Study on isobaric adsorption/desorption features of coalbed methane in Hujiahe Coal Field

in order to pronote the practices on the low ranking called methane in HAujiahe Mlinefied of Binchang Mining Area and to approve the mining recovery rate,the colection and procssing of the coal samples from the target sean-No.4 seam were conduced,the adsorption / desopion experiments with dfferent temperature coal bed methane werecompleted and the adscrption /desorption result were applied to draw the adsoption sobar.The resultshowed that the absorption volume vas reduced with the temperature inreased.At the low pressure stage.the desopion hysteresis was obvious and at the high pressure stage,the desorption processand the absoption process could be reversible, The relationshi between the CH4 absorption volume and temperature could be expressed with a quadratic function and when the temperature was higher tan the critit且l temperature(-82.5 C℃).the max absopion volume woud be distributed along a parabola. When the temperature waslower than the critial temperature,the max absorption volune would be ditributed along a straght lne.Fnally the calcu ation metod obtined ofthe CH4 absoption volume could solve the inaccurate problem of the gas content measured data of the low ranking cal when the mining recovery rate was determined.