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Wyszukujesz frazę ""elements"" wg kryterium: Temat


Tytuł:
Trace analysis of Indonesian volcanic ash using thermal and epithermal neutron activation analysis
Autorzy:
Canion, B.
Jacques, C.
Landsberger, S.
Taftazani, A.
Powiązania:
https://bibliotekanauki.pl/articles/146890.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neutron activation analysis (NAA)
trace elements
volcanic ash
rare earth elements (REE)
Mount Merapi
Opis:
There is continued great interest in determining the trace element and heavy metal content of volcanic ash for a variety of reasons. The motivation stems from the desire to understand the geochemistry of volcanic ash in imbedded geological formations, the impact on seawater, and the possible release of toxic elements into the environment that may impact livestock grazing and water systems. Ash from volcanic plumes can go as high 8-18 km thus affecting climate and air traffic. We have employed Compton suppression neutron activation analysis (NAA) with thermal and epithermal neutrons to determine trace elements in volcanic ash from Indonesian eruption of Mount Merapi in October 2010. We found a wide range of elements, including several rare earth elements.
Źródło:
Nukleonika; 2012, 57, 4; 585-589
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Controls on the distribution of rare earth elements in the Kupferschiefer series of SW Poland
Autorzy:
Oszczepalski, S.
Chmielewski, A.
Mikulski, S.
Powiązania:
https://bibliotekanauki.pl/articles/2060523.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
rare earth elements (REE)
redistribution
Kupferschiefer
Zechstein
SW Poland
Opis:
This study deals with the spatial distribution and the PAAS-normalized patterns of rare earth elements (REE) studied by ICP-MS in the Kupferschiefer series of SW Poland. The most characteristic feature is a progressive enrichment in REE content (including Y and Sc) outward from the rocks with pyritic and Pb-Zn mineralisation, across the rocks with copper mineralisation, towards the oxidized (Rote Fäule) areas. The same trend can also be observed with respect to LREE, MREE and HREE. Whereas REE distribution diagrams for shales with pyrite and Pb-Zn mineralisation are almost flat, diagrams for shales with hematite and copper mineralisation are convex-upward and the strongest convexity is attributed to the transition from hematitic alteration to copper-rich rocks. REE distribution diagrams normalized to PAAS show strong MREE enrichment relative to LREE and HREE, which is typically the highest in the hematite zone, lower in shale with copper mineralisation, and the lowest in shales with Pb-Zn and pyrite mineralisation. The systematic increase in the concentration of REE towards the Rote Fäule, and the strong enrichment in MREE in the transition zone are indicative of variable intensity of leaching and formation of the REE enrichments (including MREE) by MREE>HREE>LREE fluids, as evidenced by the MREE-enriched signatures. Overprinting of secondary enrichments over the original REE pattern due to redistribution along the pathways of expanding fluids are postulated to account for the apparent differences in the distribution and concentration of REE (including the MREE-enriched trend) between the oxidized rocks, copper-bearing rocks, and reduced lithologies barren in copper.
Źródło:
Geological Quarterly; 2016, 60, 4; 811--826
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of rare earth elements content in hard coal type 31.1
Autorzy:
Baron, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/409812.pdf
Data publikacji:
2020
Wydawca:
STE GROUP
Tematy:
mining industry
processing of hard coal
rare earth elements (REE)
Opis:
The aim of the article is to present the results of laboratory analyses determining the content of rare earth elements (REE) in hard coal type 31.1. Coal was extracted directly from the mining excavation located in the Upper Silesian Coal Basin. Mass spectrometry tests with ionization in inductively coupled plasma (ICP-MS), were aimed at the quantitative analysis of the share of REE in coal, taking into account the economic aspects of recovery of these elements. Fine ground hard coal samples and ashes obtained after coal burning were assessed for the rare earth elements concentration. Results of the rare earth elements concentration (lanthanum and cerium) in hard coal are similar in the values obtained in previous tests. The current analyses present higher concentration of europium or neodymium. The article also contains the concept of possible future research work, consisting in the recovery of rare earth elements using, among others, a classifying hydrocyclone.
