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在KBS–3核废料储存库的早期及非恒温演变期,热梯度变化能改变膨润土缓冲层的矿物特性,且由于矿物质沉淀作用,黏土颗粒将相互胶结起来。据此,使用已发表的有关结晶岩石中缓冲黏土的水–热转换的试验结果,研究并评估一种缓冲胶结的反应–传递模型。模型的预测值能够定性地与高温下缓冲区的观测试验值相吻合,表明次生矿物的沉淀(无水石膏±无定形二氧化硅(opal-CT)±方解石)和由 Na 基蒙脱石变为 Ca 基蒙脱石±皂石的相交替过程。与现场观测中的一种情况不同的是,模型没有预测出这一区域中石英、高岭土和长石的大量溶解,这种不一致现象可能是由于缺乏热动力基本数据造成的,使得在高岭土–蒙脱石混合地层中高电荷蒙脱石变为低电荷蒙脱石过程中的水–热转换在模型中不能加以表示。然而,在整体上模型预测与试验观测还是较为符合的。这表明,用已知的时间–温度及再饱和过程的试验数据,该模型能够用于对 KBS–3 近场潜在的缓冲胶结进行长至几百年的敏感性分析。
During the early and non-isothermal evolution phases of the KBS-3 nuclear waste repository, the thermal gradient changes the mineral properties of the bentonite buffer and the clay particles will cemented due to the mineral deposition. Accordingly, a published buffer-cement reaction-transfer model has been studied and evaluated using published results on water-heat transfer of clayey clays in crystalline rocks. Predicted values of the model can be qualitatively consistent with observed experimental values at high temperatures in the buffer zone indicating that the precipitation of secondary minerals (anhydrous talc ± opal-CT ± calcite) Become Ca-Montmorillonite ± saponite phase alternation process. In contrast to one of the observations in the field, the model does not predict a large amount of dissolution of quartz, kaolin and feldspar in this area. This inconsistency may be due to the lack of basic thermodynamic data, The water-to-heat conversion in the process of converting the high-charge montmorillonite into the low-charge montmorillonite in the tremolite-mixed stratum can not be expressed in the model. However, the overall model prediction and experimental observation is more consistent. This shows that using known test data of time-temperature and resaturation processes, the model can be used to conduct sensitivity analyzes of potential buffer cements in the near-field of KBS-3 for up to several hundred years.