A method for detecting hidden fire source in deep mine goafs based on radon measurement and its experimental verification. (June 2020) - Wen, Hu
Abstract: A method of detecting hidden fire sources in the goafs of deep mines is proposed, based on the analysis of the characteristics of radon measurements by combining, theoretical research, and experiments. Taking loose coal as the research object, the relationship between radon exhalation and coal temperature, the migration of radon, and its applicable conditions were studied with respect to temperature and location of a fire source point, based on programmed-temperature and spontaneous-combustion test beds. The results showed that radon exhalation first increased with coal temperature and then decreased after reaching the ignition temperature. During spontaneous combustion of loose coal, when 5 < L < 125 cm, where L is the distance between the measuring point and the air inlet, the radon concentration increased linearly along the axis direction and radon migration mainly occurred by seepage. With the increase of coal temperature at high temperatures, the range of radon seepage along the axis decreased. The temperature range of the sudden change of radon exhalation was 65–75 °C, and the change of the position of the high-temperature point occurred between 65 °C and 75 °C, which was consistent with the initial and final temperature values of the sudden change in radon emission temperature range. Graphical abstract: Image 1 Highlights: Relationship between radon exhalation and coal temperature was studied. Trends of radon migration during spontaneous combustion of loose coal was explored. Applicable conditions of radon exhalation and migration were analyzed.