Using an activated natural magnesium silicate (serpentinite) in a binary starting mixture, we have produced cordierite electroceramics containing up to 88% cordierite and having characteristics that ...meet relevant standard requirements.
Addition of magnesium hydrosilicate particles (talcum and serpentinite) with sizes of 1–30 μm to Litol-24 ARGO grease reduces surface wear of balls made of steel grade ShKh15. Between friction ...surfaces, local metal–mineral composite films are generated with high microhardness which reduce wear of friction elements. Forsterite, wollastanite, and some other modifications serve as minerals; they are generated owing to solidification of talcum and serpentinite under high pressures and temperatures.
The experimental production of sinter with the addition of a byproduct of magnesite production— serpentinite–magnesite—is considered. This additive improves the strength of the sinter produced. ...Recommendations are made regarding the best use of serpentinite–magnesite in the sintering shop at Ural Steel.
The article presents the results of computational studies of the radiation changes in serpentinite concretes of "dry" radiation shield of the Water-Water Energetic Reactor (WWER/VVER) type of nuclear ...power plants built in the Russian Federation and other countries. The research was carried out in connection with the increase in radiation loads on the concrete of the "dry" protection of modern nuclear power plants, and also in connection with the possible use in "dry" protection of the modern nuclear power plants of concretes with serpentinite aggregates which mineral composition and structure differ from the composition and structure of the previously used serpentinites. The calculation studies were performed using the developed and experimentally tested methods for the analytical determination of radiation and thermal changes in concretes and their components. It was found out that the relative number of displaced by irradiation atoms from 0.026 to 0.1, degree of perfection of the crystal structure of serpentinite minerals, availability of impurities in serpentinite minerals (magnetite, chlorite, olivine, pyroxenes, hornblende, brucite, magnesite, calcite, dolomite, ankerit, mica, feldspar in quantity from 0 to 40%, medium mineral grain size in the range of 0.0001 cm up to 0.02 cm influence on the radiation changes in the volume and strength of serpentinite concretes. There was also performed comparison of radiation and thermal changes. The research has showed that the lowest radiation changes will occur in the serpentinite concrete with aggregates consisting only of serpentine, especially with imperfect structure. The availability and quantity of magnetite, chlorite, calcite, brucite, feldspars and mica show insignificant influence on the radiation changes. The presence of dolomite, magnesite, ankerite and especially olivine, hornblende, pyroxenes with an increase in their volume content, as well as growth in the size of grains of minerals, the radiation changes in serpentinite concretes may grow up to 2-4 times. By increasing the duration of exploitation and power capacity of the reactor, as well as by extending the service life of a nuclear power plant, the radiation changes in the serpentinite concretes of "dry" radiation shield may grow up to 6-12 times.
Investigation of the processing of serpentinites Sagarunyan, S. A.; Sarkisyan, A. M.; Knyazyan, N. B. ...
Theoretical foundations of chemical engineering,
07/2017, Letnik:
51, Številka:
4
Journal Article
Recenzirano
The processing of serpentinites by sintering them with caustic alkali has been shown. The majority of silica is leached from the resulting sinter and is recovered from the concentrate magnesium using ...solutions of strong mineral acids. Amorphous silica is leached from the residue with alkaline solution. The solutions and the solid residue are processed according to the existing technologies.
In A World From Dust, Ben McFarland brings together the latest genetic, chemical, mathematic, and geological evidence to tell the story of how life has evolved on this planet over billions of years.