Źródło:
Management Systems in Production Engineering; 2020, 4 (28); 240-246
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability of monazite and disturbance of the Th-U-Pb system under experimental conditions of 250–350 °C and 200–400 MPa
Autorzy:
Budzyń, B.
Konečný, P.
Kozub-Budzyń, G. A.
Powiązania:
https://bibliotekanauki.pl/articles/191272.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
monazite
apatite
steacyite
rare earth elements (REE)
geochronology
experimental petrology
Opis:
This experimental study provides important data filling the gap in our knowledge on monazite stability under conditions of fluid-mediated low-temperature metamorphic alteration and post-magmatic hydrothermal alterations. The stability of monazite and maintenance of original Th-U-total Pb ages were tested experimentally under P-T conditions of 250–350 °C and 200–400 MPa over 20–40 days. The starting materials included the Burnet monazite + K-feldspar ± albite ± labradorite + muscovite + biotite + SiO2 + CaF2 and 2M Ca(OH)2 or Na2Si2O5 + H2O fluid. In the runs with 2M Ca(OH)2, monazite was unaltered. REE-enriched apatite formed at 350 °C and 400 MPa. The presence of the Na2Si2O5 + H2O fluid promoted the strong alteration of monazite, the formation of secondary REE-enriched apatite to fluorcalciobritholite, and the formation of REE-rich steacyite. Monazite alteration included the newly developed porosity, patchy zoning, and partial replacement by REE-rich steacyite. The unaltered domains of monazite maintained the composition of the Burnet monazite and its age of (or close to) ca. 1072 Ma, while the altered domains showed random dates in the intervals of 375–771 Ma (250 °C, 200 MPa run), 82–253 Ma (350 °C, 200 MPa), and 95–635 Ma (350 °C, 400 MPa). The compositional alteration and disturbance of the Th-U-Pb system resulted from fluid-mediated coupled dissolution-reprecipitation. In nature, such age disturbance in monazite can be attributed to post-magmatic alteration in granitic rocks or to metasomatic alteration during metamorphism. Recognition of potentially altered domains (dark patches in high-contrast BSE-imaging, developed porosity or inclusions of secondary minerals) is crucial to the application of Th-U-Pb geochronology.
Źródło:
Annales Societatis Geologorum Poloniae; 2015, 85, 2; 405-425
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potencial management of waste phosphogypsum with particular focus on recovery of rare earth metals
Autorzy:
Podbiera-Matysik, K.
Gorazda, K.
Wzorek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/778042.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
phosphogypsum waste
phosphogypsum conversion
rare earth elements (REE)
environmental threats
Opis:
Phosphogypsum is a noxious industrial waste contributing to global environmental and economic problems. This publication focuses above all on phosphogypsum resulting from the processing of apatite as a phosphorus bearing compound, since it contains considerable amounts of lanthanides due to its magma origin. The possibilities of its waste-free processing are large, however they require the application of suitable technologies, frequently expensive ones, and allowing for the individual characteristics of the given waste. The research works conducted so far confirm the possibility of applying phosphogypsum for the recovery of lanthanides, and the process enhances the removal of remaining impurities, thanks to which the purified calcium sulphate (gypsum) may find application for the production of construction materials.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 1; 55-61
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The stability of xenotime in high Ca and Ca-Na systems, under experimental conditions of 250–350°C and 200–400 MPa : the implications for fluid-mediated low-temperature processes in granitic rocks
Autorzy:
Budzyń, B.
Kozub-Budzyń, G. A.
Powiązania:
https://bibliotekanauki.pl/articles/2060298.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
xenotime
yttrium fluorapatite
yttrium silicate
rare earth elements (REE)
experimental petrology
Opis:
he stability of xenotime was tested by experiments in the presence of a silicate mineral assemblage and two different fluids, 2M Ca(OH)2 or Na2Si2O5 + H2O, under P-T conditions of 200-400 MPa and 250-350°C. The xenotime was stable in runs with 2M Ca(OH)2, replicating the low-temperature metasomatic alterations of granitic rocks, except in experiment at 350°C and 400 MPa, where some (Y,REE)-rich fluorapatite formed. Experiments with Na2Si2O5 + H2O resulted in significant xenotime alteration and partial replacement by an unknown (Y,HREE)-rich silicate, and in the formation of minor amounts of (Y,REE)-rich fluorapatite. The latter indicate preferential partitioning of Y and REE into silicates over phosphates during low-temperature, metasomatic processes in a high Na-Ca system, similar to peralkaline granitic rocks.
