Mineralogical, chemical composition and distribution of rare earth elements in clay-rich sediments from Southeastern Nigeria

2015 ◽  
Vol 102 ◽  
pp. 50-60 ◽  
Author(s):  
A.N. Odoma ◽  
N.G. Obaje ◽  
J.I. Omada ◽  
S.O. Idakwo ◽  
J. Erbacher
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Southeastern Nigeria

scholarly journals Modification of Non-Metallic Inclusions by Rare-Earth Elements in Microalloyed Steels

2012 ◽  
Vol 12 (2) ◽  
pp. 129-134 ◽  
Author(s):  
M. Opiela ◽  
A. Grajcar
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Mechanical Treatment ◽  
Induction Furnace ◽  
Microalloyed Steels ◽  
Metallurgical Process ◽  
Metallic Inclusions ◽  
Mean Size ◽  
Thermo Mechanical Treatment

Modification of Non-Metallic Inclusions by Rare-Earth Elements in Microalloyed Steels 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 thermo-mechanical 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 μm2. The chemical composition and morphology of non-metallic inclusions was modified by Ce, La and Nd, what results a small deformability of non-metallic inclusions during hot-working.

scholarly journals Geochemical Characterization and Presence of Rare Earth Elements in the Recent Depositions at the Islands of the Eastern Bay of Bengal, Bangladesh

2020 ◽  
Vol 11 (1) ◽  
pp. 40-47
Author(s):  
Farah Deeba ◽  
Syed Hafizur Rahman ◽  
Mohammad Zafrul Kabir ◽  
Mohammad Rajib
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Bay Of Bengal ◽  
Heavy Mineral ◽  
Heavy Minerals ◽  
Mineral Concentration ◽  
Near Surface ◽  
Geochemical Characterization ◽  
X Ray

This study presents geochemical characterization, as well as, quantification of rare earth elements in the recent beach deposition at the two major islands of the eastern Bay of Bengal-Kutubdia and Moheshkhali. Placer sand samples from near surface depositions were analyzed by heavy mineral separation, mineralogical identification, chemical composition and elemental mapping. X-ray diffraction (XRD), X-ray fluorescence (XRF), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) were used to obtain these results. The heavy mineral concentration in different raw sand samples resulted by heavy liquid separation technique revealed that the average abundance of heavy minerals is 69.67% in Kutubdia island and 9.32% in Moheshkhali island, respectively. The X-ray patterns of Kutubdia and Moheshkhali sand samples show the presence of zircon, quartz, hematite, magnetite, ilmenite, chromite, kyanite, anatase, rutile and garnet. Chemical composition of heavy mineral sands from Kutubdia and Moheshkhali islands were analyzed using X-ray fluorescence method (XRF) for major oxides and trace elements. The concentration is of Na2O, MgO, Al2O3, SiO2, P, K2O, CaO, TiO2, V2O5, Cr2O3, MnO, Fe2O3, CoO, ZnO, SrO, Y2O3 ZrO2, Nb2O5, MoO3, HfO2, WO3, ThO2, U3O8, CeO2, Nd2O and Er2O3 were determined. A significant amount of various rare earth elements (REEs) in the elemental composition of few samples was also identified. The study is expected to be useful in the baseline and environmental aspects of both the islands.

Spatial distribution of the sediments in the Gangkou River catchment: Evidence from chemical composition, rare earth elements, and lead isotopes

2021 ◽  
Author(s):  
Hung-Chun Chao
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Lead Isotopes ◽  
Sediment Geochemistry ◽  
Beach Sediment ◽  
River Catchment ◽  
Core Samples ◽  
Beach Sediments ◽  
High Terrace

<p>    Sediment geochemistry has been widely used to indentify the source of the sediments delivered from catchment to the deposition basin.  In this study, bed load sediments, high terrace soils, beach sediments, and cores drilled at estuary were collected at the catchment of Gangkou River and its tributary, Linlu River, southern Taiwan.  All sediments were sieved by 0.062 μm sifter and exchangeable, carbonate, and iron oxide phases were leached and only residue silicate phase were digested.  Chemical composition, rare earth elements (REEs), and lead isotopes were measured.  The results show that two major catchments, Linlu River and Gangkou River, as well as high terrace soil and beach sediments can be successfully classified by chemical composition and lead isotopes.  However, REEs show signature of upper continental crust and no differences among all the samples, possibly due to the same source of high REEs minerals.  The characteristic of chemical composition and lead isotopes are different between two catchments and the estuary sediments as well as beach sediments near the estuary imply mixing behavior between two catchments.  The upper most of the estuary core samples, presented as modern sediment, have similar chemical composition and lead isotopes compared with the mainstream.  However, the beach sediment on the top of the dune and the lower part of the core samples, which are elder than 7 ka, have distinct chemical and isotopic characteristics, indicating different sediment sources.  In, summary, chemical composition and the lead isotopes are robust tracers for the leached fine sediments in Gangkou River catchment but REEs are not.  The results of estuary core indicate that the sediment source of the estuary before 7 ka is different from the present.</p>

scholarly journals SOIL GEOCHEMISTRY ADJACENT TO CARBONATITES FROM CAÇAPAVA DO SUL, RS, BY FLUORESCENCE OF X-RAYS BY DISPERSIVE ENERGY

