Diffusion behavior of Re(VII) in compacted illite-, hematite- and limonite-montmorillonite mixtures

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• 作者：Zhifen Wang ; Jianying Zhang ; Jiang Chen…
• 关键词：Re(VII) ; Diffusion ; Mixed montmorillonite
• 刊名：Journal of Radioanalytical and Nuclear Chemistry
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：311
• 期：1
• 页码：655-661
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Nuclear Chemistry; Physical Chemistry; Nuclear Physics, Heavy Ions, Hadrons; Diagnostic Radiology; Inorganic Chemistry;
• 出版者：Springer Netherlands
• ISSN：1588-2780
• 卷排序：311

文摘

A through-diffusion method was used to investigate the Re(VII) (as a surrogate to 99Tc(VII)) diffusion in compacted illite-, hematite- and limonite-montmorillonite mixtures. The effective diffusion coefficient D_e values were in the range of (4.29–6.71) × 10−11 m2/s at pH 3.0 and (3.44–5.72) × 10−11 m2/s at pH 9.0, respectively. Compared to montmorillonite, both D_e and α values enhanced at least three-folds in montmorillonite mixtures, indicating that the impurities changed the diffusion path. Interestingly, the K_d values of (0.63–3.94) × 10−4 kg/m3 were found in montmorillonite mixtures. However, the change of D_a value was less than two-folds, indicating that the illitization and iron corrosion of a back-fill material had no obvious influence on Re(VII) diffusion velocity.