Źródło:
Geological Quarterly; 2015, 59, 2; 316-324
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rare earth elements distribution in fine-grained deposits from the uppermost Triassic and Lower Jurassic of the Polish Basin : provenance and weathering of source area
Autorzy:
Brański, P.
Mikulski, S. Z.
Powiązania:
https://bibliotekanauki.pl/articles/2059878.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
rare earth elements (REE)
provenance
palaeoweathering
uppermost Triassic
Lower Jurassic
Polish Basin
Opis:
Nineteen samples of uppermost Triassic and Lower Jurassic claystones and mudstones, which were formed in the epicontinental Polish Basin, were analysed by inductively coupled plasma mass spectrometry (ICP-MS) for rare earth elements (REE) and other selected trace elements (Sc, Y, Th, Zr and U). The results indicate that the source of most of the claystones and mudstones studied were sedimentary rocks of the upper continental crust of old cratonic areas, where the protolith had a mainly felsic character. However, in the latest Triassic a characteristic layer formed, implying significant input from mafic volcanic protolith. It was also found that moderately intense chemical weathering usually favoured increased concentration of the rare earths. Extremely strong hydrolysis, related to episodes of very hot and humid climate (greenhouse events), caused conspicuous impoverishment in REE in residual clays. Weathering and recycling processes modified the composition of REE to some extent, but generally did not obliterate the original characteristics of the protolith. In some samples, enrichment in rare earth elements was observed, caused by admixtures of accessory minerals (being a main carrier of REE) and/or increased sorting during recycling.
Źródło:
Geological Quarterly; 2016, 60, 2; 441--450
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane zagadnienia otrzymywania miszmetalu i innych metali ziem rzadkich
Selected Issues of Mischmetal and Other Rare Earth Metal Obtaining
Autorzy:
Jarosiński, A.
Madejska, L.
Powiązania:
https://bibliotekanauki.pl/articles/319288.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
pierwiastki ziem rzadkich
miszmetal
odzysk
produkcja
rare earth elements (REE)
mischmetal
recovery
production
Opis:
W skład metali ziem rzadkich wchodzą lantanowce oraz skand, itr i lantan i zazwyczaj określane są w skrótcie REE (ang. Rare Earth Elements). Za krytyczne dla gospodarki Unii Europejskiej uznana 20 surowców o ważnym znaczeniu ekonomicznym, w tym REE. Pierwiastki te limitują rozwój nowoczesnych wysoko zaawansowanych technologie. Wybór racjonalnego sposobu pozyskiwania metali ziem rzadkich jest związany z jego właściwościami fizycznymi i chemicznymi. W niniejszym artykule scharakteryzowano podstawowe technologie procesów otrzymywania stopu tzw.miszmetalu oraz innych metali ziem rzadkich. Przedstawiono kierunki postępu w technologiach otrzymywania miszmetalu i innych metali ziem rzadkich.
Rare earth metals forming the group of lanthanides as well as scandium, yttrium, lanthanum and usually they are referred to in brief REE (Rare Earth Metals).As a critical to the EU economy, 20 raw mineral of major economic importance were discriminated, therein RRE. The elements limit the development of modern advanced technologies. The choice of rational process for the preparation of rare earth elements is related to their physical and chemical properties. The present article was devoted some technologies for mischmetal obtaining and other rare earth metals. There have been presented trends in progress in technologies of mischmetal and other REE obtaining.
Źródło:
Inżynieria Mineralna; 2016, R. 17, nr 1, 1; 249-256
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active optical fibres for application in laser and broadband ASE sources
Autorzy:
Dorosz, D.
Dorosz, J.
Zając, A.
Żmojda, J.
Kochanowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/201633.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
active optical fibres
double-clad fibres
RE doped glasses
rare earth elements (REE)
Opis:
The article brings into focus the present state of technology employing active fibres doped with rare earth (RE) ions for applications requiring power supply of several dozen watts and broadband ASE sources. Current trends in development of glasses and in construction of active fibres used in fibre sources of radiation within VIS-NIR range are presented. Technological constraints in the doping of fibre core glasses are discussed, with particular consideration of optimal RE concentration for technical applications. Characteristics of glasses are offered, and the glasses are used for manufacturing optical fibres with luminescence within the visible as well as near- and mid-infrared ranges. Also, requirements and luminescence properties concerning glasses co-doped with e.g. Nd3+/Yb3+,Tm3+/Ho3+ and Yb3+/Tb3+ are discussed. Results of research on the impact of technological parameters of glass matrices on luminescence properties of core glasses and optical fibres are quoted. For the doped glasses of which luminescence in a wide spectral range is desired, conditions for their processing into optical fibre systems are mentioned. Additionally, the impact of phonon energy in the glass on producing emission in a specified spectral range is analyzed. Furthermore, the article presents directions of technological studies to solve problems persisting in the phase of glass matrix design, as well as in determining the influence of fibre drawing process on the luminescence properties of core glasses and optical fibres, confirming the differences in luminescence stemming from the drawing process. Finally, some original designs of core glasses and active multicore fibre systems devised for construction of fibre radiation sources are presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 4; 673-682
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza możliwości pozyskania pierwiastków ziem rzadkich z węgli kamiennych i popiołów lotnych z elektrowni
Analysis of the possibilities of rare earth elements obtaining from coal and fly ash
Autorzy:
Całus-Moszko, J.
Białecka, B.
Powiązania:
https://bibliotekanauki.pl/articles/216628.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
metale ziem rzadkich
węgiel kamienny
popioły lotne
rare earth elements (REE)
coal
fly ash
Opis:
Pierwiastki ziem rzadkich nazywane powszechnie REE (Rare Earth Elements) to grupa 15 lantanowców od lantanu do lutenu, a także skand i itr, które charakteryzują się podobnymi właściwościami chemicznymi. Stanowią surowce uznane przez Unię Europejską za jedne z listy 14 surowców krytycznych, o znaczeniu strategicznym dla rozwoju nowoczesnych wysoko zawansowanych technologii. Światowe wydobycie REE kształtuje się aktualnie na poziomie 139 tys. Mg, a głównym producentem są Chiny, które dostarczają około 93% światowego zapotrzebowania na surowce ziem rzadkich. W związku z sytuacją na światowym rynku metali ziem rzadkich (REE), w ostatnich latach rozpoczęto wiele projektów w celu poszukiwania nowych źródeł REE. W artykule omówiono znaczenie ziem rzadkich w gospodarce światowej. Głównym celem pracy było określenie potencjału i form występowania pierwiastków ziem rzadkich w węglach kamiennych i odpadach z energetycznego wykorzystania węgla, jako alternatywnego źródła ich pozyskania. Na podstawie analizy literatury oraz przeprowadzonych badań własnych wytypowanych próbek polskich węgli kamiennych i popiołów z elektrowni, przedstawiono zawartości pierwiastków ziem rzadkich REE w wybranych węglach i popiołach lotnych z elektrowni na świecie i w Polsce. Średnia zawartość REE w węglach na świecie wynosi 60 ppm natomiast w badanych węglach polskich z KWK Jankowice REE wynosiła 77 ppm, dla pozostałych węgli uzyskano niższe zawartości od 8 do 40 ppm. Ponadto praca przedstawia perspektywiczne światowe zasoby tych pierwiastków, które mogą stać się ich cennym, alternatywnym źródłem w ciągu najbliższych lat.
Rare earth elements commonly called REE (Rare Earth Elements) it is a group of 15 Lanthanides, from lanthanum to luten, and yttrium, and scandium which have similar chemical properties. Rare earth elements are the materials considered by the European Union as one of a list of 14 critical raw materials of strategic importance for the development of new highly advanced technology.World production of shaped REE is currently at the level of 139 thousand Mg, and the main producer is China, which supplies about 93% of the global demand for rare earth materials. Considering the situation on the worldmarket of rare earth elements (REE) in recent years,many projects started to look for new sources of REE. This article discusses the importance of rare earths in the world economy. The main objective of this study was to determine the potential and forms of occurrence of rare earth elements in hard coals and waste from energy use of coal as an alternative source of acquisition. On the basis of literature overview and own research on selected samples of Polish hard coals and ash from power stations this work shows the content of rare earth elements in some coals and power plant fly ashes in Poland and around the world. The average content of coals REE in the world is 60 ppm while in researched Polish coals from the coal mine Jankowice REE is 77 ppm, for the other coals a lower content from 8 ppm to 40ppm was obtained. Moreover, the world’s perspective resources of these elements, which may become valuable resource in the next few years, are presented.
