scholarly journals Mobility and fractionation of rare earth elements in argillaceous sediments: Implications for dating diagenesis and low-grade metamorphism

1994 ◽  
Vol 58 (1) ◽  
pp. 289-312 ◽  
Author(s):  
Matthias Ohr ◽  
Alexander N Halliday ◽  
Donald R Peacor
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Low Grade ◽  
Grade Metamorphism

Leaching behaviour of rare earth elements from low-grade weathered crust elution-deposited rare earth ore using magnesium sulfate

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 505-514
Author(s):  
Kaihua Chen ◽  
Jiannan Pei ◽  
Shaohua Yin ◽  
Shiwei Li ◽  
Jinhui Peng ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnesium Sulfate ◽  
Low Grade ◽  
Second Stage ◽  
Leaching Solution ◽  
Weathered Crust ◽  
Leaching Behaviour ◽  
N Pollution ◽  
Leaching Efficiency

ABSTRACTThe present study investigates the use of magnesium sulfate (MgSO4) instead of (NH4)2SO4 as a lixiviant in the recovery of rare earth elements (REEs) from clays. Experiments were carried out to investigate the influence of leaching conditions such as leaching time, lixiviant concentration and liquid:solid ratio on the leaching efficiency. The optimum leaching conditions, leading to 75.48% of total REE leaching efficiency, required a stirring speed of 500 rpm, a leaching time of 30 min, a lixiviant concentration of 3 wt.% and a liquid:solid ratio of 3:1. After extension of the leaching process by a second stage, the leaching efficiency may reach up to 96.19%, which is slightly higher than that obtained by (NH4)2SO4. Leaching varies from element to element, with Ce presenting the lowest leaching efficiency, and the partition in leaching solution is in agreement with that in raw ore other than for Ce. Based on these findings, MgSO4 lixiviant is an excellent alternative leaching agent for a sustainable REE industry because it reduces or eliminates NH4+–N pollution.

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.

Factors influencing the release rate of uranium, thorium, yttrium and rare earth elements from a low grade ore

2012 ◽  
Vol 39 ◽  
pp. 165-172 ◽  
Author(s):  
D.J. Sapsford ◽  
R.J. Bowell ◽  
J.N. Geroni ◽  
K.M. Penman ◽  
M. Dey
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Release Rate ◽  
Low Grade ◽  
Factors Influencing

Separation of Uranium and Rare Earth Elements with High Purity from Low-Grade Gibbsite-Bearing Shale Ore by Different Chelating Resins

2012 ◽  
Vol 33 (4) ◽  
pp. 482-489 ◽  
Author(s):  
Mohammed F. Hamza ◽  
Ibrahim E. El Aassy ◽  
Fadia Y. Ahmed ◽  
Adel A.-H. Abdel-Rahman ◽  
Ayman M. Atta
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
High Purity ◽  
Low Grade ◽  
Chelating Resins

scholarly journals Nd(III) and Gd(III) Sorption on Mesoporous Amine-Functionalized Polymer/SiO2 Composite

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1049
Author(s):  
Khalid A. M. Salih ◽  
Mohammed F. Hamza ◽  
Hamed Mira ◽  
Yuezhou Wei ◽  
Feng Gao ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
High Selectivity ◽  
Chemical Properties ◽  
Rare Earth Ions ◽  
High Tech ◽  
Low Grade ◽  
Selective Precipitation ◽  
Composite Support ◽  
Functionalized Mesoporous Silica

The strong demand for rare-earth elements (REEs) is driven by their wide use in high-tech devices. New processes have to be developed for valorizing low-grade ores or alternative metal sources (such as wastes and spent materials). The present work contributed to the development of new sorbents for the recovery of rare earth ions from aqueous solutions. Functionalized mesoporous silica composite was synthesized by grafting diethylenetriamine onto composite support. The physical and chemical properties of the new sorbent are characterized using BET, TGA, elemental analysis, titration, FTIR, and XPS spectroscopies to identify the reactive groups (amine groups: 3.25 mmol N g−1 and 3.41 by EA and titration, respectively) and their mode of interaction with Nd(III) and Gd(III). The sorption capacity at the optimum pH (i.e., 4) reaches 0.9 mmol Nd g−1 and 1 mmol Gd g−1. Uptake kinetics are modeled by the pseudo-first-order rate equation (equilibrium time: 30–40 min). At pH close to 4–5, the sorbent shows high selectivity for rare-earth elements against alkali-earth elements. This selectivity is confirmed by the efficient recovery of REEs from acidic leachates of gibbsite ore. After elution (using 0.5 M HCl solutions), selective precipitation (using oxalate solutions), and calcination, pure rare earth oxides were obtained. The sorbent shows promising perspective due to its high and fast sorption properties for REEs, good recycling, and high selectivity.

