摘要
为抑制高放废液玻璃固化过程中黄相的产生,采用Ba(NO_(3))_(2)对模拟高硫高钠高放废液进行预处理,再利用熔融法制备硼硅酸盐玻璃固化体,研究了预处理对玻璃固化体熔制过程中黄相的形成及其物相组成、显微结构的影响,并对比分析了预处理前后玻璃固化体中的硫含量。结果表明:Ba^(2+)与模拟高放废液中的SO_(4)^(2-)在酸性环境反应生成了BaSO_(4),预处理使玻璃固化体熔制过程中产生的黄相显著减少;预处理前黄相主要成分为Na_(2)SO_(4)和LiNaSO_(4),还含有少量CaMoO_(4)和Na_(2)CrMoO_(4),预处理后黄相中LiNaSO_(4)相衍射峰有所减弱,并出现了BaSO_(4)、BaMoO_(4)和BaCrO_(4)相;预处理前玻璃固化体中的硫含量随温度升高逐渐降低,预处理后玻璃固化体中的硫含量在850~1050℃基本保持不变,随着温度进一步升高,硫含量逐渐降低;当废物中硫酸盐含量较高时,预处理对提高硫酸盐的包容能力尤为显著。
In order to supress the formation of yellow phase during vitrification,simulated high-level liquid waste(HLLW)with high content of sulfur and sodium were pretreated by adding Ba(NO_(3))_(2)solution,and then borosilicate glass waste forms were prepared by traditional melting method.The effects of pretreatment on the formation of yellow phase and its phase structure and microstructure were mainly investigated.The sulfur content retained in the glass waste forms before and after pretreatment were compared.The results show that SO_(4)^(2-)ions in the simulated HLLW can be immobilized in BaSO_(4).The amount of yellow phase during the vitrification process can be markedly reduced by the pretreatment.For the generated yellow phase before pretreatment,the main constituents are Na_(2)SO_(4)and LiNaSO_(4)along with a small amount of CaMoO_(4)and Na_(2)CrMoO_(4).After pretreatment,the X-ray diffraction peak intensity of LiNaSO_(4)decreases and BaSO_(4),BaMoO_(4),and BaCrO_(4)phases appear.The sulfur content retained in the glass waste form before pretreatment decreases gradually with increasing temperature.The sulfur content retained in the glass waste form after pretreatment remains almost unchanged in the temperature range of 850-1050℃,and decreases gradually with further increasing temperature.The pretreatment is helpful to improve the sulfur retention especially for the higher sulfate-bearing HLLW.
作者
吴浪
徐立国
雷杰
王宾
滕元成
WU Lang;XU Li-guo;LEI Jie;WANG Bin;TENG Yuan-cheng(School of Materials Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;Sichuan Environmental Protection and Engineering Co.,LTD,Guangyuan 610006,China)
出处
《核化学与放射化学》
CAS
CSCD
北大核心
2021年第6期459-464,I0002,共7页
Journal of Nuclear and Radiochemistry
基金
国家自然科学基金资助项目(11775182)。
