Rare Earth Phosphates in the Kerch Caviar Ironstones

2021 ◽  
Author(s):  
A.V. Nekipelova ◽  
E.V. Sokol ◽  
S.N. Kokh ◽  
P.V. Khvorov
Keyword(s):  
Solid Solution ◽  
Trace Elements ◽  
Rare Earth ◽  
Major And Trace Elements ◽  
Environmental Risks ◽  
Solid Solution Series ◽  
Unconventional Resources ◽  
Total Budget ◽  
Low Costs ◽  
Clay Type

Abstract —The mineralogy and contents of major and trace elements (including REE+Y) in bulk samples and separate size fractions of caviar-like ironstones from the Kamysh-Burun deposit (Kerch iron province) are studied to estimate the contributions of different REE+Y species to the total budget. The analyzed ore samples contain MREE adsorbed on Fe3+-(oxy)hydroxides, as well as LREE authigenic phosphates. The predominant rhabdophane-type (Ce(PO4)⋅nH2O) phases are enriched in La, Pr, Nd, and Ca, depleted in Ce, and free from Th. The REE carriers belong to solid solution series of two main types: LREE(PO4)·nH2O – (Ca,Ce,Th)(PO4)·H2O (rhabdophane-like phase and brockite) or LREE(PO4)·nH2O – (Ca,U,Fe3+)((PO4),(SO4))·2H2O (rhabdophane-like phase and tristramite). REE phosphates occur most often in the ≤ 0.25 mm fractions of ironstones, where average and maximum ΣREE contents (Xav = 606–1954 ppm; Xmax = 769–3011 ppm) are comparable with the respective amounts in the Chinese industrial clay-type REE deposits. The Kerch ores are commercially attractive unconventional resources of highly demanded Pr and Nd: they can be extracted at relatively low costs, due to high Pr/Ce and Nd/Ce ratios, while low Th and U reduce the environmental risks from stockpiled wastes.

scholarly journals Identifying Correlation of Coal Seams in the Tien Hai Area, Northern Vietnam by Using Multivariate Statistic Methods

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
The Hung KHUONG ◽  
Phuong NGUYEN ◽  
Thi Cuc NGUYEN ◽  
Nhu Sang PHAM ◽  
Danh Tuyen NGUYEN
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Coal Seam ◽  
Rare Earth Elements ◽  
Major And Trace Elements ◽  
Coal Seams ◽  
Multivariate Statistic ◽  
Northern Vietnam ◽  
Coal Deposits ◽  
Indicator Elements

In northern Vietnam, the Tien Hai area is considered a high potential area of coal deposits. Twohundred fifty-six geochemical coal samples of 13 cores in the Tien Hai area investigate coal seams andcoal deposits to identify the correlation of coal seams. According to the statistical method and clusteranalysis of geochemical samples, the results indicate that the Mg, V, As, Ca, Zn, Cr, Co, K, Na, Sr, Fe,Ge, Re, U, Mo, Th, and Ga elements are good indicator elements of the major and trace elements in coal.Most of them comply with the normal or lognormal distribution rules. Besides, the Yb, Sc, Ho, Er, Tm,Lu, Y, Tb, Pr, Dy, and Sm elements are also good indicator elements for rare earth elements in the region.Therefore, the selected elements are used to identify the correlation of the coal seams in the Tien Hai area.Based on the similarity degree between studied objects, the results of grouping boreholes in coal seamsshow that the correlation of coal seam TV2-11 is suitable and acceptable, the coal seams TV3-6a, TV3-6b, and TV3-6c can be grouped into the coal seam TV3-6. These results present that the models can helpstudy geochemical coal samples and identify the correlation of the coal seams in the Tien Hai area.Additionally, the statistical analysis shows a remarkable degree to determine the correlation of the coalseams. Geochemical coal data can help to evaluate the indicator elements of the major, trace elements,and rare earth elements in coal seams and coal rashing of adjoining and pillar rocks in the Tien Hai area,northern Vietnam.

scholarly journals Distribution of Arsenic Inclusions in Rare Earth Steel Ingots

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 146 ◽  
Author(s):  
Hongpo Wang ◽  
Silu Jiang ◽  
Peng Yu ◽  
Bin Bai ◽  
Lifeng Sun ◽  
...  
Keyword(s):  
Solid Solution ◽  
Trace Elements ◽  
Rare Earth ◽  
Single Phase ◽  
Arsenic Concentration ◽  
Distribution Characteristic ◽  
Dramatic Decrease ◽  
Full Profile ◽  
Steel Ingots ◽  
Peeling Off

