高庙子钠基膨润土化学性能热力学模拟  

Thermodynamic Simulations on Chemical Properties of Gaomiaozi Na-Bentonite

作　　者：李娜娜[1,2] 康明亮 刘月妙[1,2] 郭永海[1,2] 苏锐 LI Nana;KANG Mingliang;LIU Yuemiao;GUO Yonghai;SU Rui(CNNC Key Laboratory on Geological Disposal of High-level Radioactive Waste,Beijing Research Institute of Uranium Geology,Beijing 100029,China;CAEA Innovation Center for Geological Disposal of High-level Radioactive Waste,Beijing 100029,China;Sun Yat-sen University,Zhuhai,Guangdong 519082,China)

机构地区：[1]核工业北京地质研究院,中核高放废物地质处置评价技术重点实验室,北京100029 [2]国家原子能机构高放废物地质处置创新中心,北京100029 [3]中山大学,广东珠海519082

出　　处：《世界核地质科学》2022年第2期269-279,共11页World Nuclear Geoscience

基　　金：核设施退役治理专项资助科研项目(编号:科工二司[2020]194号)资助。

摘　　要：高放废物处置库近场地球化学稳定性主要由膨润土和地下水之间的长期化学作用控制。为了查明膨润土与地下水作用演变情况,以PHREEQC为计算平台,从热力学角度分别模拟了不同温度条件下高庙子钠基膨润土在纯净水和北山地下水中的反应进程,计算得出次生矿物、pH值和液相主要阳离子随反应进度的变化情况。结果表明:膨润土在纯净水中依次生成的次生矿物有三水铝石、针铁矿、镁蒙脱石和钙蒙脱石;在北山地下水中依次生成的次生矿物为三水铝石、针铁矿、镁蒙脱石和方解石;溶液的pH值均能维持在碱性范围;温度对次生矿物的种类影响不大,对反应进度有影响。最后以计算结果为基础,得出了不同温度条件下膨润土-北山地下水体系关键矿物的SiO_(2)浓度-pH值平衡相图。The geochemical stability of near field in high level radioactive waste disposal repository is mainly controlled by long term chemical interaction between bentonite and groundwater.The reaction processes of GMZ Na-bentonite in purified water and Beishan groundwater at different temperatures were calculated respectively from thermodynamic aspects using software PHREEQC in the paper.Secondary minerals,pH value and main cation composition were simulated.The results showed that secondary minerals generated in purified water were gibbsite,goethite,Mg-montmorillonite,and Ca-montmorillonite,the secondary minerals generated in Beishan groundwater were gibbsite,goethite,Mg-montmorillonite,and calcite successively,as well as pH value could maintain in the alkaline range.The secondary mineral species were not affected by temperature,but interaction process could be influenced by temperature.The SiO_(2) concentration-pH equilibrium phase diagrams of key minerals in bentonite-groundwater system at different temperatures were obtained at last.

关 键 词：高庙子钠基膨润土 热力学 PHREEQC 温度 次生矿物 PH值 

分 类 号：TL942[核科学技术—辐射防护及环境保护]