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Wyszukujesz frazę "rare elements" wg kryterium: Temat


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
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:
Effect of Bismuth and Rare Earth Elements on Graphite Structure in Different Section Thicknesses of Spheroidal Graphite Cast Iron Castings
Autorzy:
Glavas, Z.
Strkalj, A.
Maldini, K.
Kozina, F.
Powiązania:
https://bibliotekanauki.pl/articles/353810.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spheroidal graphite cast iron casting
graphite structure
bismuth
rare earth elements
microstructure
Opis:
Effects of additions of 0.00064, 0.001 and 0.0042 wt.% Bi on the graphite structure in the section thicknesses of 3, 12, 25, 38, 50, 75 and 100 mm of spheroidal graphite cast iron castings containing 2.11 wt.% Si and rare earth (RE) elements (Ce + La + Nd + Pr + Sm + Gd) in the range from 0.00297 to 0.00337 wt.% were analyzed in this paper. Addition of Bi was not necessary for obtaining high nodule count and nodularity higher than 80% in section thicknesses of 3, 12 and 25 mm. RE elements showed a beneficial effect on the nodule count and nodularity in these sections. Nodularity was below 80% in section thicknesses of 38, 50, 75 and 100 mm when Bi was not added. Detrimental effect of RE elements on graphite morphology in these sections was neutralized by adequate addition of Bi. Addition of 0.001 wt.% Bi (ratio of RE/Bi = 3.27) was enough to achieve nodularity above 80% in the section thickness of 38 mm. Nodularity was increased above 80% in section thicknesses of 50, 75 and 100 mm by addition of 0.0042 wt.% Bi (ratio of RE/Bi = 0.78). At the same time, Bi significantly increased the nodule count. Nodularity above 80% and the high nodule count in the section thicknesses of 75 and 100 mm were also achieved by using an external metallic chill in the mold. In this case, addition of Bi was not required.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1547-1553
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Rare Earth Cerium Addition on Oxidation Behavior of Co-Al-W Alloys at 800°C
Autorzy:
Migas, Damian
Liptáková, Tatiana
Moskal, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/2048827.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rare earth elements
REE
cyclic oxidation
γ-γ′ cobalt-based superalloys
Co-Ce
Opis:
The γ/γ′ Co-based alloys are a new class of cobalt superalloys, which are characterized by remarkable high temperature strength owing to strengthening by γ′-Co3(Al, X) phases. In this investigation, the effect of cerium addition on oxidation behavior of model Co-Al-W alloys was studied. The introduction of Ce aimed at improvement of the oxidation resistance of γ′-forming Co-based superalloys. The minor additions of cerium (0.1, 0.5 at.%) were added to the base alloy Co-9Al-9W. The alloys were prepared via induction vacuum melting (VIM). Further, a primary microstructure of the alloys was analyzed with particular regard to a segregation of Ce. The thermogravimetric analysis (TG) under non-isothermal conditions was used to preliminary estimate the oxidation behavior of alloys at different temperatures. During experiment, differential thermal analysis (DTA) was performed simultaneously. After this test, cyclic oxidation expermients was carried out at 800°C for 500 h. In as-cast state, Ce segregates to interdendritic areas and forms intermetallic phases. The effect connected with melting of interdendritic precipitates was observed at 1160°C. Ce-containing alloys were less prone of oxide spallation. Moreover, oxidation rate of these alloys substantially decreased after 100h of oxidation, whereas mass of the sample corresponding to base alloy continued to increase.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 1; 203-208
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
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:
Mechanical alloying of Mg-Zn-Ca-Er alloy
Autorzy:
Hrapkowicz, Bartłomiej
Lesz, Sabina
Kremzer, Marek
Karolus, Małgorzata
Pakieła, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/2086890.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnesium
mechanical alloying
erbium
rare earth elements
magnez
stopowanie mechaniczne
erb
pierwiastki ziem rzadkich
Opis:
