Natural desorption of carbon monoxide during the crushing of coal simulating natural rock mass pressure.

Carbon monoxide is the principal gaseous indicator in the assessment of indigenous fire hazard. The aim of the research was to determine the natural gas background, not related to the development of endogenous fire in goafs, but resulting from the natural crushing of coal under the pressure of overlaying rocks. A special prototype research devise simulating the processes occurring a coal mine was designed and constructed to achieve the objective of the study. The paper presents a practical method of fire risk assessment in caving longwall goafs taking into consideration the natural emission of carbon monoxide. The authors discuss the results obtained with the application of a prototype research device designed to determine an estimative natural emission of gases from coal. The value of the index of carbon monoxide desorption intensity enables to recognize and forecast the degree of fire hazard. The method consists in measuring the components of atmosphere emitted from a coal sample compressed with a force reflecting the pressure exerted on the rock mass. The method considers in particular the exploitation longwalls with residual coal in goafs. It was observed that the index of carbon monoxide desorption intensity is useful for the assessment of endogenous fire hazard in a coal mine.