scholarly journals Rare earth elements in soils of saline agrolandscapes of the Baraba plain

2021 ◽  
Vol 51 (3) ◽  
pp. 5-14
Author(s):  
N. V. Semendyaeva ◽  
A. A. Morozova ◽  
N. I. Dobrotvorskaya ◽  
N. V. Elizarov
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Soil Profile ◽  
Humus Content ◽  
Total Content ◽  
Agricultural Landscapes ◽  
Earth’S Crust ◽  
Depth Study ◽  
Earth's Crust ◽  
Humus Horizons

The total content of rare earth elements in the soil profile of saline agricultural landscapes catena of the Baraba plain within Novosibirsk region was studied. The total content of zirconium, yttrium, scandium, gallium, including lanthanides - cerium, lanthanum and ytterbium was determined. Rare earth elements are extremely poorly analyzed. At present, their influence on plants, organisms of animals and humans is being actively studied, although the maximum permissible and tentatively permissible concentrations for them have not yet been developed. The total content of rare earth elements, determined in the soils of the catena, depends on the granulometric composition and the degree of humus content of the soil horizons. It was revealed that in the studied soils they are mainly contained in the number of clarkes of the earth's crust, with the exception of lanthanum in the humus horizons, where its content is almost 1.5 times (44-48 mg/kg) higher than the clarke in the earth's crust (29 mg/kg), and ytterbium (10 times higher than the clarke). Along the soil profile, an insignificant movement of rare earth elements in both vertical and horizontal directions was noted, which indicates a low mobility of their compounds. Zirconium predominates in the profile of the studied soils from the group of rare earth elements. Its content in the humus horizons of soils of eluvial positions is within the clarke of the earth's crust; variations along the profile are insignificant. Ytterbium is contained in large quantities - from 1.89 to 4.05 mg/kg of soil, which is significantly higher than the clarke of the earth's crust (0.3 mg/kg of soil). The role of lanthanides in the soil -plant - animal - human system requires further in-depth study.

scholarly journals An Overview of Rare Earth Ores Beneficiation in Vietnam

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Thi Kim Dung NHU ◽  
Van Luan PHAM ◽  
Thi Chinh VU ◽  
Van Duoc TRAN
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnetic Materials ◽  
Animal Feed ◽  
Rare Earth Metals ◽  
Earth’S Crust ◽  
Research Projects ◽  
Essential Minerals ◽  
Different Types ◽  
Earth's Crust

Rare earth metals are used in electricity, electronics, nuclear, optics, space, metallurgy,superconducting and super magnetic materials, glass and ceramics, and agriculture. Some rare earthelements are added to fertilizers for crops and some trials for animal feed. Rare earth elements, exceptfor radioactive promethium, are relatively abundant in the earth's crust. Vietnam has a tremendous rareearth potential, distributed mainly in the Northwest, including Nam Xe, Dong Pao, Muong Hum, andYen Bai. There are many research projects on rare earth ores of different types globally, but the focus ismainly on the essential minerals, including monazite, xenotime, and bastnaesite. This report summarizesresearch data on rare earth ore intending to produce a general assessment of rare earth ore and itsbeneficiation technology in Vietnam.

scholarly journals An Updated Review of Toxicity Effect of the Rare Earth Elements (REEs) on Aquatic Organisms

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1663
Author(s):  
Nemi Malhotra ◽  
Hua-Shu Hsu ◽  
Sung-Tzu Liang ◽  
Marri Jmelou M. Roldan ◽  
Jiann-Shing Lee ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Chemical Elements ◽  
Life Forms ◽  
Department Of Energy ◽  
Earth’S Crust ◽  
Aquatic Biota ◽  
Aquatic Life ◽  
Toxicity Effect ◽  
Earth's Crust