Magnesium-based materials constitute promising alternatives for medical applications, due to their characteristics, such as good mechanical and biological properties. This opens many possibilities for biodegradable materials to be used as less-invasive options for treatment. Degradation is prompted by their chemical composition and microstructure. Both those aspects can be finely adjusted by means of proper manufacturing processes, such as mechanical alloying (MA). Furthermore, MA allows for alloying elements that would normally be really hard to mix due to their very different properties. Magnesium usually needs various alloying elements, which can further increase its characteristics. Alloying magnesium with rare earth elements is considered to greatly improve the aforementioned properties. Due to that fact, erbium was used as one of the alloying elements, alongside zinc and calcium, to obtain an Mg₆₄Zn₃₀Ca₄Er₁ alloy via mechanical alloying. The alloy was milled in the SPEX 8000 Dual Mixer/Mill high energy mill under an argon atmosphere for 8, 13, and 20 hours. It was assessed using X-ray diffraction, energy dispersive spectroscopy and granulometric analysis as well as by studying its hardness. The hardness values reached 232, 250, and 302 HV, respectively, which is closely related to their particle size. Average particle sizes were 15, 16, and 17 μm, respectively.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 5; e137587, 1--7
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
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:
Comparison of Sensitivity of Autotrophic and Heterotrophic Microorganisms to the Pollution of Natural Water with Rare Earth Elements (Lanthanum and Cerium)
Autorzy:
Lozhkina, Roza A.
Olkova, Anna S.
Koval, Ekaterina V.
Tomilina, Irina I.
Sysolyatina, Maria A.
Powiązania:
https://bibliotekanauki.pl/articles/2086379.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
rare earth elements
lanthanum
cerium
bioassay
Nostoc linckia
Chlorella vulgaris
Paramecium caudatum
Escherichia coli
Opis:
The purpose of the work was to compare the sensitivity of autotrophic and heterotrophic organisms used in bioassay to lanthanum and cerium under the conditions of a model experiment with aqueous media. Using bioassay methods, the pre-lethal effects of La and Ce in heterotrophic Paramecium caudatum and Escherichia coli, as well as autotrophic Chlorella vulgaris and Nostoc linckia were determined. Model solutions of La2 (SO4)3∙8H2O and Ce2 (SO4)3∙8H2O were tested in the concentration range of 0.1–200 mg/l. As a result, it was shown that heterotrophic organisms are more sensitive to water pollution with La and Ce than autotrophic ones. According to the totality of experiments, cerium turned out to be more toxic than lanthanum. When planning the environmental studies of wastewater or reservoirs polluted with REE, it is recommended to focus on comparative sensitivity of bioassay methods, taking into account the test-functions used: bioassay for chemotaxis of P. caudatum > bioassay for changes in bioluminescence of E. coli (strain M-17) > bioassay for the content of chlorophyll а and intensity of lipid peroxidation in N. linckia > bioassay on the increase in the number of Cl. vulgaris.
Źródło:
Journal of Ecological Engineering; 2022, 23, 4; 58--63
2299-8993
Pojawia się w:
Journal of Ecological Engineering
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:
Afghanistan’s raw materials policy regarding rare earth elements after the Taliban victory
Afghanistan’s raw materials policy regarding rare earth elements after the Taliban victory [Polityka surowcowa Afganistanu dotycząca metali ziem rzadkich po zwycięstwie Talibów]
Autorzy:
Kamprowski, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/32306494.pdf
Data publikacji:
2024
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
rare earth elements
Afghanistan
raw materials policy
Taliban
metale ziem rzadkich
Afganistan
polityka surowcowa
Talibowie
Opis:
The Taliban victory in Afghanistan in 2021 has not only raised geopolitical concerns but has also sparked questions about the state’s policies and strategies concerning its rare earth elements reserves. The main objective of the presented article is to indicate how the current political change in Afghanistan may affect the raw material policy regarding the extraction of rare earth elements, taking into account geopolitical factors. Rare earth elements are a group of critical minerals that are of great importance to modern technologies, ranging from electronics and renewable energy to defence systems. Afghanistan is known to possess significant deposits of these valuable resources, which have the potential to play a crucial role in global supply chains, especially in the face of ongoing rivalry between the People’s Republic of China and the United States of America. The research problem of the considerations undertaken in this article is to assess the key challenges and opportunities in harnessing Afghanistan’s rare earth element resources after the Taliban’s return to power. The research conducted shows that despite having a significant amount of rare earth elements, Afghanistan lacks the infrastructure necessary to extract and process these valuable minerals. After the Taliban victory, the newly established government sees the potential benefit in extracting rare earth elements and is willing to align itself with China to exploit them.
