Statistical appraisal of intrinsic factors affecting spontaneous combustion of coal

Abstract

This study is concerned with the statistical prediction of the liability of coal to spontaneous combustion. The experimental data consisted of adiabatic oxidation test results on 47 different coals, together with the laboratory evaluation of intrinsic properties of individual coal samples. The measures of propensity of coal to spontaneous combustion was based on the initial rate of heating and total temperature rise in an adiabatic oxidation experiment. These parameters were statistically correlated with various intrinsic properties of coal to isolate the most important intrinsic factors affecting the spontaneous heating potential of coal. A multiple regression analysis between initial rate of heating and total temperature rise and thirteen independent variables have generated a set of equations to predict the liability of coal to spontaneous combustion. It is shown that the predictive equations derived by subdividing the data set according to rank classification can permit accurate prediction of temperature rise, thus evaluating the liability of coal to self-heating. The contribution made by various intrinsic factors to the self-heating potential of coal have also been evaluated by using isolated factor analysis techniques.