HAc-PAC改性泥水盾构废弃泥浆絮凝脱水性能研究

Study on Flocculation and Dehydration Performance of HAc-PAC Modified Shield Tunneling Slurry

采用醋酸(HAc)和聚合氯化铝(PAC)改性泥水盾构废弃泥浆,并分析了改性前后脱水性能和微观结构变化.结果表明,HAc掺量为0.23%,PAC的掺量为0.48%时,对废弃泥浆的改性效果最好.与原状废弃泥浆相比,含水率降低了4.43%,pH值由9.5降低到7.37,毛细吸水时间值(t CST)降低了77.33%,旋转黏度值降低了67.17%,X射线衍射(XRD)和扫描电子显微镜(SEM)分析膨润土的微观层间距也有了显著的增加,孔隙结构发生了明显的变化.

Waste slurry of shield structure was modified by acetic acid(HAc)and polyaluminum chloride(PAC),and the dehydration properties and microstructure changes before and after modification were analyzed.The results show that,when HAc content is 0.23%and PAC content is 0.48%,the best modification effect was achieved.Compared with the original waste slurry,the moisture content was reduced by 4.43%,and the pH value was reduced from 9.5 to 7.37,the capillary absorption time value(t CST)was reduced by 77.33%,and the rotational viscosity value was reduced by 67.17%.The analysis results of bentonite by X-ray diffraction(XRD)and scanning electron microscope(SEM)also showed a significant increase in the micro-layer spacing,and the pore structure also changed significantly.