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Topic: Rare earth element


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  Rare earth element - Wikipedia, the free encyclopedia
"Rare earth elements" and "rare earth metals" are trivial names sometimes applied to a collection of 17 chemical elements in the periodic table, namely scandium, yttrium, and the lanthanides.
At the time of their discovery, earths of these elements were believed to be scarce in abundance as minerals.
The principal economic sources of rare earths elements are the minerals bastnasite, monazite, and loparite and the lateritic ion-adsorption clays.
en.wikipedia.org /wiki/Rare_earth_element   (189 words)

  
 Rare Earth
The rare earth elements (or rare earth metals) include the elements with atomic numbers 57 through 71, and, named in order, are lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.
Rare earth elements are separated from other elements in a mineral by precipitation with a suitable reagent.
Separation of the rare earth elements from each other by ordinary chemical means is difficult because their chemical properties are similar, and the isolation of an individual element may involve hundreds of fractional crystallizations.
www.candldevelopment.com /rare_earth_overview.htm   (368 words)

  
 Properties of the Rare Earth Metals - Element Chemistry
The rare earth metals are found in group 3 of the periodic table, and the 6th (5d electronic configuration) and 7th (5f electronic configuration) periods.
The rare earth metals naturally occur together in minerals (e.g., monazite is a mixed rare earth phosphate).
Rare earths are found with non-metals, usually in the 3+ oxidation state.
chemistry.allinfoabout.com /features/rareearth.html   (405 words)

  
 [No title]   (Site not responding. Last check: 2007-10-08)
The rare earth element is essential to the production of electromagnetic, or light emission from the metal oxide body, and the oxygen and/or fluorine atoms attach to the atoms of the rare earth element (s) and operate to put the rare earth element (s) into a 3+ state that is needed for emission to occur.
In an embodiment of the invention, where erbium is the rare earth doping element and where oxygen is also present as an activator, the erbium atoms are in a 3+ state because the erbium atoms have given up the outer three electrons to neighboring oxygen atoms.
The activator atom within the metal oxide body raises the ionization of the rare earth element to +3, so that when the rare earth element is impacted by electrons, the rare earth element causes the generation of, and the emission of, electromagnetic radiation.
www.wipo.int /cgi-pct/guest/getbykey5?KEY=00/16454.000323&ELEMENT_SET=DECL   (5232 words)

  
 Rare earth supported catalyst useful for preparation of alkanolamines and process for preparing same - Patent 5880058
A rare earth element is used as the active component of the catalyst of this invention.
As raw materials of the rare earth elements, any ones can be used so long as they become insoluble in the reaction solutions by the heat treatment during the catalyst preparation steps, and particularly can be used nitrates, sulfates, carbonates, acetates, oxalates, heteropolyacid salts, phosphates, halides, oxides hydroxides, etc. of the elements.
To 100 g of the rare material powder (m) for a catalyst were added 30 g of Avicel (crystalline cellulose produced by Asahi Chemical Co., Ltd.) and water in the same weight as the total of the weights of the raw material powder (m) for a catalyst and the Avicel.
www.freepatentsonline.com /5880058.html   (5012 words)

  
 Tin base white metal bearing alloys - Patent 4150983
In the embodiments described hereinafter, a mixture of rare earth elements, i.e., a misch metal consisting of 48% Ce, 30% La, 10% Nd, 5% Pr and 7% in total of Pm, Sm and Eu was used.
Also clear from the graph is the point that both rare earth element or elements and Mg are not effective in refining cubic crystal grains when these amounts are less than 0.001% and that neither increase the effect any more when the amounts of these exceed 1%.
The amounts of other elements, which were 3.5% Cu, 9% Sb, 0.1% Cr and 0.1% rare earth element or elements and 0.5% Mg, all of which being percentages by weight, were all kept constant.
www.freepatentsonline.com /4150983.html   (3384 words)

