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Tytuł:
The influence of nitrogen fertilization with ENTEC-26 and ammonium nitrate on the concentration of thirty-one elements in carrot (daucus carota l.) storage roots
Wpływ nawożenia azotem z ENTEC-26 i saletrą amonową na zawartość trzydziestu jeden pierwiastków w korzeniach spichrzowych marchwi (Daucus carota L.)
Autorzy:
Smolen, S.
Sady, W.
Wierzbinska, J.
Powiązania:
https://bibliotekanauki.pl/articles/1188055.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:
nitrogen fertilization
nitrification inhibitor
DMPP
heavy metals
rare elements
trace elements
Opis:
Aplikowanie inhibitorów nitryfikacji wraz z nawozami azotowymi (zawierającymi zredukowane formy azotu: amonową i amidową) może wzmacniać zakwaszające działanie tych nawozów na glebę. W efekcie może to prowadzić do obniżenia pH oraz zmian zawartości dostępnych dla roślin form metali ciężkich i pierwiastków śladowych w glebie. Celem badań była ocena wpływu stosowania nawozów azotowych z ENTEC-26 (zawierającego inhibitor nitryfikacji 3,4-dimetylopyrazolofosfat /DMPP/) i saletrą amonową na skład mineralny korzeni spichrzowych marchwi. Przeprowadzono dwuletnie badania z polową uprawą marchwi Kazan Fj. Doświadczenie założono metodą split-plot w czterech powtórzeniach. Obiektami badań były kombinacje ze zróżnicowanym nawożeniem azotem: 1 - kontrola (bez nawożenia azotem), 2 - ENTEC-26 35+35, 3 - ENTEC-26 70+70, 4 - ENTEC-26 105+105, 5 - saletra amonowa 35+35, 6 - saletra amonowa 70+70, 7 - saletra amonowa 105+105, gdzie: 35+35, 70+70 i 105+105 oznacza dawkę azotu w kg N ha- 1 stosowaną w nawożeniu przedsiewnym i w nawożeniu pogłównym. w korzeniach spichrzowych oraz w glebie po uprawie marchwi zawartość: Ag, Al, B, Ba, Ca, Ce, Co, Cr, Dy, Fe, Ga, In, K, La, Li, Lu, Mg, Mn, Na, Ni, P, Pb, S, Sc, Sn, Sr, Ti, Tm, Y, Yb i V była oznaczana techniką ICP-OES. Nawożenie azotem miało istotny wpiyw na zawartość Co, Fe, In, Li, Mn, Ni, S, Sc, Sr, Y, Yb i V w marchwi. Jednakże wpiyw ten był zróżnicowany w zależności od zastosowanego sposobu nawożenia azotem w badanych kombinacjach. Nie stwierdzono natomiast istotnego oddziaływania nawożenia azotem na zawartość Ag, Al, B, Ba, Ca, Ce, Cr, Dy, Ga, K, La, Lu, Mg, Na, P, Pb, Ti i Sn w marchwi. W porównaniu z kontrolą, zastosowane nawożenie azotem we wszystkich dawkach zarówno w formie ENTEC-26, jak i saletry amonowej powodowało zmniejszenie zawartości Mg, Al, B, Ba, Ce, Fe, Ga, La, Ni, Pb, Ti, Y, V, Cr, Dy, In, Li, Lu, Sc i Yb oraz zwiększenie zawartości Ca, Sr i Ag w glebie po uprawie marchwi. Jednakże wykazane zmiany zawartości tych pierwiastków w glebie pod wpływem nawożenia azotem nie miały odzwierciedlenia w ich zawartości w korzeniach spichrzowych marchwi.
Źródło:
Journal of Elementology; 2012, 17, 1; 115-137
1644-2296
Pojawia się w:
Journal of Elementology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possibilities of recovery and separation of rare earth elements
Autorzy:
Fila, Dominika
Powiązania:
https://bibliotekanauki.pl/articles/2079965.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
rare earth elements
resources
recovery
separation
Opis:
Rare earth metals are a group of elements widely used in high technology products. They are included in the group of critical mineral resources for the EU economy. Rare earth elements are found in computers and mobile phones, as well as in low-emission energy technologies. They are also applied in chemical processes as catalysts in the oil refining. Some of them occur even in considerable quantities in the earth's crust but not very often in the concentrations justifying the profitability of their extraction. Additionally, the constantly growing demand and the current market situation cause that alternative resources of rare earth elements recovery are sought after. Therefore, the recovery and separation methods as well as recovery from the secondary sources are becoming more and more important. The following paper presents the possibilities of recovery and separation of rare earth elements from primary and secondary sources.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia; 2018, 73, 1; 99-110
2083-358X
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lithologically-related rare earth element variations the Mio-Pliocene Poznań Formation (Poland)
Autorzy:
Retka, J.
