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 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.

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 Brockite in wallrock metasomatites of the Safyanovskoe copper-sulphide deposit (Middle Urals)

2020 ◽  
Vol 59 (3) ◽  
pp. 35-40
Author(s):  
Elena Industrovna SOROKA ◽  
◽  
Lyubov’ Vladimirovna LEONOVA ◽  
Mikhail Egorovich PRITCHIN ◽  
◽  
...  
Keyword(s):  
Rare Earth ◽  
South Urals ◽  
Middle Urals ◽  
Copper Sulphide ◽  
The Urals ◽  
Sulphide Deposit ◽  
Environment Change ◽  
Rare Earth Minerals ◽  
Composition Of Minerals ◽  
Academy Of Sciences

The relevance of the work is due to the need to study ore copper-sulphide deposits in the Urals. Purpose of the work: description of accessory brockite in metasomatites of the Safyanovskoe copper-sulphide deposit. Research methodology: the chemical composition of minerals was determined using the Jeol JSM-6390LV scanning electron microscope with an INCA Energy 450 X-Max 80 energy dispersive attachment from Oxford Instruments (Institute of Geology and Geochemistry of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg). Results and conclusions. For the first time for the Safyanovskoe copper-sulphide deposit (Middle Urals), an aqueous rare earth phosphate of calcium and thorium, brockite, has been determined; it belongs to the group of rhabdophane (Ca,Th,REE)[PO]4 ∙ _H2 O. The mineral is rare for the Urals and was described earlier in granite pegmatites of the Middle and South Urals, as well as in dikes of metaplagiogranites of the Bazhenov ophiolite complex. Brockite was found in the rocky metasomatites of the Safyanovskoe copper-sulphide deposit after crystalline lithoclastic tuff (tuffaceous sandstone) of acid composition. The main mass of the rock consists of quartz, kaolinite (sericite), carbonates (dolomite, Fe-magnesite) with rare inclusions of pyrite. Brockite is found in the dolomite-quartz matrix of the sample in intergrowths with REE-goyazite – strontium aluminophosphate. It is assumed for the Safyanovskoe copper-sulphide deposit that an alumina association with an ore mineral association and rare earth minerals, in particular, REE-alumophosphates and phosphates, will form closely at the same time as the temperature drops and the redox conditions of the mineral formation environment change.

Two new rare-earth-rich mineral associations in the Ilímaussaq alkaline complex, South Greenland

2001 ◽  
pp. 143-144
Author(s):  
Igor V. Pekov ◽  
Irina A. Ekimenkova
Keyword(s):  
Rare Earth ◽  
Chemical Compositions ◽  
Alkaline Complex ◽  
Complex Type ◽  
Unit Cell Parameters ◽  
Widespread Occurrence ◽  
Cell Parameters ◽  
Mineral Associations

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Pekov, I. V., & Ekimenkova, I. A. (2001). Two new rare-earth-rich mineral associations in the Ilímaussaq alkaline complex, South Greenland. Geology of Greenland Survey Bulletin, 190, 143-144. https://doi.org/10.34194/ggub.v190.5185 _______________ Two new types of REE-rich mineral associations have been discovered at Kvanefjeld in the northern part of the Ilímaussaq alkaline complex. Type 1 consists of ussingite veins intersecting lujavrite and containing 5–7% nacareniobsite-(Ce) and 2–4% steenstrupine-(Ce); the adjacent altered lujavrite contains up to 10–12% nacareniobsite-(Ce). Type 2 consists of cavernous sodalite-rich veinlets and vugs in lujavrite containing 5–8% vitusite-(Ce). The chemical compositions and unit cell parameters of REE minerals are given. Nacareniobsite-(Ce) and vitusite-(Ce) were considered to be extremely rare minerals in the Ilímaussaq complex. Nacareniobsite-(Ce) is now known to be of more widespread occurrence in some hyper-agpaitic rocks of the Ilímaussaq complex, and vitusite-(Ce) is known to be the precursor of the widespread occurrence of the yellow pseudomorphs termed erikite.

Chemical Migration by Contact Metamorphism between Pegmatite and Country Rocks: Natural Analogs for Radionuclide Migration

1983 ◽  
Vol 26 ◽  
Author(s):  
J. C. Laul ◽  
R. J. Walker ◽  
C. K. Shearer ◽  
J. J. Papike ◽  
S. B. Simon
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
South Dakota ◽  
Trace Element ◽  
Black Hills ◽  
The Other ◽  
Contact Metamorphism ◽  
Relative Degree ◽  
Radionuclide Migration ◽  
Other Hand

ABSTRACTComparison of trace element signatures of country rocks as a function of distance from the contact with two pegmatites, Tin Mountain and Etta, in the Black Hills of South Dakota, suggests that some elements such as K, Li, Rb, Cs, As, Sb, Zn and Pb, have migrated to distances of 4 to 40 meters during contact metamorphism. The relative degree of migration varies depending on the element. On the other hand, there is virtually no migration of rare earth elements (REE), Al, Sc, Cr, Hf, U, and Th. Biotite and muscovite are effective trace element traps for Li, Rb and Cs. Biotite has a greater affinity for Rb, Cs and Li than muscovite.

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.

scholarly journals To reconstruction of the river’s categories which formed sedimentary basins of Riphean basins in the region of the Eastern European platform and modern south Urals juncture

2019 ◽  
pp. 28-36
Author(s):  
A. V. Maslov
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Bottom Sediments ◽  
Sedimentary Basins ◽  
Southern Urals ◽  
South Urals ◽  
The Caspian Sea ◽  
The Southern Urals ◽  
Volga River ◽  
Clay Rocks

Information on the distribution of trace and rare-earth elements in the bottom sediments of estuarine zones of various river categories (large rivers, rivers draining water collections, composed of sedimentary or magmatic and metamorphic rocks, etc.) of silt and pelitic dimensions can be considered as the data, reflecting characteristic features of the suspention, transported to marine basins from various catchment provinces. In certain situations, the composition of the surface bottom sediments of the marine basin is determined by the suspension composition of any large river flowing into it (the Caspian Sea and the Volga River, the Laptev Sea and the Lena River, etc.). The similarity and difference in the rare-earth elements (REE) systematics of bottom sediments of estuarine zones and suspended particulate matter of rivers of various categories is quite well expressed in the pair diagrams (La/ Yb)N–(Eu/Sm)N, (La/Yb)N–Th, etc. A comparison of the features of the distribution of REE and Th in the Riphean clay rocks of the Southern Urals and in bottom sediments of the estuaries of various categories of recent rivers has been performed. It has been concluded that clay rocks forming a typical Riphean section are formed due to the erosion of mainly or predominantly sedimentary and/or metasedimentary complexes that existed during the PreRiphean or the Riphean in the east part of the East European platform and have not survived to date.

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.

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