Variation of the distribution coefficients of rare earth elements in modern coral-lattices: species and site dependencies

2004 ◽  
Vol 68 (10) ◽  
pp. 2265-2273 ◽  
Author(s):  
T Akagi ◽  
Y Hashimoto ◽  
Fu F-F ◽  
H Tsuno ◽  
H Tao ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Distribution Coefficients

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.

scholarly journals Reduction in Technogenic Burden on the Environment by Flotation Recovery of Rare Earth Elements from Diluted Industrial Solutions

2021 ◽  
Vol 11 (16) ◽  
pp. 7452
Author(s):  
Natalia Dzhevaga ◽  
Olga Lobacheva
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Building Materials ◽  
Sodium Dodecyl ◽  
Construction Materials ◽  
Distribution Coefficients ◽  
Industrial Plant ◽  
Flotation Recovery ◽  
Industrial Solutions ◽  
The Impact

Unconventional raw materials are widely used in construction sectors; for example, phosphate sludge with the addition of rare earth elements (REE) when producing brick. The second example is nanostructured composite systems of REE when forming covers of construction materials. This article studies flotation recovery of REE, the impact of chlorides on distribution coefficient, and pH recovery. The study proves the possibility of effective REE recovery from diluted industrial solutions and, consequently, the significant decrease in their content in wastewaters, which allows the improvement of the ecological situation in the industrial plant areas. In this article, optimum flotation conditions of REE by flotation are given by the example of yttrium (III) and lanthanum (III) salts. The processes of rare earth elements recovery by sodium dodecyl sulphate as salts of various compositions were studied. Distribution coefficients for target components as a function of aqueous phase pH and the presence of foreign anions were determined. The analysis of dependences obtained by the comparison of rare earth elements’ chloro and hydroxo complexes stability constants was made. The products of REE obtained by the authors will be used when manufacturing various kinds of building materials: carbon cement, baked brick, light construction materials, and high-tensile steel.

scholarly journals Studies of the Sorption of Rare Earth Element Nitrate Complexes in the C2H5OH–HNO3 System on the Strongly Basic Anion Exchanger Wofatit SBW

1998 ◽  
Vol 16 (6) ◽  
pp. 487-492 ◽  
Author(s):  
Z. Hubicki ◽  
M. Olszak
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earth Element ◽  
Anion Exchanger ◽  
Earth Element ◽  
Breakthrough Curves ◽  
Distribution Coefficients ◽  
Basic Anion Exchanger ◽  
Basic Anion ◽  
Nitrate Complexes

The possibility of removing rare earth element(III) nitrate complexes selectively from the 90% v/v C2H5OH–10% v/v 7 M HNO3 system on Wofatit SBW × 6% DVB was examined. Weight and bed distribution coefficients were determined from the breakthrough curves of individual rare earth elements. Based on these, the affinity series of rare earth element nitrate complexes in this system was determined. The effect of crosslinking the anion exchanger Wofatit SBW × 2%, 4%, 6%, 8%, 12% and 16% DVB on the sorption of rare earth element nitrate complexes in the 90% v/v C2H5OH–10% v/v 7 M HNO3 system was also investigated.

Flame spectra of the rare-earth elements*

1962 ◽  
Vol 18 (4) ◽  
pp. 1127-1153
Author(s):  
V FASSEL ◽  
R CURRY ◽  
R KNISELEY
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
The Rare Earth
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