构造煤与原生结构煤孔隙特征及瓦斯解吸规律试验

Experiment on pore characteristics and gas desorption law of structural coal and primary structure coal

为了研究卧龙湖矿8煤层构造煤与原生结构煤孔隙特征及瓦斯解吸规律,分别采用压汞法和解吸试验对4组煤样进行试验研究。试验结果表明:构造煤中孔和大孔孔容所占比例高于原生结构煤,构造作用对煤的中孔和大孔有明显的改造效果,而且可能产生新的微孔和小孔;构造煤微孔和小孔的比表面积和分别占总比表面积的98.85%和98.74%,原生结构煤微孔和小孔的比表面积和分别占总比表面积的99.52%和99.37%,表明微孔和小孔决定煤的比表面积,构成煤层瓦斯的主要吸附空间;同时构造煤瓦斯解吸能力显著强于相同煤阶的原生结构煤,原因在于构造煤含有较多的中孔和大孔,为瓦斯的运移提供了通道。构造作用对煤的孔隙结构改造进而影响煤的解吸性能,增加了煤与瓦斯突出的危险性。

In order to study the pore characteristics and gas desorption law of No. 8 seam structure coal and the primary structure coal in Wolonghu Mine,the mercury intrusion porosimetry and the adsorption experiment were individually applied to the experiment study on four groups of the coal samples. The experiment results showed that the percentage of the medium and large pore＇s pore volume in the structure coal would be higher than the primary structure coal,the structure role would have obvious reconstruction effect to the medium and large pores of the coal and new micro pores and small pores would be occurred. The specific surface area sum of the micro pores and small pores in the structure coal would individually take 98.85% and 98.74% of the total specific surface area,and the specific surface area sum of the micro pores and small pores in the primary structure coal would individually take 99.52% and 99.37% of the total specific surface area.Therefore,the micro pore and small pore would determine the specific surface area and would be the main adsorption space of the gas in the seam. Meanwhile,the gas desorption capacity of the structure coal was obviously higher than the primary structure coal in a same coal rank and due to the structural coal with many medium and large pores in the structure coal,those pores could provide the channels of the gas migration. The reconstruction of the coal pore structure by the structure role would be affected to desorption performances of the coal would increase the danger of the coal and gas outburst.