磨细粉煤灰调控矿渣基充填材料配比优化以及硬化机理研究  

Study on the Proportion Optimization and Hardening Mechanism of Slag-Based Filling Materials Regulated by Finely Ground Fly Ash

作　　者：滑怀田 王清亚[2] HUA Huaitian;WANG Qingya(Department of Mining Engineering,Shanxi Institute of Technology,Yangquan,Shanxi 045000,China;School of Earth Sciences,East China University of Technology,Nanchang,Jiangxi 330013,China)

机构地区：[1]山西工程技术学院矿业工程系,山西阳泉市045000 [2]东华理工大学地球科学学院,江西南昌330013

出　　处：《矿业研究与开发》2024年第2期33-40,共8页Mining Research and Development

基　　金：阳泉市科技局项目(2020YF040);山西工程技术学院科研项目(2020SQD-01)。

摘　　要：为实现粉煤灰与高炉矿渣的高效利用,并研发低原料成本高性能的矿山用胶结充填材料,开展了一系列正交配比优化试验,探究了粉煤灰掺量、Ca(OH)_(2)、Na_(2)SO_(4)与料浆质量浓度等因素对矿渣基胶结充填材料的抗压强度、流动性与凝结时间等性能的影响,并获得了最优的参数配比,同时利用热重差热分析以及扫描电镜微观分析研究了磨细粉煤灰对矿渣基材料的调控机制与硬化机理。结果表明:正交试验中充填体7 d与28 d的抗压强度分别大于2.6 MPa与6.8 MPa;Ca(OH)_(2)的碱激发对提升3 d抗压强度起到重要作用,而粉煤灰掺量对充填体各龄期的抗压强度提升起到重要作用;充填材料最优参数配比(Y样品)为:磨细粉煤灰掺量30%、Ca(OH)_(2)掺量15%、Na_(2)SO_(4)掺量5%与料浆质量浓度80%。硬化机理分析表明:磨细粉煤灰的掺入,使矿渣基胶结充填材料110℃附近的C-S-H与钙矾石等水化产物吸热峰增大,Y样品3 d与28 d的失重量分别为4.80%与4.96%,证明充填材料体系不断反应,产生更多的C-S-H与钙矾石,二者连接生长在一起,充填体的结构比较密实且孔隙减少,提供较大的抗压强度。In order to achieve the efficient utilization of fly ash and blast furnace slag,as well as develop the low-cost and high-performance cemented filling materials for mining,a series of orthogonal ratio optimization experiments were conducted.The effects of fly ash content,Ca(OH)_(2)content,Na_(2)SO_(4)content,and slurry mass concentration on the compressive strength,fluidity,and setting time of the slag-based cemented filling materials were explored,so as to obtain the optimal parameter proportion.At the same time,the regulation mechanism and hardening mechanism of finely ground fly ash on slag-based materials were studied by thermogravimetric differential thermal analysis and scanning electron microscopy.The results show that the compressive strength of the backfill at 7 days and 28 days in the orthogonal experiments exceeds 2.6 MPa and 6.8 MPa,respectively.The alkaline activation of Ca(OH)_(2)plays a crucial role in enhancing the compressive strength at 3 days,while the fly ash content has a significant effect on the overall compressive strength of the backfill.The optimal parameter proportion of filling materials(Y sample)is:30%finely ground fly ash content,15%Ca(OH)_(2)content,5%Na_(2)SO_(4)content,and 80%slurry mass concentration.The analysis of the hardening mechanism indicates that the addition of finely ground fly ash increases the endothermic peak of the hydration products such as C-S-H and ettringite around 110℃in the slag-based cemented filling materials.The weight loss of Y samples at 3 days and 28 days is 4.80%and 4.96%,respectively,which indicates continuous reactions within the filling materials,resulting in the formation of more C-S-H and ettringite.The interconnection and growth of these products lead to a denser structure and reduce porosity in the filling body,contributing to higher compressive strength.

关 键 词：磨细粉煤灰 充填材料配比 硬化机理 流动性 抗压强度 

分 类 号：TD853.34[矿业工程—金属矿开采]