Adiabatic oxidation study on the propensity of pulverised coals to spontaneous combustion

This paper presents the results of adiabatic oxidation studies on the prope nsity of 18 pulverised coals to spontaneous combustion. All the coal sample s were tested at an initial temperature of 40 degrees C and three samples a t 60 degrees C to mimic the condition in a coal mill. Their propensities to spontaneous combustion were ranked according to their initial rate of heat ing (IRH) and total temperature rise (TTR) values. The influence of initial temperature, moisture content, particle size and coal ageing on spontaneou s combustion were also studied. The results demonstrated that air humidity is an important factor in determining whether a heating will progress rapid ly or not. The particle size distribution of the coal affects the IRH and T TR values, with relatively smaller particles tending to be more reactive. A ged and pre-oxidised coals have higher IRH and lower TTR values, and the co al becomes less reactive. The magnitude of the temperature rises (TTR) incr eases with increasing initial temperature. No direct correlation was observ ed between the adiabatic oxidation values and the individual coal propertie s. (C) 1999 Elsevier Science Ltd. All rights reserved.