纳米氮化硅复配三乙醇胺激活粉煤灰对煤矿封孔材料早强性能的研究

Study on the Influence of Nano-Si3N4 Compounding Triethanolamine Activating Fly Ash on the Early-strength Properties of Coal Mine Sealing Material

针对煤矿封孔材料在井下高温高湿环境中存在的早期强度不足、凝结时间不稳定、流动度不佳等问题,采用一部分粉煤灰替代普通硅酸盐水泥,结合纳米Si3N4复配有机早强组分三乙醇胺(TEA),借助早期抗压强度、凝结时间、流动性、XRD、电镜扫描(SEM)和热重(TG-DSC)等力学参数试验和微观结构分析,研究纳米Si3N4复配三乙醇胺对粉煤灰封孔材料的早强性能的影响和粉煤灰激发效果。结果显示,当纳米Si3N4质量比2%,粉煤灰质量比10%、三乙醇胺质量比为0.05%时,水泥样品早强性能最优,其1,3,7,28d抗压强度分别达到8.92,22.35,29.78,57.36 MPa,较空白水泥样品分别提升了32.7%、39.9%、36.7%、39.6%,且其流动性优异,凝结时间明显缩短。根据XRD、SEM和热重等微观结构分析,纳米Si3N4复合三乙醇胺能有效促进粉煤灰活性的激发,水泥的水化反应速度加快,生成更多的硅酸盐以及水化硅酸钙包裹在粉煤灰颗粒四周,各凝胶之间相互穿插,使得内部结构稳定致密,水泥材料的早期性能和耐久性得到了提高。

Aiming at the problems of insufficient early strength,unstable setting time and poor fluidity of coal mine sealing materials in underground environments with high temperature and high humidity,apart of fly ash was used instead of ordinary portland cement.Then combined with nano-Si3N4 compounding organic early-strength component triethanolamine(TEA),its effects on the early-strength properties of fly ash sealing materials were studied,as well as its activation effect on the fly ash through the early compressive strength,setting time,fluidity,XRD,electron microscopy(SEM)and thermogravimetry(TGDSC).The results show that when the mass ratio of nano-Si3N4,fly ash and triethanolamine is 2%,10% and 0.05%respectively,the early strength performance of cement samples is the best.The compressive strength of 1,3,7,and 28 dcan reach 8.92,22.35,29.78 and 57.36 MPa respectively,which increases by 32.7%,39.9%,36.7% and 39.6% respectively compared with the blank cement sample,with an excellent fluidity and shorter setting time.According to XRD,SEM and thermogravimetric analysis,nano-Si3 N4 compounding triethanolamine can effectively promote the activation of fly ash,accelerate the hydration reaction speed of cement,and generate more silicates and hydrated calcium silicate wrapping around the fly ash particles.The gels are interspersed with each other to make the internal structure stable and dense,so that the early performance and durability of the cement material are improved.