Chemistry and thermodynamics of europium and some of its simpler inorganic compounds and aqueous species

Rard, Joseph A.

doi:10.1021/cr00070a003

Cited by 103 publications

(51 citation statements)

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“…Europium, indeed, may be reduced to Eu 2+ , which is a result of its different geochemical behavior during the magmatic process in comparison with other lanthanides (Rard, 1985). Such reduction is possible in extremely reductive conditions (such as hydrothermal solutions), which do not occur in natural water systems.…”

Section: Rare Earth Elementsmentioning

confidence: 99%

Rare Earth Elements of Orzeskie Beds of South-West Part Upper Silesian Coal Basin (Poland) / Pierwiastki Ziem Rzadkich Z Pokładów Węgla Warstw Orzeskich Południowo-Zachodniej Części Gzw (Polska)

Adamczyk¹,

Białecka²,

Moszko³

et al. 2015

Archives of Mining Sciences

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PIERWIASTKI ZIEM RZADKICH Z POKŁADÓW WĘGLA WARSTW ORZESKICH POŁUDNIOWO-ZACHODNIEJ CZĘŚCI GZW (POLSKA)The subject of the research concerned the coal samples from 360/1, 361 and 362/1 seams of the Orzesze beds in the "Pniówek" coal mine. The obtained samples were characterized by low ash content -2.22-6.27% of the mass. The chemical composition of the ash indicates the presence of aluminosilicate minerals in the analyzed coal samples -most likely clay minerals, the presence of which has been confirmed in microscopic tests of the petrographic composition of channel samples of coal.The content of rare earth elements (REE sum) in the ash of the tested coal seams ranged from 364 to 1429 ppm. Variation of the REE content has been observed within a single seam.The fraction of REE indicates a relation with a mineral substance. No relation of the REE fraction and the presence of red beds has been found based on the tested samples.The content of REE found in ash, normalized to chondrites, is characterized by LREE enrichment in relation to HREE. The Eu anomaly is most likely related to tuff and tonstein levels occurring in Orzesze beds, which accompany the coal seams in the Upper Silesian Coal Basin (i.a., south of the studied area).The research has indicated that LREE in the tested samples are more related to the mineral substance, while HREE have a stronger affinity with organic substances.Keywords: rare earth elements (REE), coal, Orzesze beds, USCB Przedmiotem badań były próbki węgla z pokładów 360/1, 361 i 362/1 warstw orzeskich KWK Pniówek. Próbki te charakteryzują się niewielką zawartością popiołu 2,22-6,27% mas. Skład chemiczny popiołów wskazuje na obecność w analizowanych próbkach węgla minerałów z grupy glinokrzemianów najprawdopodobniej minerałów ilastych, których obecność była stwierdzona w badaniach mikroskopowych składu petrograficznego próbek bruzdowych węgla.Zawartości pierwiastków ziem rzadkich (suma REE) w popiołach badanych pokładów węgla wahają się od 364 do 1429 ppm. Obserwuje się zróżnicowanie zawartości REE w obrębie jednego pokładu. 158Udział REE wykazuje związek z substancją mineralną. Nie stwierdzono związku udziału REE, w badanych próbkach, z obecnością utworów pstrych w stropie karbonu.Zawartości REE oznaczone w popiołach, znormalizowane do chondrytów, charakteryzują się wzbogaceniem LREE wobec HREE. Anomalia Eu związana jest prawdopodobnie z występującymi w warstwach orzeskich (m.in. na północ od obszaru badań) Górnośląskiego Zagłębia Węglowego poziomami tufów i tonsteinów, które towarzyszą pokładom węgla.Badania wykazały, że LREE w badanych próbkach związane są raczej z substancją mineralną, natomiast HREE posiadają silniejsze powinowactwo z substancją organiczną.Słowa kluczowe: pierwiastki ziem rzadkich (REE), węgiel kamienny, warstwy orzeskie, GZW

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Section: Rare Earth Elementsmentioning

confidence: 99%

Rare Earth Elements of Orzeskie Beds of South-West Part Upper Silesian Coal Basin (Poland) / Pierwiastki Ziem Rzadkich Z Pokładów Węgla Warstw Orzeskich Południowo-Zachodniej Części Gzw (Polska)

Adamczyk¹,

Białecka²,

Moszko³

et al. 2015

Archives of Mining Sciences

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“…Europium can be reduced to Eu 2+ in the magmatic processes, which results in distinct geochemical behavior of Eu relative to the other REE. Reduction of Eu only occurs under extreme reducing condition such as hydrothermal fluid venting at midoceanic ridges, which does not exist within natural aquatic systems (Rard, 1985). Figure 6.…”

Section: Trace Elementsmentioning

confidence: 99%

Petrology and Geochemistry of the Jurassic Coals in Southwestern Ordos Basin, China

