concentration rare elements

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 ...

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 …

(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

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.

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 ...

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 ...

Upper crustal abundances of trace elements: A revision …

Upper crustal samples used in this study come from those previously well-characterized by major and many of the trace element compositions (Table 1).They include (1) the suite of Post-Archean Shales (PAAS) which Taylor and his co-workers originally used to constrain the rare earth element (REE) contents of the upper crust (Nance and …

Rare Earth Elements

Rare earth elements occur in many minerals but typically in concentrations too low to be refined in an economical manner; the concentration of REEs in the Earth's crust is …

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.

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 …

Examination of rare earth element concentration patterns …

Rare earth element concentrations were also found to be higher in benthic fish species compared to pelagic species collected from Xiamen Bay, an industrialized harbor in China (Guo et al., 2003). The mean and range of ΣREE concentrations from 28 saltwater species of fish collected from Xiamen Bay were 0.078 (range 0.012–0.597) mg …

Concentrations of rare earth elements in maternal serum during

Rare earth elements (REEs) are ubiquitous in the environment. Animal experiments have shown that many REEs have adverse impacts on the health of fetuses. However, data from humans are scarce. In this study, we examined the associations between concentrations of 10 REEs in maternal serum and the risk …

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 …

Maximum Permissible Concentrations and Negligible Concentrations for

The concentration of lanthanides (rare earth elements) in plant and soil samples were determined by means of atomic emission spectroscopy with inductively coupled plasma (AES-ICP).

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.

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.

Hypertension risk is associated with elevated concentrations of rare

Concentrations of the 21 elements were dichotomized by the median concentrations of the subjects. The ORs associated with hypertension risk were presented in Fig. 2 . The univariate ORs (UORs) of 6 elements (Cu, Sm, Gd, Dy, Yb and La) were significantly higher than 1 ( p < 0.05) and the UORs of another 5 elements (Cd, Pb, Se, …

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. …

Notes on the Potential for the Concentration of Rare …

Open Access Article. Notes on the Potential for the Concentration of Rare Earth Elements and Yttrium in Coal Combustion Fly Ash. by. James C. Hower. 1,*, John G. Groppo. 1, Kevin R. Henke. 1, …

Anomalous concentrations of rare earth elements in the …

The distribution of REEs in the moss-soil system differed considerably, but all the samples showed the average percent of increase of medium rare earth elements. The shale-normalized concentration ratios calculated for selected elements (LaN/YbN, GdN/YbN, LaN/SmN) were in the range of 1.22-2.43, 1.74-3.10 and 0.86-1.09.

Concentrating on rare-earth elements | Lawrence …

Using a bioengineered protein-based technology, Lawrence Livermore National Laboratory (LLNL) scientists and collaborators will develop a new separation technique that …

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 …

(PDF) Concentrations of Rare Trace Elements in Major Irrigated Rice

Thirty-two (32) soil and plant samples were collected in agricultural areas of the Philippines representing the major soil series devoted to irrigated rice production. Soil Sr levels were higher ...

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 …

Rare earth element concentrations and Nd …

[1] Three vertical profiles of rare earth element concentrations and Nd isotopic compositions have been measured in the remote southeast Pacific Ocean. The three stations represent …

Concentrations of rare earth elements in maternal serum …

Concentrations (ng/mL) of rare earth elements (REEs) in serum samples from women with pregnancies affected by total NTDs and those who delivered healthy infants (controls) in Shanxi Province, China, 2010–2018. REE Detection rate(%) a Total NTDs (N = 200) Control (N = 400)

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.

Rare earth elements: A review of applications

Rare earth elements (REE) include the lanthanide series elements (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) plus Sc and Y. Currently these metals have become very critical to several modern technologies ranging from cell phones and televisions to LED light bulbs and wind turbines.

Hypertension risk is associated with elevated concentrations of rare

The association of rare earth element (REE) exposure with hypertension is not well understood. • Concentrations of Ce and La in serum were found to be higher in the cases than the control.. Concentrations of Ce and La in serum were positively correlated with blood pressure.. Environmental exposure to REEs, especially Ce and La, …

Understanding Rare Earth Elements concentrations, …

Rare Earth Elements (REEs) are commonly used in geochemistry as process and/or source tracers, as they behave in a coherent way along the lanthanide series. ... rare earth elements and twenty-two other trace element concentrations in the Natural River Water Certified Reference Material SLRS-6 (NRC - CNRC) Geostand. …