Zwycięstwo Talibów w Afganistanie w 2021 r. nie tylko wzbudziło obawy geopolityczne, ale także wywołało pytania o politykę i strategie państwa dotyczące rezerw metali ziem rzadkich. Głównym celem niniejszego artykułu jest wskazanie, jak obecne zmiany polityczne w Afganistanie mogą wpłynąć na politykę surowcową w zakresie wydobycia metali ziem rzadkich, uwzględniając czynnik geopolityczny. Omawiane metale to grupa minerałów krytycznych o ogromnym znaczeniu dla nowoczesnych technologii, począwszy od elektroniki i energii odnawialnej, po systemy obronne. Wiadomo, że Afganistan posiada znaczne złoża tych cennych zasobów, które mogą potencjalnie odegrać kluczową rolę w globalnych łańcuchach dostaw, zwłaszcza w obliczu nieustającej rywalizacji między Chińską Republiką Ludową a Stanami Zjednoczonymi. Problem badawczy podjętych w tym artykule rozważań polega na ocenie kluczowych wyzwań i szans w wykorzystaniu metali ziem rzadkich w Afganistanie po powrocie Talibów do władzy pomimo zawiłości geopolitycznej. Z przeprowadzonych badań wynika, że pomimo posiadania znacznych ilości pierwiastków ziem rzadkich, Afganistanowi brakuje infrastruktury niezbędnej do wydobywania i przetwarzania tych cennych minerałów. Po zwycięstwie Talibów, nowo utworzony rząd dostrzega potencjalne korzyści z wydobycia metali ziem rzadkich i jest skłonny sprzymierzyć się z Chinami w celu ich eksploatacji.
Źródło:
Przegląd Politologiczny; 2024, 1; 113-121
1426-8876
Pojawia się w:
Przegląd Politologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two new separation schemes for the group isolation of rare earth elements (REE) from biological and other matrices and their determination by ICP-MS, NAA and chromatographic methods
Autorzy:
Dybczyński, R. S.
Samczyński, Z.
Bartosiewicz, I.
Kulisa, K.
Polkowska-Motrenko, H.
Pyszynska, M.
Zuba, I.
Powiązania:
https://bibliotekanauki.pl/articles/147581.pdf
Data publikacji:
2017
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
rare earth elements
REE
lanthanides
ion exchange chromatography
NAA
ICP-MS
accuracy
certified reference materials
CRM
Opis:
Two new group separation schemes, based on ion exchange chromatography, for the selective and quantitative isolation of rare earth elements (REE) from accompanying elements, were devised. After checking their performance with the aid of radioactive tracers, the schemes were further used together with ICP-MS, NAA and ion exchange chromatography for the determination of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in two certified reference materials (CRMs). The results were compared with another series of analyses, where the REEs were determined directly, i.e. without pre-separation, by instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS). It was demonstrated that while direct INAA and ICP-MS in most instances provide reliable results for the majority of REEs, for some elements, notably Sc, Yb and Tm in the cases of ICP-MS and INAA, respectively, systematic errors occur or may potentially occur.
Źródło:
Nukleonika; 2017, 62, 3; 199-211
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural Characterization of the As-cast AZ91 Magnesium Alloy with Rare Earth Elements
Autorzy:
Grzybowska, A.
Braszczyńska-Malik, K.
