Release of Silicon and Aluminum from Montmorillonite Surfaces in Aqueous Systems

Sondi, Ivan; Tomašić, Vlasta; Filipović-Vinceković, Nada (2008) Release of Silicon and Aluminum from Montmorillonite Surfaces in Aqueous Systems. Croatica Chemica Acta, 81 (4). pp. 623-629. ISSN 0011-1643

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Abstract

The release of silicon and aluminum from purified Na-montmorillonite surfaces in aqueous systems was investigated in dependence of pH at 25 degrees C. This study has shown that the dissolution of montmorillonite solid involves several parallel and sequential physico-chemical processes. The initial fast exchange of surface cations by hydrogen ions is followed by the release of aluminum and silicon. The dissolution rate of Si is higher than that of Al and influenced by the relative ratios of basal siloxane and edge surfaces. It is quantitatively described by the dissolution rate constants depending on pH, These results are in agreement with the heterogeneity of montmorillonite Surfaces and the dominant presence of the siloxane basal surface. The shift of pH to more basic values by the ion exchange processes, and the hydrolysis of dissolved species. induces the formation of secondary amorphous solids. which may serve as, precursors for the formation of amorphous aluminosilicates.

Item Type:	Article
Uncontrolled Keywords:	aluminum; clay minerals; geochemistry; montmorillonite; pH; silicon; surfaces; atomic-force microscopy; rasa river estuary; dissolution kinetics; smectite dissolution; in-situ; mineral dissolution; acidic conditions; room-temperature; ph; clays
Subjects:	NATURAL SCIENCES > Chemistry
Divisions:	Division of Physical Chemistry
Projects:	Project title Project leader Project code Project type Razvoj matematičkih metoda za opis strukture, dinamike i reaktivnosti molekula [53240] Darko Babić 098-0982915-2942 MZOS Površinski aktivne tvari, procesi u otopinama i na međupovršinama [231293] Maja Dutour Sikirić 098-0982915-2949 MZOS Međudjelovanje minerala i okoliša [96490] Vladimir Bermanec 119-0000000-1158 MZOS
Depositing User:	Vlasta Tomašić
Date Deposited:	22 Oct 2013 11:29
URI:	http://fulir.irb.hr/id/eprint/822

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