Image and ultrasonic analysis-based investigation of coal core fracturing by microwave energy

Formation microwave heating treatment (FMHT) is a potential method for degassing coalbed methane. Camera pictures and ultrasonic method were used to evaluate the crack propagation on the surface and in the interior of the coal cores, respectively. The results suggest that the fracture induced by microwave energy would remarkably increase with increased heating time. New fractures and pore sizes produced by microwave energy decreased P- and...