水浸干燥后煤的孔隙结构及瓦斯吸附特性变化规律

司磊磊; 席宇君; 王洪洋; 温志辉; 魏建平

doi:10.3969/j.issn.1001-1986.2021.01.010

水浸干燥后煤的孔隙结构及瓦斯吸附特性变化规律

doi: 10.3969/j.issn.1001-1986.2021.01.010

司磊磊^1,2,3,
席宇君^1,2,3,
王洪洋^1,2,3,
温志辉^1,2,3,
魏建平^1,2,3, ,

基金项目:

中原科技创新领军人才项目（204200510032）；国家自然科学基金项目（52004083）

详细信息

第一作者:
司磊磊,1991年生,男,河南博爱人,博士,讲师,从事矿井瓦斯防治工作.E-mail:si_leilei@hpu.edu.cn

通信作者:
魏建平,1971年生,男,河南驻马店人,博士,教授,从事矿井瓦斯防治工作.E-mail:hpuwjp@163.com

中图分类号: TD712
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- 被引次数: 0
出版历程
- 收稿日期: 2020-11-03
- 修回日期: 2020-12-28
- 发布日期: 2021-02-25

The characteristics of pore structure and gas adsorption for water-immersion coal after drying

SI Leilei^1,2,3,
XI Yujun^1,2,3,
WANG Hongyang^1,2,3,
WEN Zhihui^1,2,3,
WEI Jianping^{1,2,3
, ,}

摘要

摘要: 在富含水煤系或水力措施后的煤层中，受水溶液的浸泡，煤的孔隙结构及吸附特性发生改变，为了深入研究其变化规律，在实验室利用蒸馏水对2种不同变质程度煤样进行了长时间（60 d）浸泡，采用低温N₂吸附实验和CO₂吸附实验测试水浸前后煤样的孔隙结构变化规律，采用高压容量法测试水浸前后煤样的瓦斯吸附特性。结果表明，水浸干燥后煤体孔容和比表面积总体呈降低趋势。其中，低温N₂吸附实验结果表明，煤体中大中孔的比表面积最高可降低48.9%；CO₂吸附实验结果表明，水浸干燥后2种煤样的微孔孔容和比表面积也呈不同程度的降低趋势。将水浸煤样孔隙结构变化分为3个阶段，即矿物质溶出“增孔”阶段、煤基质局部膨胀变形“缩孔”阶段和煤基质整体溶胀变形“扩孔”阶段。此外，水浸干燥后煤对瓦斯的吸附能力下降，主要是由于水浸促使煤体产生膨胀变形，且导致微孔隙相互连通，从而降低了煤体微孔孔容和比表面积，降低瓦斯吸附能力。研究成果对进一步掌握富含水煤系或水力化措施后煤层的瓦斯抽采具有指导意义。
- 水浸 /
- 比表面积 /
- 孔容 /
- 孔隙结构 /
- 等温吸附
Abstract: In order to investigate the characteristics of pore structure and methane adsorption for water-immersion coal after drying, two coal samples with different ranks were soaked in distilled water for a long time(60 d). Then, the low-temperature N₂ adsorption experiments and CO₂ adsorption experiments were carried out to investigate the changing rules of pore structure for coal before and after water immersion, and the high-pressure capacity method was used to test the characteristics of methane adsorption. Results showed that the pore volume and specific surface area of coal decreased after water immersion. According to the results of low-temperature N₂ adsorption, the specific surface area of mesopore and macropore can be reduced by up to 48.9%. CO₂ adsorption experiments shows that the pore volume and specific area of micropore decrease in varying degrees. The changes of pore structure consists of three stages, namely, the "pore increase" stage of mineral dissolution, the "shrinkage" of local expansion of coal matrix, and the "pore expansion" of overall swelling of coal matrix. In addition, the adsorption capacity of coal decreases after water immersion due to the interconnection of micropores caused by coal expansion and deformation, which reduces the pore volume and specific surface area of coal micropores. The research results have a guiding significance for gas drainage in water-rich coal measures and coal seam after hydraulic measures.
- water immersion /
- specific surface area /
- pore volume /
- pore structure /
- adsorption isotherm

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