构造煤与原生结构煤吸附放散特征研究

摘要

Gas adsorption and emission characteristics of two kinds of coal from five pairs of mines were studied .The adsorption experiment show that tectonic coal have a little higher adsorption capacity than original‐structure‐coal and changing amplitude increases as coal rank decreases .And Langmuir adsorption constant“a” of tectonic coal is bigger than original‐structure‐coal with a variation about 1% ~4% ,while adsorption constant“b”have no obvious change .By estimation of specific surface free energy ,it is found that most tectonic coal have a higher surface activity .The gas emission experiment show that tectonic coal samples have a 14% ~25% higher initial diffusion speed of tectonic coal except Qilin mine which indicates tectonic coal have a stronger gas emission capacity .The results reveal that tectonic coal have a broken structure which not only enhances adsorption but also emission capacity .And these characteristics contribute to coal and gas outburst occurs .%本文研究了5对矿井的两种煤样的吸附与放散特性。吸附实验发现构造煤与原生结构煤相比吸附量有所增加，但增加幅度不大，且这种变化的幅度随着变质程度降低而逐渐变大。构造煤煤样的Langmuir吸附常数“a”值均比原生结构煤较大，变化幅度约为1％～4％，而“b”值却没有明显的变化规律。对比原生结构煤与构造煤的煤体表面吸附自由能估算结果得知大部分构造煤样的比表面自由能有所提高，吸附的表面活性增大。瓦斯放散实验发现，构造煤的瓦斯放散初速度变化相对较大，除麒麟矿外，变化幅度在14％～25％之间。这说明构造煤具有更强的放散瓦斯能力。在长期的地质应力作用下，构造煤煤体更加破碎，不仅吸附能力得到了一定的提高，瓦斯能更加顺利的放散。这也是地质构造带具有更大的瓦斯突出危险性的一个原因。