NaCl溶液对电脉冲致裂煤体孔隙结构影响的实验研究

摘要

利用搭建的高压电脉冲致裂煤体增渗实验系统,对蒸馏水和不同浓度NaCl溶液浸泡后的贵州林华无烟煤进行电脉冲击穿实验,并结合扫描电镜、能谱分析和压汞分析等测试方法,研究了不同浓度NaCl溶液处理后,电脉冲击穿煤体的孔隙结构变化特征.实验结果表明,煤体在NaCl溶液浸泡的过程中,大量的导电离子Na+和Cl-进入煤体内部的原生孔隙裂隙,有效的改善了煤体的导电性,与蒸馏水浸泡的煤体相比,NaCl溶液浸泡的煤体在电脉冲击穿后破碎的程度更充分.同时,随着NaCl浓度的增加,电脉冲击穿煤体的比表面积、孔容、孔径以及孔隙度均有一定程度的增加,特别是大孔和中孔孔容增加显著,孔隙的连通性变好,有效地改善了煤体孔隙结构.%A self-designed experimental system was established to study the effect of NaCl solution on the pore structure 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 concentrations.Subsequently,the scanning electron microscopy,energy spectrum analysis,and mercury injection experiment 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 under 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 macropore clearly increased,and the pore connectivity was enhanced,demonstrating that the pore structure was improved.