WANG Te, LU Zhangxian, LI Jia, SHANG Yali, WANG Guohua, YANG Haitao
(Nuclear Power Institute of China, Chengdu 610213, Sichuan, China)
Abstract: The effects of temperature, pH, storage time, urea/U molar ratio and other factors on the stability of sol solution were studied. When the storage temperature was 0 °C, the sol solution could be stably stored for 6 h, with the viscosity of the sol solution to gradually increase with increasing temperature and storage time. Urea has protective effect on metal ions in the sol. When the molar ratio of urea/U is larger than 1, it is helpful to prepare ceramic microspheres with high sphericality. Inorder to explore the cause of sol solidification, comparative experiments were conducted, verifying that solidification of thesol solution is mainly attributed to the hydrolysis condensation reaction of uranyl ions. Finally, the technical route for calcination recovery of the solidified sol was developed. X-ray diffraction results proved that the solidification sol was completely converted into U3O8 powder after calcination at 800 °C, while the uranium content was determined by chemical titration to be 83.24%, which could be directly used for acid deficiency dissolution to prepare acid deficiency uranyl nitratesolution. Ceramic microspheres with uniform size were obtained by glue, dispersion, washing, aging and sintering.
Key words: broth; stability; calcination recycling; ceramic microspheres; inner gel