The Geology of Rare Earth Elements
The estimated average concentration of the rare earth elements in the Earth's crust, which ranges from around 150 to 220 parts per million (table 1), exceeds that of many other metals that are mined on an industrial scale, such as copper (55 parts per million) and …
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Relationship between concentration of rare earth …
Rare earth elements (REEs) are a group of elements whose concentration in numerous environmental matrices continues to increase; therefore, the use of …
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Online preconcentration ICP‐MS analysis of rare earth elements …
[1] The rare earth elements (REEs) with their systematically varying properties are powerful tracers of continental inputs, particle scavenging intensity and the oxidation state of seawater. However, their generally low (∼pmol/kg) concentrations in seawater and fractionation potential during chemical treatment makes them difficult to …
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Electro-Assisted Sorption Behavior and Mechanism of Low-Concentration …
A method is given for the quantithtive separation and determination of individual rare earth elements in minerals. The method utilizes ion-exchange chromatography (0.5 M ammonium lactate in pH = 3 ...
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Concentration of Rare Earth Elements in surface …
The paper presents the results of analyses of the content of rare earth elements (REEs) in surface water and bottom sediment in the river-lake system of Lake Wadąg located in the Masuria Lakeland ...
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Concentration levels of rare-earth elements and thorium in …
Plants and soils from a natural thorium and rare-earth element occurrence (Morro do Ferro, Brazil) were analyzed by alpha spectrometry (Th) and ICP-AES (REE), after pre-concentration of the elements by solvent extraction, co-precipitation and ion exchange procedures. Leaching experiments with humic acid solutions and different soils …
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Key concepts in interpreting the concentrations of …
Key concepts in interpreting the concentrations of the rare earth elements in zircon. Antony D.Burnham. Show more. Add to Mendeley. …
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The Occurrence and Concentration of Rare Earth Elements …
Acid mine drainage (AMD) contains rare earth element (REE) concentrations several orders of magnitude higher than those of the rest of natural waters and could be a secondary source of REEs. In ...
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Predicting element concentrations by machine learning …
The correlation relationships in the concentrations of rare earth elements are shown in Fig. 2f. In the case of determining the concentrations of elements with medium lives, such as La and Sm, calculating the concentration of La is enough to predict the concentration of Sm through machine learning models.
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Concentration of rare earth elements in the Faixa Placha tin …
The values exceed 1000 ppm in light rare earth elements (LREEs) and 500 ppm in heavy rare earth elements (HREEs) + Y in the parent granite. REE concentrations in greisenized granites and greisens are similar to that of the parent granite, indicating that the enrichment in REE is due to the presence of REE-bearing primary minerals and that ...
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Rare-earth element
Rare-earth element - Abundance, Occurrence, Reserves: As noted above, the rare earths are fairly abundant, but their availability is somewhat limited, primarily because their …
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Concentration of rare earth elements during high temperature pyrolysis
Rare earth elements are not exactly rare in nature; these can be found in more than 200 minerals (British Geological Survey, 2011). However, key difficulties in their mining are caused by low concentrations in poor grade ores for economic and sustainable mining, the production of radioactive thorium as a biproduct, regulatory pressures etc ...
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Fossil Bioapatites with Extremely High Concentrations of Rare …
Deep-sea sediments containing high concentrations of rare earth elements (REE) and yttrium (Y), termed REY-rich sediments, have attracted considerable attention and are widely distributed in the ...
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Concentration of heavy metals and rare earth elements in
The blood concentration of 47 elements was assessed by ICP-MS in 26 brain tumour patients and 21 healthy subjects from Bucharest (Romania). All 47 elements were detected in the brain tumour tissue, and 22 were detected in > 80% of samples; this implies that these elements can cross the blood-brain barrier.