Źródło:
Gospodarka Surowcami Mineralnymi; 2013, 29, 1; 67-80
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pierwiastki ziem rzadkich (REE) w środowiskach powierzchniowych litosfery
Rare Earth Elements (REE) in surface environments of the lithosphere
Autorzy:
Kwecko, P.
Powiązania:
https://bibliotekanauki.pl/articles/2075552.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
pierwiastki ziem rzadkich
REE
gleba
skały
minerały
rare earth elements (REE)
soil
rocks
minerals
Opis:
In the Polish geochemical literature there is no general discussion of the occurrence and behaviour of REE in surface environments. This text is an attempt to review the world literature concerning the REE occurrence and behaviour mainly in rocks, minerals (primary and secondary) and soils, and during hypergenic and soil-forming processes. The article also presents the atomic structure and properties of REE, their divisions and participation in the biosphere, organic matter and sediments of selected Polish lakes and, additionally, anthropogenic sources. Particular attention is given to primary and secondary REE minerals and their presence in rocks, soils (including soil-forming processes) and hypergenic processes. The main source of REE is the primary minerals of acid and siliceous igneous rocks and secondary minerals of sedimentary rocks. Among primary minerals the largest quantities of REE are concentrated in heavy minerals (anatase, ilmenite, sphe- ne, rutile and zircon). Basic silicate weathering leads to the formation of secondary clay minerals which, together with iron and manganese oxides and carbonates, are the main sources of REE as secondary minerals.
Źródło:
Przegląd Geologiczny; 2016, 64, 11; 902--917
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Processes and technologies for the recycling of spent fuorescent lamps
Autorzy:
Kujawski, W.
Pospiech, B.
Powiązania:
https://bibliotekanauki.pl/articles/780020.pdf
Data publikacji:
2014
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
fluorescent lamps
recycling
rare earth elements (REE)
hydrometallurgical process
pyrometallurgical
process
solvent extraction
leaching
Opis:
The growing industrial application of rare earth metals led to great interest in the new technologies for the recycling and recovery of REEs from diverse sources. This work reviews the various methods for the recycling of spent fluorescent lamps. The spent fluorescent lamps are potential source of important rare earth elements (REEs) such as: yttrium, terbium, europium, lanthanum and cerium. The characteristics of REEs properties and construction of typical fluorescent lamps is described. The work compares also current technologies which can be utilized for an efficient recovery of REEs from phosphors powders coming from spent fluorescent lamps. The work is especially focused on the hydrometallurgical and pyrometallurgical processes. It was concluded that hydrometallurgical processes are especially useful for the recovery of REEs from spent fluorescent lamps. Moreover, the methods used for recycling of REEs are identical or very similar to those utilized for the raw ores processing.
Źródło:
Polish Journal of Chemical Technology; 2014, 16, 3; 80-85
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Purification And Separation Of Rare Earth Elements From CCFL With Extraction Chromatography
Oczyszczanie i separacja metali ziem rzadkich z lamp fluorescencyjnych z zimną katodą (CCFL) przy użyciu chromatografii ekstrakcji
Autorzy:
Kim, J. G.
