scholarly journals Geochemistry and Mineralogy of Rare Earth Elements (REE) in Bauxitic Ores of the Catalan Coastal Range, NE Spain

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 562 ◽  
Author(s):  
Nils Reinhardt ◽  
Joaquín Proenza ◽  
Cristina Villanova-de-Benavent ◽  
Thomas Aiglsperger ◽  
Telm Bover-Arnal ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Critical Metals ◽  
Major Element Composition ◽  
Precursor Material ◽  
Rare Earth Minerals ◽  
Future Supply ◽  
Alkaline Conditions ◽  
Coastal Range ◽  
Ne Spain

Karst bauxite deposits are currently investigated as a new resource for rare earth elements (REE) in order to avoid present and future supply shortfalls of these critical metals. The present work focuses on the geochemistry and mineralogy of the REE in karst bauxite deposits of the Catalan Coastal Range (CCR), NE-Spain. It is revealed that the studied bauxitic ores have a dominant breccia and local ooido-pisoidic and pelitomorphic texture. The bauxitic ores are mostly composed of kaolinite and hematite, as well as of lesser amounts of boehmite, diaspore, rutile and calcite. The mineralogy and major element composition indicate incomplete bauxitization of an argillaceous precursor material possibly derived from the erosion of the Mesozoic Ebro massif paleo-high. The studied bauxites are characterized by ∑REE (including Sc, Y) between 286 and 820 ppm (av. 483 ppm) and light REE to heavy REE (LREE/HREE) ratios up to 10.6. REE are mainly concentrated in phosphate minerals, identified as monazite-(Ce) and xenotime-(Y) of detrital origin and unidentified REE-phosphates of a possible authigenic origin. REE remobilization presumably took place under acidic conditions, whereas REE entrapment in the form of precipitation of authigenic rare earth minerals from percolating solutions was related to neutral to slightly alkaline conditions. During the bauxitization process no significant REE fractionation took place and the REE distribution pattern of the bauxitic ores was governed by the REE budget of the precursor material. Finally, adsorption as a main REE scavenging mechanism in the studied CCR bauxite deposits should not be considered, since the presented data did not reveal significant REE contents in Fe-and Mn-oxyhydroxides and clay minerals.

scholarly journals Recovery of Metals and Rare Earth Elements by Microwave heating Technology - A Review

2020 ◽  
Vol 7 (3) ◽  
pp. 196-206
Author(s):  
Shunda Lin ◽  
Mamdouh Omran ◽  
Shenghui Guo
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Microwave Heating ◽  
Industrial Applications ◽  
Metallurgical Waste ◽  
Microwave Technology ◽  
Valuable Metals ◽  
Rare Earth Minerals ◽  
Save Energy ◽  
Heating Technology

: Microwave heating technology is considered one of the most likely to replace traditional heating methods due to its efficient, quick, and green heating transmission that meets the requirements of sustainable development. Microwave heating can strengthen chemical reactions and change the morphology of minerals, and it can save energy and achieve rapid and efficient heating, clean production, and emission reduction. Therefore, this paper summarizes the research status of microwave heating in the recovery of valuable metals (Cu, Au, V),) from metallurgical waste ore and rare earth elements from rare earth minerals in recent years, expounds the principle of microwave heating, and summarizes the previous experimental phenomena. Finally, the development potential, opportunities, and difficulties of microwave technology in future industrial applications are discussed.

scholarly journals Material efficiency: rare and critical metals

2013 ◽  
Vol 371 (1986) ◽  
pp. 20110563 ◽  
Author(s):  
Robert U. Ayres ◽  
Laura Talens Peiró
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Platinum Group Metals ◽  
Rare Metals ◽  
Critical Metals ◽  
The Past ◽  
Material Efficiency ◽  
Aluminium Copper ◽  
Copper Zinc ◽  
Industrial Metals

In the last few decades, progress in electronics, especially, has resulted in important new uses for a number of geologically rare metals, some of which were mere curiosities in the past. Most of them are not mined for their own sake (gold, the platinum group metals and the rare Earth elements are exceptions) but are found mainly in the ores of the major industrial metals, such as aluminium, copper, zinc and nickel. We call these major metals ‘attractors’ and the rare accompanying metals ‘hitch-hikers’. The key implication is that rising prices do not necessarily call forth greater output because that would normally require greater output of the attractor metal. We trace the geological relationships and the functional uses of these metals. Some of these metals appear to be irreplaceable in the sense that there are no known substitutes for them in their current functional uses. Recycling is going to be increasingly important, notwithstanding a number of barriers.

