Clays and Clay Minerals, Vol. 55, No. 6, 593–598, 2007.
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Authors
Cho, Yunchul
Komarneni, Sridhar
Issue Date
2007
Type
Article
Language
Keywords
Periodicals , Geology , Hydrothermal Treatment , Hydroxy-Al Interlayered Vermiculite (HIV) , K-depleted Biotite , K-depleted Muscovite , Topotactic Cation Exchange , Transformation
Alternative Title
Topotactic Cation Exchange In Transformed Micas under Hydrothermal Conditions
Abstract
The formation of hydroxylated phases was investigated using K-depleted biotite (Na-biotite) and K-depleted muscovite (Na-muscovite) under hydrothermal treatment with alkali (Li+, K+, NH4 +, Rb+ and Cs+), alkaline earth (Mg2+, Ca2+, Sr2+ and Ba2+), and aluminum (Al3+) cations at 200ºC for 1 and/or 3 days. The K-depleted biotite treated with alkali cations produced anhydrous hydroxylated phases, while the K-depleted muscovite did not significantly exchange alkali cations but dehydrated to form Namuscovite in all cases. The alkaline earth cations, however, produced hydrous hydroxylated phases with both K-depleted micas. The degree of hydration energy of cations and the charge density of micas were found to influence the formation of anhydrous and hydrous phases from the K-depleted micas. This type of topotactic cation exchange potentially could be used for fixation and immobilization of radioactive species such as Cs, Sr, Ra, etc. in the transformed micas. The K-depleted biotite and muscovite treated with Al3+ were transformed to hydroxy-Al interlayered vermiculites (HIV) because of hydrolysis and polymerization of Al3+. These HIV phases could also serve as useful adsorbents for soil and groundwater contaminants.
Description
Clays and Clay Minerals, Vol. 55, No. 6, 593–598, 2007. Topotactic Cation Exchange In Transformed Micas under Hydrothermal Conditions. Yunchul Cho; Sridhar Komarneni. DOI: 10.1346/CCMN.2007.0550606. Copyright © 2007, The Clay Minerals Society
Citation
Clays and Clay Minerals, Vol. 55, No. 6, 593–598, 2007.
Publisher
The Clay Minerals Society
License
Copyright © 2006-2018, The Clay Minerals Society