Powiązania:
https://bibliotekanauki.pl/articles/352470.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
extraction chromatography
CCFL
rare earth elements (REE)
amberite
recycling
chromatografia ekstrakcyjna
pierwiastki ziem rzadkich
recykling
Opis:
In this study, Amberite XAD-7HP was used as the solvent-impregnated resin to separate each REE from the standard solution, which was mixed with the REEs (e.g., La Eu, Tb, Y and Ba). About 100 ppm of each of the REEs was separated from DI water using extraction chromatography. REEs were separated by extraction chromatography using Amberite XAD-7HP resin, the changes in the pH values of the HCl and HClO4 were between 0.2 N and 5 N, and the extraction rate of the solution was between 0.5 and 3 ml/min. The La solution with the separated REEs was leached. The solid-state REEs were annealed between 1083K. The extraction result was analyzed with ICP-AES and an X-ray diffractometer. Each REE was successfully separated with HCl and HClO4 with pH values between 0.1 N and 3 N and with extraction rate between 1.0 m/min and 3.0 m/min.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1529-1533
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pierwiastki ziem rzadkich w wybranych złożach surowców ilastych Niżu Polskiego (neogen)
Rare earth elements in selected clay deposits of the Polish Lowland (Neogene)
Autorzy:
Duczmal-Czernikiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/2062528.pdf
Data publikacji:
2012
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
pierwiastki ziem rzadkich
złoża iłów
neogen
Niż Polski
rare earth elements (REE)
clay deposits
Neogene
Polish Lowland
Opis:
Przedstawiono zawartość pierwiastków ziem rzadkich w złożach neogeńskich surowców ilastych na obszarze Niżu Polskiego. Ziemie rzadkie zbadano w surowych iłach o barwie czerwonej, zielonej oraz w konkrecjach węglanowych. Na podstawie współczynników korelacji, stwierdzono silną dodatnią korelację ziem rzadkich do itru, słabą do kobaltu i cyrkonu. Lekkie pierwiastki ziem rzadkich (La–Eu) wykazują słabą pozytywną korelację z K2O i MgO. Zawartość ziem rzadkich jest zgodna ze średnią ich zawartością w osadach ilastych, jednak obserwuje się wzbogacenie w lekkie ziemie rzadkie odmiany czerwonej w stosunku do zielonej oraz znaczne wzbogacenie w ciężkie ziemie rzadkie konkrecji węglanowych, w stosunku do otaczających je iłów. Zmiany zawartości pierwiastków ziem rzadkich są wynikiem uziarnienia osadów, składu mineralnego i chemicznego a także procesów wietrzenia i związanych z nimi zmian warunków fizykochemicznych.
The paper presents the content of rare earth elements in the Neogene deposits of clay raw materials in the Polish Lowland. Rare earths have been studied in red and green raw clays, and in carbonate nodules. Based on the correlation coefficients, a strong positive correlation between the rare earths and yttrium, and a weak correlation to cobalt and zirconium were found. Light rare earth elements (La–Eu) show a weak positive correlation to K2O and MgO. The content of rare earths is in line with their average contents in clays and shales, however there is enrichment in a red variety of light rare earths in relation to the green variety, and significant enrichment in heavy rare earths of carbonate nodules in relation to the surrounding claystones. Changes in the content of rare earth elements are the result of sediment grain size, mineralogical and chemical composition, weathering processes and the associated changes of physicochemical conditions.
Źródło:
Biuletyn Państwowego Instytutu Geologicznego; 2012, 448 (2); 419--430
0867-6143
Pojawia się w:
Biuletyn Państwowego Instytutu Geologicznego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Mechanical Properties of Experimental Mg-Al-RE-Mn Magnesium Alloys
Autorzy:
Braszczyńska-Malik, K.N.
Powiązania:
https://bibliotekanauki.pl/articles/379996.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnesium alloy
aluminum
rare earth elements (REE)
mechanical properties
stop magnezu
aluminium
pierwiastki ziem rzadkich
właściwości mechaniczne
Opis:
The results of some mechanical properties of four Mg-5Al-xRE-0.4Mn (x=1–5) alloys are presented. The microstructure of experimental alloys consisted of an σ-Mg phase and an α+γ semi-divorced eutectic, Al11 RE3 phase and an Al10 RE2 Mn7 intermetallic compound. For gravity casting in metal mould alloys, Brinell hardness, impact strength, tensile and compression properties at ambient temperature were determined. The performed mechanical tests allowed the author to determine the proportional influence of the mass fraction of rare earth elements in the alloys on their tensile strength, yield strength, compression strength and Brinell hardness. The impact strength of the alloys slightly decreases with a rise in the rare earth elements mass fraction.
Źródło:
Archives of Foundry Engineering; 2014, 14, 1; 13-16
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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