Experimental study of the effect of NaCl solution on the pore structure of coal body with high-voltage electrical pulse treatments

A self-designed experimental system was established to study the effect of NaCl solution on the pore struc- ture of coal body with high-voltage electrical pulse. The anthracite coal samples of Linhua coal mine in Guizhou were broken down by high-voltage electrical pulse after being soaked in distilled water and NaCl solution at different con- centrations. Subsequently,the scanning electron microscopy,energy spectrum analysis,and mercury injection experi- ment were carried out on +the coal- samples. The results reveal that during the coal soaking in NaCl solution,a large amount of conductive Na and Cl ions entered into the primary pores of coal,effectively improving the conductivity of the coal. Compared with the coal soaked in distilled water,the coal soaked in NaCl solution was more fully broken un- der the action of the high-voltage electrical pulse. Moreover,the porosity,pore volume,and distribution range of pore size were increased with the increase in the concentration of NaCl. Furthermore,the volumes of mesopore and macro- pore clearly increased,and the pore connectivity was enhanced,demonstrating that the pore structure was improved.