Wang

2010

Energy Exploration & Exploitation

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This study is related to seven Jurassic bituminous coal samples collected from four mines of the Huanglong coalfield, southwestern Ordos Basin, China. Petrological and geochemical characteristics of these samples were investigated. The results show that these Jurassic coals are high in inertinite (54 vol. %), followed by vitrinite (31.7 vol.%) and liptinite (3.7 vol.%). The mineralogy of the coals is dominated by illite, kaolinite, quartz, calcite, pyrite, and less siderite, feldspar, goyazite, anatase, illite-smectite, dolomite, and marcasite. These coals are low in sulfur (0.18-0.71%). With the exception of the No. 4 coal from the Dafosi mine, in which the total sulfur is 1.32% and the pyritic sulfur is up to 0.78%. Compared to common Chinese coals, the Jurassic coals are much high in CaO (2.12%), MgO (0.26%), P 2 O 5 (0.21%), Sr (591 µg/g), Ba (476 µg/g), and F (187 µg/g). The excess P, Sr, and Ba in the BMF-2 and BMF-4 are mainly present in goyazite-gorceixite series minerals (goyazite). The content of rare earth elements ranges from 32.2 to 154 µg/g (mean 80.6 µg/g). The chondritenormalized distribution pattern is typically characterized by the enrichment of LREE over HREE. And the high anomaly Eu value (0.86) of these Jurassic coals was probably inherited from its source detrital rocks.

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“…Europium may also exist in the +2 oxidation state under very reducing conditions (Rard 1985). Essentially no information is available for the aqueous geochemistry and environmental behavior of Eu(II), but the Eu +2 ion will likely have a geochemical behavior similar to Sr +2 and substitute for Ca +2 in minerals given the similarities in their ionic radii.…”

Section: Europiummentioning

confidence: 99%

“…The geochemical behavior of europium and the other rare-earth elements in aqueous solutions have also been investigated extensively due to their importance to the disposal of nuclear waste. Rare-earth elements are produced in significant quantities as a result of the fission of uranium and plutonium reactor fuels (Rard 1985). In addition, the use of europium and the other rare earth elements as analogues in the study the geochemical behavior of trivalent actinide elements, such as Am(III) and Cm(III), is well accepted (Choppin 1989;Krauskopf 1986).…”

Section: A143 Europiummentioning

confidence: 99%

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Geochemical Processes Data Package for the Vadose Zone in the Single-Shell Tank Waste Management Areas at the Hanford Site

Cantrell¹,

Zachara²,

Dresel³

et al. 2007

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Companion reports that review other subject matter areas relevant to contaminant transport within the vadose zone beneath the SST WMAs, the IDF, and groundwater have been recently published. The specific subject areas include the geology of the SST WMAs iv contaminants released to the vadose zone exhibit a wide range of mobility behaviors. Many tank waste contaminants have been strongly retarded by adsorption and precipitation reactions (e.g., cesium, plutonium, americium, and europium), while others have remained mobile (e.g., technetium, nitrate, and selenium). Still others show variable, waste-specific behaviors (e.g., cesium [where sodium concentrations are very high], strontium, chromium, and uranium) that are closely tied to evolving composition of pore water in the sediments, and for chromium, a change in oxidation state. The temperature of in-ground tank waste has moderated by heat exchange with the subsurface sediment, and high concentrations of base (OH -) have been neutralized through reactions with sediment minerals and secondary mineral precipitation. Major geochemical features that may potentially affect the mobility of key contaminants of interest in the vadose zone include oxidation state, aqueous speciation, solubility, and adsorption reactions.Processes suspected of facilitating the far-field migration of immobile radionuclides, such as formation of stable aqueous complex formation and mobile colloids, were found to be potentially operative, but unlikely to occur in the field. An exception is the enhanced migration of cobalt-60 facilitated by the formation of highly stable aqueous-cyanide complexes. Certain fission-product oxyanions (e. • Adsorption is suppressed by large concentrations of tank waste anions (e.g., NO 3 -, OH -, and CO 3 2-)• Surface charge of clay-size minerals is negative and will therefore tend to repel anions• Unlike chromium, their less-soluble, less-mobile reduced forms are unstable in oxidizing environments.Laboratory studies conducted through PNNL's Vadose Zone Characterization Project and basic-science geochemical studies are expected to continue in partnership to provide information to further refine the conceptual model used for risk assessment modeling. Results of these studies can be used to help ascertain uncertainties associated with the refinement of the conceptual models for contaminant migration in the vadose zone beneath the single-shell tanks. Results can also provide improved parameterization, such as distribution coefficients (K d ), and mathematical constructs used by modelers to predict contaminant mobility under these conditions, and to decrease the degree of conservatism incorporated in these models.For various reasons, risk assessment models typically use various approximations to represent the conceptual model developed for the site. Adsorption is frequently approximated using empirical distribution coefficients (K d s). Although the use of empirical distribution coefficients can potentially lead to erroneous results under certain conditions where the...

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Chemistry and thermodynamics of europium and some of its simpler inorganic compounds and aqueous species

Cited by 103 publications

References 64 publications

Rare Earth Elements of Orzeskie Beds of South-West Part Upper Silesian Coal Basin (Poland) / Pierwiastki Ziem Rzadkich Z Pokładów Węgla Warstw Orzeskich Południowo-Zachodniej Części Gzw (Polska)

Rare Earth Elements of Orzeskie Beds of South-West Part Upper Silesian Coal Basin (Poland) / Pierwiastki Ziem Rzadkich Z Pokładów Węgla Warstw Orzeskich Południowo-Zachodniej Części Gzw (Polska)

Petrology and Geochemistry of the Jurassic Coals in Southwestern Ordos Basin, China

Geochemical Processes Data Package for the Vadose Zone in the Single-Shell Tank Waste Management Areas at the Hanford Site

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