Immobilization of simulated An4+ radioactively contaminated zeolite: Solidify mechanism and theory investigation

The radioactively contaminated zeolite poses a serious threat to human health and the ecological environment, so the safe disposal of radioactively contaminated zeolite is essential. The simulated contaminated zeolite was successfully immobilized without the use of additional agents. The mechanical properties, chemical durability, and microstructure of sintered samples were studied. The solid solubility limit of the sintered sample could reach 43 ​wt%. The maximum values of density and Vickers hardness are 3.34 ​g ​cm-3 and 7.44 ​GPa. The NRCe under different pH (pH ​= ​4, 7, 10) conditions were 1.56 ​× ​10-3 ​g ​m-2 ​d-1, 2.40 ​× ​10-5 ​g ​m-2 ​d-1 and 3.63 ​× ​10-4 ​g ​m-2 ​d-1 at 28d, respectively. The theoretical results showed that glass network structures were comprised of [AlO4] and [SiO4]. This work will provide basic data for the treatment of radioactively contaminated zeolite. The natural zeolite was mixed with CeO2 to simulate An4+ radioactive contaminated zeolite, and the solidified body was prepared by high-temperature sintering. The solid solution limit of the solidified body can reach 43 ​wt% through phase detection. Simultaneously, the solidified body shows the best mechanical properties. [Display omitted] •The simulated radioactive contaminated zeolite was successfully immobilized.•The sintered sample structure was studied by characterization and MD calculation.•The sintered sample has reliable mechanical stability and chemical durability.