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EN
During the geological prospecting works conducted in 2013 on Bangka Island (Indonesia), high monazite content was identified in the wastes produced during processing of cassiterite deposits. Monazite, among 250 known minerals containing REE, is one of the most important minerals as primary source of REE. The monazite content in this waste is up to 90.60%. The phase composition of the investigated tailing proves that the sources of minerals accompanying the placer sediments tin mineralization are granitoids. The tailing is composed of numerous ore minerals, including monazite, xenotime, zircon, cassiterite, malayaite, struverite, aeschynite-(Y), ilmenite, rutile, pseudorutile and anatase. Monazite grains belong to the group of cerium monazite. Its grains are characterized by high content of Ce2O3 27.12–33.50 w t.%, La2O3 up to 15.46 w t.%, Nd2O3 up to 12.87%. The total REE2O3 + Y content ranges from 58.18 to 65.90 wt.%. Monazite grains observations (SEM-BSE) revealed the presence of porous zones filled with fine phases of minerals with U and Th content. The radiation intensity of 232Th is ATh = 340 ± 10 Bq and 238AU = 114 ± 2 Bq. High content of monazite and other REE minerals indicates that tailing is a very rich, potential source of REEs, although the presence of radioactive elements at the moment is a technological obstacle in their processing and use. The utilization of monazite bearing waste in the Indonesian Islands can be an important factor for development and economic activation of this region and an example of the good practice of circular economy rules.
PL
W trakcie geologicznych prac prospekcyjnych prowadzonych w 2013 roku na indonezyjskiej wyspie Bangka stwierdzono wysokie zawartości monacytu w odpadach powstałych po przeróbce osadów kasyterytonośnych. Monacyt jest jednym z najważniejszych pierwotnych źródeł REE wśród 250 znanych minerałów zawierających REE. Zawartość monacytu w badanym odpadzie wynosi do 90,60%. Skład fazowy badanych odpadów wskazuje, że źródłem minerałów towarzyszących w cynonośnych złożach okruchowych były granitoidy. W składzie odpadu przeróbczego, metodą XRD zidentyfikowano obecność licznych minerałów złożowych, wśród nich: monacyt, ksenotym, cyrkon, kasyteryt, malayait, strüveryt, aeschynit-(Y), ilmenit, rutyl, pseudorutyl i anataz. Badania składu chemicznego ziaren monacytu z użyciem EPMA ujawniły, że należy on do grupy monacytu cerowego. Jego ziarna cechują się wysoką zawartością Ce2O3 27,12–33,50% wt., La2O3 do 15,46% wt., Nd2O3 do 12,87%. Całkowita zawartość REE2O3 + Y mieści się w zakresie od 58,18 do 65,90% wt. Obserwacje ziaren monacytu (BSE) ujawniły w nich obecność stref porowatych wypełnionych drobnymi fazami minerałów z udziałem U oraz Th. Aktywność promieniotwórcza 232Th wynosi ATh = 340 ± 10 Bq, a 238U = 114 ± 2 Bq. Wysoka zawartość monacytu oraz innych minerałów nośników REE wskazuje, że odpad przeróbczy stanowi bardzo bogate, potencjalne źródło pierwiastków ziem rzadkich, choć zawartość pierwiastków promieniotwórczych stanowi obecnie przeszkodę technologiczną w ich przetwarzaniu i wykorzystaniu. Wykorzystanie monacytonośnych odpadów z wysp Indonezji może być ważnym czynnikiem rozwoju i aktywizacji gospodarczej tego regionu oraz przykładem dobrej praktyki stosowania zasad gospodarki o obiegu zamkniętym.