Powiązania:
https://bibliotekanauki.pl/articles/2059369.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Poznań Formation
rare earth elements
clay lithotypes
Opis:
Concentrations of rare earth elements (REEs) were determined in 129 clay samples collected from the Mio-Pliocene Poznań Formation in Poland. The REEs occur in a relatively wide range from 58.2 to 1,709 mg/kg. Low North American Shale Composite (NASC)-normalized total REE contents with heavy rare earth element (HREE) depletion were noted in most of the samples analysed. Small variations were detected in the REE contents in the lithologies distinguished. Red clays are characterised by slightly lower REE concentrations relative to green and grey clays. All the Poznań Formation clays exhibit a negative Eu anomaly when normalized to the average of chondrites. Values increase according to the following sequence: grey clays < red clays < green clays. The NASC-normalized REE concentration curves show a positive Eu anomaly. The LaNASC/YbNASC ratio indicates HREE depletion. A small variation in this ratio was observed in the sequence green clays > grey clays > red clays. The variability of the REE contents of the Poznań Formation decreased from west to east.
Źródło:
Geological Quarterly; 2018, 62, 1; 146--154
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Leaching kinetic study of Y and Eu from waste phosphors using hydrochloric acid solution containing hydrogen peroxide
Autorzy:
Yu, M.
Jiang, Z.
Mei, G.
Chen, X.
Powiązania:
https://bibliotekanauki.pl/articles/949690.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
waste phosphors
leaching
kinetics
rare earth elements
Opis:
The leaching kinetics of Y and Eu from waste phosphors using a hydrochloric acid (HCl) solution containing hydrogen peroxide (H2O2) were investigated. Characterization of the waste phosphors was performed using XRD to ascertain the phases as (Y0.95Eu0.05)2O3 (red phosphors), (Ce0.67Tb0.33)MgAl11O19 (green phosphors), (Ba0.9Eu0.1)Mg2Al16O27 (blue phosphors), and SiO2 (quartz). The influence of factors such as HCl concentration, addition amount of H2O2, temperature, and reaction time on the leaching performance of Y and Eu was investigated. The maximum leaching recoveries of Y (99.87%) and Eu (88.72%) were obtained at 4 M HCl, 0.2 cm3/g H2O2, 60 ℃ temperature, and 180 min of reaction time at a liquid-to-solid ratio of 7.5 cm3/g. Leaching kinetic results showed the best fit with the shrinking sphere model (1-(1-x)1/3)=kct), ensuring that the overall leaching process was governed by a chemical control mechanism. Activation energies of 42.35 and 33.28 kJ/mol were acquired for leaching of Y and Eu, respectively, at 40-70 ℃, which further supports the proposed chemical control leaching process.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 238-248
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solubility of Eskisehir thorium/rare earth ores in sulphuric and nitric acids
Autorzy:
Kursun, I.
Tombal, T. D.
Terzi, M.
