Determination of light rare earth elements in apatite by x-ray fluorescence spectrometry after anion exchange extraction

Roelandts, Iwan

doi:10.1021/ac00227a023

Cited by 43 publications

(8 citation statements)

References 53 publications

(48 reference statements)

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“…The proposed method using Raman instrument is validated using some alternative modern analytical technique. The content of the REEs in the potential mineral sample should be determined either by: inductively coupled plasma mass spectroscopy (ICP-MS) [31][32][33][34][35][36][37][38], X-ray fluorescence (XRF) [39][40][41][42], neutron activation analysis (NAA) [43][44][45], ionchromatography (IC) [46][47][48], particle induced X-ray emission (PIXE) [49,50], scanningelectron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) [51] or synchrotron radiation [52] because the concentrations of REEs needed for the experiment are often below the limit of detection of conventional analytical techniques. In this work, a k 0 -method of instrumental neutron activation analysis (k 0 -INAA) was applied and the results for the REEs in the studied almandine and spessartine samples are given in Table 1 and Figure 3.…”

Section: Resultsmentioning

confidence: 99%

Simple and efficient method for detection of traces of rare earth elements in minerals by raman spectroscopy instrumentation

Makreski

Jovanovski

Runčevski

et al. 2011

Maced. J. Chem. Chem. Eng.

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As an effort to increase the knowledge about the abundance, distribution and geochemical behaviorof the rare earth elements (REEs), a simple and effective Raman spectroscopic method for detection of REEsin minerals is proposed. The proposed method based on Raman spectroscopy provides a lower detectionlimit for REEs compared to the modern analytical techniques. It could be practiced even in laboratoriesequipped only with FT-Raman instrumentation. This simple, inexpensive, rapid and straightforward Ramanmethod for REEs detection in minerals is a convenient experiment for undergraduate and postgraduatelaboratory courses.

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Section: Resultsmentioning

confidence: 99%

Simple and efficient method for detection of traces of rare earth elements in minerals by raman spectroscopy instrumentation

Makreski

Jovanovski

Runčevski

et al. 2011

Maced. J. Chem. Chem. Eng.

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“…The Ca1 atoms locate in the center of six phospho-tetrahedrons at upper and lower layers, and collected with nine O atoms in the vertices of six phospho-tetrahedrons. This special structure leads to a quite large channel parallel to the c-axis [12]. The two F atoms located in the channel form a coordination octahedron with the six Ca2 atoms of the upper and lower layers.…”

Section: Computational Models and Methodsmentioning

confidence: 99%

“…For example, for the Zhijin Xinhua rare earth phosphate deposits in western China (the largest rare earth resources reserve of phosphate rock [10]), the average grade of rare earth oxide (REO) is 0.05% to 0.13%, and La, Ce, Nd and Y account for 81.20% of the total REOs [11]. Test data [12,13] showed that REEs replace calcium mainly in the form of isomorphism in the phosphate rock (mainly fluorapatite or carbonate-fluorapatite). Although the apatite and dolomite or calcite contain the same element Ca in crystals, the REEs can be only displaced into the apatite lattice rather than the dolomite or calcite, and there is no relevant explanation for that.…”

Section: Introductionmentioning

confidence: 99%

“…Research on occupancy and spectral behavior of REEs in apatite structures has been quite active [14][15][16][17][18]. According to the results of structure determination, light REEs mainly occupied the smaller Ca2 site [12,19]. According to the results of calculated valence parameters based on bond strength and bond distance [20], fluorapatite is insufficient at the Ca2 site, but excessive at the Ca1 site, so REE 3+ tends to occupy the Ca2 site to compensate for the insufficiency of bond valence.…”