Research on the Reaction Behavior of Rare Earth Elements in Reduction

2012 ◽  
Vol 454 ◽  
pp. 268-272 ◽  
Author(s):  
Peng Gao ◽  
Yue Xin Han ◽  
Yong Sheng Sun ◽  
Chao Chen
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnetic Separation ◽  
Sem Images ◽  
Reaction Behavior ◽  
Rare Earth Minerals ◽  
Iron Phase ◽  
Occurrence State ◽  
Bayan Obo ◽  
Depth Reduction

Occurrence state of rare earth elements in the different deoxidization stages and the behavior of rare earth elements in the process of depth reduction were studied by analyzing XRD and SEM images of Bayan Obo oxide ore in different deoxidization time. The results showed that deoxidization time had a great effect on the occurrence state of rare earth elements. With the increase of deoxidization time, rare earth minerals gradually translated from bastnaesite and urdite into (CaO•2Ce2O3•3SiO2).This phase was white with a small size. It was columnar or massive in most cases and could be easily separated from the iron phase. 97.18% of the rare earth elements, which could be recovered by flotation, gravity separation and magnetic separation, entered the iron tailings.

scholarly journals Identification of rare-earth minerals associated to K-feldspar: Capacsaya project in Peru

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
J. Ochoa ◽  
E. Monteblanco ◽  
L. Cerpa ◽  
A. Gutarra-Espinoza ◽  
L. Avilés-Félix
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Size Range ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Particle Size Range ◽  
X Ray ◽  
Rare Earth Minerals ◽  
Heavy Rare Earth Elements ◽  
The Rare Earth

AbstractA recently discovered the rare-earth-rich site in Capacsaya, located at 123 km northwest of Cusco, at the south of Peru, contains significant quantities of light and heavy rare-earth elements such as neodymium, lanthanum, cerium, europium, and yttrium. This work reports the identification of rare-earth elements and their associated minerals using scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analyses. Five (5) samples extracted from different locations at the Capacsaya site were characterized and identified K-feldspar as the mineral associated with the rare-earth elements in a representative sample with a high concentration of lanthanum and cerium. The results showed rare-earth elements contained within the mineral phase monazite, being cerium the dominant element in the phase (La, Ce, Nd)PO$$_4$$ 4 . Finally, through the electrostatic separation process we demonstrate that it was possible to achieve an efficient separation of the K-feldspar phase in the particle size range 75–150 $$\upmu$$ μ m.

scholarly journals Mineralogical and geochemical aspects of rare-earth elements behavior during metamorphism (on the example of the Upper Precambrian structural-material complexes of the Bashkir megaanticlinorium, South Urals)

Georesursy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 56-66
Author(s):  
Sergey G. Kovalev ◽  
Andrey V. Maslov ◽  
Sergey S. Kovalev
Keyword(s):  
Rare Earth ◽  
Structural Material ◽  
Rare Earth Elements ◽  
Contact Metamorphism ◽  
South Urals ◽  
Chemical Compositions ◽  
Temperature Regimes ◽  
Mineral Associations ◽  
Rare Earth Minerals ◽  
Thermobaric Conditions

The article provides new data on geochemistry and mineralogy of rare-earth elements (REE) in rocks of structural-material complexes of the Bashkir megaanticlinorium, which underwent metamorphic transformations of various nature: contact metamorphism (Suran section); syn- and postgenetic contact-dislocation metamorphism (Shatak complex) and hydrothermal metamorphism (Uluelga-Kudashmanovo zone). It has been established that when a magmatic melt is exposed to sediments, the latter are enriched with REEs with the formation of rare earth minerals (monazite, allanite, xenotime et al.). The study of the chemical composition of monazites and allanites showed that all variations of oxides in the composition of the former are due to isomorphous Ce-Ca-Th substitutions in the structure of minerals, but redistribution of these elements was an independent process characteristic of each structural-material complex. The study of allanites made it possible to establish the presence of isomorphism according to the Ca↔Ce, La, Nd principle, as well as the sharp difference between the characterized minerals in the amount of MgO, Fe* and MnO from analogues from other regions, which indicates the presence of a regional component in the chemical compositions of minerals altogether, geotectonic settings of mineralization formation. The temperature regimes of mineral-forming processes with metamorphic transformations of rocks calculated from chlorite and muscovite compositions (344-450°C – Suran section, 402-470°C – Shatak complex, 390-490°C – Uluelga-Kudashmanovo zone) indicate the possibility of stable coexistence of the association monazite-allanite. It was established that when a magmatic melt on the sedimentary substrate of the frame, the lanthanides enrich the exocontact rocks with the formation of newly formed REE-mineral associations. At the same time, the processes of formation of rare-earth mineralization are largely determined by the physicochemical parameters and thermobaric conditions of the accompanying and subsequent metamorphism.

