Experimental study on the Electromagnetic Radiation (EMR) during the fracture of coal or rock

Electromagnetic radiation (EMR) during coal or rock fracture is measured and analyzed by both laboratory and site experimental study. The results show that EMR truly exists during the fracture of coal or rock (containing or not containing gas), it follows Hurst statistical distribution, and it is enhanced during the process of breaking. The EMR strength and frequency are correlated to coal or rock fracture process, and the signal of EMR is more sensitive than that of AE. Based on these properties a new method for coal and methane outbursts prediction is proposed — the so called EMR method. It makes the prediction of coal and methane outbursts easier, with continuing measurement and without touching the coal surface.