B2O3–Bi2O3–ZnO based materials for low-sintering temperature immobilization of iodine adsorbed waste

The treatment of radioactive iodine waste is a difficulty in the field of nuclear waste disposal. In this work, the B 2 O 3 –Bi 2 O 3 –ZnO based materials with 50 ​mol% of B 2 O 3 is chosen to immobilize silver-coated silica gel with different iodine loadings at 500, 550, and 600 ​°C. The results show that the highest amorphous fraction is gotten as 0.88 for the sample with 20 ​ wt % of iodine in silver-coated silica gel sintered at 600 ​°C. In addition, both of the amorphous fraction and density increase with increasing temperature. The SEM-EDS result indicates that part of iodine is fixed into the glassy phase and other AgI grains are physically wrapped by the vitrified bulk. Our findings demonstrate the feasibility of B 2 O 3 –Bi 2 O 3 –ZnO based materials for the immobilization of silver-coated silica gel with different iodine loadings.