کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1329829 | 978928 | 2007 | 11 صفحه PDF | دانلود رایگان |

Fe2+-montmorillonite with Fe2+ ions occupying cation exchange sites is an ideal transformation product in bentonite buffer material. In our previous study on preparation and characterization of Fe2+-montmorillonite, the montmorillonite sample that adsorbed Fe2+ ions on almost all of the cation exchange sites was prepared using a FeCl2 solution under an inert gas condition [N. Kozai, Y. Adachi, S. Kawamura, K. Inada, T. Kozaki, S. Sato, H. Ohashi, T. Ohnuki, T. Banba, J. Nucl. Sci. Technol. 38 (2001) 1141]. In view of the unstable nature of iron(II) chemical species, this study attempted to determine the potential contaminant iron chemical species in the sample. Nondestructive elemental analysis revealed that a small amount of chloride ions remained dispersed throughout the clay particles. The chloride ion retention may be due to the adsorption of FeCl+ ion pairs in the initial FeCl2 solution and the subsequent containment of the Cl− ions that are dissociated from the FeCl+ ion pairs during excess salt removal treatment. Two explanations are advanced for the second process: the slow release of the remaining Cl− ions from the collapsed interlayer of the montmorillonite, and the transformation of a minor fraction of the remaining FeCl+ ion pairs to iron(III) hydroxide chloride complexes having low solubility.
The distribution of Si (left) and Cl (right) in homoionic Fe2+-type montmorillonite prepared under an inert gas atmosphere by a conventional method using a FeCl2 solution. A small fraction of chloride ions remained dispersed throughout the clay. This paper mainly discusses the potential contaminant iron chemical species in this sample other than Fe2+ ions.Figure optionsDownload as PowerPoint slide
Journal: Journal of Solid State Chemistry - Volume 180, Issue 8, August 2007, Pages 2279–2289