Sökning: "Rare earth elements"

Visar resultat 1 - 5 av 67 avhandlingar innehållade orden Rare earth elements.

  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 :NATURAL SCIENCES; NATURVETENSKAP; 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

  2. 2. Recovery of Rare Earth Elements from an Apatite Concentrate

    Författare :Mahmood Alemrajabi; Kerstin Forsberg; Åke C. Rasmuson; Koen Binnemans; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rare earth elements; precipitation; nitrophosphate process; hollow fiber supported liquid membrane extraction; Chemical Engineering; Kemiteknik;

    Sammanfattning : Rare earth elements (REE) are a group of 17 elements including lanthanides, yttrium and scandium; which are found in a variety of classes of minerals worldwide. The criticality of the application, lack of high grade and economically feasible REE resources and a monopolistic supply situation has raised significant attention in recovery of these metals from low grade ores and waste materials. LÄS MER

  3. 3. Abundance and fractionation of rare earth elements in calcite and other secondary minerals in fractures in the upper kilometre of crystalline bedrock, SE Sweden

    Författare :Olga M. Maskenskaya; Mats Åström; Kjell Billström; Linnéuniversitetet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; secondary minerals; rare earth elements; isotopes; crystalline bedrock;

    Sammanfattning : This thesis focuses on the geochemistry of secondary minerals, mainly calcite but also others such as fluorite and Ca/Al silicates, precipitated throughout the last 1.5 billion years in fractures of crystalline rock, SE Sweden. LÄS MER

  4. 4. Agpaitic Rocks of the Norra Kärr Alkaline Complex: Chemistry, Origin, and Age of Eudialyte-hosted Zirconium and Rare-earth Element Ore

    Författare :Axel S.L. Sjöqvist; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Norra Kärr alkaline complex; agpaitic rocks; eudialyte; rare-earth elements; geochronology; radiogenic isotope geochemistry;

    Sammanfattning : Agpaites are peralkaline nepheline syenites that are denominated by rock-forming complex silicate minerals such as eudialyte. The exotic mineralogy and chemistry of these rocks are not only interesting for research, but globally these rocks also have potential as polymetallic resources of elements such as zirconium, niobium, rare-earth elements, zinc, and uranium. LÄS MER

  5. 5. Origin and mobility of major and key trace elements (Cs, YREEs) in fracture groundwater in the upper 1.2 kilometres of coastal granitoids - Implications for future repositories of spent nuclear fuel

    Författare :Frédéric A. Mathurin; Mats E. Åström; Marcus Laaksoharju; Birgitta Kalinowski; Niklaus Waber; Linnéuniversitetet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; fracture groundwater; groundwater mixing; seawater intrusion; water-rock interactions; cation exchange; Cesium; Rare Earth Elements; colloidal speciation; humic substances; dual porosity; inverse modelling; Äspö HRL; Laxemar; Forsmark; eaux de fractures; mélange d eaux; intrusion d eau de mer; interactions eau-roche; échanges cationiques; Césium; Elements Terres Rares; spéciation colloïdale; substances humiques; double porosité; modélisation inverse; Äspö HRL; Laxemar; Forsmark; sprickvatten; grundvatten mixing; havsvattenintrusion; vatten-berg interaction; katjonbyte; cesium; sällsynta jordartsmetaller; kollidal speciation; humusämnen; dual porositet; invers modellering; Äspölaboratoriet; Äspötunneln; Laxemar; Forsmark; Miljövetenskap; Environmental Science;

    Sammanfattning : This thesis focuses on the chemical and isotopic features of groundwater residing in the upper 1.2 km of sparsely fractured crystalline bedrock of the Baltic Shield. LÄS MER