Research And Application Of Mucus Sealing Material For Gas Drainage Drilling Holes

Gas is a byproduct of coal mining,and coal and gas outbursts are one of the main hazards in the coal production process,posing a serious threat to mine safety and affecting coal production capacity.Gas drainage through drilling is an effective means of preventing and controlling coal mine gas disasters.However,issues such as rapid concentration attenuation and low effective utilization rate of boreholes have been affecting the effectiveness of gas control and utilization in mines.Currently,the most commonly used sealing materials are cement mortar and polyurethane.However,these solid sealing materials have low deformability,and under stress,they can deform and generate new cracks,thereby developing into gas leakage channels,which affects gas drainage efficiency.To improve the shortcomings of the aforementioned materials,this study is based on the concept of "solid-liquid coupling,dynamic sealing,and active pressure." A highly absorbent resin is used as a sealing material.This material has good initial fluidity and can penetrate and seal gas in microcracks,resulting in better sealing performance.Depending on the sealing process,secondary and multiple sealings can be achieved,enabling continuous and high-quality gas drainage through boreholes.In summary,this paper first studied the optimal preparation conditions of CMC/CMS-Na dual matrix highly absorbent resin and CMS-Na/CMN highly absorbent resin.The influence of factors such as matrix mass ratio,monomer mass ratio,polymerization reaction temperature,degree of acrylate neutralization,initiator dosage,crosslinking agent dosage,etc.,on the resin material properties was investigated using the single-factor controlled variable method.Subsequently,the performance of SAP(CMC/CMS-Na)and SAP(CMS-Na/CMN)was analyzed and compared.Orthogonal experiments were designed to determine the performance parameters of the two materials at different mass ratios,and the optimal water-to-material ratio of the sealing material was determined as SAP(CMC/CMS-Na): SAP(CMS-Na/CMN):water = 1:1:100.To address the problem of dynamic sealing and multiple sealings of boreholes after traditional sealing materials are used,the study focused on the preparation of highly absorbent resin mucilage sealing material.A bag-pressure dynamic sealing process was designed,wherein cement mortar was injected into the bag as a plug,and the middle sealing zone was filled with highly absorbent resin mucilage sealing material.This process achieves dynamic sealing of the boreholes and allows for secondary and multiple grouting injections,meeting the requirements of long-term gas drainage for borehole sealing effectiveness.Finally,based on the research findings mentioned above,field industrial experiments were conducted at the Xiangshan Coal Mine of Shanxi Coal Group.The results show that compared to the traditional bag-cement mortar sealing method,the bag-pressure dynamic sealing using highly absorbent resin significantly increased the gas drainage concentration,slowed down the gas concentration attenuation rate,and showed a significant improvement in gas concentration after secondary grouting.The average gas concentration throughout the entire process increased by approximately30%,demonstrating significant effectiveness.The paper has 70 figures,8 tables,and 110 references.