Powiązania:
https://bibliotekanauki.pl/articles/109924.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
thorium
rare earth elements
bastnaesite
leaching
solubility
Opis:
Nuclear energy is considered as one of the most important energy resources in the world. Thorium (Th) has a significant potential to be used in electricity production by nuclear energy since its existence is not depended on the presence of another radioactive elements, and it has larger potential reserves than uranium. Bastnaesite ((Ce, La)CO3F) is one of the minerals from which Th can be economically extracted. In this study, solubility of bastnaesite containing ore obtained from Eskisehir, Turkey was investigated by leaching with H2SO4 and HNO3 in terms of leaching performance of thorium and some rare-earth elements (Ce, Nd, La). In this context, representative samples were taken from three different areas in Eskisehir-Kizilcaoren region, and a composite sample was prepared to be used for the leaching experiments. The effects of several parameters such as the solid ratio, leaching time, acid amount and pulp temperature, on dissolution efficiencies of Th, Nd, Ce and La was investigated. The best results were obtained using 3.42 mol/dm3 HNO3, solid–to–liquid ratio of 35%, 120 min leaching time and 60 oC temperature. Under these optimum conditions, the dissolution efficiencies of Th, Ce, Nd, and La were obtained as 94%, 82%, 77% and 70%, respectively.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 476-483
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phytoextraction of rare earth elements
Autorzy:
Gmur, Dominika
Siebielec, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/2143646.pdf
Data publikacji:
2022-09
Wydawca:
Instytut Uprawy Nawożenia i Gleboznawstwa – Państwowy Instytut Badawczy
Tematy:
rare earth elements
phytoextraction
hyperaccumulation
environmental remediation
Opis:
Rare earth elements (REE) are a group of 17 elements with similar physicochemical properties. Most of the world’s REE extraction belongs to China. Due to the growing demand for REE and limited resources, the European Commission has identified REE as critical materials. On the other hand, little is known so far about the possible effects of long-term exposure of living organisms and the ecosystem to REE. Therefore, potential solutions for the recovery of distributed REE are being sought. Phytoextraction is a method that allows the recovery of elements from the environment. For this purpose, two strategies are gener- ally used: the use of plants with the natural ability to accumulate REE (hyperaccumulators) and the support of the process through the use of chelators. Twenty two species have been identified as REE hyperaccumulators, e.g. Phytolacca americana, Dicranop- teris linearis, Blechnum niponicum or Carya tomentosa. For the total REE, an accumulation limit of 100 mg kg-1 dry weight was established. Natural chelators are used as additives, e.g. humic acids or low molecular weight acids, as well as synthetic ones: EDTA or EGTA. In addition, the efficiency of the process is also influenced by other factors, such as the sorption capacity of the soil, the content of organic matter in the soil or soil pH. The aim of this article is to present the plant species useful in REE phy- toextraction and the potential for enhancing the method with the use of chelators.
Źródło:
Polish Journal of Agronomy; 2022, 50; 3-11
2081-2787
Pojawia się w:
Polish Journal of Agronomy
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:
The recycling-oriented material characterization of hard disk drives with special emphasis on NdFeB magnets
Autorzy:
Dańczak, A.
Chojnacka, I.
Matuska, S.
Marcola, K.
Leśniewicz, A.
Wełna, M.
Żak, A.
Adamski, Z.
Rycerz, L.
Powiązania:
https://bibliotekanauki.pl/articles/109315.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hard disk drives
rare earth elements
permanent magnets
recycling
Opis:
Hard disk drives (HDDs) consist of many components made from various materials: e.g. aluminum, steel, copper and rare earth elements (REEs). Recycling and reuse of these materials is desirable for economic and environmental reasons. Developing of potential HDDs recycling methods requires knowledge about HDDs material characteristic. The study aims to explore knowledge about structure and chemical composition of HDDs main components with special emphasis on NdFeB magnets. HDDs collected for the experiments came from Desktop PCs and Notebooks. The dependence between the average mass of HDDs components and such parameters as producer, year and country of production and disk capacity was analyzed. Chemical composition of NdFeB magnets and the heaviest components (i.e. top cover, mounting chassis, platters and metallic plates from magnet assembly of actuator) was analyzed by various analytical methods. The heaviest HDDs main components: top cover and mounting chassis, with the highest recycling potential, are made of aluminum and steel respectively. The majority of HDDs components showed also the existence of different alloy additions: C, Mg, Si, P, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sn and Pb. NdFeB magnets constitute 2.2 ± 1.1% of the average HDD from Desktop PC (517.3 ± 64.2 g) and 3.2 ± 1.2% from Notebook (108.2 ± 24.3 g). The chemical composition of NdFeB magnets from collected HDDs changes in the wide range: Fe (53–62%), Nd (25–29%), Pr (2–13%), Dy (0.1– 1.4%), Ni (2–6%), Co (0.5–3.6%), B (0.8–1.0%). Recycling of permanent magnets based on NdFeB alloys is potential remedy to fill the gap in the supply of rare earth elements on the global REEs market.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 363-376
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Complex Processing of Phosphogypsum - a Way of Recycling Dumps with Reception of Commodity Production of Wide Application
Autorzy:
Lutskiy, D.
Litvinova, T.
Ignatovich, A.
Fialkovskiy, I.
