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