中文摘要：

与传统硅酸盐基油井水泥相比,改性磷铝酸盐水泥具有优秀的耐腐蚀特性,但其稠化时间不易控制,难以用于实际工程。以自制木质素磺酸钠接枝聚合物为试验用改性磷铝酸盐水泥缓凝剂,测试水泥浆掺入一定量缓凝剂的稠化时间,考察缓凝剂对水化放热的影响,借助XRD分析不同龄期的水化产物,并以此分析缓凝剂对水泥水化的作用机理。结果表明：自制木质素磺酸钠接枝聚合物缓凝剂能显著延长改性磷铝酸盐水泥浆的稠化时间,且使浆体具有“直角稠化”特性;缓凝剂大幅降低早期水化放热量,进而抑制水泥的快速水化;基于各龄期的水化热分析,将缓凝剂的作用过程分为从起始作用到作用失效的六个阶段;缓凝剂的作用机制是其对浆体中Ca^2＋的“键合作用”及对熟料矿物和水化产物吸附作用的协同。

英文摘要：

Compared with conventional Portland-based oil well cement, modified phosphoaluminate cement （MPAC） has excellent corrosion resistance. However,the thickening time of MPAC is difficult to control,thereby making it difficult to use in practice. Sodium lignosulfonate-based copolymer developed in the laboratory was used as a retarder to extend the thickening time of MPAC slurry. The influence of retarder content on the thickening time was tested,and the hydration heat of MPAC slurry with and without retarder was also obtained. The hydration prod-ucts of MPAC slurry can be confirmed by X-ray diffraction,and the mechanism of the retarder can also be analyzed. Experimental results show that the sodium lignosulfonate-based copolymer retarder can significantly extend the thickening time,and the slurry with retarder exhibits right angle thickening. The retarder can decrease the early- stage hydration heat,thereby indicating that the hydration process has been retarded. The retarding process can be divided into six stages from beginning to termination. The acting mechanism of the retarder is the bonding effect on the Ca^2＋ in the slurry and the synergistic effect on the adsorption of clinker mineral and hydration products.