Powiązania:
https://bibliotekanauki.pl/articles/124643.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
phosphogypsum
utilization
building materials
agriculture
rare earth elements
conversion
Opis:
The article analyzes the information on modern developments in the utilization of phosphogypsum. Only a few directions give the prospect of large-scale use of both freshly formed phosphogypsum and phosphogypsum accumulated in dumps. Under the conditions of the Russian Federation, it is promising to use phosphogypsum for the production of building materials, as well as for agriculture, for reclamation of soil and the creation of mounds of a certain type. The possibility of using phosphogypsum as a raw material for obtaining rare-earth elements is shown.
Źródło:
Journal of Ecological Engineering; 2018, 19, 2; 221-225
2299-8993
Pojawia się w:
Journal of Ecological Engineering
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:
Effect of Magnet Scrap Size on the Extraction Behavior of Heavy Rare Earth Elements by Liquid Metal Extraction
Autorzy:
Nam, Sun-Woo
Rasheed, Mohammad Zarar
Park, Sang-Min
Lee, Sang-Hoon
Kim, Do-Hyang
Kim, Taek-Soo
Powiązania:
https://bibliotekanauki.pl/articles/355705.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
liquid metal extraction
rare earth elements
recycling
oxidation
magnet scrap
Opis:
Liquid metal extraction (LME) process results in 100% neodymium (Nd) extraction but the highest extraction efficiency reportedfor Dysprosium (Dy) so far is 74%. Oxidation of Dy is the major limiting factor for incomplete Dy extraction. In order to enhance the extraction efficiency and to further investigate the limiting factors for incomplete extraction, experiments were carried out on six different particle sizes of under 200 μm, 200-300 μm, 300-700 μm, 700-1000 μm, 1000-2000 μm and over 2000 μm at 900°C with magnesium-to-magnet scrap ratio of 15:1 for 6, 24 and 48 hours, respectively. This research identified Dy2 Fe17 in addition toDy2 O3 phase to be responsible for incomplete extraction. The relationship between Dy2 Fe17 and Dy2O3 phase was investigated, and the overall extraction efficiency of Dy was enhanced to 97%.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 4; 1273-1276
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of alkali processing for the recycling of rare earth values from spent fluorescent lamps
Autorzy:
Shukla, Neha
Tanvar, Himanshu
Dhawan, Nikhil
Powiązania:
https://bibliotekanauki.pl/articles/1449193.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fluorescent lamps
rare earth elements
activation energy
recovery
cerium
terbium
Opis:
Phosphor samples collected after crushing and sieving of discarded fluorescent lamps comprise approximately 31 % rare earth elements in the form of $Y_{1.90}Eu_{0.10}O_3$, $Al11Ce_{0.67}MgO_{19}Tb_{0.33}$, and $Al_{10.09}Ba_{0.96}Mg_{0.91}O_{17}$: $Eu^{2+}$ phase. Direct leaching and mechanical activation assisted leaching are incapable of recovering $Ce$, $Tb$ values from the $Al_{11}Ce_{0.67}MgO_{19}Tb_{0.33}$ phase. Heat treatment with $NaOH$ was found successful for dissociation of $Ce$, $Tb$ phase via substitution of rare-earth ion by $Na^+$ ion to form rare earth oxide and water-soluble $NaAlO_2$. $Y$, $Eu$, $Ce$, and $Tb$ values were recovered from heattreated mass in a two-step leaching process followed by recovery from the leach solution by oxalic acid precipitation. Over 95 % extraction rate was attained after heat treatment at 400 °C with 150 wt-% $NaOH$ for 1 h. It was found that $Y$, $Eu$ containing phase does not take part in the heat treatment process whereas the $Ce$, $Tb$ phase undergoes a solid-state chemical reaction with $NaOH$ via product layer diffusion model with 41.5 kJ/mol activation energy. Approximately 15 g mixed oxide (purity >95 %) of $Y$ (79 %), $Eu$ (7 %), $Ce$ (5 %), and $Tb$ (4 %) could be recovered from 100 units of discarded FLs. Microwave treatment of phosphor and $NaOH$ (50 wt-%) yielded approximately 42 % $Y$, 100 % $Eu$, 65 % $Ce$, and 70 % Tb recovery in just 5 min. Approximately 9 g of REO and 5 g of cerium enriched leach residue were recovered from the microwave route within 5 min and depicted high microwave potential application in the recovery of $Ce$ and $Tb$ values from waste phosphor sample.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 710-722
