scholarly journals Bioparticles coated with an ionic liquid for the pre-concentration of rare earth elements from microwave-digested tea samples and the subsequent quantification by ETV-ICP-OES

2016 ◽  
Vol 8 (43) ◽  
pp. 7808-7815 ◽  
Author(s):  
Sara Hosseinzadegan ◽  
Winfried Nischkauer ◽  
Katharina Bica ◽  
Andreas Limbeck
Keyword(s):  
Ionic Liquid ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Analytical Procedure ◽  
Icp Oes

An analytical procedure for straight-forward quantification of rare earth elements (REEs) in tea was developed.

scholarly journals Selective Roasting of Nd–Fe‒B Permanent Magnets as a Pretreatment Step for Intensified Leaching with an Ionic Liquid

2019 ◽  
Vol 6 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Martina Orefice ◽  
Amy Van den Bulck ◽  
Bart Blanpain ◽  
Koen Binnemans
Keyword(s):  
Ionic Liquid ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Permanent Magnets ◽  
Metallic Phase ◽  
Process Step ◽  
Mechanical Removal ◽  
Oxidative Roasting ◽  
Roasting Temperature ◽  
The Rare Earth

AbstractOxidative roasting of Nd–Fe‒B permanent magnets prior to leaching improves the selectivity in the recovery of rare-earth elements over iron. However, the dissolution rate of oxidatively roasted Nd–Fe‒B permanent magnets in acidic solutions is very slow, often longer than 24 h. Upon roasting in air at temperatures above 500 °C, the neodymium metal is not converted to Nd2O3, but rather to the ternary NdFeO3 phase. NdFeO3 is much more difficult to dissolve than Nd2O3. In this work, the formation of NdFeO3 was avoided by roasting Nd–Fe‒B permanent magnet production scrap in argon atmosphere, having an oxygen content of $$ p_{{{\text{O}}_{2} }} \, \le \,10^{ - 20} \;{\text{atm}}, $$pO2≤10-20atm, with the addition of 5 wt% of carbon as an iron reducing agent. For all the non-oxidizing iron roasting conditions investigated, the iron in the Nd–Fe‒B scrap formed a cobalt-containing metallic phase, clearly distinct from the rare-earth phase at microscopic level. The thermal treatment was optimized to obtain a clear phase separation of metallic iron and rare-earth phase also at the macroscopic level, to enable easy mechanical removal of iron prior to the leaching step. The sample roasted at the optimum conditions (i.e., 5 wt% carbon, no flux, no quenching step, roasting temperature of 1400 °C and roasting time of 2 h) was leached in the water-containing ionic liquid betainium bis(trifluoromethylsulfonyl)imide, [Hbet][Tf2N]. A leaching time of only 20 min was sufficient to completely dissolve the rare-earth elements. The rare-earth elements/iron ratio in the leachate was about 50 times higher than the initial rare-earth elements/iron ratio in the Nd–Fe‒B scrap. Therefore, roasting in argon with addition of a small amount of carbon is an efficient process step to avoid the formation of NdFeO3 and to separate the rare-earth elements from the iron, resulting in selective leaching for the recovery of rare-earth elements from Nd–Fe‒B permanent magnets.

Method validation and uncertainty for the determination of rare earth elements, yttrium, thorium and phosphorus in monazite samples by ICP-OES

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Simple Procedure ◽  
Optical Emission ◽  
Icp Oes ◽  
Limit Of Quantification ◽  
Inductively Coupled ◽  
Relative Standard

A method is described for the inductively coupled plasma optical emission spectrometric (ICP-OES) determination of rare earth elements (REE), yttrium (Y), thorium (Th) and phosphorus (P) in monazite samples. Sample preparation was carried out by fuming with sulphuric acid followed by fluoride fusion of the remaining residue. The method was validated using the single laboratory approach by assessment of analytical performance characteristics like specificity, linearity, range, accuracy and precision. Spectral interferences were observed in the case of some heavy REE (Ho,Er,Tm) by light REE (Nd) and correction factors were deduced and applied. The limit of quantification, instrument linearity and the method range were evaluated. Relative standard deviation (RSD) values ranging from 2.6 to 10.2 % were obtained for repeatability studies and RSD values ranging from 1.7 to 11.1% for intra-lab reproducibility studies. Accuracy was established by application to a monazite certified reference material (CRM) and also through comparison of results obtained by present method with those obtained by an alternate method. The validation results were compliant with the acceptance criteria for the various parameters assessed. A simple procedure has been described for the estimation of associated measurement uncertainty using the GUM “bottom-up” modelling approach and results presented in this paper. The validated method was applied to the determination of REE, Y, Th and P in some monazite samples from India.

Development of a simple and robust microwave-assisted decomposition method for the determination of rare earth elements in coal fly ash by ICP-OES

2017 ◽  
Vol 9 (13) ◽  
pp. 2031-2040 ◽  
Author(s):  
M. V. Balarama Krishna ◽  
G. Venkateswarlu ◽  
D. Karunasagar
Keyword(s):  
Rare Earth ◽  
Fly Ash ◽  
Rare Earth Elements ◽  
Decomposition Method ◽  
Coal Fly Ash ◽  
Icp Oes ◽  
Step Method ◽  
Microwave Assisted ◽  
Assisted Decomposition

A novel two-step method based on hotplate treatment (HT) in combination with microwave-assisted decomposition (MWD) was developed for the determination of rare earth elements (REEs) in coal fly ash samples by ICP-OES.

