The Effect of Drying Heat and Moisture Content on the Maximum Temperature Rise During Spontaneous Heating of a Moist Coal Pile

Abstract

Recent work has suggested that the moisture of a sub-bituminous coal may exist in three forms, namely free moisture, loosely bound moisture and tightly bound moisture (these moistures do not include chemically bound moisture). The complete drying of each type of moisture requires a stepwise changing amount of energy, known as the heat of drying. This stepwise change in the heat of drying in relation to the moisture content of coal was, in the current study, incorporated into a mathematical model that describes the spontaneous heating process. More detail of the influence of moisture transfer on the maximum possible temperature rise in moist coal piles are revealed. Comparison between the predicted temperature levels and the published experimental observations provided greater confidence in using the proposed mathematical model and the physical and chemical parameters to predict quantitatively the spontaneous ignition process.

Assessment of Emission of Selected Gaseous Components from Coal Processing Waste Storage Site

“…Many factors, including non-fulfillment of the basic principles of fire prevention, the use of improper technologies, as well as the absence of waste segregation and compaction in the storage process, resulted in self-ignition of mine waste dumps. Coal and pyrite included in waste material are oxidized when exposed to air and water vapor, which leads to self-heating of the deposited material, and in consequence to fires [2,3]. Coal mine waste dumps are therefore often thermally active objects characterized by high internal and surface temperatures and presence of exhalation zones emitting exhaust gases [4].…”

Review of experimental methods to determine spontaneous combustion susceptibility of coal – Indian context

“…free moisture (chemically bound moisture is not included) which may influence the susceptibility of a coal to spontaneously combust (Chen, 1994). Some researchers have concluded that a low moisture content may assist rather than retard the combustion whilst a high moisture retards the combustion(B.…”