Detecting concealed fire sources in coalfield fires: An application study

Abstract

A majority of coal mines in China are susceptible to fires, especially those affected by concealed fire sources in coalfield fire areas. Hence, to mitigate this problem, the efficient and precise detection of high-temperature anomalous areas is significant and needed, which mainly involves determining the range and depth of concealed fire sources. In this paper, the strengths and weaknesses of each detection method (e.g., remote sensing, electromagnetic radiation, magnetic detection, geological radar detection, resistivity detection, transient electromagnetic, excitation potential method, gas analysis, radon levels detection, infrared images) were investigated, analyzed, evaluated and then compared. Furthermore, after taking their respective practicality and effectiveness into account, an integrated methodology was proposed that uses radon levels, infrared imaging techniques, and drilling methods to detect and verify high-temperature anomalous areas in a coalfield. We carried out the detection in the Ningxia autonomous region. Our testing results revealed that radon levels show positive correspondence with the temperature of potential fire sources. That is to say, higher radon levels usually have higher temperature signal for detection. Accordingly, high-temperature anomalous areas in coalfield fire areas can be distinguished and delineated successfully by their radon levels and verified by infrared imaging techniques and drilling methods.