Study On Curing And Properties Of Simulated Nuclides In Borosilicate Glass And Glass Ceramics

The work in this thesis mainly included the addition of 5 wt%Nd₂O₃ as simulated nuclides in the borosilicate glass system?SiO₂-B₂O₃-Na₂O-CaO-Al₂O₃?through melting method to prepare the simulated nuclide doped borosilicate glass form.And the influence of Si/B ratio on the construction and property of prepared borosilicate glass was also investigated.Further,chemical stability and density were also analyzed to evaluate the capacity of simulated nuclides in the borosilicate glass system.The results shown that,with the decrease of Si/B,the content of B₂O₃ was increased,and melting temperature decreased with the glass transition temperature?T_g?increasing first followed by the further decrease.The content of[BO₃]in the glass increased,and when the content of[BO₃]and[BO₄]reached into balance,the glass contained the densest structure of network.Besides,the density of the prepared glass was reached at the maximum and decreased following.With product consistency test,the LR_Nd of prepared glass form increased first and decreased following,with the content of B₂O₃ at 16.53 wt%,the chemical stability was the best.Even when the content of Nd₂O₃ increased into 7 wt%,the resistance of leaching property was still in the good level.With different amounts of CaO,ZrO₂,TiO₂ as the nucleation agents,the simulated nuclides doped zirconolite borosilicate glass system was prepared with the two-step method.The influence of nucleation agent content,thermal treatment conditions?nucleation temperature and crystallizing temperature?and actinide nuclides simulation on the phase construction,micro-structure and chemical stability was investigated.The results showed that in the temperature range of 615-650^oC,the T_g of prepared sample increased with the nucleation agent increasing.As the increase of nucleation agent,the amount of SiO₂ phase decreased,while the CaZrTi₂O₇ phase increased.As the content of CTZ was 45%,the amount of CaZrTi₂O₇ could reach the maximum with the more stable structure of CaZrTi₂O₇-2M formation.When the CTZ content reached at 50%,the ZrO₂ phase was formed.The positive effect of nucleation agent could be found during the formation process of glass ceramic.Nucleation temperature had merely influence on the types and numbers of the formed crystals.As the temperature lower than 950^oC,the increase of crystallization temperature could improve the formation of zirconolite phase,while as the temperature higher than 950^oC,the amount of zirconolite phase reached into the maximum,and sphene phase could be found.In the range of 950-1050^oC,with the temperature increase,the diffraction intensity of zirconolite phase decreased and that of sphene phase increased.The diffraction intensity of zirconolite phase could be increased with the content of Nd₂O₃ decreasing.When the content of Nd₂O₃increased into 9 wt%,the perovskite phase could be found.As the content of Nd₂O₃ was 7wt%,the prepared ceramic glass could still maintain the good chemical stability.28 days after,LR_B,LR_Ca and LR_Ndd could be 7.97×10^-3 g·m^-2·d^-1,2.47×10^-3 g·m^-2·d^-1 and 5.25×10^-6 g·m^-2·d^-1,respectively.