Recovery of Lanthanides from Indonesian Low Grade Bauxite Using Oxalic Acid

2018 ◽  
Vol 929 ◽  
pp. 171-176 ◽  
Author(s):  
Eny Kusrini ◽  
Zakaria Jaka Bahari ◽  
Anwar Usman ◽  
Arif Rahman ◽  
Eko Adi Prasetyanto
Keyword(s):  
Rare Earth ◽  
Optimum Condition ◽  
Oxalic Acid ◽  
Rare Earth Elements ◽  
Acid Leaching ◽  
Experimental Result ◽  
Low Grade ◽  
Icp Oes ◽  
Temperature Dependent ◽  
Economical Method

The present work describes the extraction of lanthanide (rare earth elements, REE) from low grade bauxite using acid leaching method. The aim of this study is to obtain the best condition for extraction of lanthanides from low grade bauxite. The effect of different parameters such as temperatures and concentration of oxalic acid in leaching process were investigated. The content of La, Ce and Y elements were determined using ICP-OES. The experimental result shows that the efficiencies of lanthanide leaching are the temperature-dependent. Increasing leaching temperature from 45°C to 85°C did not improve recoveries of lanthanides. The most optimum condition was found at oxalic acid leaching of 1 mol/L, leaching temperature at 40°C, and time for 2 hours. The obtained results show that the lanthanides can be leached using oxalic axid. This finding may lead to more effective and economical method to separate lanthanides from low grade bauxite.

scholarly journals Pemisahan Unsur-unsur pada Monasit Bangka dengan Pengendapan Bertingkat

EKSPLORIUM ◽  
2021 ◽  
Vol 42 (1) ◽  
pp. 69
Author(s):  
Anggi Novriyanisti ◽  
Riesna Prassanti ◽  
Kurnia Setiawan Widana
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Optical Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Icp Oes ◽  
Effect Of Ph ◽  
Ph Variation ◽  
Inductively Coupled ◽  
Uv Visible ◽  
Ph Variations

ABSTRAK Monasit merupakan mineral hasil samping pengolahan timah yang memiliki kandungan utama unsur uranium (U), torium (Th), logam tanah jarang (LTJ), dan senyawa fosfat (PO4). Di samping unsur-unsur utama tersebut, monasit juga mengandung logam-logam lain seperti aluminium (Al), besi (Fe), bismut (Bi), galium (Ga), dan talium (Tl). Unsur-unsur pada monasit harus dipisahkan agar dapat dimanfaatkan. Penelitian ini bertujuan untuk mengetahui pengaruh variasi pH dalam pemisahan unsur-unsur pada monasit dengan pengendapan bertingkat serta menentukan unsur apa saja yang dihasilkan dari setiap variasi pH. Variasi pH yang digunakan dimulai dari pH 0,5 sampai 10 dengan selisih antar-pH sebesar nol koma lima. Unsur-unsur dalam monasit dipisahkan secara bertahap dimulai dari proses dekomposisi menggunakan natrium hidroksida (NaOH), pelarutan dengan asam klorida (HCl), dan pengendapan bertingkat dengan amonium hidroksida (NH4OH). Unsur dianalisis menggunakan instrumen Inductively Coupled Plasma Optical Spectroscopy (ICP-OES) dan Spektrofotometer UV-Visible. Pengaruh variasi pH menghasilkan endapan pada pH 3, pH 6, pH 6,5, dan pH 7. Unsur yang dihasilkan pada setiap variasi pH adalah uranium, torium, logam tanah jarang, aluminium, besi, bismut, galium, dan talium. Uranium dan torium paling banyak berada pada endapan pH 3 dengan recovery U 72,3% dan Th 46,33% serta logam tanah jarang pada pH 6,5 dengan recovery 41,87%. Unsur Fe dan Bi paling banyak mengendap pada pH 3 dengan kadar 37,9 ppm dan 100,9 ppm. Unsur Al, Ga, dan Tl paling banyak mengendap pada pH 6,5 dengan kadar 30,2 ppm, 69,8 ppm, dan 8 ppm.ABSTRACT Monazite is a mineral side product of tin processing, which mainly contains uranium (U), thorium (Th), rare earth elements (REE), and phosphate compounds (PO4). Besides these main elements, monazite also contains other metals such as aluminum (Al), iron (Fe), bismuth (Bi), gallium (Ga), and thallium (Tl). The elements in monazite must be separated to be used. This study aims to determine the effect of pH variations in the separation of components in monazite with multilevel precipitation and determine elements produced from each pH variation. The variation pH starts from pH 0,5 to 10 with a different pH of zero points five. The elements in monazite are separated gradually, beginning from the decomposition process using sodium hydroxide (NaOH), dissolving with hydrochloric acid (HCl), and graded deposition with ammonium hydroxide (NH4OH). The elements were analyzed using the instrument Inductively Coupled Plasma Optical Spectroscopy (ICP-OES) and UV-Visible Spectrophotometer. The effect of pH variations produced precipitated pH 3, pH 6, pH 6.5, and pH 7. The elements produced at each pH variation are uranium, thorium, rare earth elements, aluminum, iron, bismuth, gallium, and thallium. Uranium and thorium were mostly at pH 3 with the recovery of U 72.3% and Th 46.33% and rare earth elements at pH 6.5 with 41.87% recovery. The elements Fe and Bi mostly settle at pH 3 with levels of 37.9 ppm and 100.9 ppm. The elements Al, Ga, and Tl, precipitate most at pH 6.5 with grades of 30.2 ppm, 69.8 ppm, and 8 ppm respectively.

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