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Separation of rare earth elements from the leaching solution of waste phosphors by solvent extraction with Cyanex 272 and its mixture with Alamine 336
Autorzy:
Xing, Weidong
Lee, Man Seung
Powiązania:
https://bibliotekanauki.pl/articles/1449503.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phosphors
rare earth elements
HCl solution
solvent extraction
Cyanex 272
Opis:
Waste phosphors contain rare earth elements (REEs) such as yttrium (Y), europium (Eu), cerium (Ce), terbium (Tb) and lanthanum (La). Separation of these REEs from the leaching solution of waste phosphors was investigated by solvent extraction with single Cyanex 272, binary mixture (mixture of Cyanex 272 and Alamine 336), ionic liquid (prepared by Cyanex 272 and Aliquat 336) in kerosene. The effect of solution pH and extractants concentration was mainly investigated. The results indicated that Y(III) was selectively extracted by single Cyanex 272 over the other four REEs from the HCl solution with initial pH range from 3 to 5. Synergistic extraction with the binary mixture was enough for the extraction of Y(III), Tb(III) and Eu(III) with a small amount of Ce(III). Scrubbing with pure Y(III) solution with intermediate acidity was effective in scrubbing Ce(III) from the loaded binary mixture organic phase. Stripping behavior of the Y(III), Tb(III) and Eu(III) by HCl solution was similar to each other. Tb(III) and Eu(III) can be separated by extraction with the binary mixture followed by scrubbing with pure Tb(III) solution. McCabe-Thiele diagrams were constructed for the extraction of Y(III) by single Cyanex 272 and that of Tb(III) by the mixture. A process was proposed for the separation of REEs from the leaching solution of waste phosphors by solvent extraction.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 1; 184-194
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
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:
Comparative analysis of soil magnetic susceptibility and concentration of rare earth elements in soil of problematic areas
Autorzy:
Zawadzki, Jarosław
Fabijańczyk, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2064859.pdf
Data publikacji:
2019
Wydawca:
STE GROUP
Tematy:
soil pollution
rare earth elements
magnetometry
magnetic susceptibility
industrial areas
Opis:
Soil contamination with rare earth metals (REE) can have both direct and indirect connection with industrial activity and ore-exploration. In the studies conducted so far, the presence of rare earth elements in coal seams, coal combustion waste as well as fly ash was found. It is important that detailed studies of the REE content in soil were not carried out in Poland. Until now, in a few studies, a high content of cerium and lanthanum was found in relation to the average content of the torn ones in the world. This work focuses on the areas under the influence of the industry associated with the extraction and combustion of hard coal, but also with other types of industry. Analyzes of REE content in soil were conducted in selected areas of the Upper Silesian Industrial Region and Norway, located near the Bjornevatn mine. In study areas, soil samples were collected and used for chemical and magnetometric measurements. Firstly, concentrations of REE were determined, and after that soil samples were used to measure soil magnetic susceptibility. Finally, statistical analyses were performed in order to check the correlation between REE concentrations in soil and soil magnetic susceptibility.
