循环流化床粉煤灰对矸石胶结充填材料性能的影响

Influence of Circulating Fluidized Bed Fly Ash on Properties of Gangue Cemented Filling Materials

为充分利用循环流化床粉煤灰(CFA),应用CFA制备矸石胶结充填材料。考察了粉煤灰-水泥体系的净浆流动度、流变特性和自由膨胀率随CFA掺量的变化规律,以及CFA对充填材料工作性和力学性能的影响规律,探讨应用CFA制备充填材料的可行性。结果表明:粉煤灰-水泥体系复合浆体的流变模型仍为Bingham流体模型,而随着CFA掺量增大,塑性粘度增大,流动度降低,浆体流动性变差。掺加0%~60%的CFA,能够制备出性能良好的充填材料。在CFA掺量低于60%时,新拌浆体的坍落度、扩展度、含气量降低幅度较小,泌水情况减少,充填材料工作性可完全满足工程设计;新拌浆体硬化后孔隙率更低,力学性能良好。应用CFA制备充填材料具备可行性。

In order to make full use of circulating fluidized bed fly ash(CFA),the gangue cemented filling materials were prepared with CFA.The fluidity,rheological properties and free expansion rate of fly ash-cement systems with different content of CFA were discussed,as well as the workability and mechanical properties of the filling materials were studied.Base on properties characterized above,the feasibility of preparing filling materials with CFA was analyzed.The results show that the rheological model of fly ash-cement slurry systems still belongs to Bingham fluid model.With the increase of CFA content,the plastic viscosity increases and the fluidity decreases,which leads to the poor fluidity of slurry.The filling materials with good properties are prepared when CFA accounts for 0%-60%.When the CFA content is less than 60%,the slump,slump flow and air content of fresh slurry reduce slightly and the bleeding decreases,so the workability of filling materials fully meets the engineering design.Meanwhile,fresh slurry has lower porosity and good mechanical properties after hardening.It is feasible to prepare the new filling materials with CFA.