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An Overview of Rare Earth Ores Beneficiation in Vietnam

Nhu Thi Kim Dung, Pham Van Luan, Vu Thi Chinh, Tran Van Duoc

Inżynieria Mineralna

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2021

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no. 2

227--236

EN

Rare earth metals are used in electricity, electronics, nuclear, optics, space, metallurgy, superconducting and super magnetic materials, glass and ceramics, and agriculture. Some rare earth elements are added to fertilizers for crops and some trials for animal feed. Rare earth elements, except for radioactive promethium, are relatively abundant in the earth's crust. Vietnam has a tremendous rare earth potential, distributed mainly in the Northwest, including Nam Xe, Dong Pao, Muong Hum, and Yen Bai. There are many research projects on rare earth ores of different types globally, but the focus is mainly on the essential minerals, including monazite, xenotime, and bastnaesite. This report summarizes research data on rare earth ore intending to produce a general assessment of rare earth ore and its beneficiation technology in Vietnam.

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Przegląd głównych minerałów pierwiastków ziem rzadkich : złoto XXI wieku

Ryder P., Nowak M.

Przegląd Geologiczny

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2015

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Vol. 63, nr 6

348--362

EN

The constant evolution of civilisation and ever more advanced technologies have forced the global economy to search for new and renewable resources. Since the 1950s, rare earth elements (REE) have played an increasingly significant role in the production of new materials. The REE form a group of 17 elements (15 lanthanides, yttrium and scandium) with special properties that distinguish them from the other elements. These unique and essential raw materials have numerous applications nowadays. Without the rare earths, many branches of industry would not be able to function. The main resources of the REE come from the rocks with mineralization enriched in minerals with a higher REO (rare earth oxides) contents. Although there are around 270 different REE-bearing mineral species, the exploitation of the REE refers to less than 10 minerals. Five major REE minerals (the major minerals from group of bastnäsite (bastnaesite), monazite, xenotime, apatite and perovskite (loparite)) are characterized and described. The REO percentage content varies from max. 16% in apatite to max. 79% in bastnäsite. The examples shown were chosen due to their importance and level of extraction. This review-paper has been based on the compilation of data from mineralogical publications, mineralogical data websites and metallurgical articles about the alloys and their compounds.

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The stability of xenotime in high Ca and Ca-Na systems, under experimental conditions of 250–350°C and 200–400 MPa : the implications for fluid-mediated low-temperature processes in granitic rocks

Budzyń B., Kozub-Budzyń G. A.

Geological Quarterly

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2015

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Vol. 59, No. 2

316–324

EN

he stability of xenotime was tested by experiments in the presence of a silicate mineral assemblage and two different fluids, 2M Ca(OH)2 or Na2Si2O5 + H2O, under P-T conditions of 200-400 MPa and 250-350°C. The xenotime was stable in runs with 2M Ca(OH)2, replicating the low-temperature metasomatic alterations of granitic rocks, except in experiment at 350°C and 400 MPa, where some (Y,REE)-rich fluorapatite formed. Experiments with Na2Si2O5 + H2O resulted in significant xenotime alteration and partial replacement by an unknown (Y,HREE)-rich silicate, and in the formation of minor amounts of (Y,REE)-rich fluorapatite. The latter indicate preferential partitioning of Y and REE into silicates over phosphates during low-temperature, metasomatic processes in a high Na-Ca system, similar to peralkaline granitic rocks.

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New potential source of rare earth elements

Szamałek K., Konopka G., Zglinicki K., Marciniak-Maliszewska B.

Gospodarka Surowcami Mineralnymi

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2013

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T. 29, z. 4

59--76

PL

Pierwiastki ziem rzadkich (REE) są niezwykle istotnym, choć rzadko występującym zasobem mineralnym odgrywającym ważną rolę w gospodarkach krajów wysoko rozwiniętych. Zakłócenia na międzynarodowym rynku surowcowym metali ziem rzadkich związane z monopolem Chin w zakresie ich produkcji i podaży zmuszają państwa wysoko rozwinięte do podejmowania intensywnych działań dla znalezienia nowych źródeł tych pierwiastków (wśród nich odpadów poprzeróbczych). W artykule przedstawiono wyniki badań składu mineralnego odpadów powstających na wyspie Bangka w trakcie wzbogacania koncentratu kasyterytowego. Badane próbki odpadów zawierają monacyt w ilości do 21,23 %w oraz do 17,55 %w ksenotymu (próbka z Sungkap, Bangka), ponadto występują w nich cyrkon, ilmenit, anataz, rutyl, pseudorutyl i kasyteryt. Poza pierwiastkami REE – zidentyfikowano niob i tantal w żużlu powstającym podczas wytopu cyny. Autorzy oceniają, że rocznie możliwe jest dostarczanie do dalszej przeróbki minimum 10 tys. ton minerałów zawierających pierwiastki ziem rzadkich (zarówno lekkich LREE obecnych w monacycie, jak i ciężkich HREE w ksenotymie).