Źródło:
Multidisciplinary Aspects of Production Engineering; 2019, 2, 1; 81--90
2545-2827
Pojawia się w:
Multidisciplinary Aspects of Production Engineering
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:
Study on REE occurrence in a Svanbergite and basic ore characteristics
Autorzy:
Ma, Keyu
Zhang, Jie
Deng, Qiufeng
Men, Pengpeng
Zhang, Yusong
Shi, Xiulin
Powiązania:
https://bibliotekanauki.pl/articles/2146882.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
svanbergite
rare earth elements (REEs)
occurrence state
crandallite
ore characteristics
Opis:
Svanbergite in Sichuan Province, China is a special middle-low grade phosphorus ore. It contains rare earth elements (REEs), aluminum, and strontium that can be exploited and utilized. In this study, several methods were used to systematically study the occurrence of REEs in the ore and basic ore characteristics. The ore, which was rich in REEs, Al, and Sr, was classified as marine sedimentary low-grade phosphorus ore. The main ore mineral was crandallite and pyrite, and independent REE minerals were not found. Crandallite was the main carrier mineral of useful elements, including P, REEs, Al, and Sr. REE+ was inferred to mainly exist in crandallite via isomorphism by replacing Ca2+ and H+. The crandallite was mainly characterized as fine-grained, and minerals were closely disseminated. The results from this study will provide a valuable reference for expanding available REE resources and the efficient comprehensive utilization of svanbergite.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 3; art. no. 147377
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-temperature carbothermal dephosphorization of Malaysian monazite
Autorzy:
Udayakumar, Sanjith
Sheikh Abdul Hamid, Sheikh Abdul Rezan
Baharun, Norlia
Pownceby, Mark
Powiązania:
https://bibliotekanauki.pl/articles/2146886.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
malaysian monazite concentrate
dephosphorization
carbothermal reduction
rare earth elements
graphite
Opis:
High-temperature carbothermal reduction experiments with graphite powder were conducted to assess the dephosphorization behavior of Malaysian monazite concentrate. Thermodynamic analysis of the possible dephosphorization reactions was conducted to evaluate the feasibility of the carbothermal reduction of the monazite phases. The effects of temperature, particle size, and monazite to carbon ratio were then investigated under different conditions. The carbothermal reduction experiments were conducted based on the Taguchi design method, and up to 97% of phosphorous removal was achieved under optimized conditions. The optimal conditions for dephosphorization were determined as; a reduction temperature of 1350 °C, a particle size of -75 μm, and monazite to carbon molar ratio of 0.3. Microstructural and phase characterization of the dephosphorized products revealed that CeO2, Nd2O3, La2O3, and Pr2O3 oxide phases were prominent, and no residual peaks of monazite remained in the reduced products. The information gained from the study can aid in the design of a suitable post-dephosphorization hydrometallurgical treatment for exploiting Malaysian monazite as a local source of REEs.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 6; 140--155
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
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:
Distribution of Trace Elements, Rare Earth Elements and Ecotoxicity in Sediments of the Kosva Bay, Perm Region (Russia)
Autorzy:
Ushakova, Evgeniya
Menshikova, Elena
Blinov, Sergey
Vaganov, Sergey
Perevoshchikov, Roman
Powiązania:
https://bibliotekanauki.pl/articles/2086373.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
trace element
rare earth elements
sedimentation
bottom sediment
ecotoxicity
acid mine drainage
Opis:
Over a long period of time, a huge amount of technogenic bottom sediments has been accumulating in the Kosva Bay with significant concentrations of amorphous iron and aluminium hydroxides, which, in turn, are active sorbents of pollutants. This study examines the distribution of trace elements and rare earth elements and their toxicity in the Kosva Bay of the Kama Reservoir (Perm Region, Russia). In the middle reach, the Kosva River crosses the Kizel coal basin, where acid mine water is discharged from closed mines. The average content of trace elements in the samples of bottom sediments of the bay varies from 0.10 mg/kg (Se) to 176.36 mg/kg (Ba). The amount of rare earth elements varies from 66.8 to 83.6 mg/kg. The ecological significance of trace elements and rare earth elements was studied using an element-by-element assessment (EF and Igeo), Potential Ecological Risk Index (RI), Mean Probable Effect Concentration Quotient (PECQ), and two bioassays (Daphnia magna Straus and Scenedesmus quadricauda (Turp.) Breb. The highest Hg enrichment was found at two sampling points. Taking into account the average value of Igeo, the pollution by Co, V, Nb, Hg, Sn, Zn, Sm, Ni, Cr, and Gd is the highest and corresponds to extremely contaminated category. The RI values indicate that pollution categories vary from moderate risk to considerable risk. According to mean PECQ values, bottom sediments of the bay have moderate potential toxicity towards biological communities. Results of chronic and acute toxicity on test objects D. magna and Scenedesmus quadricauda Breb show the water extract from bottom sediments having no effects on the test objects. The results of the study show that in order to assess the quality of bottom sediments, an integrated approach, combining chemical and ecotoxicological analyses, is needed.