EN
Many granitic intrusions display evidence of magma mixing processes. The interaction of melts of contrasting composition may play a significant role during their generation and evolution. The Strzegom-Sobótka massif (SSM), located in the Sudetes (SW Poland) in the north-eastern part of the Bohemian Massif of the Central European Variscides, exhibits significant evidence of magma mingling on the macro- and micro-scales. The massif is a composite intrusion, with four main varieties: hornblende-biotite granite (with negligible amount of hornblende) and biotite granite in the western part, and two-mica granite and biotite granodiorite in the eastern part. Field evidence for magma mingling is easily found in the biotite granodiorite, where dark enclaves with tonalitic composition occur. Enclaves range from a few centimeters to half a meter in size, and from ellipsoidal to rounded in shape. They occur individually and in homogeneous swarms. The mixing textures in the enclaves include fine-grained texture, acicular apatite, rounded plagioclase xenocrysts, ocellar quartz and blade-shaped biotite. The most interesting feature of the enclaves is the presence of numerous monazite-(Ce) crystals, including unusually large crystals (up to 500 μm) which have grown close to the boundaries between granodiorite and enclaves. The crystallization of numerous monazite grains may therefore be another, previously undescribed, form of textural evidence for interaction between two contrasting magmas. The textures and microtextures may indicate that the enclaves represent globules of hybrid magma formed by mingling with a more felsic host melt. Chemical dating of the monazite yielded an age of 297±11 Ma.
3
Content available New potential source of rare earth elements
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.
EN
Primary REE-enriched fluorapatite and fluorbritholite-(Ce) in nepheline syenite from the Mariupol Massif (SE Ukraine), contain textural and chemical evidence of late- to post-magmatic metasomatic alteration. REE mobilization and replacement of the primary phases by fluid-mediated coupled dissolution-reprecipitation strongly depended on the distance between the altered minerals in the host rock. Fluorapatite and fluorbritholite-(Ce) forming individual pristine grains were partially replaced by the same phase with a new composition, resulting in the presence of patchy zoning in altered grains. the increased REE contents in altered fluorapatite rim domains are related to REE mobilization from the altered REE-depleted rim domains of the fluorbritholite-(Ce). The REEs were transported by a fluid with high F activity. The alteration of fluorapatite and fluorbritholite-(Ce) grains in contact resulted in the partial replacement of the primary phases by the same phase with a new composition, but also in the partial replacement of the fluorapatite by secondary monazite and fluorite. The REE mobilized from the fluorbritholite-(Ce) in the presence of a F-rich fluid in an alkali-rich system promoted formation of monazite as the new phosphate REE-host. The presence of secondary parisite in the altered domains of the fluorapatite and fluorbritholite-(Ce) indicates a CO2 component in the fluid during metasomatic alteration.
EN
The oldest geochronological results between 2.69–2.57 Ga was previously obtained by using K–Ar method on biotite from pegmatite from Jastrzębna IG–1 borehole. In consequence, in many published reports up to 1998, the Mazowsze (or Masovian) granitoid massif has been regarded as Archean age structure. Therewithal, other rocks in the area, e.g. Bargłów gneiss sequence traditionally were described as Archean in age. In the paper we present new U–Pb SHRIMP zircon and monazite results for above mentioned rocks which have been considered as Archean. Cathodoluminescence images and SHRIMP analysis were carried out for zircons and monazites from Jastrzebna IG–1 pegmatite of 514 m depth (a historical sample previously dated by K–Ar method) and for zircon magmatic cores from Bargłów IG–2 orthogneiss of the 708 m depth. The obtained U–Pb ages of 1826 š12 Ma (zircon) and 1789š34 Ma (monazite), and 1835š28 Ma (zircon) for two rock samples respectively have shown Paleoproterozoic origin. Only 4 of the 24 analysed zircons have clearly discordant results, which are all from the Jastrzebna pegmatite, where Pb–loss was possible (in partially metamict U–rich zircon grains). The new U–Pb SHRIMP dating indicates that Jastrzębna pegmatite and Bargłów magmatic protolith of the orthogneiss is only Late Paleoproterozoic in age and in general about 700 Ma younger than previously reported by K–Ar method. Therefore, there is no unequivocal evidence of the presence of Archean rocks in crystalline basement of NE Poland. This study has been undertaken as a part of a collaborative research agreement between the Polish Geological Institute and Geochronology and Isotope Geochemistry Research School of Earth Sciences of the Australian National University in Canberra.
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