焦作矿区含瓦斯煤体电阻率变化规律研究

Study on the variation rules of electrical resistivity on being loaded gas-filled coal

在低频率(100～10 000 Hz)条件下测试了煤体在吸附瓦斯过程中和含瓦斯煤在三轴压缩条件下的电阻率变化规律.实验结果表明,煤体在吸附瓦斯过程中和含瓦斯煤三轴压缩条件下,电阻率值分别随着吸附时间和应力的增加,出现先大幅度减小后小幅度增大的变化规律.运用电介质物理学理论对含瓦斯煤体导电机理分析表明,电子和离子在煤孔隙表面上的迁移、游离瓦斯对煤颗粒的挤压作用和正负电荷在外电场作用下产生移动,三者共同造成煤体在吸附瓦斯过程和含瓦斯煤体受载过程中电阻率的降低.

Under the condition of the low frequency of 10 kHz, the electric resistivity in the processes of the coal with gas adsorption and coal samples containing gas with triaxial compression is measured. The experimental results show that both the electric resistivity values decrease with the gas adsorb and the stress increase respectively. The variation value is bigger at first than the late. With classic dielectric physics theory, the conductive mechanism of gas-filled coal is analyzed. The reason on the decrease of the electric resistivity in the processes of the coal with gas adsorption and coal Samples containing gas with triaxial compression is： the migration of electrons and ions on the surface of coal pores, the free gas squeezing action to coal particles, the displacement of positive and negative charge with the external electric field. All the three elements caused simultaneously the electric resistivity variation.