• Login
    View Item 
    •   Home
    • Theses & Dissertations
    • 2022 - Mines Theses & Dissertations
    • View Item
    •   Home
    • Theses & Dissertations
    • 2022 - 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

    Role of manganese in cycling metals in mining-impacted environments, The

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Doyle_mines_0052E_12423.pdf
    Size:
    2.169Mb
    Format:
    PDF
    Download
    Author
    Doyle, Sarah
    Advisor
    Figueroa, Linda A.
    Date issued
    2022
    Keywords
    electrolysis
    manganese oxide
    mine water treatment
    molybdenum
    sorption
    waste rock reclamation
    
    Metadata
    Show full item record
    URI
    https://hdl.handle.net/11124/15460
    Abstract
    Manganese oxides are well-known scavengers of metals in the environment and are also chemically active, with changes in pH or redox leading to dissolution or precipitation. These properties can be both beneficial, allowing for treatment of toxic metals through control of manganese, and harmful, as changing geochemical conditions can lead to unintended release of manganese and associated metals. This research focuses on three aspects of manganese in mining-impacted environments. First, manganese-rich sludge from a mine water treatment plant was evaluated for use in removing molybdenum from mine water. Batch tests showed that over 90% of molybdenum was removed from solution by sorption onto the sludge at pH 6 and below. Sorption was found to be sensitive to mine water composition and pH. Impurities in the sludge sorbent did not reduce sorption relative to pure-phase manganese oxide; a finding which broadens the range of applicable sorbents and potential for reuse of manganese-rich materials onsite. Second, the role of manganese oxides in controlling metals mobility was evaluated for waste rock from a 100+ year old pile. Although manganese was found to be a small fraction of the waste rock (1.3% by mass), sequential extraction tests demonstrated that approximately one-third of the extractable copper, lead, and zinc is associated with manganese oxides. During reclamation, metals associated with the oxides can be released if organic carbon amendments cause geochemically reducing conditions. Lastly, electrolytic methods were evaluated for manganese removal from mine water at low pH. Manganese concentrations in pH 3 mine water were reduced from approximately 40 mg/L to less than 2 mg/L in batch and flow-through tests with applied voltages of 3.5 V. Electrolytic treatment of manganese has potential to reduce chemical addition and sludge mass compared to conventional treatment methods, which precipitate manganese hydroxides at pH 10, followed by neutralization prior to discharge. Collectively, these studies demonstrate the wide range of properties of manganese oxides and their ability to act as a sink for metals in the environment. Manganese oxides have potential to be used in water treatment applications; however, due to the wide range of characteristics, site-specific studies are necessary.
    Rights
    Copyright of the original work is retained by the author.
    Collections
    2022 - 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.