大气条件下高庙子钠基膨润土化学缓冲特性研究

深地质处置目前被国际上公认为是处置高放废物的最有效可行的方法。我国采用多重工程屏障系统和适宜的地质体共同作用来确保与生物圈的安全隔离。缓冲材料是高放废物重要的工程屏障材料之一，我国选用高庙子钠基膨润土作为缓冲材料的基础材料。膨润土作为缓冲材料的一个重要性能表现为缓冲孔隙水的化学变化。介绍了GMZ-1钠基膨润土大气条件下与蒸馏水的反应试验，并对试验结果进行了讨论。批式试验反应溶液中钠离子来源于钠基膨润土层间阳离子和矿物溶解，镁离子来源于钠基膨润土层间阳离子，钾离子和钙离子来源于矿物溶解，相关研究认识对于高放废物处置库近场核素迁移研究和评价工程屏障的长期稳定性具有重要意义。

Study on chemical buffering property of GMZ sodium bentonite under atmospheric condition

At present, the deep geological disposal is regarded as the most reasonable and effective way to safely disposal the high-level radioactive wastes in the world. The conceptual model of HLW geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineered barrier system. The buffer is one of the engineered barrier materials and GMZ Na-bentonite is selected as the basic material. One of the most important functions related to buffer is the chemical buffering, which means buffering the changes in pore water chemistry. This paper presents the experiments of GMZ-1 Na-bentonite reacted with distilled water under atmospheric condition. The batch tests and results discussion are reported. Na and Mg in batch test solution are co-provided by interlayer cations of montmorillonite and solids dissolution, K and Ca are provided by dissolution of solids. The result is a pre-requisite for predicting near-field nuclide migration and assesses the long-term stability of the engineered barrier materials.