煤的润湿性是煤-水界面作用体现，也是影响甲烷吸附/解吸的重要因素。为了分析不同宏观煤岩组分润湿性差异及对甲烷吸附/解吸的影响，基于大佛寺井田4号煤不同类型镜煤、暗煤样品(空气干燥基样、平衡水样及不同活性剂改性后煤样）润湿性及甲烷吸附/解吸实验结果，分析不同宏观煤岩组分润湿性差异及其对吸附/解吸的影响。结果表明，煤-水接触角均小于90°，具亲水性，镜煤为66.9°，暗煤为61.2°，暗煤润湿性比镜煤好。不同活性剂溶液对煤样处理后润湿性由差到好依次为G502样(疏水性）、6501样、LAS样、JFC样，G502促使煤润湿反转，镜煤和暗煤接触角分别增大至98.8°、90.3°，其他3种活性剂均可改善煤的润湿性，接触角最低降至32.5°。相较于暗煤，镜煤的微孔隙相对发育，占比高达80%，孔隙连通性差，润湿性差，吸附甲烷能力较强，但甲烷解吸效率低于暗煤。煤的润湿性与吸附甲烷的能力负相关，不同样品饱和吸附量为5.63～26.98 cm3/g，G502样、空气干燥样、平衡水样、6501样、JFC样、LAS样吸附能力依次变弱。解吸能力则与润湿性呈正相关，解吸能力由低到高依次为G502样、6501样、JFC样、LAS样。煤的润湿性越好，煤-水界面分子作用越强，煤基质表面易被大量水分子占据，水、甲烷分子竞争吸附，煤吸附甲烷能力变弱，但同时也促进了甲烷解吸。

The wettability of coal reflects the interaction between coal and water,and is also an important factor affecting methane adsorption/desorption. The wettability differences of vitrain and durain of No.4 coal seam in the Dafosi coal field their influence on methane adsorption/desorption are analyzed,based on the data of wettability and methane adsorption/desorption test. The results show that the contact angle between coal and water is less than 90°,indicating the coal is hydrophilic,which of vitrain is 66.9°and durain is 61.2°. The wettability of durain is better than vitrain. The wettability sequence of coal samples treated by different active agent solutions is G502 samples (hydrophobicity),6501 samples,LAS samples and JFC samples,from poor to good. G502 promotes the wettability reversal of coal,resulting in the contact angle of vitrain and durain increased to 98.8° and 90.3°,respectively. And the other three active agents can improve the wettability of coal samplesresulting in the contact angle reduced to 32.5°. Compared with durain,vitrain has relatively more micropores,with a proportion of 80%,poor pore connectivity and wettability,strong methane adsorption capacity and lower methane desorption efficiency. The wettability of coal is negatively correlated with methane adsorption capacity,ranging from 5.63 to 26.98 cm3/g and the adsorption capacity from strong to weak is G502 sample,air dried sample,water balanced sample,6501 sample,JFC sample and LAS sample. The desorption capacity was positively correlated with the wettability,and the desorption capacity from low to high was G502 sample,6501 sample,JFC sample and LAS sample. The better the wettability of coal,the stronger the coal-water interface molecular interaction,and the coal matrix surface is easier to be occupied by a large number of water molecules,thus the coal methane adsorption capacity is weakened because of competitive adsorption of water and methane molecules,but that also promote methane desorption.

0 引言

1 样品与试验

2 煤样基本特征

   2.1 煤岩煤质特征

   2.2 孔隙特征

   2.3 润湿性

3 吸附解吸特征

   3.1 镜煤/暗煤吸附解吸特征

   3.2 润湿性对吸附/解吸影响

4 结论