Trace element arsenic is detrimental to the quality and properties of steel products. We used lanthanum to modify the distribution of arsenic by the formation of arsenic rare earth inclusions and investigated all inclusions on the full profile of the ingots prepared in the laboratory. The results show that the addition of lanthanum has dramatically influenced the distribution of arsenic in the ingots by the formation of arsenic inclusions. The arsenic inclusions turn out to be mainly the cluster-shaped La-S-As, as well as its composite inclusions combined with LaS and La-As. La-S-As can be considered a solid solution of LaS and LaAs. They distribute mainly at the top surface of the ingots within 3 mm, at the side and bottom surfaces within 1.5 mm, leading to a dramatic decrease of arsenic concentration at the inner part of the ingots. This distribution characteristic of La-S-As can be used to manufacture steel ingots with very low arsenic concentration by peeling off these (La-S-As)-containing layers. On the contrary, the distribution of composite inclusions (La-S-As)-(La-As) and single-phase La-As, is uniform. Except for the reaction with arsenic, lanthanum can also react with phosphorous and antimony to modify the existing state of these trace elements.

scholarly journals Geochemistry of garnet megacrysts from the Mir kimberlite pipe (Yakutia) and the nature of prothokimberlite melt

2019 ◽  
Vol 486 (5) ◽  
pp. 583-587
Author(s):  
A. M. Agashev
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Negative Correlation ◽  
Kimberlite Pipe ◽  
Major And Trace Elements ◽  
Major Elements ◽  
Incompatible Elements ◽  
Composition Study ◽  
Melt Composition

The paper presents the results of major and trace elements composition study of garnet megacrysts from Mir kimberlite pipe. On the major elements composition those garnets classified as low Cr and high Ti pyropes. Concentrations of TiO2 show a negative correlation with MgO и Cr2O3 contents in megacrysts composition. Fractional crystallization modeling indicates that the most appropriate melt to reproduce the garnet trace elements signatures is the melt of picritic composition. Composition of garnets crystallized from kimberlite melt do not correspond to observed natural garnets composition. Kimberlites contain less of Ti, Zr, Y and heavy REE (rare earth elements) but more of very incompatible elements such as light REE, Th, U, Nb, Ba then the model melt composition that necessary for garnet crystallization.

scholarly journals The distribution of the trace element contents in lignite and ash from Drama lignite deposit, using multivariate statistical analysis

2001 ◽  
Vol 34 (3) ◽  
pp. 1255
Author(s):  
S. PANILAS ◽  
G. HATZIYANNIS
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Statistical Analysis ◽  
Rare Earth Elements ◽  
Multivariate Statistical Analysis ◽  
Major And Trace Elements ◽  
Major Elements ◽  
Geochemical Data ◽  
Multivariate Statistical ◽  
Inorganic Matter

Multivariate statistical analysis was used on existing geochemical data of the Drama lignite deposit, eastern Macedonia, Greece. Factor analysis with varimax rotation technique was applied to study the distribution of major, trace and rare earth elements in the lignite and 850°C lignitic ash, to find a small set of factors that could explain most of the geochemical variability. The study showed that major elements AI, Na, Κ, contained in the lignite samples, presented high correlation with most of the trace and rare earth elements. In 850°C lignitic ashes major and trace elements present different redistribution. Only Al remained correlated with the trace elements Co, Cr, Rb, Ta, Th, Ti, Sc and rare earths related with inorganic matter in the lignite beds. Trace elements Fe, Mo, U, V, W, and Lu were associated with organic matter of lignite and had also been affected by the depositional environment.

X-ray investigations of solid solutions of monocalcium aluminate and monostrontium aluminate important phases in cement and phosphorescence materials

2014 ◽  
Vol 29 (2) ◽  
pp. 141-146 ◽  
Author(s):  
H. Pöllmann ◽  
R. Kaden
Keyword(s):  
Solid Solution ◽  
Rare Earth ◽  
Solid Solutions ◽  
Calcium Aluminate ◽  
Solid Solution Series ◽  
Strontium Aluminate ◽  
X Ray ◽  
Hydration Behaviour ◽  
Orthorhombic Modification ◽  
High Temperature Form

Calcium monoaluminate is the main phase in calcium aluminate cements and participates in the hydration, forming calcium aluminate hydrates. The amount of incorporation of foreign ions influences the hydration behaviour. Strontium aluminate is an important phase in producing phosphorescent materials when doped with rare-earth elements (REE) such as Eu, Dy, and La. These monoaluminates occur in different forms. Monocalcium aluminate forms a monoclinic and an orthorhombic modification, whereas monostrontium aluminate forms a monoclinic low-temperature and a hexagonal high-temperature form. Monoclinic calcium monoaluminate and monoclinic strontium aluminate form a partial solid-solution series. The hydration behaviour of different solid solutions was also investigated using calorimetry. The newly formed strontium aluminate hydrates could be identified while similar strontium aluminate hydrates are formed. Solid solutions of strontium- and calcium-aluminate hydrates will be investigated.

Levels of major and trace elements, including rare earth elements, and 238U in Croatian tap waters

2014 ◽  
Vol 22 (9) ◽  
pp. 6789-6799 ◽  
Author(s):  
Željka Fiket ◽  
Martina Rožmarić ◽  
Matea Krmpotić ◽  
Ljudmila Benedik
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Major And Trace Elements
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