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Modes of occurrence and pre-concentration of rare earth elements …
1. Introduction. Generally, rare earth elements include 15 lanthanides (La–Lu) and yttrium (Y), namely REE + Y, so rare earth elements are usually referred to as REY. 1 REY has excellent magnetic, optical and electrical properties, which is widely used not only in traditional fields such as military, petrochemical, metallurgy, but also in the …
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Adsorption of yttrium (Y3+) and concentration of rare earth elements
Chitin powder and chitin-aerogel were prepared from shrimp wastes and used to uptake Y 3+ from aqueous solutions and concentrate this rare earth element from phosphogypsum (PG). Chitin aerogel displays a specific surface area of 945 m 2 /g, while chitin powder is 3.6 m 2 /g, which largely influences its adsorption ability. Regarding the …
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Rare earth elements: A review of applications
The estimated average concentration of the REE in the Earth's crust which ranges from around 130 μg/g to 240 μg/g which is actually significantly higher than …
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(PDF) Concentration Mechanisms of Rare Earth …
Concentration Mechanisms of Rare Earth Element-Nb-Zr-Be Mineralization in the Baerzhe Deposit, Northeast China: Insights from Textural and Chemical Features of Amphibole and Rare Metal Minerals
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Relationship between concentration of rare earth elements …
Rare earth elements (REEs) are a group of elements whose concentration in numerous environmental matrices continues to increase; therefore, the use of biological methods for their removal from soil would seem to be a safe and reasonable approach. The aim of this study was to estimate the phytoextrac …
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Global natural concentrations of Rare Earth Elements in …
The entire database compiled 19,354 data of REEs, with 19,013 concentrations of individual REE and 341 data of ∑REEs. The number of available data per REE (Fig. 1 A) shows a factor of 2 between the most frequently detected REE (La) and the least detected REE (Tm).Except for La, even-numbered REEs (i.e. Ce, Nd, Sm, Gd, Dy, Er, Yb) are …
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Review of rare earth element concentrations in oil shales of …
The Green River oil shales had lower rare earth element concentrations (66.3 to 141.3 micrograms per gram, μg g-1) than are typical of material in the upper crust (approximately 170 μg g-1) and were also lower in rare earth elements relative to the North American shale composite (approximately 165 μg g-1). Adjusting for dilution of rare ...
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Concentration of rare earth elements during high …
An in-depth investigation was carried out on the recovery of rare earth elements (REEs) from a variety of waste printed circuit boards (PCBs). ... Concentration of rare earth elements during high temperature pyrolysis of waste printed circuit boards Waste Manag. 2018 Aug;78:602-610. doi: 10.1016/j.wasman.2018.06.041.
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Relationship between concentration of rare earth elements …
The concentration of rare earth elements was diverse for organs of all three plant species growing at 1, 10, and 25 m distance from the edge of the road (Table (Table3). 3). Generally, concentration of REEs, HREEs, and LREEs in plant organs decreased with the distance from the road.
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Global natural concentrations of Rare Earth Elements …
Global natural concentrations of Rare Earth Elements in aquatic organisms: Progress and lessons from fifty years of studies - ScienceDirect. Science of The Total Environment. …
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Effective adsorption and recovery of rare earth elements …
The extraction process of ion-type rare earth mines generates a significant amount of wastewater containing rare earth elements (REE) with low concentration. It is of great significance to recover REE from the wastewater in order to reduce environmental toxicity and improve the utilization efficiency of rare earth mining.
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Quantitative separation of thorium from rare earth elements …
1. Introduction. In 2018, the United States Geological Survey (USGS) designated rare earth elements (REEs), including the lanthanides, scandium, and yttrium, as well as 34 other modern minerals, as critical [1].The demand for REEs is expected to continue to rise, as they are crucial for producing technological devices and for many …
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Maximum Permissible Concentrations and Negligible Concentrations …
Publiekssamenvatting. In this report maximum permissible concentrations (MPCs) and negligible concentrations (NCs) are derived for Rare Earth Elements (REEs), which are also known as lanthanides. The REEs selected for derivation of environmental risk limits in this report are Yttrium (Y), Lanthanum (La), Cerium (Ce), Praseodymium (Pr ...
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The Occurrence and Concentration of Rare Earth …
The conventional rare earth element (REE) industry has historically sought to develop ore deposits where geologic processes have produced mineralized zones with …
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Spatial variations in dissolved rare earth element concentrations …
The rare earth element profiles from the water column of five stations in the Okinawa Trough are shown in Fig. 4. The REE profile of Station 2011-5 shows markedly higher concentrations than those of the other stations at depths of less than nearly 400 m, especially for LREEs and MREEs.
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