Powiązania:
https://bibliotekanauki.pl/articles/382210.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Mg-Al-Zn alloy
rare earth elements
microstructure
stop Mg-AI-Zn
pierwiastki ziem rzadkich
mikrostruktura
Opis:
Microstructural analysis of as-cast Mg-9Al-0.9Zn-xRE (x = 0, 1, 2, 3, 5 wt.%) magnesium alloys is presented. Light microscopy (LM) and scanning electron microscopy (SEM+EDX) were used to characterized the obtained material. The results revealed that the as-cast AZ91 alloy consists of α – Mg matrix, binary eutectic α + γ (where γ is Mg17Al12). While rare earth elements were introduced to the Mg-Al-Zn alloy new Al11RE3 phase was formed. Additionally, in the experimental alloys instead of Al-Mn phase, ternary Al-Mn-RE compound was observed. What is more, the influence of RE addition on the area fraction of eutectic and needle-like phase was analysed. With increasing addition of RE, the amount of γ phase decreased, but the amount of Al11RE3 phase increased.
Źródło:
Archives of Foundry Engineering; 2012, 12, 2s; 23-26
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of non-metallic inclusions by rare-earth elements in microalloyed steels
Autorzy:
Opiela, M.
Grajcar, A.
Powiązania:
https://bibliotekanauki.pl/articles/382841.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
pierwiastki ziem rzadkich
wtrącenia niemetaliczne
stal mikrostopowa
rare earth elements (REE)
non-metallic inclusions
microalloyed steels
Opis:
The modification of the chemical composition of non-metallic inclusions by rare-earth elements in the new-developed microalloyed steels was discussed in the paper. The investigated steels are assigned to production of forged elements by thermomechanical treatment. The steels were melted in a vaccum induction furnace and modification of non-metallic inclusions was carried out by the michmetal in the amount of 2.0 g per 1 kg of steel. It was found that using material charge of high purity and a realization of metallurgical process in vacuous conditions result in a low concentration of sulfur (0.004%), phosphorus (from 0.006 to 0.008%) and oxygen (6 ppm). The high metallurgical purity is confirmed by a small fraction of non-metallic inclusions averaging 0.075%. A large majority of non-metallic inclusions are fine, globular oxide-sulfide or sulfide particles with a mean size 17 m2. The chemical composition and morphology of non-metallic inclusions was modified by Ce, La and Nd, what results a small deformability of nonmetallic inclusions during hot-working.
Źródło:
Archives of Foundry Engineering; 2012, 12, 2; 129-134
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
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
Tytuł:
Potencjał i zasoby metali ziem rzadkich w świecie oraz w Polsce. Artykuł przeglądowy
The potential and resources of rare earth metals in the world and in Poland. Review article
Autorzy:
Całus Moszko, J.
Białecka, B.
Powiązania:
https://bibliotekanauki.pl/articles/340449.pdf
Data publikacji:
2012
Wydawca:
Główny Instytut Górnictwa
Tematy:
pierwiastki ziem rzadkich
występowanie
pozyskiwanie
zastosowanie
Polska
świat
rare earth elements (REE)
occurrence
acquisition
application
Polska
world
Opis:
Pierwiastki ziem rzadkich, tworzące grupę 15 lantanowców oraz skand i itr, określane są powszechnie skrótem REE (ang. Rare Earth Elements). Zaliczone zostały przez Unię Europejską do surowców krytycznych o znaczeniu strategicznym dla rozwoju nowoczesnych wysoko zawansowanych technologii. Niniejszy artykuł poświęcono występowaniu REE na świecie i w Polsce. Scharakteryzowano podstawowe technologie procesów pozyskiwania metali ziem rzadkich, a także omówiono główne możliwości ich praktycznego stosowania w różnych gałęziach gospodarki. Następnie przedstawiono perspektywiczne światowe zasoby naturalne i alternatywne dla omawianych pierwiastków, które mogą stać się ich cennym źródłem w ciągu najbliższych kilku lat.