2020 ◽  
Vol 39 (04) ◽  
pp. 953-963
Author(s):  
Cristiane Heredia GOMES ◽  
Plínio BRIOSCHI NETO ◽  
Guilherme Alves MARQUES ◽  
Guilherme Pazinato DIAS ◽  
Diogo Gabriel SPERANDIO
Keyword(s):  
Rare Earth ◽  
Calcium Carbonate ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
X Rays ◽  
Soil Geochemistry ◽  
High Chance

Currently, carbonatites are being severally studied in a prospective matter due to their high chance of containing calcium carbonate, magnesium and iron. They are also considered extremely rich in phosphate and minerals rich in Rare Earth Elements (ETR). In this context, the municipality of Caçapava do Sul has two occurrences of carbonatites: Picada de Tocos and Passo Feio. In order to enrich knowledge and assist in carbonate prospecting, this work aimed to characterize the soil geochemistry at the occurrences of the carbonatites in Caçapava do Sul. The data obtained revealed that there is an anomalous presence of Ca, Mg, Fe, Ti, P, Mn, Co, Th and Ce elements. This anomaly is directly linked to the presence of carbonatites in the region and their chemical composition.

scholarly journals Zr-Rich Eudialyte from the Lovozero Peralkaline Massif, Kola Peninsula, Russia

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 982
Author(s):  
Taras L. Panikorovskii ◽  
Julia A. Mikhailova ◽  
Yakov A. Pakhomovsky ◽  
Ayya V. Bazai ◽  
Sergey M. Aksenov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Kola Peninsula ◽  
Marginal Zone ◽  
X Ray Diffraction ◽  
Eudialyte Group ◽  
X Ray ◽  
Marginal Zones

The Lovozero peralkaline massif (Kola Peninsula, Russia) has several deposits of Zr, Nb, Ta and rare earth elements (REE) associated with eudialyte-group minerals (EGM). Eudialyte from the Alluaiv Mt. often forms zonal grains with central parts enriched in Zr (more than 3 apfu) and marginal zones enriched in REEs. The detailed study of the chemical composition (294 microprobe analyses) of EGMs from the drill cores of the Mt. Alluaiv-Mt. Kedykvyrpakhk deposits reveal more than 70% Zr-enriched samples. Single-crystal X-ray diffraction (XRD) was performed separately for the Zr-rich (4.17 Zr apfu) core and the REE-rich (0.54 REE apfu) marginal zone. It was found that extra Zr incorporates into the octahedral M1A site, where it replaces Ca, leading to the symmetry lowering from R3¯m to R32. We demonstrated that the incorporation of extra Zr into EGMs makes the calculation of the eudialyte formula on the basis of Si + Al + Zr + Ti + Hf + Nb + Ta + W = 29 apfu inappropriate.

scholarly journals Petrographic and geochemical characteristics of the Nui Chua pegmatoid mafic-ultramafic series, Northern Vietnam: Significance in petrogenesis and Fe-Ti-V metallogenesis

2020 ◽  
Vol 43 (1) ◽  
pp. 80-94
Author(s):  
Pham Thi Dung ◽  
Tran Tuan Anh ◽  
Tran Quoc Hung ◽  
Tran Trong Hoa ◽  
R. A. Shelepaev ◽  
...  
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Fractional Crystallization ◽  
Geochemical Characteristics ◽  
Ultramafic Rocks ◽  
Magma Source ◽  
Distribution Characteristics ◽  
Magmatic Origin ◽  
Northern Vietnam

The pegmatoid intrusions of the Nui Chua complex are one of the important mafic-ultramafic intrusive series associated with Fe-Ti-V ores in northern Vietnam. These intrusions consist of plagiowebsterite, clinopyroxenite, melanogabbronorite, mesogabbro, gabbronorite, and leucogabbronorite. The Fe-Ti oxide ores being massive or disseminated appear layered or veined in pegmatoid rocks. The geochemical characteristics of pegmatoid rocks are rich in Fe, Ti, V and poor Mg; their HREE are higher than LREE, with [La/Yb]N of 0.49 to 0.91 (average: 0.67), showing negative anomalies at Nb, Ta, Th, U, Sr, Zr and positive anomalies at Cs, Ti, and K. The chemical composition and distribution characteristics of trace and rare earth elements of mafic and ultramafic rocks show that they share the same magma source. Having the same geochemical tendency of intrusive formations, Fe-Ti oxide ores are magmatic origin associated with intrusive pegmatoid rocks. The pegmatoid rocks of the Nui Chua complex and Fe-Ti oxide ores are formed as a product of the fractional crystallization of Fe-Ti-rich residual melts after crystallization of the layered rocks.