Rare earth elements (REEs) or “technology metals” were coined by the U.S. Department of Energy, a group of seventeen elements found in the Earth’s crust. These chemical elements are vital and irreplaceable to the world of technology owing to their unique physical, chemical, and light-emitting properties, all of which are beneficial in modern healthcare, telecommunication, and defense. Rare earth elements are relatively abundant in Earth’s crust, with critical qualities to the device performance. The reuse and recycling of rare earth elements through different technologies can minimize impacts on the environment; however, there is insufficient data about their biological, bioaccumulation, and health effects. The increasing usage of rare earth elements has raised concern about environmental toxicity, which may further cause harmful effects on human health. The study aims to review the toxicity analysis of these rare earth elements concerning aquatic biota, considering it to be the sensitive indicator of the environment. Based on the limited reports of REE effects, the review highlights the need for more detailed studies on the hormetic effects of REEs. Aquatic biota is a cheap, robust, and efficient platform to study REEs’ toxicity, mobility of REEs, and biomagnification in water bodies. REEs’ diverse effects on aquatic life forms have been observed due to the lack of safety limits and extensive use in the various sectors. In accordance with the available data, we have put in efforts to compile all the relevant research results in this paper related to the topic “toxicity effect of REEs on aquatic life”.

scholarly journals How Rare Are Rare-Earth Elements in Living Things?

2021 ◽  
Vol 8 ◽  
Author(s):  
Rocío Bustillos-Cristales ◽  
Yagul Pedraza-Pérez ◽  
Luis Ernesto Fuentes-Ramírez
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Chemical Elements ◽  
Living Organism ◽  
Earth’S Crust ◽  
Future Research ◽  
Living Things ◽  
Earth's Crust ◽  
Living Organisms

Rare-earth elements (REEs) are a group of metallic chemical elements that share some properties and that despite their name are not too rare in the Earth’s crust. Until recently, we did not know of any REEs that were necessary for any living organism. Now we know that there are some bacteria that use REEs to perform reactions that let them consume alcohol. Humans are also interested in REEs because these elements are valuable for many technological applications. In this article, we will explain the only known participation of REEs in living organisms and explain why future research on REEs is important.

scholarly journals To the Issue of the Presence of the Occurrence of Rare Earth Elements in the Structure of Chromium Pyrope Garnet

2021 ◽  
Vol 38 ◽  
pp. 71-87
Author(s):  
V. V. Lin ◽  
◽  
A. I. Turkin ◽  
A. A. Chepurov ◽  
◽  
...  
Keyword(s):  
High Pressure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Total Content ◽  
Kimberlite Pipe ◽  
Distribution Coefficients ◽  
Water Soluble ◽  
Refractory Oxide ◽  
Mineral Association ◽  
Initial Charge

