Curtin University Homepage
  • Library
  • Help
    • Admin

    espace - Curtin’s institutional repository

    JavaScript is disabled for your browser. Some features of this site may not work without it.
    View Item 
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item

    Replacement and ion exchange reactions of scolecite in a high pH aqueous solution

    Access Status
    Fulltext not available
    Authors
    Dunkel, K.G.
    Putnis, Andrew
    Date
    2014
    Type
    Journal Article
    
    Metadata
    Show full item record
    Citation
    Dunkel, K.G. and Putnis, A. 2014. Replacement and ion exchange reactions of scolecite in a high pH aqueous solution. European Journal of Mineralogy. 26: pp. 61-69.
    Source Title
    European Journal of Mineralogy
    DOI
    10.1127/0935-1221/2013/0025-2346
    ISSN
    0935-1221
    URI
    http://hdl.handle.net/20.500.11937/47817
    Collection
    • Curtin Research Publications
    Abstract

    The interaction of single crystals of a zeolite, scolecite (CaAl2Si3O103H2O), with NaCl and NaOH solutions of different concentrations and pH values was investigated in autoclaves at temperatures up to 200 C. Only the experiments with 1 or 2MNaOH at 200 C led to significant reactions, namely one or two reaction rims, depending on the reaction time. The products were studied using electron microscopy, electron-microprobe analysis and X-ray diffraction. An inner reaction rim of mesolite(Na2Ca2Al6Si9O308H2O) was only observed in longer-term experiments. At all reaction times, however, a reaction rim consisting of Na,Al-substituted tobermorite 11 A ° (Ca4.5Na1.3Si5.2Al1.0O16(OH)2) formed. The reaction interfaces are sharp, and the product phases form porous pseudomorphs of the original scolecite. Some advancements of the tobermorite rim are connected to fracturesformed in the scolecite. Additional Cs exchange experiments (2 104 M CsCl, 24 C, 18 h) on the partly reacted samples showed that Cs-Na exchange in the tobermorite did not start simultaneously in the whole reaction rim, but only at the outer part. The results indicate that replacement of scolecite takes place by coupled dissolution-precipitation, independent of the similarity between the structure of scolecite and the reaction product. There is less fluid mobility around separate crystals in a solution than could be expected, which emphasises the importance of interfacial fluids. The infiltration of the fluid into the crystal partially depends on reaction-induced fracturing.

    Related items

    Showing items related by title, author, creator and subject.

    • Cellobiose Decomposition in Hot-Compressed Water: Importance of Isomerization Reactions
      Yu, Yun; Shafie, Zainun; Wu, Hongwei (2013)
      This paper reports an investigation on the fundamental reaction mechanism of cellobiose decomposition in hotcompressed water (HCW) using a continuous reactor system at 225-275 °C. The importance of isomerization reactions ...
    • Formation and characteristics of glucose oligomers during the hydrolysis of cellulose in hot-compressed water
      Yu, Yun (2009)
      Energy production from fossil fuels results in significant carbon dioxide emission, which is a key contributor to global warming and the problems related to climate change. Biomass is recognized as an important part of ...
    • Formation of mg-rich olivine pseudomorphs in serpentinized dunite from the Mesoarchean Nuasahi Massif, Eastern India: Insights into the evolution of fluid composition at the mineral-fluid interface
      Majumdar, A.; Hövelmann, J.; Vollmer, C.; Berndt, J.; Mondal, S.; Putnis, Andrew (2016)
      We present a detailed investigation of the micrometer-to nanometer-scale textural-chemical features in partially serpentinized dunites from the lower ultramafic unit of the Mesoarchean Nuasahi Massif, eastern India; these ...
    Advanced search

    Browse

    Communities & CollectionsIssue DateAuthorTitleSubjectDocument TypeThis CollectionIssue DateAuthorTitleSubjectDocument Type

    My Account

    Admin

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Follow Curtin

    • 
    • 
    • 
    • 
    • 

    CRICOS Provider Code: 00301JABN: 99 143 842 569TEQSA: PRV12158

    Copyright | Disclaimer | Privacy statement | Accessibility

    Curtin would like to pay respect to the Aboriginal and Torres Strait Islander members of our community by acknowledging the traditional owners of the land on which the Perth campus is located, the Whadjuk people of the Nyungar Nation; and on our Kalgoorlie campus, the Wongutha people of the North-Eastern Goldfields.