多种纳米材料协同优化矿用密封材料性能研究

Study on Synergetic Optimization of Mine Seal Materials with Several Kinds of Nanomaterials

煤矿井下抽采瓦斯不仅使瓦斯能源得到利用,同时也有助于消除煤炭开采过程中的瓦斯灾害风险。瓦斯抽采钻孔的密封性能直接影响抽采效果,因此本文通过对水泥基密封材料进行改性优化,提升瓦斯抽采率,降低瓦斯事故发生的概率。本文讨论了纳米二氧化硅(NS)、多壁碳纳米管(MWCNTs)和氧化石墨烯(GO)对钻孔密封材料孔隙率、微观结构和力学性能的影响。结果表明,三种纳米材料的协同作用促进了水合硅酸钙(C-S-H)、钙矾石(Aft)等水化产物的生成,优化了微观孔结构。然而当NS的含量从2 wt%增加到4 wt%时,力学性能的改善明显减弱。2wt%NS、0.1wt%MWCNTs、0.03 wt%GO为最佳配比,与纯水泥相比,力学性能提高24.7%,总孔隙率降低23.9%。研究结果表明纳米水泥基改性材料优化了密封材料孔隙结构及力学性能,对于提高瓦斯抽采具有重要意义。

Underground gas extraction in coal mines not only makes use of gas energy,but also helps to eliminate the risk of gas disasters in the process of coal mining.The sealing performance of the gas drainage hole directly affects the drainage effect.Therefore,this paper improves the gas drainage rate and reduces the probability of gas accidents by modifying and optimizing the cement-based sealing material.In this paper,the effects of nano-silica(NS),multi-walled carbon nanotubes(MWCNTs)and graphene oxide(GO)on the porosity,microstructure and mechanical properties of drilling sealing materials are discussed.The results show that the synergistic effect of the three nanomaterials promotes the formation of hydration products such as calcium silicate hydrate(CSH)and ettringite(Aft),and optimizes the microscopic pore structure.However,when the content of NS was increased from 2 wt%to 4 wt%,the improvement of mechanical properties was significantly weakened.2wt%NS,0.1wt%MWCNTs,and 0.03 wt%GO were the optimal ratios,and compared with pure cement,the mechanical properties were improved by 24.7%,and the total porosity was reduced by 23.9%.The research results show that the nano-cement-based modified material optimizes the pore structure and mechanical properties of the sealing material,which is of great significance for improving gas drainage.