EN

REE metals are a vital yet scarce resource which play a particularly significant role in developed countries and their technologically advanced economies. Disturbances in the international mineral commodities market for REE’s caused by the Chinese supply monopoly force industrialized countries to launch intensive programs to discover new sources of these elements (even considering post-processing tailings). This paper discusses the mineral composition of tailings obtained in cassiterite extraction on Bangka Island. The analyzed tailing samples contain up to 21.23%w monazite, up to 17.55%w xenotime (Sungkap, Bangka), as well as zircon, ilmenite, anatase, rutile, pseurorutile, and cassiterite. Aside fromREE’s, niobiumand tantalum were identified in slag formed during tin smelting. The authors estimate that annually a minimum of 10,000 tons of minerals containing REE’s (both LREE’s-monazite and HREE’s-xenotime) can be further processed.

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Xenotime from the Podwiśniówka mine pit, Holy Cross Mountains (South-Central Poland)

Migaszewski Z. M., Gałuszka A.

Mineralogia

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2010

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Vol. 41, iss. 1/2

3--9

EN

This report presents the results of petrographical and mineralogical (optical microscopy, SEM/EDS) study of xenotime derived from the Upper (Middle?) Cambrian rocks (Wiśniówka Sandstone Fm.) of the abandoned Podwiśniówka mine pit. This is the first work on this mineral from the Holy Cross Mts. The authigenic xenotime occurs primarily as overgrowths around/on zircon in siliciclastic rocks. Moreover, this mineral is characterized by the large size of the overgrowths reaching 50 μm long and 20 μm wide. The presence of pyritecoated zircon/xenotime aggregates indicates that the xenotime formed prior to hydrothermal quartz-pyrite mineralization. The apparent lack of xenotime and vein pyrite in the tuff-bearing series, compared to the other two series displaying hydrothermal signature (pyrite, hematite, nacrite, jarosite), as well as considerable variations of the xenotime overgrowths in size and morphology, and their dominant irregular patchy-zonal microtexture may provide evidence for direct precipitation of this mineral from hydrothermal fluids.

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Genesis and stability of accessory phosphates in silicic magmatic rocks: a Western Carpathian case study

Broska I., Perik I.

Mineralogia

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2008

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Vol. 39, iss. 1/2

53--65

EN

The formation of accessory phosphates in granites reflects many chemical and physical factors, including magma composition, oxidation state, concentrations of volatiles and degree of differentiation. The geotectonic setting of granites can be judged from the distribution and character of their phosphates. Robust apatite crystallization is typical of the early magmatic crystallization of I-type granitoids, and of late magmatic stages when increased Ca activity may occur due to the release of anorthite from plagioclase. Although S-type granites also accumulate apatite in the early stages, increasing phosphorus in late differentiates is common due to their high ASI. The apatite from the S-types is enriched in Mn compared to that in I-type granites. A-type granites characteristically contain minor amounts of apatite due to low P concentrations in their magmas. Monazite is typical of S-type granites but it can also become stable in late I-type differentiates. Huttonite contents in monazite correlate roughly positively with temperature. The cheralite molecule seems to be highest in monazite from the most evolved granites enriched in B and F. Magmatic xenotime is common mainly in the S-type granites, but crystallization of secondary xenotime is not uncommon. The formation of the berlinite molecule in feldspars in peraluminous melts may suppress phosphate precipitation and lead to distributional inhomogeneities. Phosphate mobility commonly leads to the formation of phosphate veinlets in and outside granite bodies. The stability of phosphates in the superimposed, metamorphic processes is restricted. Both monazite-(Ce) and xenotime-(Y) are unstable during fluid-activated overprinting. REE accessories, especially monazite and allanite, show complex replacement patterns culminating in late allanite and epidote formation.

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Ksenotym w łupkach łyszczykowych zmineralizowanych kasyterytem z pasma łupkowego Starej Kamienicy

Bobiński W., Siemiątkowski J., Starnawska E.

Przegląd Geologiczny

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2004

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Vol. 52, nr 1

61-63

EN

Xenotime in mica schists with chlorite was analysed with EDS microprobe combined with scanning electron microscope JEOL JSM 35. The samples come from two boreholes (C-XI-41 and C-XII-54) drilled in the western part of Stara Kamienica Range. Xenotime crystals are of zoning and patchy character due to the changing composition of HREE elements. Xenotime is probably of hydrothermal origin which is connected with premetamorphic cassiterite and sulfide mineralization.