Sökning: "RARE-EARTH ELEMENTS"

Visar resultat 1 - 5 av 65 avhandlingar innehållade orden RARE-EARTH ELEMENTS.

  1. 1. 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

  2. 2. Modeling and Optimization of Rare Earth Element Chromatography

    Författare :Mark Max-Hansen; Institutionen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rare Earth Elements; Chromatography; Modeling; Optimization;

    Sammanfattning : The Rare Earth Elements are a group of metals, that are of growing technical and economical importance. Current separation techniques can be detrimental to the environment, and a clean technology for separation has been devised, based on analytical chromatography of the REEs. LÄS MER

  3. 3. Robust Multi-objective Optimization of Rare Earth Element Chromatography

    Författare :Hans-Kristian Knutson; Institutionen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chromatography; Rare earth elements; Modeling; Multi-objective optimization; Robust optimization; Chromatography; Rare earth elements; Modeling; Multi-objective optimization; Robust optimization;

    Sammanfattning : Rare earth elements comprise the metallic elements known as lanthanides as well as scandium and yttrium. They are extensively used in modern technological industries and are considered as strategic commodities in many countries. LÄS MER

  4. 4. Hydrometallurgical recovery of rare earth elements from flourescent lamp waste fractions

    Författare :Cristian Tunsu; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; rare earth elements; recycling; fluorescent lamp waste; solvent extraction; waste treatment; Cyanex 572; leaching; Cyanex 923;

    Sammanfattning : Recovery and reuse of materials is important for a circular economy. In recent years the recovery of critical metals from end-of-life products has received increased attention. Various streams, e.g. LÄS MER

  5. 5. Radiative Properties of Rare Earth Elements - Free and Bound in Crystals

    Författare :Huailiang Xu; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Laser Spectroscopy; Upconversion; Lifetimes; Atomic and molecular physics; Atom- och molekylärfysik; Laser technology; Laserteknik; Rare earth Elements; Fysicumarkivet A:2004:Xu;

    Sammanfattning : This thesis is devoted to fundamental aspects, and to spectroscopic applications of radiative properties in free atoms and ions, as well as in ions doped into crystals. Using the time-resolved laser-induced fluorescence technique, measurements of radiative lifetimes for rare earth elements have been performed in neutral Pr, Nd, Tm, and in singly ionized Sm, Er, Nd, Tm, Yb, as well as in doubly ionized Tm and Tb ions. LÄS MER