scholarly journals Less-common and rare earth elements of the Pechenga region ores

2021 ◽  
Vol 11 (3) ◽  
pp. 406-421
Author(s):  
K.V. Lobanov ◽  
◽  
A.V. Grigoryeva ◽  
A.V. Volkov ◽  
M.V. Chicherov ◽  
...  
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
The Arctic ◽  
High Tech ◽  
Wide Range ◽  
Ore Minerals ◽  
High Enrichment ◽  
Host Rocks

The article presents the investigations in the Pechenga ore region — one of the largest industrial regions in the Arctic zone of Russia, located on the territory of the Murmansk area. The researchers obtained new data on the chemical composition of the main ore minerals, the content of trace elements, including rare earths (REE), in the ores of the Pilguyarvi and Vostok deposits and late polymetallic veins of the Pechenga region. They found that the main textural types of ores (massive, veined and disseminated) differ significantly in chemical composition and content of rock and ore-forming components. They also revealed the enrichment of ores with a wide range of trace elements. In comparison with the upper crust, the Pechenga ores are clearly enriched with chalcophilic and siderophilic trace elements. The enrichment coefficients of ore elements reach mainly tens (Cr, Au, Cd) hundreds (Ag, Se, Re, Pt) and thousands (Ni, Cu, Ir) times. The distribution of trace elements in various types of Cu-Ni ores has a great similarity, which indicates their geochemical affinity and synchronous participation in ore formation. The geochemical features are in good agreement with the mineral composition of the ores. The concentration of rare earth elements in the main types of ores, with the exception of massive ores and late polymetallic veins, exceeds the level of the chondrite standard and the REE fractionation is weak. The composition of the REE in ores came by from the host rocks. The research has established the high enrichment of all types of Re, Bi and Cd ores, which are potentially industrially significant as high-tech metals and are of considerable interest for associated mining.

scholarly journals Rare Earth Elements (REE) in Claystones with Selected Coal Seams of the Mudstone and Sandstone Series of the Upper Silesian Coal Basin

2016 ◽  
Vol 32 (3) ◽  
pp. 39-66
Author(s):  
Magdalena Kokowska-Pawłowska
Keyword(s):  
Rare Earth ◽  
Chemical Composition ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Correlation Coefficients ◽  
Coal Seams ◽  
Coal Basin ◽  
High Positive Correlation ◽  
The North ◽  
Ignition Loss

AbstractIn this paper results of investigation on the variability of REE contents in the clayey rocks accompanying selected coal seams from Zaleskie and Ruda beds of western part of Upper Silesia Coal Basin (USCB) have been presented. 75 samples have been analysed from the claystones coexisting with coal seams 405 and 408 collected from the USCB area. Contents of selected REE have been assessed with a use of the Instrumental Neutron Activation Analysis (INAA). In regard to the constraints of this method following elements underwent evaluation: scandium (Sc), lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm), Europium (Eu), terbium (Tb), ytterbium (Yb), and lutetium (Lu). Contents of yttrium (Y) was determined with a use of the Fusion-Inductively-Coupled Plasma (FUSICP) method.In all featured groups of claystone (claystone, sandy claystone and siderite claystone) the highest, although diverse content of SiO2, Al2O3, Fe2O3and K2O were observed. Whatever the petrographic character of the claystone rocks, among the analyzed rare earth elements, the highest participation of Ce, La, Y, Nd and Sc were found. Other analyzed REE showed significantly lower content. Some regional diversity of REE in the area of study was also observed. In the south-western part of the USCB, higher participation showed: Y, Sm and Nd, while in the north-western part: Sc. To determine the dependence between content of rare earth elements and chemical composition, the correlation-coefficients were calculated. In the calculations ratio SiO2/Al2O3and increased content of P2O5, ignition loss and Fe2O3were taken into account. Most of the elements analyzed in group of rocks distinguished by increased content of P2O5and ignition loss, showed high positive correlation with chemical composition. In almost all groups of rocks negative correlation with MnO, loss on ignition and sometimes with CaO was found. Rocks represented by siderite claystone are characterized by the highest values of correlation coefficients of rare earth elements with Fe2O3.

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