  
 Rare Earth Element Mines, Deposits, and Occurrences
Rare Earth Minerals - rare earth-bearing minerals 10.
This dataset was compiled for the University of Arizona's Center for Mineral Resources Rare Earth monograph, a summary document intended to reflect our current knowledge of the geology and mineral economics of the rare earths, including yttrium.
This report is the most complete compilation of rare earth mines, deposits, and occurrences known.
geo-nsdi.er.usgs.gov /metadata/open-file/02-189/metadata.faq.html   (1206 words)

  
 An MBendi Profile: World: Mining - Tantalum, Niobium and Rare Earth Element Mining - Commodity Properties and Uses
The principal economic sources of rare earths are the minerals bastnasite, monazite, and loparite and the lateritic ion-adsorption clays.
The rare earths are a relatively abundant group of 17 elements composed of scandium, yttrium, and the lanthanides.
The elements range in crustal abundance from cerium, the 25th most abundant element of the 78 common elements in the Earth's crust at 60 parts per million, to thulium and lutetium, the least abundant rare-earth elements at about 0.5 part per million.
www.mbendi.co.za /indy/ming/othr/p0005.htm   (1127 words)

  
 [No title]   (Site not responding. Last check: 2007-10-08)
Preferably, the REE in the REE oxide is Er, Tm, Yb, Nd, or Ce.
The content of alkali and alkaline earth metals and additional elements included in the glass may be adjusted to vary the refractive index and to increase or decrease thermal expansivity.
Light from the pump laser excites the rare earth ions, raising them to a series of higher energy states where they oscillate between these states at a transition energy or frequency corresponding to the optical signal to be amplified.
www.wipo.int /cgi-pct/guest/getbykey5?KEY=01/99241.011227&ELEMENT_SET=DECL   (3590 words)

  
 ARS | Publication request: Rare Earth Element Oxides for Tracing Sediment Movement
Thus we developed a method using special chemicals called Rare Earth Elements, which bind strongly to soil and sediment particles and can be measured in sediment and soil samples.
Five REE oxides in powder form were uniformly mixed with the soil on different parts of a 10% slope in a four by four meter soil bed.
REE concentration in soil samples taken from the bed and sediment sampled from runoff was determined by Inductively Coupled Plasma Mass-Spectrometry.
www.ars.usda.gov /research/publications/Publications.htm?seq_no_115=139557&pf=1   (612 words)

  
 Rare Earth Element
Rare earth elements (REE) and yttrium (Y) are used in petroleum cracking catalysts, in the electronics industry, and in the manufacture of super conductors, permanent magnets, ceramics, glass, and metal alloys.
REE or the lanthanide series, constitute a group of 15 elements beginning with lanthanum (atomic no. 57) and ending with lutetium (atomic no. 71).
REE are more abundant than elements such as gold, silver, and uranium, but they rarely form distinct minerals in nature, occurring instead in trace amounts in over 250 minerals.
www.ir.gov.sk.ca /Default.aspx?DN=3559,3541,3538,3385,2936,Documents   (284 words)

  
 Rhodes eResearch Repository - Rare earth element geochemistry of the Insizwa lobe of the Mount Ayliff Complex, Eastern ...
Rare earth element geochemistry of the Insizwa lobe of the Mount Ayliff Complex, Eastern Cape, South Africa
Marsh, J.S. Rare earth element geochemistry of the Insizwa lobe of the Mount Ayliff Complex, Eastern Cape, South Africa.
New rare earth element (REE) data from all lithologies of the Insizwa lobe, Mount Ayliff Complex, are presented.
eprints.ru.ac.za /108   (215 words)

  
 Glasgow ePrints Service - Rare earth element geochemistry of upper Ordovician cherts from the Southern Uplands of ...
Rare earth element geochemistry of upper Ordovician cherts from the Southern Uplands of Scotland
Owen, A.W. and Armstrong, H.A. and Floyd, J.D. Rare earth element geochemistry of upper Ordovician cherts from the Southern Uplands of Scotland.
The REE signatures can be used as fingerprints to differentiate between some of the fault-bounded formations within the area.
eprints.gla.ac.uk /148   (232 words)

  
 www.mineweb.net | co_releases Rare Element Resources   (Site not responding. Last check: 2007-10-08)
Rare Element Resources Ltd is a special kind of company and I‘m very pleased that the Company’s Board of Directors has appointed me president and CEO.
Rare Element Resources offers an investment opportunity that combines the short-term speculative value of the publicly traded resource market with the long-term growth potential of the high-tech and energy-efficient world of the near future.
Rare Element Resources began this advanced stage of the Bear Lodge exploration in late 2004.
www.mineweb.net /co_releases/471675.htm   (1011 words)