Rare earth elements (REE) in garnet are of interest in various fields of modern geology. The geochemistry of REEs in magmatic minerals is widely used in determining the distribution coefficients of crystal/melt and crystal/fluid, modeling the processes of melting and crystallization of magmatic rocks, studying deep mantle processes, age estimates and other issues of petrogenesis. The aim of the present work was a synthesis of a peridotite mineral association including the garnet containing REE at high pressure and high temperature. The initial sample consisted mainly of natural serpentine collected from ophiolites of the Eastern Sayan (Russia). As is known, the extreme stage of the regressive metamorphism of peridotites is serpentinization. It is depleted in calcium, but can recrystallize at high PT conditions into a harzburgite paragenesis, and at the initial stage of the experiment the chemical composition of the sample was a model harzburgite depleted in calcium and chromium, as well as a fluid of predominantly aqueous composition. As a source of chromium, chromite grains of 1–2 mm in size from peridotite xenoliths of the Udachnaya kimberlite pipe (Yakutia) were used. REE were added to the initial charge in the form of water-soluble salts. The experiment at a pressure of 5 GPa and temperature 1300 was performed on a multi-anvil high-pressure apparatus of the “split sphere” type (BARS) designed and developed at the V.S. Sobolev Institute of Geology and Mineralogy SB RAS. A container based on refractory oxide ZrO2 was used as a highpressure medium. The pressure in the cell before sample heating was estimated using the reference substances Bi and PbSe. The temperature was measured by a platinum-platinum-rhodium thermocouple PtRh30-PtRh6. The quenched was performed by switching off the voltage in the heater circuit. The experiment products contain an association of olivine + garnet + orthopyroxene + newly formed spinel. The predominant phase was olivine of a forsterite composition. A low-Fe orthopyroxene (1.49 – 1.68 wt% FeO) was found in elongated grains uniformly distributed throughout the sample. The newly formed spinel shows the faceted grains. The chromium content in the spinel significantly exceeds that of the initially added to the initial charge, 61.63 and 54.04 wt% Cr2O3, respectively. The garnet is characterized by a purple color, and was identified in the sample volume between olivine grains in the form of individual faceted crystals or their clusters. The largest garnets reached 0.5 mm in size. The synthesized garnet was determined as a high-Cr low-Ca pyrope variety. The contents of Cr2O3 and CaO are 10.15-11.21 and 0.06-0.11 wt%, respectively. The total content of REE in the garnet identified by the microprobe analysis is relatively high reaching 5-7 wt%. As a result of the work a mineral association corresponding to the peridotite paragenesis was obtained, including the subcalcic Crrich pyrope containing rare earth elements in significant amounts. It was estimated that their content in garnet mainly depends on the size of the ionic radius and, accordingly, on the atomic weight. This is consistent with the known facts about the preferable position of heavy REEs into the garnet structure compared to the light REEs.

Ion-adsorption rare earth ores of China

2021 ◽  
pp. 63-68
Author(s):  
E. P. Bugrieva ◽  
A. V. Tarkhanov ◽  
Yu. M. Trubakov
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Layer Structure ◽  
Quantitative Estimation ◽  
Total Content ◽  
Lateritic Soil ◽  
Ion Adsorption ◽  
Material Constitution ◽  
Heavy Lanthanides ◽  
Weathered Layer

Geology and geochemistry of China’s ion-adsorption rare earth ores are discussed. The structure and material constitution of Lognan, Huashan, Guposhan and Heling deposits are compared. The weathered layer structure, as well as the distribution, differentiation and occurrence forms of rare earth elements (REE) in the weathered layer are described. The prospecting indicators and criteria of readily dissociated adsorbed REE ore are identified to find this type ores in the territory of Russia. The weathered layer enclosing ion-adsorption rare earth ore features specific differentiation of REE. General composition of such ores is governed by the composition of the primary rare earth mineralization in mother granites. If granites contain much yttrium and heavy lanthanides, then ion-adsorption rare earth ore contain also much yttrium and heavy lanthanides. Regarding differentiation of REE, yttrium and heavy lanthanides mainly concentrate in the middle, most clayey part of the weathered layer, while cerium accumulates in subsurface lateritic soil. The prime feature of ion-adsorption rare earth ore is the prevalence of readily dissociated REE, which can reach a quantity of 80% and more but not less than a half. The rest REE concentrate in relict rock-forming minerals and accessories. The quantitative estimation of adsorption form of REE is necessary for the geological and economic appraisal of a deposit. It is assumed that the quantity of readily soluble REE should be not less than 0.05–50% of the total content. Russia has many regions with such geotectonic environment. It is required to explore ion-adsorption rare earth ore occurrences in these regions.

The Fate of Rare Earth Elements in Post-Fire Soils in the Pocono Mountains, Pennsylvania (USA)

2021 ◽  
Author(s):  
Gregory Pope ◽  
Jennifer Callanan ◽  
Jason Darley ◽  
Michael Flood ◽  
Jeffrey Wear ◽  
...  
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Forest Fires ◽  
Soil Profile ◽  
Major Elements ◽  
Wood Ash ◽  
Parent Material ◽  
Biomass Ash ◽  
Pocono Mountains

