Performance of New Inorganic Retarding Sealing Material for Gas Drainage Boreholes

Gas drainage in coal mines plays a fundamental role in preventing coal mine accidents, relieving environmental pollution and utilizing coalbed methane (CBM) resources. Since the quality of borehole sealing technology is the key to efficient gas drainage, it is of great significance to develop a sealing material with excellent performance to ensure the long-term high-efficiency operation of gas drainage boreholes. Based on an analysis and summary of currently available research findings, the idea of sealing boreholes with liquid materials was proposed in this study. Firstly, the new inorganic retarding sealing material was briefly introduced, and its properties were tested. Secondly, the self-designed crack grouting test system was applied to test the diffusion performance of the material. The experimental results showed that the new inorganic retarding sealing material was characterized by great stability, thermal stability, fluidity, and thixotropy. The flow and diffusion of selected grout with different water-cement ratios in cracks under different conditions provided guidance for the selection of grouting pressure and the judgment of grouting diffusion distance for on-site grouting. Through the field test of Chengjiao Coal Mine, the effect of sealing is significantly improved compared with traditional materials.