Application of Electromagnetic Radiation (EMR) Technology in Monitoring and Warning of Coal and Rock Dynamic Disasters

Coal and rock dynamic disasters induced by the large-scale deformation and fracture of surrounding coal and rock, have significant impact on the safe and efficient extraction of coal. Effective and accurate early warning is the elementary basis for the efficient and affordable prevention and control of such kind of disasters. Laboratory experiments have demonstrated that EMR signals are generated during the process of deformation and fracturing of coal or rock under various loading conditions. EMR are paroxysmal pulse signals and increase with stress applied; and the higher the load, the larger the EMR signals. The genetic mechanism, characteristics and laws of EMR of coal and rock were studied by laboratory experiments, based on which, an EMR monitoring and warning method has been put forward. Based on the research results and the method, EMR detectors, Model KBD5 and KBD7, have been developed and employed to predict coal and rock dynamic disasters, such as coal and gas outbursts, rockbursts, monitor goaf roof stability, observe pressure of the surrounding rocks, and determine the width of relief areas. Before the occurrence of a coal and rock dynamic disaster, EMR usually has a corresponding precursor. According to the characteristics of the EMR precursor in time and space, it is possible to recognize the dangerous areas of rockbursts around underground openings and thus give early warnings of the dynamic phenomena as well.