scholarly journals Fractionation Trends and Variability of Rare Earth Elements and Selected Critical Metals in Pelagic Sediment from Abyssal Basin of NE Pacific (Clarion-Clipperton Fracture Zone)

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 320 ◽  
Author(s):  
Dominik Zawadzki ◽  
Łukasz Maciąg ◽  
Tomasz Abramowski ◽  
Kevin McCartney
Keyword(s):  
Grain Size ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Fracture Zone ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Critical Metals ◽  
Icp Ms ◽  
Clipperton Fracture Zone ◽  
Clarion Clipperton Fracture Zone

The geochemical and mineralogical characteristics of pelagic sediments collected from the Interoceanmetal Joint Organization (IOM) claim area, located in the eastern part of the Clarion-Clipperton Fracture Zone (CCFZ; eastern tropical Pacific), are described in this paper. The concentrations of rare earth elements (REE), as well as other selected critical elements contained in 135 sediment samples of siliceous clayey silts, are presented. The vertical and spatial variabilities of elements, with particular emphasis on REE as well as metals of the highest economic interest such as Cu, Ni, and Co, are detailed. The applied methods include grain size analysis by laser diffraction, geochemistry examination using ICP-MS, XRF, AAS, and CNS spectrometry, and XRD analysis of mineral composition (Rietveld method). Additionally, statistical methods such as factor analysis (FA) and principal components analysis (PCA) were applied to the results. Finally, a series of maps was prepared by geostatistical methods (universal kriging). Grain size analysis showed poor sorting of the examined fine-grained silts. ICP-MS indicated that total REE contents varied from 200 to 577 ppm, with a mean of 285 ppm, which is generally low. The contents of critical metals such as Cu, Ni, and Co were also low to moderate, apart from some individual sampling stations where total contents were 0.15% or more. Metal composition in sediments was dominated by Cu, Ni, and Zn. A mineral composition analysis revealed the dominance of amorphous biogenic opaline silica (27–58%), which were mostly remnants of diatoms, radiolarians, and sponges associated with clay minerals (23% to 48%), mostly Fe-smectite and illite, with mixed-layered illite/smectite. The high abundance of diagenetic barite crystals found in SEM−EDX observations explains the high content of Ba (up to 2.4%). The sediments showed complex lateral and horizontal fractionation trends for REE and critical metals, caused mostly by clay components, early diagenetic processes, admixtures of allogenic detrital minerals, or scavenging by micronodules.

X-Ray Fluorescence Analysis of Individual Rare Earths in Complex Minerals

1968 ◽  
Vol 22 (5) ◽  
pp. 426-430 ◽  
Author(s):  
Harry J. Rose ◽  
Frank Cuttitta
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rare Earths ◽  
Earth Element ◽  
Fluorescence Analysis ◽  
Cellulose Powder ◽  
Dilute Acid ◽  
X Ray ◽  
Analytical Scheme ◽  
Rare Earth Minerals

A combined chemical x-ray fluorescence method is described for determining rare-earth elements in small amounts of complex rare-earth minerals. These elements yield a complex x-ray spectrum in which many of the analytical emission Lα lines of a given element coincide with the Lβ and/or Lγ lines of a lighter rare-earth element several atomic numbers removed. The proposed analytical scheme corrects for these interferences. Sixteen elements consisting of the lanthanides, yttrium, and scandium can be determined on as little as a 1-mg portion of the separated oxides. The oxides are dissolved in 1 ml of dilute acid, absorbed onto cellulose powder and pressed into a pellet for x-ray excitation. Chemically analyzed geologic standards are not required for calibration.

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