煤岩成分对煤孔隙结构发育特征的影响——以桃园煤矿气煤为例

Influence of Coal Rock Composition on Pore Structure Development Characteristics of Coal:Taking Taoyuan Coal Mine Gas Coal as an Example

为研究煤岩成分对煤孔隙结构的影响,采集了淮北煤田桃园井田原生结构煤样。通过低温氮吸附-解吸实验,建立了煤孔隙结构参数和煤岩成分的关系。结果表明,暗煤吸附量最大(2.8 cm^(3)/g STP),其次是亮煤(1.6 cm^(3)/g STP),再次是镜煤(1.2 cm^(3)/g STP);暗煤比表面积(1.01 m^(2)/g)和孔容(0.004 4 cm^(3)/g)最大,其次是亮煤(分别为0.80 m^(2)/g和0.002 5 cm^(3)/g),镜煤最小(分别为0.47 m^(2)/g和0.001 9 cm^(3)/g);暗煤的中孔和过渡孔孔容及比表面积明显高于亮煤和镜煤;微孔对比面积的贡献最大,其次是过渡孔,再次是中孔;暗煤、亮煤和镜煤孔隙体积分形维数分别为3.219 7、3.360 2和3.332 2,比表面积分形维数分别为2.923 6、3.199 2和3.134 5,暗煤孔隙比亮煤和镜煤复杂。

In order to study the influence of coal rock composition on coal pore structure,primary structural coal samples were collected from Taoyuan mine field in Huaibei coalfield.Through low temperature nitrogen adsorption and desorption experiments,the relationship between coal pore structure parameters and coal rock composition was established.The results show that dark coal has the highest adsorption capacity(2.8 cm^(3)/g STP),followed by bright coal(1.6 cm^(3)/g STP)and mirror coal(1.2 cm^(3)/g STP).Dark coal has the largest specific surface area(1.01 m^(2)/g)and pore volume(0.0044 cm^(3)/g),followed by bright coal(0.80 m^(2)/g and 0.0025 cm^(3)/g),and mirror coal has the smallest(0.47 m^(2)/g and 0.0019 cm^(3)/g).The pore volume and specific surface area of medium pore and transition pore of dark coal are obviously higher than those of bright coal and mirror coal.The contribution of micropore contrast area was the largest,followed by transition pore and mesopores.The fractal dimension of pore volume of dark coal,bright coal and mirror coal is 3.2197,3.3602 and 3.3322 respectively,and the specific surface integral dimension is 2.9236,3.1992 and 3.1345 respectively.The pore of dark coal is more complex than that of bright coal and mirror coal.