The Experiment of Coal Body Electrical Parameters under Triaxial Stress

The variation of coal body electrical parameters are important parameters for researches on the propagation of electromagnetic radiation and acoustic emission in coal. Therefore, experiments of coal body electrical parameters under triaxial stress are carried out. Studies have shown that, the resistivity of coal body decreases with the loading of axial compression and confining pressure. And the decline of raw coal is relatively more obvious, while the decline of briquette is smaller. Moreover, the resistivity of coal body retains relatively stable when the stress is greater than 3MPa. With the increase of axial compression and confining pressure, the dielectric constant of coal body will also increase and it will be basically stable when the stress is greater than 3MPa.