Rare earth elements forming the group of 15 lanthanides as well as scandium and yttrium are referred to commonly as REE. They have been numbered by the European Union as critical resources of strategic importance for the development of modern advanced technologies. The present article was devoted to discuss the occurrence of REE in the world and in Poland. Basic technologies for rare earth metals extraction processes have been characterized, and also the main capabilities of their practical application in different branches of the economy have been discussed. Then, the list of prospective world natural resources and the elements alternative to those discussed, which can become their valuable source over the next few years, have been presented.
Źródło:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa; 2012, 4; 61-72
1643-7608
Pojawia się w:
Prace Naukowe GIG. Górnictwo i Środowisko / Główny Instytut Górnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
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)
Autorzy:
Adamczyk, Z.
Białecka, B.
Całusz Moszko, J.
Komorek, J.
Lewandowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/219118.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rare earth elements (REE)
coal
Orzesze beds
USCB
pierwiastki ziem rzadkich (REE)
węgiel kamienny
warstwy orzeskie
GZW
Opis:
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 minerale 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.
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. Udział 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.
Źródło:
Archives of Mining Sciences; 2015, 60, 1; 157-172
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microscopic characteristic of Nd-Fe-B magnets structure - magnets recovered from electric motors
Autorzy:
Kapustka, K.
Ziegmann, G.
Sdrenka, S.
Elwert, T.
Klimecka-Tatar, D.
Powiązania:
https://bibliotekanauki.pl/articles/108989.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
NdFeB magnets
rare earth elements
microscopic analysis
structure of NdFeB
materiały magnetyczne twarde
struktura NdFeB
analiza mikroskopowa
Opis:
The rare earths (RE) are characterized with their strong metallic atomic bonds. They are used in magnetic materials used in computer technology and electric powered vehicles. The advancing globalization and the increasing standard of living both lead to massive waste disposal problems, therefore, the methods of recovering used metallic materials are sought. In this paper, the microscopic characteristic of magnetic powder from old electric engines has been presented.
Źródło:
Archiwum Wiedzy Inżynierskiej; 2017, 2, 1; 39-41
2544-2449
Pojawia się w:
Archiwum Wiedzy Inżynierskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrochemical behavior and morphology of selected sintered samples of Mg65Zn30Ca4Pr1 alloy
Autorzy:
Hrapkowicz, Bartłomiej
Lesz, Sabina
Drygała, Aleksandra
Karolus, Małgorzata
Gołombek, Klaudiusz
Babilas, Rafał
Popis, Julia
Gabryś, Adrian
Młynarek-Żak, Katarzyna
Garbiec, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/27311410.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
magnesium
SPS
spark plasma sintering
corrosion
rare earth elements
magnez
pierwiastki ziem rzadkich
korozja
spiekanie plazmowe iskrowe
Opis:
In order to investigate the effect of the milling time on the corrosion resistance of the Mg65Zn30Ca4Pr1 alloy, powders of the alloy were prepared and milled for 13, 20, and 70 hours, respectively. The samples were sintered using spark plasma sintering (SPS) technology at 350◦C and pressure of 50 MPa. The samples were subjected to potentiodynamic immersion tests in Ringer’s solution at 37◦C. The obtained values of Ecorr were –1.36, –1.35, and –1.39 V, with polarization resistance Rp = 144, 189, and 101 Ω for samples milled for 13, 20 and 70 h, respectively. The samples morphology showed cracks and pits, thus signaling pitting corrosion.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 3; art. no. e145564
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In the pursuit of raw materials independence. A comparative analysis of Donald Trump and Joe Biden policies towards rare earth elements
W dążeniu do niezależności surowcowej. Analiza porównawcza polityki Donalda Trumpa i Joe Bidena wobec metali ziem rzadkich
Autorzy:
Kamprowski, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/30147185.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
rare earth elements
raw materials
raw materials policy
Donald Trump
Joe Biden
metale ziem rzadkich
surowce
polityka surowcowa
Opis:
The main aim of the presented article is to find similarities and differences in the approach to the strategic role of rare earth elements during the presidencies of Donald Trump and Joe Biden in the United States of America. Rare earth elements are the core instruments of modern technological development in many areas and fields – both civil and military. Due to their growing importance, they have been the object of political rivalry between the People’s Republic of China and the United States of America for at least twenty years. The increasing global demand for rare earth elements and their strategic importance in various industries has highlighted the issue of the approach of political leaders to these critical minerals, espiecialy when it comes to ensuring secure and sustainable supply chain. The research problem of the considerations undertaken in this article is to assess implications and effectiveness of Donald Trump and Joe Biden Policies towards rare earth elements. The research shows that while both administrations recognized the significance of rare earth elements, their approaches differed in terms of priorities, strategies, and emphasis on environmental sustainability.
