Capability of Zircon as Waste Forms for Immobilizing Simulated Actinides With Ce⁴⁺

In order to investigate the capability of synthetic zircon for immobilization of actinides with tetravalence, Ce⁴⁺ was used as the simulacrum for tetravalent actinides, synthesis experiments were heated for 22 h under 1 500 ℃, designing 5%-20% (mole fraction) dosage of waste forms by using ZrO₂, SiO₂ and CeO₂ powders as starting materials. The phases, structure and microcosmic shape of synthetic condensates were characterized by the help of X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared absorption spectrum (IR) and laser Raman microprobe (RMP). The results indicate that the major phase of synthesized waste forms gives first place to zircon phase although having added 5%-20% of CeO₂ in the solidified body. However, they still have good crystallinity. With the enhancing of CeO₂ in solidified body, the metamict degree of synthesis waste forms is slightly increased.