江西广丰李家膨润土压实性能研究——高放废物处置缓冲/回填材料压实性能初探

Studies on Compactibility of Bentonite from the Lijia Deposit, Guangfeng, Jiangxi Province——The Preliminary Study and Implication to Buffer/Backfill Materials for HLW Repository

研究了广丰李家钠基膨润土的压实性能 ,得出了不同压实功作用下 ,膨润土干密度与含水率之间的关系 ,以及粒径、压实功等因素对压实性能的影响 ;在相同压实功和相同含水率条件下 ,膨润土粒径较小时相对应的干密度较小 ,当压实功为 2 684.9kJ/m3时 ,钠基膨润土的最大干密度可达 1.5 2 5g/cm3,最优含水率为 2 6.3 0 %。首次选用石英砂作为添加剂 ,探索了添加剂对膨润土压实性能的改善作用 ,实验结果说明石英砂添加剂的加入可以大大提高膨润土的干密度 ,减小对应的最优含水率 ,并得出约 10 %的石英砂是添加剂的最佳用量。该研究结果为钠基膨润土作为高放废物处置库缓冲 /回填材料的性能评价提供了重要的依据。

The results of this study indicate that the compactibility of bentonite is related to the grain size of bentonite and the compacted energy. With the same compacted energy and water content, the dry density reduces consistently with the decrease of grain size of the bentonite. At the compacted energy (of 2 684.9 kJ/m^3), the dry density of bentonite is up to 1.525 g/cm^3 with the optimum water content (of 26.30%). The study on quartz grains as the additive of bentonite is initially carried out in this paper. With the optimum adding quantity of about 10%, quartz grain as the additives could significantly increase the dry density of bentonite, while the optimum water content decreases at the same time. The study shows that quartz grain is one of the ideal additives which could improve the compactibility of bentonite as the buffer/backfill materials.