固结软煤层瓦斯抽采钻孔周围裂隙的弹性胶结材料研制

Development of elastic cemented material for consolidating cracks around drilling holes in gas drainage in soft coal seams

为了固结煤层中钻孔周围的裂隙,以聚二甲基硅氧烷、含氢硅油、聚丙烯纤维和秸秆纤维为原料,制备一种用于煤岩裂隙固结的弹性胶结材料,通过扫描电子显微镜和颗粒分析仪观察聚丙烯纤维和秸秆纤维在弹性胶结材料中的微观形貌,通过万能试验机研究不同掺量的聚丙烯纤维和秸秆纤维对弹性胶结材料力学性能的影响。研究结果表明:掺入一定量的聚丙烯纤维和秸秆纤维可以增强弹性胶结材料力学性能,随着聚丙烯纤维和秸秆纤维掺量的增加,弹性胶结材料的力学性能变差,聚丙烯纤维-秸秆纤维的最优掺量为0.6%~1%;聚丙烯纤维可以作为连接材料桥接弹性胶结材料内部不连续的区域,同时,聚丙烯纤维表面粗糙,可以黏结更多的胶体,增大聚丙烯纤维脱胶的阻力;当秸秆纤维掺量为0.5%和1%时,秸秆纤维在材料中的分散情况较好,而当掺量为1.5%时,材料中的秸秆纤维开始出现团聚现象,当掺量为2%时,团聚现象严重;弹性胶结材料与煤体有良好的粘结性,能够将松散的煤体黏结在一起,构成一个整体,具有一定的力学强度;加固煤体模块在力的加载过程中,逐渐变形,但加固后的煤体并未被压溃,依然保持良好的完整性;现场试验表明,随着抽采时间的增加,瓦斯混合流量缓慢下降,并未出现瓦斯混合流量剧烈波动或下降的现象,证明在抽采过程中,钻孔未发生失稳问题,钻孔孔壁保持完整。

In order to consolidate the cracks around the borehole in the coal seam,an elastic cemented material for fracture consolidation of coal and rock was prepared by using polydimethylsiloxane,PMHS,polypropylene fiber and straw fiber as raw materials.The micro mor⁃phology of polypropylene fiber and straw fiber in the elastic cemented material was observed by scanning electron microscope and particle analyzer.The effects of different contents of polypropylene fiber and straw fiber on the mechanical properties of elastic cementitious materi⁃als were studied by universal testing machine The results show that:adding a certain amount of polypropylene fiber and straw fiber can en⁃hance the mechanical properties of elastic cemented material;With the increase of content of polypropylene fiber and straw fiber,the me⁃chanical properties of elastic cemented material became worse;The optimal content of polypropylene fiber-straw fiber was 0.6%-1%.Poly⁃propylene fiber can be used as a connecting material to bridge the internal discontinuous area of elastic cemented material.At the same time,the surface of polypropylene fiber is rough,which can bond more colloids and increase the resistance of polypropylene fiber degum⁃ming.When the content of straw fiber is 0.5%and 1%,the straw fiber dispersion in the material is better,and when the content is 1.5%,the straw fiber in the material begins to appear agglomeration.When the content is 2%,the agglomeration was serious.The elastic cemented material had good cohesiveness with the coal,which can bond the loose coal together to form a whole,with a certain mechanical strength.The reinforced coal module gradually deformed in the process of force loading,but the reinforced coal is not crushed,and still maintains good integrity.The field test showed that the gas mixed flow decreased slowly with the increased of the extraction time,and there was no sharp fluctuation or decrease of gas mixing flow,which proved that there was no instability problem in the borehole during the extraction process,and the borehole wall remained intact.