摘要
高放废物处置库衬砌混凝土,在地下水溶蚀作用下释放出“水泥浸出液”,其化学成分经历4个阶段的演变过程。配制新鲜水泥浸出液模拟第I阶段水泥浸出液,与高庙子膨润土粉末混合成悬液体系,开展批式固-液静态反应,评估中国处置库膨润土缓冲材料的长期化学稳定性。静态反应256 d期间,分阶段采收的悬液分离成固、液两相。液相检测pH值、电导率和阳离子浓度。固相开展X射线衍射、Fourier红外光谱和扫描电子显微镜-能谱仪分析测试。固、液两相分析结果表明:高庙子膨润土在新鲜水泥浸出液作用下,同时发生蒙脱石矿物的溶解及伊利石/蒙脱石混层次生矿物的形成,从而降低高庙子膨润土的缓冲性能。
Because of groundwater dissolution, the lining concrete of HLW geological repository release a “cement solution”, and its chemical composition undergoes a four-stage evolution process. A young cement solution standing for I-stage cement solution was mixed with Gaomiaozi(GMZ) bentonite powder, as suspensions to prompt static solid-liquid reaction in a batch style for evaluation of long-term chemical stability of the bentonite buffer material as used in China. During 256 d test, suspensions were harvested in different time intervals and separated into solid and liquid phases. The liquid phase were analyzed for pH, electrical conductivity and cation concentration. The solid phase was characterized by means of X-ray diffraction, Fourier transform infrared spectra and scanning electron microscope-energy spectrum. The analysis results of solid and liquid indicated both the dissolution of montmorillonite mineral and the formation of mixed layer illite-smectite occur in GMZ bentonite at the same time under the action of young cement solution. This tends to reduce the buffer performance of the GMZ bentonite.
作者
张虎元
李小雅
童艳梅
于洪亮
易泉
ZHANG Huyuan;LI Xiaoya;TONG Yanmei;YU Hongliang;YI Quan(School of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China;Key Laboratory of Mechanics on Disaster and Environment in Western China,The Ministry of Education,Lanzhou University,Lanzhou 730000,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2023年第1期215-225,共11页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金项目(41972265)。
关键词
高放废物处置
缓冲屏障
模拟水泥浸出液
膨润土
蒙脱石
high level waste disposal
buffer barrier
simulated cement solution
bentonite
montmorillonite