Study on Porosity of Coal Samples Based on Low Temperature Nitrogen Adsorption Method and Mercury Porosimetry

In order to study the porosity structure features of anthracite ,the mercury porosimetry and the low temperature nitrogen adsorption method was applied to study the porosity features of the coal samples from Sihe Mine. The results showed that the low temperature nitrogen adsorption isotherm of the coal sample was clos e to type I and the micropore in the coal,specially less than 2 nm would be the adsorption spaces of the coal gas.There was no hysteresis loop in the mercury porosim etry curve and there were many column porosity and V porosity distributed.The large porosity,visible porosity and crack were well developed and made up the permeab le volume of coal which would be favorable to the gas flow and to the gas drainage.The low temperature nitrogen adsorption method could have more advantages to tes t the specific surface area of the coal.The mercury porosimetry would be more accurate to test the porosity volume distribution of the coal.Therefore the combined appli cation of both methods, the porosity structure of the anthracite could be fully analyzed.