Preconcentration and elimination of matrix effects in XRF determinations of rare earth elements by preparing a thin film through chemofiltration

2001 ◽  
Vol 16 (3) ◽  
pp. 275-278 ◽  
Author(s):  
Irma E. De Vito ◽  
Roberto A. Olsina ◽  
Adriana N. Masi
Keyword(s):  
Thin Film ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Matrix Effects

REE and TRU Incorporation into Monazite Structure Ceramics

2004 ◽  
Vol 824 ◽  
Author(s):  
S. I. Rovnyi ◽  
G. M. Medvedev ◽  
A. S. Aloy ◽  
T. I. Koltsova ◽  
S. E. Samoylov
Keyword(s):  
Thin Film ◽  
Solid Solution ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Chemical Durability ◽  
Spent Fuel ◽  
Waste Streams ◽  
Oxalate Precipitation ◽  
Spent Fuel Reprocessing ◽  
Fuel Reprocessing

AbstractOne of the high levels of actinide, and in particular Cm, waste streams at the Russian radiochemical Production Association (PA) Mayak was generated during spent fuel reprocessing. Using oxalate precipitation, the rare earth elements (REE) and transuranic elements (TRU) settled out in the form of oxalate residues. Due to in high REE contents in this residue, the mineral-like matrix based on (REE)PO4 solid solution, with monlclinic monazite structure have been proposed to use as a suitable ceramics form for final actinide immobilization. For this purpose the synthetic REE oxalates were first transformed into REE orthophosphates in a thin-film evaporator (TFE). Then the (REE)PO4 powder was compacted both by either hot uniaxial pressing (HUP) or cold uniaxial pressing followed by sintering (CUP). This ceramic with the monazite structure has a high density and exhibits chemical durability by leaching.

Rare-Earth Analysis by a Rotating Platform, Silver-Spark Technique

1968 ◽  
Vol 22 (5) ◽  
pp. 558-561
Author(s):  
Theodore R. Lyon
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Electrode Material ◽  
Matrix Effects ◽  
Small Samples ◽  
Good Sensitivity ◽  
Rotating Platform

A rotating platform, silver-spark technique has been adapted for analysis of rare-earth elements directly, either as solutions or after coprecipitation with a carrier. The platform sample electrode is compared with the rod sample electrode conventionally used, and silver is shown to provide some advantages over copper as an electrode material. Observations are reported on conditions pertaining to the preparation and excitation of samples. Three varied applications of the method are briefly described, and matrix effects are discussed. Platform electrodes are found to be more convenient and adaptable than conventional rods, and the sensitivity of the method is comparable to the copper-spark method for small samples. When larger samples are used, the sensitivity decreases; however, good sensitivity can be obtained by properly selecting conditions or equipment.

scholarly journals Detection of Rare Earth Elements in Minerals and Soils by Laser-Induced Breakdown Spectroscopy (LIBS) Using Interval PLS

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1379
Author(s):  
Nina Rethfeldt ◽  
Pia Brinkmann ◽  
Daniel Riebe ◽  
Toralf Beitz ◽  
Nicole Köllner ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Matrix Effects ◽  
Principal Component ◽  
Laser Induced Breakdown Spectroscopy ◽  
Regression Methods ◽  
Breakdown Spectroscopy ◽  
Field Samples ◽  
Laser Induced Breakdown

The numerous applications of rare earth elements (REE) has lead to a growing global demand and to the search for new REE deposits. One promising technique for exploration of these deposits is laser-induced breakdown spectroscopy (LIBS). Among a number of advantages of the technique is the possibility to perform on-site measurements without sample preparation. Since the exploration of a deposit is based on the analysis of various geological compartments of the surrounding area, REE-bearing rock and soil samples were analyzed in this work. The field samples are from three European REE deposits in Sweden and Norway. The focus is on the REE cerium, lanthanum, neodymium and yttrium. Two different approaches of data analysis were used for the evaluation. The first approach is univariate regression (UVR). While this approach was successful for the analysis of synthetic REE samples, the quantitative analysis of field samples from different sites was influenced by matrix effects. Principal component analysis (PCA) can be used to determine the origin of the samples from the three deposits. The second approach is based on multivariate regression methods, in particular interval PLS (iPLS) regression. In comparison to UVR, this method is better suited for the determination of REE contents in heterogeneous field samples.

A Combined Dilution and Line-Overlap Coefficient Solution for the Determination of Rare Earths in Monazite Concentrates

1981 ◽  
Vol 25 ◽  
pp. 133-137
Author(s):  
T. K. Smith
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Atomic Number ◽  
Rare Earths ◽  
Microprobe Analysis ◽  
Matrix Effects ◽  
Emission Spectra ◽  
X Ray ◽  
Overlap Coefficient

The rare earth elements (REE) together give guite complex X-ray emission spectra with a considerable number of overlaps at analytical energies by lines of other REE with lower atomic numbers. Where the concentration of REE is high, as in lanthanide minerals, this Interference is more difficult to rectify. Smith and Gold resolved a similar problem with lower atomic number elements in energy dispersive microprobe analysis by establishing a series of overlap coefficients. They asserted that accurate corrections were necessary because of the relatively poor overall resolution of the instrument and that these should not be limited to the major coincidences. Some of the smaller values had probably been ignored because they were considered statistically Insignificant. The mathematical matrix of Smith and Gold covered 22 elements from fluorine to barium, with intensity coefficients (other than intraelement) quoted from 0.01% to 282.1% and with ZAF corrections necessary in cases of K to L conversion. The overlap coefficients were also adjusted for matrix effects.

scholarly journals Energy converting layers for thin-film flexible photovoltaic structures

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 820-825 ◽  
Author(s):  
Katarzyna Znajdek ◽  
Natalia Szczecińska ◽  
Maciej Sibiński ◽  
Przemysław Czarnecki ◽  
Gabriela Wiosna-Sałyga ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Luminescent Properties ◽  
High Energy ◽  
Visible Range ◽  
Active Particles ◽  
Light Capture ◽  
Energy Converting

Abstract The paper presents research focused on the efficiency improvement of inorganic flexible thin-film solar cells, using energy converting layers. The light capture enhancement was achieved through the introduction of layers based on rare-earth elements, as top coatings on the amorphous silicon photovoltaic structures. Such luminescent layers are converting high-energy photons into low-energy ones, which are more efficient in photovoltaic conversion of the investigated solar cells. Towards this goal, powders consisting rare-earth elements were applied as active particles in polymer layer. For practical experiments, the screen-printing method, as a cheap, reliable and industrially-ready technology was used for layers deposition. For the experiments two compositions were selected: Sr4Al14O25: Eu,Dy (BGL-300M) and SrAl2O4: Eu,Dy (G-300M). These materials are characterized by excellent thermal and optical stability and interesting luminescent properties (they absorb ultraviolet and emit in the visible range). For the verification of investigated materials and methods, various compositions of powders and proportions were tested and analyzed.

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