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以重烧氧化镁、磷酸二氢钾、硼砂为原料制备磷酸镁水泥(MPC)快速固化模拟放射性核素~(90)Sr。研究了龄期对磷酸镁水泥固化体抗压强度的影响、不同Sr掺量对磷酸镁水泥固化体体积收缩的影响和不同温度、pH值对磷酸镁水泥固化体早期浸出性能影响,采用X射线衍射分析和扫描电镜探讨不同龄期磷酸镁水泥固化体的物相组成及微观结构。结果表明:磷酸镁水泥固化体抗压强度在2 h~1 d增长速度最快,1 d时抗压强度达34.3 MPa;随着Sr掺量提高,磷酸镁水泥固化体收缩率增大;低温和碱性环境下磷酸镁水泥固化体累计浸出分数较高;磷酸镁水泥固化体微观结构随龄期增长而变致密,掺入Sr会阻碍磷酸镁水泥水化产物形成。
The fast curing pseudo - radionuclide (90) Sr was prepared by re - calcining magnesium oxide, potassium dihydrogen phosphate and borax with magnesium phosphate cement (MPC). The effect of aging on the compressive strength of magnesium phosphate cement cured body was studied. The effect of different Sr content on the volume shrinkage of magnesium phosphate cement cured body and the influence of different temperature and pH value on the early leaching performance of magnesium phosphate cement cured body were studied. X-ray Diffraction Analysis and Scanning Electron Microscopy Study on Phase Composition and Microstructure of Magnesium Phosphate Cement Cured Body at Different Stages. The results show that the compressive strength of magnesium phosphate cement solidified body increases fastest from 2 h to 1 d, and the compressive strength reaches 34.3 MPa at 1 d. With the increase of Sr content, the shrinkage of solidified magnesium phosphate cement increases. In alkaline environment, the cumulative leaching fraction of magnesium phosphate cement solidified body is higher. The microstructure of magnesium phosphate cement solidified body becomes denser with age, and incorporation of Sr will hinder the formation of hydration product of magnesium phosphate cement.