibitors to retard the spontaneous combustion of coal

Because of the complex structure of coal, selecting an efficient chemical inhibitor to retard or prevent its spontaneous combustion remains a challenging task. In the present work, the distributions and concentrations of functional groups on coal surfaces were analyzed using in situ FTIR. The active functional groups and their oxidation processes were elucidated so as to develop an efficient approach to selecting effective chemical inhibitors. The validity of the experimental approach was demonstrated by measuring various performance metrics for samples with and without a chemical inhibitor, including crossing point temperature (CPT), oxygen consumption, carbon monoxide (CO) emission rates and changes in active functional groups. The results indicate that the chemical inhibitor chosen using the proposed approach effectively slows the oxidation of coal, thereby demonstrating the validity of the selection method. (C) 2013 Elsevier Ltd. All rights reserved.