Celem niniejszego artykułu jest znalezienie podobieństw i różnic w podejściu do strategicznej roli metali ziem rzadkich w okresie prezydentury Donalda Trumpa i Joe Bidena w Stanach Zjednoczonych Ameryki. Metale ziem rzadkich stanowią fundament współczesnego rozwoju technologicznego w wielu dziedzinach – zarówno cywilnych, jak i wojskowych. Ze względu na rosnące znaczenie, od co najmniej dwudziestu lat są przedmiotem rywalizacji politycznej między Chińską Republiką Ludową a Stanami Zjednoczonymi Ameryki. Rosnące globalne zapotrzebowanie na pierwiastki ziem rzadkich i ich strategiczne znaczenie w różnych gałęziach przemysłu uwypukliło problematykę podejścia przywódców politycznych do tych krytycznych minerałów, zwłaszcza jeśli chodzi o zapewnienie bezpiecznego i zrównoważonego łańcucha dostaw. Problemem badawczym rozważań podjętych w niniejszym artykule jest ocena implikacji i skuteczności polityki Donalda Trumpa i Joe Bidena wobec pierwiastków ziem rzadkich. Z przeprowadzonych badań wynika, iż chociaż obie administracje uznawały kluczowe znaczenie metali ziem rzadkich, ich podejście różniło się pod względem priorytetów, strategii i nacisku na problematykę zrównoważenia środowiskowego.
Źródło:
Przegląd Strategiczny; 2023, 16; 209-218
2084-6991
Pojawia się w:
Przegląd Strategiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The management and potential risk reduction in the processing of rare earths elements
Autorzy:
Kapustka, Katarzyna
Klimecka-Tatar, Dorota
Ziegmann, Gerhard
Powiązania:
https://bibliotekanauki.pl/articles/88524.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
rare earth elements
risk management
ecological danger
human health
pierwiastki ziem rzadkich
zarządzanie ryzykiem
niebezpieczeństwo ekologiczne
zdrowie człowieka
Opis:
The rare earth elements (REE) are vital to innovation technologies and society and are important for the industry, especially for high-tech solutions. In the modern world, anumerous applications have been developed using rare earth elements (REE), implying human exposures and raising unclear questions as to REE-associated health effects. Protecting the environment and public health from disadvantageous actions of rare earth elements mining and processing as emerging pollutants is urgently desired to achieve sustainable development. All activities in mining processes like extraction, separation and after recycling of REE elements could create rick to human health and environment. In the paper the role of management in safety aspects during mining and processing of rare earth elements has been highlighted. In the paper, the potential dangerous and damaging effects on the environment and human health have been identified - the potential risk in the processing as well as the possibilities of preventing the occurrence of hazards have been analyzed.
Źródło:
System Safety : Human - Technical Facility - Environment; 2019, 1, 1; 77-84
2657-5450
Pojawia się w:
System Safety : Human - Technical Facility - Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pierwiastki ziem rzadkich – surowiec w Polsce niepożądany? : uwagi na temat stanowienia Prawa geologicznego i górniczego
Rare Earth Elements, a commodity not demanded in Poland? : some remarks on the mode of formulation of the Geological and Mining Law
Autorzy:
Nieć, M.
