• Login
    View Item 
    •   Home
    • Theses & Dissertations
    • 2017 - Mines Theses & Dissertations
    • View Item
    •   Home
    • Theses & Dissertations
    • 2017 - Mines Theses & Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of Mines RepositoryCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    Login

    Mines Links

    Arthur Lakes LibraryColorado School of Mines

    Statistics

    Display Statistics

    Physical heterogeneity control on mineral dissolution rates: from pore to continuum scale over geologic time

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Jung_mines_0052E_11401.pdf
    Size:
    5.649Mb
    Format:
    PDF
    Download
    Author
    Jung, Heewon
    Advisor
    Navarre-Sitchler, Alexis K.
    Date issued
    2017
    
    Metadata
    Show full item record
    URI
    https://hdl.handle.net/11124/172030
    Abstract
    Mineral dissolution rates are often determined by laboratory experiments performed in well-mixed conditions for a relatively short time. However, 1) geologic systems are highly heterogeneous that rarely exhibit a well-mixed condition, 2) geologic time scales cannot be reproduced in laboratories, and 3) the hydrologic accessibility of the reactive phases within the pore structure is usually not considered in experiments or continuum scale numerical simulations. These inherent differences lead to the 3~7 orders of magnitude discrepancy between field- and laboratory- measured reaction rates, which prevents direct application of laboratory measured rates to numerical simulations. The objective of this dissertation is to investigate the effect of 1) heterogeneous permeability distribution, 2) time dependent evolution of reactive surface area, and 3) pore geometry on chemical weathering rates. Reactive transport simulations conducted on random permeability fields highlight the importance of variance in permeability distribution and Péclet number in controlling the reduction of reaction rates from the laboratory measured reaction rate. In long-term simulations, highly heterogeneous domains show additional reduction in reaction rates as the remaining surface area of immobile zones over-normalizes the reaction product concentration. For the pore scale investigation, reactive microfluidic devices using silicate minerals, anorthite and albite, were fabricated with a femtosecond laser and HF etching techniques. Fluid flows that are perpendicular to the applied pressure gradient develop in a fabricated microdevice while immobile zones develop in numerical simulations, which indicate reactive microdevices can constrain numerical conditions to better represent the chemical reactions in natural pore system. Overall, the results suggest that physical heterogeneity of natural porous media could reconcile some of the large discrepancy between laboratory- and field- measured chemical weathering rates.
    Rights
    Copyright of the original work is retained by the author.
    Collections
    2017 - Mines Theses & Dissertations

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Contact Us
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.