Podrobnosti záznamu

Název
    Sorption properties of reduced-charge montmorillonites
Údaj o odpovědnosti
    Jana Hrobáriková, Peter Komadel
Další názvy
    Mid-European Clay Conference '01, Stará Lesná, 9-14 September 2001, Slovak Republic (Variant.)
Autor
    Hrobáriková, Jana
    Komadel, Peter
Jazyk
    anglicky
Zdrojový dokument - seriál
    Geologica carpathica
Svazek/č.
    Vol. 53, no. 2
Strany
    p. 93-98
Rok
    2002
Poznámky
    7 obr., 1 tab.
    il.
    Obsahuje bibliografické odkazy
    Zkr. název ser.: Geol. carpath.
Klasifikační znak
    549
    552
Skupina konspektu
    549
    552
Předmětová skupina
    iontová výměna
    jíl
    minerály jílové
    montmorillonit
    sorpce
    studie experimentální
    teplota
Geografické jméno
    Arménie
    ČR-Morava
    Ivančice (Brno-venkov, Ivančice)
    Kriva Palanka (Makedonie)
    Makedonie
    Otay (USA)
    Sarigus (Arménie)
    USA
Klíčové slovo
    Montmorillonites
    Properties
    Reduced-charge
    Sorption
Abstrakt (anglicky)
   Four series of reduced-charge montmorillonites, with ranges in layer charge, were prepared from parent Ca-montmorillonites of various chemical compositions. Fine fractions of bentonites from Otay (USA), Ivancice (Czech Republic), Sarigus (Armenia) and Kriva Palanka (Macedonia) were used. The extent of ion exchange, 62-89 per cent of CEC covered by Li+, was dependent on the mineral and on the Li+ concentration in the liquid phase. Different levels of charge reduction were achieved via Li-fixation by heating the samples for 24 h at 110-300 °C. Li+ ions were fixed in the layers of all four montmorillonites, but incomplete Li+ for Ca2+ exchange diminished the extent of charge reduction. Heating the samples at temperatures up to 140 °C caused Li-fixation and reduction in relative cation-exchange capacity (CEC) values by 32 to 48 per cent but only a decrease by 17 to 24 per cent in the sorption of water and by 4 to 14 per cent of ethylene glycol monoethyl ether.
   The greatest changes in these properties were observed among the samples prepared at 130-200 °C, while higher temperatures had little effect. The most extensive reduction in CEC, by 81 per cent after preparation at 300 °C, was obtained for the Otay montmorillonite, the mineral with the highest octahedral and the lowest tetrahedral charge and the greatest level of Li+ for Ca2+ exchange. Higher tetrahedral charge and a lower level of Li+ for Ca2+ exchange negatively affected the decrease in the cation exchange capacities, the specific surface areas and the water uptake capabilities of the prepared reduced-charge montmorillonites
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    28. 3. 2008
Datum importu
    8. 8. 2012