Powiązania:
https://bibliotekanauki.pl/articles/394673.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
pierwiastki ziem rzadkich
opłata eksploatacyjna
prawo geologiczne i górnicze
rare earth elements
Geological and Mining Law exploitation fee
Opis:
Potrzeba zabezpieczenia zapotrzebowania na pierwiastki ziem rzadkich stała się podstawą do zaliczenia ich w ustawie o nowelizacji Prawa geologicznego i górniczego w 2018 r. do kopalin, które są objęte własnością górniczą przysługującą Skarbowi Państwa. Wprowadzona została opłata za ich wydobywanie (opłata eksploatacyjna) w wysokości 500 zł/kg. Oba rozwiązania zamiast sprzyjać wykorzystaniu ziem rzadkich ze źródeł krajowych stanowić będą dla niego barierę. Termin „pierwiastki ziem rzadkich” jest nieprecyzyjny i może rodzić nieporozumienia. Ich kopaliny mieszczą się w zakresie pojęcia „rudy metali”, które są objęte własnością górniczą. Pierwiastki ziem rzadkich występują też jako składniki towarzyszące w innych kopalinach i ich odzysk jest możliwy dopiero w trakcie przetwarzania tych kopalin poza zakładem górniczym. Wówczas obciążanie ich wydobycia opłatą eksploatacyjną staje się wątpliwe. Ustalona opłata eksploatacyjna jest niewspółmiernie wysoka w stosunku do kosztów pozyskania kopalin ziem rzadkich i korzyści finansowych z ich wydobycia. Ocena skutków nowelizacji Pgg skłania do: - postulowania wymieniania w nim kopalin, których użytkowanie przysługuje właścicielowi nieruchomości gruntowej, a nie wymienionych jako przysługujących Skarbowi Państwa, - głębszej refleksji przy stanowieniu przepisów Pgg, wstępne ich formułowanie przez osoby kompetentne w dziedzinie geologii i górnictwa i dopiero następnie ich kształtowanie zgodnie z zasadami doktryny i praktyki prawniczej.
The demand for REE was the background to include them to those consisting of the property of the State Treasury in Poland, enumerated in the Geological and Mining Law (Article 10). The PLN 500/kg REE payment for exploitation of REE (exploitation tax) was introduced. Both proposals will restrain the REE recovery from exploited domestic mineral commodities. The term REE is imprecise. Their deposits are rare and may be classified 128 as “REE ore deposits”. The REE are often the accompanying constituents in varied mineral commodities and are recoverable during their processing, outside the mine. The application of an exploitation tax in such a case is inapplicable. The established value of the exploitation tax is incomparably high in respect to the value of the REE contained in mined mineral commodities. The analysis of introduced changes of mining and geological law allow to suggest the reevaluation of ownership based subdivision of mineral commodities: name the mineral commodities belonging to the land property owners and leave the list of mineral commodities consisting property of the State Treasury open. The more careful approach is also necessary in the formulation of Geological and Mining Law. It should be preliminary formulated by persons competent in geology and mining and subsequently adjusted to juridical exigencies.
Źródło:
Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN; 2018, 106; 127-132
2080-0819
Pojawia się w:
Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure of Mg–Al–RE-type Experimental Magnesium Alloy Gravity Cast into Sand Mould
Autorzy:
Braszczyńska-Malik, K. N.
Przełożyńska, E.
Powiązania:
https://bibliotekanauki.pl/articles/379591.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnesium alloy
aluminium
rare earth elements (REE)
as-cast conditions
microstructure
stop magnezu
pierwiastki ziem rzadkich
odlew
mikrostruktura
Opis:
Magnesium alloy with 5 wt% Al, 0.35 wt% Mn and 5 wt% rare earth elements (RE) was prepared and gravity cast into a sand mould. Microstructure investigations were conducted. Analyses of the Mg-Al-RE alloy microstructure were carried out by light microscopy, scanning electron microscopy and the XRD technique. In the as-cast condition, the alloy was composed of α-Mg, Al11RE3 and Al10RE2Mn7 intermetallic phases. Additionally, due to non-equilibrium solidification conditions, an Al2RE intermetallic phase was revealed.
Źródło:
Archives of Foundry Engineering; 2016, 16, 2; 115-118
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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