<p>The wood ash contribution to soils represents a unique and important part of soil organic carbon following fires.  Wood ash imparts chemical and physical changes to the soil, evident in elements other than carbon.  Our case studies are from recent wildfires and experimental burns in mixed hardwood forests in the Pocono Mountains of Pennsylvania, USA.  In these studies, we identified increases in most of the major elements and some minor elements in soils following forest fires, analyzed with ICP-MS. Elements such as Mn, Mg, Na, Ca, Na, K, Cu, and Ba, derive from an infusion of biomass ash, with variable contribution depending on, for instance, tree species. In the case of Ba and Cu, their presence is distinctly different from any mineral parent material contribution to the soil, and therefore unique signatures of fire contribution. Signature post-fire elements persist in some cases over one year following the fire, and are found in both topsoil horizons and into illuvial soil horizons.</p><p>In the course of these investigations, we also found a curious depletion of all rare earth elements (REEs) and certain trace elements from the soil following forest fires, and in adjacent stream and wetland sediments. The post-fire difference in REE concentration was statistically significant (p < 0.10, N=51) in all but Eu and U, with light REEs La, Ce and Pr showing the most significant decreases. Among other trace elements, Sc (which behaves similarly to REEs), V, Cr, Ga, and Rb also exhibited statistically significant decreases (though other elements Cu and Sr increase along with the ash input). The reasons for the depletions are unclear. Other authors report that REE dynamics in soils are poorly understood, but may be associated with phosphates, carbonates, and silicates in the soil. These are relatively enriched via post-fire biomass ash, yet the associated REEs are missing. It is unlikely that the elements would have preferentially translocated through and below the soil profile. Erosion is ruled out, otherwise the ash-associated major and trace elements would also be depleted. Two possible causes for post-fire REE loss are 1) volatilization from the soil during the fire, and 2) rapid uptake by post-fire succession plants, notably ferns, which are known to bioaccumulate REEs. Further research is warranted, following the ongoing post-fire vegetation recovery, and the dynamics of REEs within the soil profile.       </p>

scholarly journals Rare-earth elements in Cu-Ni ores of the Norilsk region

2021 ◽  
Vol 11 (1) ◽  
pp. 76-89
Author(s):  
A.V. Grigoryeva ◽  
◽  
A.V. Volkov ◽  
K.Y. Murashov ◽  
◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Total Content ◽  
Negative Slope ◽  
Primitive Mantle ◽  
High Tech ◽  
Northwestern Part ◽  
Rare Elements ◽  
High Enrichment ◽  
Host Rocks

The deposits of the Norilsk region are confined to the marginal northwestern part of the Siberian platform and are associated with the manifestation of the Early Mesozoic trap volcanism. Sulfide mineralization is concentrated in the intrusive facies of the volcano-intrusive complex. Four main types of Cu-Ni ores are distinguished according to textural features: massive, vein-disseminated, brecciated, and disseminated. The main types of Cu-Ni ores differ significantly from each other in the chemical composition and content of rock- and ore-forming components. The enrichment ratios of ore trace elements in the Oktyabrskaya and Talnakhskaya vein-disseminated ore mainly reach hundreds (S, Pt, Au, Se,Te, Pb, As, Sn, Mo) and thousands (Ni, Cu, Ag, Pd) times. A rather high enrichment of all types of Bi, Re and Cd ores has been revealed, which are potentially industrially significant as high-tech metals, and can be promising for associated mining. The amount of rare-earth elements (REE) in ores is several times less than in the upper crust and more than in the primitive mantle. The concentration of rare earths in the main types of ores, with the exception of massive ones, exceeds the level of the chondrite standard, and REE fractionation is weak. The distribution spectra of chondrite-normalized REEs have a slight negative slope: the total content of light REEs is higher than that of heavy ones. The similarity of the geometry of the REE spectra of massive, vein-disseminated, brecciated and disseminated types of ores containing a significant admixture of host rocks indicates the inheritance of the REE composition in ores from the host rocks. In the disseminated ores of common taxite gabbro-dolerites, the Eu anomaly is present in the Kharaelakhsky (Oktyabrskoye Deposit) and Talnakhsky (Talnakhskoye Deposit) intrusions, it is positive, and in the Norilsk I Intrusive (in the same rocks), it is negative. Higher concentrations of REEs and significant fractionation of light and heavy rare elements are typical for host contact-metamorphic and metasomatic rocks with vein-disseminated (exocontact) ores. For olivine-free hornfels and skarns in brecciated ores, as well as for vein-disseminated ores, significant fractionation of light REEs with relatively heavy ones and a pronounced Eu minimum are characteristic. In massive ores, the distribution of REEs is determined by the composition of xenoliths.

