Rasearch On The Adsorptivity Of Pore In Caron Materials And The Porosity Character Of Outbust Coal

Coal is one of the very important primary energies in our country. For the poor storage conditions, accidents occur frequently in coal mine, and most of them are coal and gas outburst which cause serious consequences. Coal and gas outburst is a complicated dynamic phenomenon, which power source induced is still under exploration. The indexes of coal and gas outburst include many parameters, such as gas content, gas pressure, gas desorption rate, gas emission intensity and attenuation low, coal firmness coefficient. Most of the parameters are related to the pore structure of coal. Therefore, study on the pore structure will help to explain the adsorption capacity of coal gas, to reveal the mechanism of coal and gas outburst.Based on the adsorption microcosmic theory in pores, the adsorption isotherms of anotubes with different diameter which have regular structure are obtained by adsorption experiments of nitrogen at low temperature, and analyze their pore structure characteristics by suitable methods. The adsorptivity of micro-pore and meso-pore is studied, and reliability of instrument and the reasonableness of analysis methods are examined.The adsorption isotherms and micro-pore structure characteristics of 31 coal samples are studied especially, and the difference in micro-porosity structure between outburst and non outburst coal samples and their adsorptivity are researched. The following results have been achieved in this research:(1) When the size is smaller than a certain value the adsorption behavior of its internal is micropore filling phenomenon whether circular pore or slit shaped pore by low temperature nitrogen adsorption experiment of carbon nanotubes and the coal samples.(2) The micropore filling phenomenon occurs in the micropores which pore sizes are about 1 nm. The adsorptivity of the pore with micropore filling is greater than the pore without micropore filling. And the number of micropore in outburst coal samples is largely more than the non-outburst coal sample, therefore the adsorptivity of micropore in outburst coal is higher than that in non-outburst coal.(3) The pores which width are between 3.5～7 nm in outburst coal samples are far more than that in non outburst coal samples, and the contribution rate of the pore volume and specific surface area in them are far more than that in non-outburst coal samples too.