  
 Nomenclature rare earth minerals
Now, only the dominant element in a specified crystal-structure site within isostructural minerals may be appended to the group name as a parenthesized suffix.
Of the 14 rare-earth elements (La through Lu) and Y, 6 have been observed to predominate in mineral species on the basis of atomic percentage of rare-earth elements within a single set of crystal-structure sites.
The chemical-symbol for the predominant rare-earth element is appended, in parentheses, by means of a hyphen to the group name; this results in mineral-species names such as monazite-(Ce), monazite-(La), and monazite-(Nd).
www.minsocam.org /MSA/collectors_corner/arc/nomenclaturere.htm   (742 words)

  
 ARS | Publication request: Using Rare Earth Element Oxide Tracers for Studiying Soil Erosion Dynamics   (Site not responding. Last check: 2007-10-08)
The purpose of this work was to test the feasibility of using non-hazardous Rare Earth Element oxide lanthaide for tracing sediment movement along a hill slope.
Results indicate that Rare Earth Element oxide tracers are capable of tracing sediment movement and redistribution within a field or hill slope with fairly good accuracy.
The objectives of this study were to examine the feasibility of the direct-mixing of Rare Earth Element (REE) oxides with soil materials for tracing soil erosion at a plot scale and to further explore the potential of using this tracing technique for studying soil erosion dynamics.
www.ars.usda.gov /research/publications/publications.htm?SEQ_NO_115=128112&pf=1   (476 words)

  
 Article   (Site not responding. Last check: 2007-10-08)
Abstract: The conditions for the formation of rare earth element 3,5-dimethytoxybenzoates were studied and their quantitative composition and solubilities in water at 293 K were determined.
On heating in air to 1173 K, the 3,5-dimethoxybenzoates of rare earth elements decompose in various ways.
The hydrated complexes first dehydrate to form anhydrous salts which then decompose in air to the oxides of the respective metals while in nitrogen to mixtures of carbon and oxides of the respective metals.
dx.doi.org /10.2298/JSC0310751F   (169 words)

  
 RARE EARTH ELEMENT EXPLORATION PROPERTY
The Three G¹s (15 unit) and the Three Valley (20 unit) mineral claims were located to cover several known zones, of highly anomalous Rare Earth Elements.
Anomalous Rare Earth Elements are exposed in road cuts, at elevations between 900 and 1500 meters.
Grab sampling on the claims, by government geologists has indicated that anomalous Rare Earth enrichment occurs within carbonatite lenses and pegmatite dykes and sills.
www.arris-intl.com /customer/Papers/explorationproperty.html   (598 words)

  
 Rare Earth Elements
The elements classified as "Rare Earth Elements" are located in Group 3 of the Periodic Table and in the 6th and 7th periods.
The Rare Earth Elements are of the Lanthanide and Actinide series.
Rare Earth are included in The Elements are the building blocks of Modern Science and Chemistry
www.periodic-table.org.uk /rare-earth.htm   (238 words)

  
 Neodymium isotopic composition and rare earth element concentrations in the deep and intermediate Nordic Seas: ...
Neodymium isotopic composition and rare earth element concentrations were measured in seawater samples from eleven stations in the Nordic Seas.
In addition to the neodymium isotopic composition, the rare earth element patterns suggest that these inputs occur via the remobilization (which includes resuspension and dissolution) of sediments deposited on the margins.
Whereas the neodymium isotopic composition behaves conservatively in the oceans in the absence of lithogenic inputs, and can be used as a water mass tracer, these results emphasize the role of interactions, between sediments deposited on margins and seawater, in the acquisition of the neodymium isotopic composition of water masses.
www.agu.org /pubs/crossref/2004/2004GC000742.shtml   (375 words)

