Effect of sintering temperature on structure and properties of Nd₂O₃ and CeO₂ co-doped zeolite waste

Radioactive zeolite waste is a potential threat to human health and the living environment. Therefore, the treatment and disposal of radioactive zeolite waste is an urgent problem to be solved. In this work, the co-doped simulated radioactive contaminated zeolite has been successfully immobilized. The effect of sintering temperature on the microstructure, mechanical properties and chemical durability of co-doped zeolite sintered matrix was evaluated. Samples were sintered at 1400 degrees C and 1500 degrees C for 1 h. As the sintering temperature increases, the total solid solubility limit of sintered samples increased from 25 wt.% (Nd2O3: 15 wt.%, CeO2: 10 wt.%) to 55 wt.% (Nd2O3: 20 wt.%, CeO2: 35 wt.%,). The greater Vickers hardness (6.73 GPa) and density (2.93 g center dot cm(-3)) were achieved in sample No. 9 sintered at 1500 degrees C. The normalized leaching rates of Ce and Nd in sample No. 9 sintered at 1500 degrees C are 0.83 x 10(-7) g center dot m(-2)center dot d(-1) and 3.42 x 10(-7) g center dot m(-2)center dot d(-1), respectively. (c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.