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 B2O3-Bi2O3-ZnO based materials with 50 mol% of B2O3 is chosen to immobilize silver-coated silica gel with different iodine loadings at 500, 550, and 600 degrees 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 degrees 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 B2O3-Bi2O3-ZnO based materials for the immobilization of silver-coated silica gel with different iodine loadings.