  
 Avalon Ventures Ltd. - Rare Earth Element Potential Confirmed at Thor Lake : ArriveNet Press Releases : Health   (Site not responding. Last check: 2007-10-08)
The purpose of the work was to confirm the presence of significant levels of rare earth elements ("REE's") in several of the previously identified zones of rare metal enrichment on the property.
Significant rare earth element and yttrium enrichment was confirmed in the three known mineralized zones sampled (the T, R and Lake zones).
Management is very pleased with the results received to date which confirm significant enrichment at Thor Lake in some of the specific rare earth elements such as Europium and Neodymium that are currently in the highest demand.
press.arrivenet.com /health/article.php/696076.html   (1248 words)

  
 Systematic Study of New Rare Earth Element-Iron-Antimony Skutterudites Synthesized Using Multilayer Precursors
We have synthesized a series of stable and metastable rare earth element-iron antimonides, controlling both composition and structure using multilayer reactants.
The metastable rare earth element-iron antimonides could be prepared with the entire sequence of rare earth elements.
The lattice parameters of these metastable compounds were always larger than those of the corresponding more stable analog, and the occupancy of the rare earth element cation was found to be less than 1.
pubs.acs.org /cgi-bin/abstract.cgi/inocaj/1997/36/i19/abs/ic9702375.html   (194 words)

  
 Rare Earth Elementals
We offer you the story of Rare Earth Elementals at a time when their contributions are most needed.
Like all of the Rare Earth Elements, Europium asks to be used at only precise moments when its unique beauty can be actualized.
These Rare Earth Elementals are available as Vibrational Jewelry in the form of necklaces or earrings and/or Stonessences.
www.ahhhmuse.com /product.asp?cat=5   (1646 words)

  
 Organic Rare Earth Healing   (Site not responding. Last check: 2007-10-08)
So similar to each other were these mysterious elements that as many as 40,000 preparations of Rare Earth Crystals were required to purify them.
Each Rare Earth Element is specially purified from these crystals using state-of-the-art column chromatography.
Following your Nd-10x™, you'll rest for a day to consolidate your Electron Transitions, since the Rare Earth you would otherwise receive that day, Promethium, exists only in a radioactive form whose Energy Level is far too high for safe ingestion on this Astral Plane.
members.aol.com /RSRICHMOND/rarearth.html   (468 words)

  
 DO ARCHEAN CHEMICAL SEDIMENTS RECORD ANCIENT SEAWATER RARE EARTH ELEMENT PATTERNS?
Recently, investigators have begun to employ the rare earth elements (REE) to help sort out such issues by applying these trace elements to identify protoliths of the Archean rocks in question.
Furthermore, we present REE data for 28 groundwater samples from central México that exhibit features of their shale-normalized REE patterns that closely resemble modern seawater and microbialite patterns, as well as the REE patterns of Archean rocks, including the Strelley Pool Chert and greenstones of the Isua Belt in Greenland.
The shale-normalized La-, Ce-, Gd-, Y-anomalies, and the heavy REE enrichments of these groundwaters are statistically indistinguishable from modern seawater and Holocene microbialites, and are within the range exhibited by the Archean rocks.
gsa.confex.com /gsa/2004AM/finalprogram/abstract_75735.htm   (322 words)

  
 High field strength element/rare earth element fractionation during partial melting in the presence of garnet: ...
High field strength element/rare earth element fractionation during partial melting in the presence of garnet: Implications for identification of mantle heterogeneities
A synthesis of recent garnet-melt trace element partitioning data for key trace elements (Ti, Hf, Zr, U, Th, Sm, and Yb) is used to compare and contrast the trace element signatures imparted on mantle melts by garnets from peridotitic and eclogitic source rocks.
We provide a semiquantitative explanation for the behavior of the high field strength elements based on a crystal lattice strain model in which Zr and Hf are split between the X and Y sites in Ca-rich garnet and in which significant changes in garnet elasticity occur as a function of garnet composition.
www.agu.org /pubs/crossref/2001/2000GC000133.shtml   (533 words)

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