Źródło:
Journal of Ecological Engineering; 2022, 23, 4; 1--16
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rare Earth Elements – a Novelty in Energy Security
Autorzy:
Bielawski, Radosław
Powiązania:
https://bibliotekanauki.pl/articles/125452.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
state security
energy security
critical raw materials
rare earth elements
outer space
Opis:
This study analyses the role of rare earth elements (REE) as critical resources for the energy security. This research presents the developments in the global REE extraction, i.e. the dominance of the Republic of China, which attempts to maintain and control its monopoly. The typical and novel uses of rare earth metals were presented in various applications, such as in advanced electronic and information technologies utilised in the aerospace and energy industries. Bearing in mind their vital importance to the manufacturing of high-tech products, the REE deposits are of strategic importance for the USA, the Republic of China and for the European Union. Striving to maintain the independence of raw materials, the USA is focused on the search for raw materials on its territory and furthermore on waiving the legal restrictions with respect to their extraction. China is primarily occupied with maintaining the monopoly and control over the global market of critical raw materials, including REE. The activities within the European Union concentrate on the exploration in search for the REE deposits in Europe and ensuring the continuity of supplies by maintaining good diplomatic relations with partners – the USA and Japan. In addition, extensive REE recycling initiatives are being undertaken in the EU. Further rare earth metals extraction is anticipated to extend to the outer space. However, developing the economically viable methods of extraction remains the major challenge faced by space mining, given that it requires establishing an expensive, permanent space infrastructure. What is more, mining and processing of rare earth metals raises serious environmental concerns, as it involves such hazards as radioactive products, toxic chemical compounds and waste generation. With respect to the environmental protection, this study also addresses the issues of REE substitutes and recycling. It is concluded that the environmental protection practices regarding the long-term extraction and use of REE (with a 2030 horizon) will bring substantial long-term financial benefits.
Źródło:
Journal of Ecological Engineering; 2020, 21, 4; 134-149
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Characteristics of the Ahmadabad hematite/barite deposit, Iran – studies of mineralogy, geochemistry and fluid inclusions
Autorzy:
Babaei, A. H.
Ganji, A.
Powiązania:
https://bibliotekanauki.pl/articles/94546.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
geochemistry
trace elements
rare earth elements
Semnan
geochemia
pierwiastki śladowe
pierwiastki ziem rzadkich
REE
Opis:
The Ahmadabad hematite/barite deposit is located to the northeast of the city of Semnan, Iran. Geostructurally, this deposit lies between the Alborz and the Central Iran zones in the Semnan Subzone. Hematite-barite mineralisation occurs in the form of a vein along a local fault within Eocene volcanic host rocks. The Ahmadabad deposit has a simple mineralogy, of which hematite and barite are the main constituents, followed by pyrite and Fe-oxyhydroxides such as limonite and goethite. Based on textural relationships between the above-mentioned principal minerals, it could be deduced that there are three hydrothermal mineralisation stages in which pyrite, hematite and barite with primary open space filling textures formed under different hydrothermal conditions. Subsequently, in the supergene stage, goethite and limonite minerals with secondary replacement textures formed under oxidation surficial conditions. Microthermometric studies on barite samples show that homogenisation temperatures (TH) for primary fluid inclusions range from 142 to 256°C with a temperature peak between 200 and 220°C. Salinities vary from 3.62 to 16.70 NaCl wt% with two different peaks, including one of 6 to 8 NaCl wt% and another of 12 to 14 NaCl wt%. This indicates that two different hydrothermal waters, including basinal and sea waters, could have been involved in barite mineralisation. The geochemistry of the major and trace elements in the samples studied indicate a hydrothermal origin for hematite and barite mineralisation. Moreover, the Fe/Mn ratio (>10) and plots of hematite samples of Ahmadabad ores on Al-Fe-Mn, Fe-Mn-(Ni+Co+ Cu)×10, Fe-Mn-SiX2 and MnO/TiO2 – Fe2O3/TiO2 diagrams indicate that hematite mineralisation in the Ahmadabad deposit occurred under hydrothermal conditions. Furthermore, Ba and Sr enrichment, along with Pb, Zn, Hg, Cu and Sb depletion, in the barite samples of Ahmadabad ores are indicative of a low temperature hydrothermal origin for the deposit. A comparison of the ratios of LaN/YbN, CeN/YbN, TbN/LaN, SmN/NdN and parameters of Ce/Ce* and La/La* anomalies of the hematite, barite, host volcanic rocks and quartz latite samples to each other elucidate two important points: 1) the barite could have originated from volcanic host rocks, 2) the hematite could have originated from a quartz latite lithological unit. The chondrite normalised REE patterns of samples of hematite barite, volcanic host rocks and quartz latite imply that two different hydrothermal fluids could be proposed for hematite and barite mineralisation. The comparison between chondrite normalised REE patterns of Ahmadabad barite with oceanic origin barite and low temperature hydrothermal barite shows close similarities to the low temperature hydrothermal barite deposits.
