Immobilization of simulated An4+ in radioactive contaminated clay via microwave sintering

Abstract To rapidly immobilize simulated An4+ in high-alumina soil by microwave sintering, clay sample doped with 5 wt% of CeO2 was successfully fabricated as silicate glass composite matrix at 1500 °C in 30 min Ce4+ was immobilized into glass phase, which was formed through the reaction of feldspar and quartz. The generated crystal phase Al6Si2O13 in sintered glass composite material was due to the formation of [Si2O7]6- groups, which were separated from the glass network structure. The leaching rate of Ce maintained at a magnitude of 1 × 10−7 g∙m−2 d−1 after 42 days for all samples. Moreover, increased sintering temperature is beneficial to enhance the leaching resistance of sintered clay samples.