Section: Introductionmentioning

confidence: 99%

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A Theoretical Study on the Electronic Structure and Floatability of Rare Earth Elements (La, Ce, Nd and Y) Bearing Fluorapatite

et al. 2019

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Calcium atoms are often replaced by rare earth elements (REEs) in the lattice of fluorapatite (Ca10F2(PO4)6), making the phosphate ore an important potential rare earth resource. In this paper, the electronic properties of REEs (La, Ce, Nd and Y) bearing fluorapatite crystals have been investigated by density functional theory. Results of calculation indicated that the existence of REEs increased the cell parameters of fluorapatite in varying degrees. The REEs substitution made the Fermi level of fluorapatite to move to higher energy levels, making it easier to accept electrons. Except for Y, all the other REEs (La, Ce and Nd) showed that the electronic state mainly exists in the valence band. The Fermi level of REEs were mainly contributed by La5d, Ce4f, Nd4f and Y4d, respectively. The Mulliken values of REE–F and REE–O bonds in REEs-bearing fluorapatites were larger than those of Ca–F and Ca–O bonds in the perfect crystal, and the values of Y–F and Y–O bonds were the largest. The results of interaction between fluorapatite and oleic acid by frontier molecular orbital analysis suggested that the substitution of REEs can improve the reactivity of fluorapatite with oleic acid.

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“…In contrast, preconcentration procedures for solid materials, which involve the selec tive s e p a ra t i o n o f t ra c e e l e m e n t s a n d q u a n t i t a t i v e deposition on an ion-exchange thin support, need more complex manipulations. However, this method has been successfully applied in the collection and determination of Y, Sc and rare earth elements at µg g -1 levels in rock samples, (Eby 1972, Roelandts 1981, Robinson et al 1986, Wolf et al 1987) and in recovery of gold and some platinum group elements from geological materials (Taylor andBeamish 1968, Etoubleau et al 1996).…”

Section: Ion Exchange Thin Film Proceduresmentioning

confidence: 99%

Precise Quantitative Determination of Niobium at Low Level Concentrations in Geological Samples by WD‐XRF

Étoubleau¹,

Cambon²,

Bougault³

et al. 1999

Geostandards Newsletter

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We show in this paper that wavelength dispersive X‐ray fluorescence spectrometry (WD‐XRF) can provide high quality determinations (in terms of accuracy and precision) of Nb in rocks at low level concentrations comparable with data from much more sensitive analytical techniques. Two different sample preparation methods were investigated and combined with a long count time XRF strategy. We first developed a standard additions procedure for rock powders in conjunction with a careful evaluation of the position of analytical lines (peak and background). The precision (2s) varied from within 0.03 μg g−1 to 0.2 μg g−1 in the 0‐5 μg g−1 concentration range, and the detection limit was 0.2 μg g−1. We then separated Nb from the geological matrix using the chemical procedure described by Rehkämper (1994); after separation, Nb was collected on an anion‐exchange membrane which was directly excited by X‐rays. This method yielded a precision (2s) of 0.2 μg g−1 at the μg g−1 level if 100 mg of sample was used, the detection limit being dependent on the mass of sample studied. Detailed descriptions of analytical procedures are given, particularly of innovative aspects of Nb collection on membranes. XRF results obtained by the two sample preparation methods were compared with instrumental neutron activation (INAA) Ta analysis. We found that the ion‐exchange method tended to provide Nb concentrations which were about 10‐15% lower than concentrations found by the standard additions method. We report data for fifteen international reference materials (NIM‐N, AL‐I, AN‐G, BE‐N, MRG‐1, JA‐1, JB‐2, JB‐3, JA‐2, JF‐1, JGB‐1, BIR‐1, DNC‐1, W‐1, W‐2), for which our XRF results are in good agreement with literature data.

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Determination of light rare earth elements in apatite by x-ray fluorescence spectrometry after anion exchange extraction

Cited by 43 publications

References 53 publications

Simple and efficient method for detection of traces of rare earth elements in minerals by raman spectroscopy instrumentation

Simple and efficient method for detection of traces of rare earth elements in minerals by raman spectroscopy instrumentation

A Theoretical Study on the Electronic Structure and Floatability of Rare Earth Elements (La, Ce, Nd and Y) Bearing Fluorapatite

Precise Quantitative Determination of Niobium at Low Level Concentrations in Geological Samples by WD‐XRF

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