模拟放射性含氟废液水泥固化配方的研究

本文以沸石、硅灰、石英砂为添加剂，按照质量比m（沸石）∶m(硅灰)∶m（石英砂）∶m（水泥）=1∶1∶3∶10配方对模拟放射性含氟废液进行水泥固化。由配方得到的水泥浆流动度和初、终凝时间满足桶内固化要求。测定了水泥固化体28 d的抗压强度、抗浸泡性和抗冻融性实验后的强度损失，进行了抗冲击性能测试和模拟核素浸出实验。结果表明，该配方可有效地固化模拟放射性含氟废液，固化体28 d抗压强度、各项实验强度损失和模拟核素浸出率均满足GB 14569.1-2011的要求。水泥固化体的F^-浸出率很低，XRD显示F^-以CaF₂形式存在。废液中F^-质量分数控制在1%较为合适，此时水泥固化体终凝时间为14 h，F^-的42 d浸出率为2.54×10^-3 cm/d。

Study on Cementation Formulation of Simulated Radioactive Fluoride Liquid Waste

In this paper ,the formulation with ratio of m(zeolite)∶ m(silica fume)∶ m (quartz sand)∶ m(cement)=1∶1∶3∶10 was used to solidify the simulated radioactive fluoride liquid wastes . The fluidity and setting time of the cement slurry meet the requirements of in‐drum cement solidification .28 d compressive strength and strength losses after water/freezing resistance tests were investigated ,and the shock resistance and leaching nuclide test were also conducted .The results show that it is feasible to solidify simulated radioactive fluoride liquid wastes with the formulation as prepared . The 28 d compressive strengths ,strength losses after tests and simulated nuclide leac‐hing rates of the cement solidified waste form meet the demands of GB 14569.1—2011 . Leaching rate of fluoride ion in the cement solidified waste form is very low .XRD pat‐terns show that fluoride ion is in the form of CaF2 .The suitable content of fluoride ion in the liquid wastes is 1% ,the final setting time of the cement solidified waste form is 14 h ,and the leaching rate of the fluoride ion is 2.54 × 10-3 cm/d after 42 d .