浅埋藏近距离煤层群开采煤炭自燃防治理论与技术基础

The coal seams in western mining areas are with the characteristics of easy self-ignition, shallow burial depth, close distance and thin bedrock. The warning index in oxidation process of the soaked coal after air drying will be proposed according to studying the spontaneous combustion characters of soaked coal under the condition of air drying in overlying goaf and their differences in intrinsic mechanism. By analysis of mining-induced fractures distributing characteristics, air leakage law and diffuse characteristics of the gaseous product of coal spontaneous combustion in goaf, the judging methods of distinguishing coal spontaneous combustion areas in combined close distance goaf will be formed. Based on the dynamic equilibrium principle of gas pressure in combined close distance goaf, the plugging, flowing and fire control properties of inorganic solidified foam and sand-suspended colloid and the heat and mass transfer characters and diffusion migration laws of liquid nitrogen(or liquid carbon dioxide) with large flow in loose coal rock mass, a set of integrated approach which refers to airflow control, plugging, quick inerting and cooling will be built. In this project, theories and methods of preventing coal spontaneous combustion, which takes the spontaneous combustion characteristics of soaked coal after air drying as the foundation, the air leakage law of mining-induced fractures as the prerequisite and the various fire prevention methods as the approach, will be establish. The research results will provide the theoretical guidance and technical support for preventing coal spontaneous combustion in western mining areas, as well as ensure efficient mining in coal mine groups of ten million tons.

针对西部矿区煤层易自燃、埋藏浅、间距近、基岩薄等特点，研究上覆采空区遗煤浸水风干条件下的自燃特性及其差异的内在机制，提出浸水煤体风干后氧化过程中的预警指标；研究浅埋藏近距离煤层群开采覆岩采动裂隙发育演化特征、漏风规律及煤自燃气体产物在大采空区的运移特征，形成近距离复合采空区煤自燃火源区域判定的方法；研究近距离复合采空区气压动态平衡理论，无机固化泡沫和稠化砂浆的堵漏、流动与防灭火特性，大流量液氮（二氧化碳）在松散煤岩体内的传热传质及扩散运移特征，构建以控风、堵漏与快速惰化降温为一体的浅埋藏近距离煤层群开采煤自燃防治的综合方法。通过本项目研究，建立以浸水风干煤体的自燃特性为基础、以覆岩采动裂隙漏风规律为前提、以多种防灭火方法为手段的浅埋藏近距离煤层群开采煤自燃防治理论与方法，为有效防治西部矿区煤自然发火、保障其千万吨矿井群的安全高效开采提供理论指导和技术支撑。

本项目研究了浸水溶胀煤风干条件下煤的自燃过程及特性。系统地开展了长期浸水煤风干过程中自燃特性的研究，揭示了标志性气体、交叉点温度、初始放热温度等参数的变化规律，发现了浸水煤风干过程中存在较原煤更易自燃的水份区间，掌握了煤自燃的热动力学变化过程和自然发火期，提出了浸水煤风干过程中的煤自燃预警指标；研究了浸水风干过程对煤物理和化学结构的影响，分析了孔隙结构、官能团、自由基与氧化产物和热变化的相互转化关系，揭示了浸水溶胀煤风干过程引起煤自燃特性差异的内在机制。. 研究了近距离复合采空区覆岩裂隙漏风及煤自燃气体运移规律。以神东矿区浅埋藏近距离煤层群为研究对象，通过地表裂隙和漏风实测以及相似模拟实验，构建了采空区裂隙-孔隙模型，揭示了浅埋藏近距离煤层群开采上覆岩层采动裂隙的时空演化规律、煤层群复合采空区的形成及裂隙二次发育规律，掌握了采空区上部覆岩主要漏风通道分布特征及下煤层开采时上覆采空区氧气浓度分布规律，为浅埋藏近距离煤层群开采的煤自燃防治提供理论依据。. 研究了浅埋藏近距离煤层群采空区堵漏控风及快速惰化降温方法。研制出基于抑制和消除煤中活性结构的含保水和化学阻化功能的复合阻化剂，发明了以粉煤灰和水泥为基材的高倍数低成本无机固化泡沫防灭火技术及装置，研发了强扩散、高堆积、具有成膜功能的凝胶泡沫材料，揭示了液氮在采空区的扩散运移规律。集成创新了堵漏控风、阻化隔氧、惰化降温的井上下联动防灭火技术体系，解决了浅埋近距煤层群复合采空区煤自燃防治的难题，取得了显著的经济和社会效益。. 本项目在国内外学术期刊上发表学术论文45篇（SCI检索36篇，JCR一区和二区共26篇），出版学术专著2部；授权美国等国际发明专利15项，中国发明专利15项；获省部级一等奖1项、二等奖1项；多次参加国际学术会议并作大会报告；培养了博士6人，硕士20人。