沸石掺量对磷酸镁水泥固化模拟放射性核素Sr的影响

研究了不同沸石掺量对磷酸镁水泥固化模拟放射性核素Sr的影响,测试了固化体的基本性能及抗浸出性,并采用X射线衍射仪、傅立叶变换红外光谱仪、综合热分析仪和扫描电子显微镜对固化体物相和微观结构进行分析.结果表明:掺入沸石的固化体仍具有优异的力学性能,一定范围内,沸石掺量增大,固化体的抗冻融性、抗浸泡性及抗浸出性增强;掺入沸石后固化体力学性能下降的原因是水化产物的结晶程度及整体性下降,当沸石掺量超过一定程度,水化产物含量降低也会导致固化体力学性能下降;沸石的高吸附性、沸石及磷酸镁水泥水化凝胶的双重保护,以及掺入沸石后磷酸镁水泥固化体机械阻滞作用的增强使固化体在掺入沸石后固化性能得到显著改善.

Influence of zeolite content in magnesium phosphate cement on solidification of the simulated radionuclide Sr

The solidification of simulated radionuclide Sr by magnesium phosphate cement(MPC) amended with zeolite was investigated and the characteristics and leaching of the solidified object were analyzed by using X-ray diffraction, FT-IR, comprehensive thermal analysis and scanning electron microscopy. It''s found that the solidified object amended with zeolite had excellent mechanical properties. The freeze-thaw resistance, the soak resistance and the leaching resistance of solidified object were improved by increasing certain amount of zeolite. However, after zeolite amendment, the decrease crystallinity and hydration products would weaken the mechanical properties of solidified object. The zeolite amendment enhancing solidification was attributed to the high adsorption capacity of zeolite, double protection of zeolite and MPC hydration gel and the mechanical blocking behavior of MPC.