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Registros recuperados: 5
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Determination of REE in phosphate-containing fertilizers and agricultural gypsum by Synchronous Vertical Dual View ICP OES Repositório Alice
MACHADO, R. C.; AMARAL, C. D. B. do; SCHIAVO, D.; NOBREGA, J. de A.; NOGUEIRA, A. R. de A..
2015
Tipo: Resumo em anais de congresso (ALICE) Palavras-chave: REE; Agricultural gypsum; ICP OES.
Ano: 2015 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1037844
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Rare earth element and yttrium geochemistry applied to the genetic study of cryolite ore at the Pitinga Mine (Amazon, Brazil) Anais da ABC (AABC)
Minuzzi,Orlando R.R.; Bastos Neto,Artur C.; Formoso,Milton L.L.; Andrade,Sandra; Janasi,Valcir A.; Flores,Juan A..
This work aims at the geochemical study of Pitinga cryolite mineralization through REE and Y analyses in disseminated and massive cryolite ore deposits, as well as in fluorite occurrences. REE signatures in fluorite and cryolite are similar to those in the Madeira albite granite. The highest ΣREE values are found in magmatic cryolite (677 to 1345 ppm); ΣREE is lower in massive cryolite. Average values for the different cryolite types are 10.3 ppm, 6.66 ppm and 8.38 ppm (for nucleated, caramel and white types, respectively). Disseminated fluorite displays higher ΣREE values (1708 and 1526ppm) than fluorite in late veins(34.81ppm). Yttrium concentration is higher in disseminated fluorite and in magmatic cryolite. The evolution of several parameters...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Cryolite; REE; Y; Pitinga; Amazonia.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000400012
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Chemical signature of two Permian volcanic ash deposits within a bentonite bed from Melo, Uruguay Anais da ABC (AABC)
Calarge,Liane M.; Meunier,Alain; Lanson,Bruno; Formoso,Milton L.L..
A Permian bentonite deposit at Melo, Uruguay is composed of a calcite-cemented sandstone containing clay pseudomorphs of glass shards (0-0.50 m) overlying a pink massive clay deposit (0.50-2.10m). The massive bed is composed of two layers containing quartz and smectite or pure smectite respectively. The smectite is remarkably homogeneous throughout the profile: it is a complex mixed layer composed of three layer types whose expandability with ethylene glycol (2EG 1EG or 0EG sheets in the interlayer zone which correspond to low-, medium- and high-charge layers respectively) varies with the cation saturating the interlayer zone. The smectite homogeneity through the profile is the signature of an early alteration process in a lagoonal water which was over...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Bentonite; REE; Incompatible elements; Mixed-layer minerals; Uruguay.
Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652006000300012
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Biogeochemistry of REE elements and tetrad effect in the soil-plant system: a study on volcanic rock covers in southernmost Brazil Anais da ABC (AABC)
Cunha,Maria do Carmo Lima e; Nardi,Lauro V.S.; Muller,Ingke F..
This paper deals with the distribution of REE in rock, soil and plant in an area of monzonitic rocks from southernmost Brazil. The REE patterns in Schinus lensticifolius show a negative-Ce anomaly and a prominent tetrad effect, characterized as W-type that are not present in rock and soil samples. The REE patterns in the soils and rocks sampled are very similar and there is no fractionation of REE during the processes of soil formation. The W-type patterns are interpreted as indicating that REE were absorved by S. lentiscifolius as simple ions rather than as complex ions, or, alternatively, that the transport of REE in the plant metabolic processes was as free ions. The recognition of tetrads, either, M- or W-type patterns, is an additional tool for...
Tipo: Info:eu-repo/semantics/article Palavras-chave: REE; Tetrad effect; Schinus lentiscifolius; Southernmost Brazil.
Ano: 2012 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652012000400006
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Rare earth elements and neodymium isotopes in sedimentary organic matter ArchiMer
Freslon, Nicolas; Bayon, Germain; Toucanne, Samuel; Bermell, Sylvain; Bollinger, Claire; Chéron, Sandrine; Etoubleau, Joel; Germain, Yoan; Khripounoff, Alexis; Ponzevera, Emmanuel; Rouget, Marie Laure.
We report rare earth element (REE) and neodymium (Nd) isotope data for the organic fraction of sediments collected from various depositional environments, i.e. rivers (n=25), estuaries (n=18), open-ocean settings (n=15), and cold seeps (n=12). Sedimentary Organic Matter (SOM) was extracted using a mixed hydrogen peroxide/nitric acid solution (20%-H2O2 – 0.02M-HNO3), after removal of carbonate and oxy-hydroxide phases with dilute hydrochloric acid (0.25M-HCl). A series of experimental tests indicate that extraction of sedimentary organic compounds using H202 may be complicated occasionally by partial dissolution of sulphide minerals and residual carbonates. However, this contamination is expected to be minor for REE because measured concentrations in H2O2...
Tipo: Text Palavras-chave: Organic matter; Rare earth elements; REE; Neodymium isotopes; ΕNd; Sediment; Boundary Exchange; Paleoceanography.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00191/30250/28682.pdf
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