相变溶胶化学沉积防治煤矿采空区自燃火灾基础研究

The spontaneous combustion of coal in goaf is one of major disasters which seriously threaten the safety in collieries. Traditional technologies such as nitrogen injection and grouting have been extensively used, but these methods still have some limitations. Thus, a new thought on system transformation between sol-gel is adopted for solving this problem. Aerosols produced by the cold state method are injected in the goaf for fire hazard control, and the plasmas are also provided as the auxiliary material for accelerating the settlement of aerosol particles. Meanwhile, aerosols are chemically depositing, absorbing, and cementing on the surface of coal. The thin membrane of dense gel is formed via the phase transition of sol particles. The oxidation activities of coal molecule could be effectively inhibited via the fissure filling and chemical suppression. In this study, we intend to select the optimal precursor and crosslinking agent for the phase transition sol through experiments and theoretical analysis. The impact factors, reaction mechanism and the apply technics of phase transition sol in goaf will be principally investigated. Combined with experimental platform and CFD simulation, the migration, proliferation and distribution of sol particle in goaf are studied in this research. Furthermore, in order to comprehensively reveal effects of this material on coal self-ignite, its microscopic structure, inhibition characteristics, stability and adsorption properties are measured by detection techniques such as TG/DSC, FTIR, GC/MS, XPS and AFM etc.. Research results of this project will bring about a green, economical and efficient technology in controlling of coal spontaneous combustion, also provide efficient safeguard for coal mine safety

采空区自燃火灾是严重威胁煤矿安全的主要灾害之一。注浆、注氮等传统防灭火技术虽然被广泛应用，但仍存在一定的局限性。申请者引入“溶胶-凝胶”体系转换这一新思路，通过冷态法制备气相溶胶注入采空区，并以等离子辅助溶胶粒子沉降，促使溶胶化学沉积、吸附于煤体表面，相变形成致密凝胶薄层，封堵裂隙并抑制煤分子氧化活性，高效防治煤自燃灾害。本项目拟通过实验与理论分析优选相变溶胶的前驱体与交联剂，重点研究采空区内相变溶胶转化的影响因素、控制机理与应用工艺。结合实验平台与CFD模拟研究采空区内溶胶粒子的运移、扩散及分布规律；利用TG/DSC、FTIR、GC/MS、XPS、AFM等检测技术研究相变溶胶的微观结构、稳定与吸附性能、阻燃特性，揭示其对煤自燃规律的综合影响。本项目的研究成果将形成绿色、经济、高效的煤自燃防治新技术，为矿井安全高效开采提供保障。

采空区自燃火灾是严重威胁煤矿安全的主要灾害之一，随着矿井开采条件与技术的不断变化，日益复杂的井下环境提高了矿井火灾防治的难度。针对复杂条件下煤矿采空区自燃风险加剧这一难题，本项目基于理论分析与实验测试研发用于煤矿采空区遗煤自燃灾害防治的相变冷态气溶胶材料，并探索了相变气溶胶材料抑制煤自燃灾害机理。相变溶胶以气（雾）态形式注入采空区，规避了液态惰性介质在采空区内流动覆盖范围窄的问题；粒子在煤表面沉积并反应后形成致密的隔绝层，抑制煤表面活性基团，控制煤的氧化自热，弥补气态灭火材料无法在采空区内滞留的缺点，起到经济、高效、绿色防治矿井火灾的目的。结合微观结构测试与多尺度实验模拟研究了气溶胶材料的制备关键技术、扩散运移规律及防灭火性能。以无机物为基料制备超细固体粉末颗粒，辅以惰气为载气发生冷气溶胶可用于治理采空区高温火区。含磷与含氯材料的协同使用增强了灭火效果，具备实现低温阻化与高温阻燃双重抑制的潜力，而表面改性助剂的使用保障了超细颗粒的稳定制备与储存。根据孤粒子沉降理论，气溶胶粒子良好的滞空时间使其具备障碍物空间内扩散的基础。超细颗粒气溶胶粒子在煤表面附着沉积后，在高温影响下迅速反应形成稳定的隔绝层，降温灭火的同时有效防止复燃风险。用超声波持续雾化不同组分无机盐溶液制备细水雾冷态气溶胶，同时流经煤体表面相互反应形成丰富的固态化学沉淀，处理后煤样的氧化放热与含氧官能团活性被明显削弱，在兼顾材料流动性的前提下实现了长效阻化。以低分子聚合物为原料辅以交联剂，喷洒细水雾冷气溶胶在煤表面反应形成致密凝胶层，固结水分且封堵孔裂隙，有效降低煤表面物理吸附氧气，抑制煤的进一步氧化升温。本课题的研究提供了一种潜在的新型煤炭自燃火灾防治方法，具有良好的理论价值与应用潜力，为煤自燃灾害的高效防治提供了参考。