粉煤灰-煤矸石基胶结充填材料制备与性能研究

Preparation and Performance Study of Cemented Filling Material Based on Fly Ash and Coal Gangue

为了解决我国煤矿采空区地表沉陷以及"三下"压煤资源浪费的问题,提出以粉煤灰-水泥熟料-脱硫石膏复合胶凝材料为胶结材,原状粉煤灰为细骨料,破碎后的煤矸石为粗骨料制备新型煤矿开采胶结充填材料。依据正交试验结果和各因素影响规律趋势图,确定充填材料的优化配合比。研究结果表明,适当增大水泥熟料掺量可缩短材料初凝时间,减小水胶比能使材料强度显著提高,而材料坍落度可通过选取适宜的浆体中的固体质量分数和灰矸比来有效调节,当胶凝材料中水泥含量为15%,脱硫石膏含量为8%,水胶比为2,灰矸比为2∶3,浆体中的固体质量分数为70%时,充填材料性能可达到最佳。通过试验优选材料各项参数,工业废弃物可以用来制备高质量的胶结充填材料。

To solve problems of surface subsidence caused by mining of coal mine and waste of resources caused by unexploited coal under the surface construction,water body and railway,it was held by the authors that a new type of cemented filling material should be used,which was prepared from composite cementitious material composed of fly ash,cement and flue gas desulphurization gypsum as cementing material,raw fly ash as fine aggregates and coal gangue as coarse aggregates.In the light of the results of orthogonal experiment and tendency chart of influencing factor,optimized composition of the filling material was obtained.Results show that a increase in content of cement clinker can shorten setting time,decreasing water to binder ratio can enhance strength remarkably,that slump can be adjusted effectively through choosing suitable concentration and fly ash to coal gangue ratio,and that when content of cement clinker is 15%,content of flue gas desulphurization gypsum is 8%,water to binder ratio is 2,fly ash to coal gangue ratio is 2∶3 and the mass fraction of solids in paste is 70%,filling material has optimum performances,Industrial waste can be applied to prepare high-quality cemented filling material by optimization of parameters of material.