Źródło:
Geologos; 2018, 24, 1; 55-68
1426-8981
2080-6574
Pojawia się w:
Geologos
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemiczno-mineralogiczne badania koncentracji pierwiastków rzadkich i towarzyszących w obrębie mineralizacji kasyterytowo-siarczkowej w paśmie łupkowym Starej Kamienicy w Sudetach Zachodnich – wyniki wstępne
Geochemical-mineralogical research of the rare and associated element concentrations within cassiterite-sulphide mineralization in the Stara Kamienica schist belt in the Western Sudetes - preliminary results
Autorzy:
Małek, Rafał
Mikulski, Stanisław, Z.
Powiązania:
https://bibliotekanauki.pl/articles/2075983.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
pierwiastki rzadkie
kasyteryt
siarczki
mineralizacja rudy
zasoby rudy
Sudety
rare elements
cassiterite
sulfides
ore mineralization
ore deposit
Sudetes
Opis:
Abstract. The main task of research was to quantitatively and qualitatively identify rare and associated elements that occur within a cassiterite-sulphide mineralization zone hosted Precambrian - Lower Paleozoic metamorphic rochi in the Stara Kamienica schist belt making up the part of the Izera-Karhonosze Massif. Over 70 samples from archive boreholes and abandoned Sn-ore mines were examined using modern methods like portable pXRF, geochemical analysis (ICP-MS, WD-XRF, GF-AAS), polarizing microscopy, electron microprobe analysis (EMPA) and scaning electron microscopy with EDS system (SEM-EDS). Preliminary results show interesting concentrations of associated elements such as Zn (max 0.56%), Pb (max 0.7%), Cu (max 0.33%), As (max 0.55%), and some rare elements like In, Re, Nb, Co, Bi, Pt, V, La and Ce.
Źródło:
Przegląd Geologiczny; 2019, 67; 179--182
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical and morphological characterization of polymetallic (Mn-Fe) nodules from the Clarion-Clipperton Zone in the Pacific Ocean
Autorzy:
Kozłowska-Roman, Agata
Mikulski, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/2058694.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
polymetallic nodules
critical elements
rare earth elements
deep-sea mining
Clarion-Clipperton Fracture Zone
Pacific
Opis:
Geochemical studies (WD-XRF, ICP-MS, and GF-AAS) have shown that polymetallic nodules from the eastern Clarion-Clipperton Zone (CCZ) in the Pacific Ocean are enriched in several metals such as Cu (mean 1.16%), Ni (1.15%), Co (0.15%), and Zn (0.14%), as well as remarkable contents of Mo (0.059%), V (0.04%), Ce (0.019%), Nd (0.011%), Li (0.015), and Pt (43 ppb). The average content of REE, together with Y and Sc, is 620 ppm. In nodules from the CCZ metal concentrations are often much higher than those reported in nodules from other ocean basins in the world. The bulk-nodule mean value of the Mn/Fe ratio is 5.3, which is characteristic for a mixed (hydrogenetic and diagenetic) origin of the nodules. Microprobe investigation revealed two different chemical compositions of the layers, and ascertained their general metal content. The nodules analyzed are composed mainly of concentric-collomorphic laminae of Mn and Fe (oxy)hydroxides which crystallized around mineral nuclei (e.g., quartz, clay minerals), bioclasts or rock fragments. They are from 3.3 to 7.6 cm in diameter. The chemical and physical properties of the laminae allowed distinction of two genetic types: hydrogenetic and diagenetic. Those formed as a result of hydrogenesis had increased values of Co, Si, Cl and S, while formed diagenetically showed increased levels of Cu, Ni, Mg, Zn and K. These lamina types are characterized by different growth structures, reflectivity, density and Mn/Fe ratios. The ratio of the diagenetic layers to hydrogenetic layers (192/53) in representative polymetallic nodules shows that the nodules of this study are of mixed hydrogenetic-diagenetic type. A mixed genesis was also shown by discriminant diagrams, with these CCZ samples being located at the transition between typical hydrogenetic and diagenetic fields.
Źródło:
Geological Quarterly; 2021, 65, 4; 177--194
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 86

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