覆岩离层注浆用煤矸石基充填材料微结构及充填物化性能研究  

Research on the microstructure and physicochemical properties of coal gangue-based filling material used for grouting in overlying strata

作　　者：王家乐 王学安 南娜 李耿 王传留 WANG Jia-le;WANG Xue-an;Nan Na;LI Geng;WANG Chuan-liu(Xi’an Research lnstitute,China Coal Technology and Engineering Group,Xi’an,Shaanxi 710077,China;Shaanxi Guojiahe Coal Industry Co.,Ltd,Baoji,Shaanxi 721000,China)

机构地区：[1]中煤科工西安研究院(集团)有限公司,陕西西安710077 [2]陕西郭家河煤业有限责任公司,陕西宝鸡721000

出　　处：《煤炭加工与综合利用》2024年第12期127-132,共6页Coal Processing & Comprehensive Utilization

摘　　要：煤矿区覆岩离层对地表沉降、矿区安全等有直接影响,而注浆充填是解决该问题的主要技术手段,其中充填材料决定着离层充填成本和实际效果。针对神东矿区覆岩离层注浆充填材料问题,系统性研究了神东矿区煤矸石原材料物化组成及注浆性能,探究不同水/灰比条件及不同成分级配条件下煤矸石基充填材料的物化性能。通过制备不同水/灰比的纯矸石料、矸石+粉煤灰、矸石+粉煤灰+水泥三种实验材料,研究了不同配方充填材料的固化特性、抗压强度、流动度与泌水率等关键指标,分析了粉煤灰及水泥的掺入对煤矸石基充填材料性能的影响机理。结果表明,三种充填材料的抗压强度均随着水/灰比的增加而降低;同一水/灰比下,纯矸石样品或矸石掺粉煤灰充填材料的早期抗压强度(3 d、7 d)及后期强度(28 d)较低,均在1 MPa以下;掺入水泥(矸石+粉煤灰+水泥)后,充填材料早期强度(3 d, 7 d)显著增加,后期强度(28 d)大幅提升;水泥作为胶凝材料掺入,对多棱角煤矸石骨料间起到滚珠润滑交联作用,减小骨料间机械咬合,显著改善了砂浆流动性。The overlying strata in coal mining areas have a significant impact on surface subsidence and mining safety.Grouting filling is the main method to solve this problem,where the filling material determines the cost and actual effect of separation layer filling.In order to solve the problem of grouting and filling in the separated strata of overburden in Shen-dong mining area,this paper systematically studies the physical and chemical composition and grouting properties of coal gangue raw materials in Shen-dong mining area.The performance of coal gangue-based anti-well material under various water to cement ratio and different composition grades were investigated.By preparing three experimental materials with different water to cement ratios of pure gangue,the gangue added with fly ash,and gangue blended with fly ash and Portland cement,the key properties of curing behaviors,compressive strength,fluidity,and the bleeding rate of these filling materials were analyzed.And the influence mechanism of the addition of fly ash and cement on the performance of coal gangue-based filling materials was investigated.Results indicate that the compressive strength of the three filling materials decreases with the increase of water to cement ratio.The early strength(3 d,7 d)and late strength(28 d)of the pure gangue and the gangue mixed with fly ash are all lower under the same water to cement ratio,which are below 1 MPa.After adding cement into the filling materials,the early strength(3 d,7 d)of this material(gangue+fly ash+cement)significantly increases,and the later strength(28 days)are greatly enhanced.As a cementitious material,cement plays an important role in ball-lubricated and cross-linking between multi-angular coal gangue aggregates,reducing mechanical engagement between aggregates and improving the fluidity of mortars.

关 键 词：煤矸石 离层注浆 充填材料 物化性质 力学性能 

分 类 号：TD849.5[矿业工程—煤矿开采]