Mechanisms of uptake of rare earth elements (REEs) were investigated, particularly those by REE accumulator species (autumn fern). Rare earth elements are practically insoluble under natural conditions, suggesting some unknown mechanism in REE accumulator species. In the present investigation, two notable phenomena were observed. (I) Concerning the ionic-radius dependence of REE uptake by leave...

Definitions and characteristics The rare earth elements (REE) (sometimes referred to as the rare earth metals) are a group of 17 chemically similar metallic elements, including the 15 lanthanides, scandium and yttrium. The lanthanides are elements spanning atomic numbers 57 (lanthanum, La) to 71 (lutetium, Lu) (Table 1). The lanthanides all occur in nature, although promethium, the rarest, only...

Rare earth elements (REE) are either housed in exotic REE minerals that sporadically populate the host rock or they occur as ionic substitutions in the crystal structure of existing rock-forming minerals. The genesis of REEs in carbonatite rocks can result in intricate mineralogical textures between REE minerals, host rock minerals, and minerals formed by later processes. Upfront mineralogical ...

Rare earth elements (REE) have been recognised as critical raw materials, crucial for many clean technologies. As the gap between their global demand and supply increases, the search for their alternative resources becomes more and more important, especially for the countries which depend highly on their import. Coal fly ash (CFA), which when not utilised is considered waste, has been regarded ...

An analytical method for the determination of traces of rare earth elements (REE) as impurities in high pure lanthanum oxide (La O ) 2 3 ́ produced in the Instituto de Pesquisas Energeticas e Nucleares (IPEN) and compared with the oxide of commercial lanthanum as a certified reference is discussed in this work. The REE as impurities in the lanthanum oxide were separated from the matrix by a high...

An analytical method for the determination of traces of rare earth elements (REE) as impurities in highly pure praseodymium oxide ́ (Pr O ) produced at the Instituto de Pesquisas Energeticas e Nucleares (IPEN) and a comparison with commercial praseodymium oxide 6 11 as a certified reference is reported. REE as impurities in praseodymium oxide were separated from the matrix by high-performance li...

Rare earth elements (REE) are widely used in advanced technology. Praseodymium (Pr), neodymium (Nd), samarium (Sm) and dysprosium (Dy) are used in high-power permanent magnets. Ytterbium (Yb), erbium (Er) and holmium (Ho) are used in lasers. Lanthanum (La), gadolinium (Gd), terbium (Tb), europium (Eu) and Yb are components of luminescent and fluorescent phosphors, used in fluorescent lamps, rad...