Sökning: "birnessite"

Hittade 5 avhandlingar innehållade ordet birnessite.

  1. 1. Microbially mediated formation of birnessite-type manganese oxides and subsequent incorporation of rare earth elements, Ytterby mine, Sweden

    Författare :Susanne Sjöberg; Christophe Dupraz; Rienk Smittenberg; Volker Brüchert; Helena Filipsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; microbial diversity; manganese oxides; birnessite; rare earth elements; subterranean; Ytterby mine; geokemi; Geochemistry;

    Sammanfattning : Microbes exert extensive control on redox element cycles. They participate directly orindirectly in the concentration and fractionation of elements by influencing the partitioningbetween soluble and insoluble species. LÄS MER

  3. 2. Microbially mediated manganese oxides enriched in yttrium and rare earth elements in the Ytterby mine, Sweden

    Författare :Susanne Sjöberg; Christophe Dupraz; Per Persson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; manganese oxidizers; birnessite; yttrium and rare earth elements YREE ; biofilms; shallow subsurface; Ytterby mine; geomicrobiology; microbial geochemistry; manganoxiderare; birnessit; yttrium och sällsynta jordartsmetaller YREE ; underjordisk; Ytterby mine; geomikrobiologi; mikrobiell kemi; geokemi; Geochemistry;

    Sammanfattning : Microorganisms are able to manipulate redox reactions and thus exert extensive control on chemical speciation and element partitioning in nature, affecting the formation and dissolution of certain minerals. One of these redox active elements is manganese (Mn), which in its oxidized states (III/IV), commonly forms Mn oxide-hydroxide minerals. LÄS MER

  4. 3. Molecular-level controls on water and organics intercalation in layered minerals

    Författare :Jerry Lindholm; Michael Holmboe; Jean-Francois Boily; Virginie Marry; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Minerals; Dynamic Vapor Sorption; montmorillonite; XRD; adsorption model; intercalation;

    Sammanfattning : Layered minerals are naturally abundant and often display a large surface area in relation to their weight. For swelling layered minerals, most of this area is contained between the layers in the interlayer space. LÄS MER

  5. 4. Potential of fly ashes for neutralisation of acid mine drainage from coal mine waste rock

    Författare :Asif Qureshi; Josef Mácsik; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Sammanfattning : Many countries around the world use coal as fuel for the purpose of power generation. The extraction of coal produces large volumes of waste rock (WR) that are sometimes sulphide rich (principally containing iron sulphides such as pyrite (FeS2) and pyrrhotite (Fe1-xS)), with varying quantities of trace elements such as As, Si, Cu, Zn, Ni, Co, Mo and Cr etc). LÄS MER

  7. 5. Co-disposal of waste rock and lignite fly ash to mitigate the environmental impact of coal mining

    Författare :Asif Qureshi; Björn Öhlander; Christian Maurice; Thomas Pabst; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acid mine drainage AMD ; coal mine waste rocks; coal fly ash; co-disposal; mixing blending; dry-cover; prevention neutralisation; Tillämpad geokemi; Applied Geochemistry;

    Sammanfattning : Waste rocks (WRs) from coal mining and fly ash (FA) from coal combustion were studied to determine the potential of the WRs to generate AMD, FAs to neutralise it and estimate their impacts on environment. The ultimate goal was to develop a methodology based on co-disposal to mitigate the environmental problems associated to both wastes. LÄS MER