Geochemical and Sr-Nd isotopic characteristics of the lamprophyre in the Tethyan Himalaya, South Tibet

2020 ◽  
Author(s):  
Zhi-Chao Liu ◽  
Jian-Gang Wang ◽  
Xiao-Chi Liu
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Lithospheric Mantle ◽  
Indian Plate ◽  
Late Triassic ◽  
Geochemical Data ◽  
Low Grade ◽  
Northern Margin ◽  
Two Samples ◽  
Tethyan Himalaya

<p>A lamprophyre dyke has been found in Ramba area within the Tethyan Himalaya. It intruded into the Late Triassic low-grade metasedimentary rocks (Langjiexue Group) and show typical porphyritic textures, with phlogopite as the dominant phenocrysts. In this study, we performed phlogopite 40Ar/39Ar dating and whole-rock major and trace element as well as Sr and Nd isotope geochemical analyses on the lamprophyre. The <sup>40</sup>Ar/<sup>39</sup>Ar plateau ages (13.1 ± 0.2 Ma and 13.5 ± 0.2 Ma) of the phlogopites from two samples are both in excellent agreement with the inverse isochron ages of 13.1 ±0.3 Ma and 13.6 ± 0.3 Ma, recording the times at which the lamprophyre dyke has cooled below ~300 °C. The lamprophyre has low contents of SiO<sub>2</sub> (51.43–55.15 wt%) and Al<sub>2</sub>O<sub>3</sub> (11.10–11.85 wt%), high Fe<sub>2</sub>O<sub>3T</sub> (8.57–9.27 wt%) and MgO (9.14–9.49 wt %) contents with Mg<sup>#</sup> of 66–69, higher content of K<sub>2</sub>O (3.26–5.57 wt%) relative to Na<sub>2</sub>O (0.50–1.39 wt%) with K<sub>2</sub>O/Na<sub>2</sub>O of 2.3–11.1. Furthermore, the lamprophyre has high abundances of large ion lithophile elements (e.g., Rb, Ba, Sr), shows depletions in high field strength elements (e.g., Nb, Ta, Ti), and displays enrichment in light rare-earth elements over heavy rare earth elements with (La/Yb)<sub>N</sub> of 42.3~47.0. Besides, the lamprophyre is characterized by high initial <sup>87</sup>Sr/<sup>86</sup>Sr ratios of 0.7196~0.7204 and negative ε<sub>Nd</sub>(t) values of -10.7~-10.8. Geochemical data suggest that the Ramba lamprophyre was likely generated by partial melting of a metasomatized, phlogopite-bearing harzburgite lithospheric mantle source, followed by crystal fractionation and varying degree of crustal assimilation. The studied lamprophyre provides a window into the composition of the subcontinental lithospheric mantle (SCLM) in the northern margin of the Indian plate. We suggest that the northern Indian plate might be involved in the Andean-type orogeny from the subduction of the Proto-Tethys Ocean during Cambrian to Early Ordovician.</p>

scholarly journals Obtaining a new kind of organic fertilizer on the basis of low-grade phosphorite of Central Kyzylkum

2018 ◽  
Vol 65 (3) ◽  
pp. 157-165
Author(s):  
Nodirjon Abdihakimovich Doniyarov ◽  
Ilkhom Ahrorovich Tagayev
Keyword(s):  
Rare Earth ◽  
Liquid Phase ◽  
Rare Earth Elements ◽  
Activated Sludge ◽  
Organic Fertilizer ◽  
Production Unit ◽  
Low Grade ◽  
Biochemical Purification ◽  
Real Possibility

Abstract The paper presents the results of processing low-grade phosphorites by microorganisms of activated sludge from the biochemical purification production unit of JSC “Navoiazot”. The obtained results on the leaching of rare and rare-earth elements into the liquid phase make it possible to separate them and thus enrich the phosphorites. Other options are the gravitational separation of the crushed calcite particles. In addition to this, there is a real possibility of creating complex organomineral fertilisers.

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