scholarly journals Regularities of La distribution in humic psammozem profile of Transbaikalia and soil-root layer microzones of maize during the vegetation period

2014 ◽  
Vol 3 (2) ◽  
pp. 167-174
Author(s):  
Larisa Afanasyeva ◽  
Nina Kozhevnikova
Keyword(s):  
Rare Earth ◽  
Soil Profile ◽  
Maximum Concentration ◽  
Total Content ◽  
Vegetation Period ◽  
Selective Extraction ◽  
Water Soluble ◽  
Mobile Form ◽  
Field Approach ◽  
Mobile Forms

In Transbaikalia information about accumulation, distribution of rare earth elements (REEs) in soils, their transportation from soil to plants is very rare. The aim of this study was to assess the migration of lanthanum in a soil profile and soil-root layer microzones of maize during the vegetation period. The study is based on a field approach in non-polluted natural sites. Concentration of total content La and its mobile form (acid-soluble, exchangeable and water-soluble) in the soil and soil root layer of maize was determined using method of selective extraction Gobran and Glegg. Maximum concentration total La was founded in the upper part of the soil (0 to 15 cm depth). The content of the La mobile forms is 6.9-11.2% from the total amount. The distribution of the element mobile forms within the profile is relatively even. Results indicated that concentration La mobile forms changed in accordance with the phase of maize development. The higher concentration of mobile forms (17-120% from germination period) was founded in soil-root layer microzones in the blossom period. DOI: http://dx.doi.org/10.3126/ije.v3i2.10527 International Journal of the Environment Vol.3(2) 2014: 213-220

scholarly journals Content of rare earth elements in basalt aggregate from Winna Góra, Poland

2021 ◽  
pp. 315-326
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Mineral Composition ◽  
Rietveld Method ◽  
Total Content ◽  
Trace Element Content ◽  
Icp Ms ◽  
A Minor ◽  
Minor Content ◽  
Lower Silesia

Seek for new Rare Earth Elements (REE) sources encourage looking for easily available sources located in Europe. REE in evolved magmatic systems are predominantly associated with alkali environments. Therefore, it was decided to identify the content of REE in alkali igneous rocks of the Winna Góra basalt quarry located in Lower Silesia, Poland. In this study, a commercially available basalt aggregate from Winna Góra deposit located in the south-western part of Poland near Jawornik was examined for REE content. Mineral content and chemical composition were examined with a light microscope, XRD and XRF, whereas trace element content was measured with the ICP-MS technique. A new method of sample preparation for the purpose of REE identification in basalt aggregate based on pressure microwave mineralisation was developed. Mineral composition and TAS diagram classify aggregate as tephrite. The mineral composition of samples reflects typical mafic and ultramafic rocks. Quantitative mineralogical analysis by the Rietveld method showed that the main minerals are anorthite (46.7%) and augite (37.4%) with a minor content of forsterite (7.5%), nepheline (7.4%) and apatite below 1%. The total content of REE does not exceed 132 ppm. Chondrite normalised curves show the highest concentration of La and Pr. In the case of HREE, the majority of elements (Eu, Tb, Dy, Ho, Er, Yb) concentrations were below 1 ppm, a Tm and Lu were not detected. The low enrichment in HREE was also reflected in La/Gd ratios. Obtained results are comparable to the REE contents in the western part of the Cenozoic European Volcanic Province.

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