In the territory of Kosovo there are many serpentine mountain massifs. The largest complexes are found in the valley of the Ibër River, and the same are continued in a discontinuous chain through ...Koznica and Golesh to the southwest of the territory of Kosovo. Vegetation on the serpentine bedrock is rich in rare species and communities, which cannot be found in the Balkans and Europe. The communities appearing on the serpentine bedrock are characteristic and important for science. They are endemic due to the presence of endemic species in their species composition. Drenica Mountain (1051 m) is part of the Central Kosovo Mountains. These terrains are situated in the central part of Kosovo, between Çiçavica, Kosovo plain (Golesh), Llapusha, the Carraleva Mountains and the Anadrini region. A considerable part of these areas consists of serpentine bedrock, which is covered by interesting flora and vegetation. In the vegetation of Drenica Mountain 10 communities have been identified. Two of them are found on serpentine bedrock: ass. Hyperico-Euphorbietum glabriflorae and ass. Potentillo-Fumanetum bonapartei. These communities belong to the open space, and are also located in other parts of Kosovo, but only on serpentine bedrock. On Drenica Mountain there are two localities where these two communities appear. In this paper we focus in particular on ass. Hyperico-Euphorbietum glabriflorae
Na Kosovu so številni gorski masivi iz serpentinita. Največje površine so v dolini reke Ibër. Nadaljujejo se v prekinjeni verigi skozi Koznico in Golesh proti jugozahodnem delu Kosova. Vegetacija na serpentinitu je bogata z redkimi vrstami in združbami, ki ne uspevajo nikjer drugje na Balkanu in v Evropi. Te združbe na serpentinitu so pomembne, ker vsebujejo endemične vrste. Drenica (1051 m) je del osrednjega gorovja na Kosovu. To območje se nahaja v osrednjem delu Kosova, med kraji Çiçavica, Golesh, Llapusha, gorovjem Carraleva in območjem Anadrini. Precejšen del območja je na serpentinitu. V vegetaciji gore Drenica je najdenih deset združb. Dve sta na serpentinitu: asociacija Hyperico-Euphorbietum glabriflorae in asociacija Potentillo-Fumanetum bonapartei. Najdemo ju na odprtih rastiščih. Na Drenici sta dve najdiščiteh dveh združb. V članku je predstavljena predvsem asociacija Hyperico-Euphorbietum glabriflorae
Numerous serpentinite seamounts on the forearc of the Izu-Bonin-Mariana (IBM) subduction zone present the only known locations worldwide where mantle wedge serpentinites and blueschist-facies ...metamafic fragments can be directly sampled. These fragments have been transported diapirically in a low temperature fluid-mud matrix from within this active subduction zone from a depth of >20 km below seafloor, i.e., directly from the slab-mantle-interface. At South Chamorro Seamount (ODP Leg 195), ~85 km distal from the trench axis, the slab surface is at ~27 km depth, where estimated temperatures are <350 °C, typical for blueschist-facies, sub-forearc subduction zone environments.This is the first study which combines high-resolution results on light element (Li, Be, B) and d11B distribution of both slab-derived metamafic rocks and serpentinized mantle rocks from an active subduction zone. Mobile in aqueous fluids and sensitive as tracers of fluid source and mobilization, Li, Be and B in (Na-)amphibole, phengite, chlorite and serpentine provide (i) information to quantify devolatilization of the subducting mafic oceanic crust in shallow regions and (ii) information about fluid infiltration into the forearc mantle peridotite due to fluid transfer from the dehydrating slab into the overlying mantle wedge.Analyses of Li, Be and B contents and B isotope ratios were performed using secondary ion mass spectrometry (SIMS). Light element distribution maps were made using Time-of-Flight SIMS. Micro-Raman was used to identify serpentine polymorphs and brucite in serpentinites.The fine-grained metamafic fragments (<5 mm in diameter) comprise a large variety of mineral assemblages. These assemblages indicate a range of protoliths that have been subjected to mechanical mixing and metasomatism within a mélange zone at surprisingly shallow depths. Minerals such as chlorite, Na- and Ca-amphibole, phengite, epidote and Na-pyroxene in paragenesis with pumpellyite correlate with blueschist-facies conditions at ~27 km depth (at ~300 °C). The main Li, Be and B carriers are phengite > chlorite + amphibole. Estimated concentrations of light elements in bulk rocks are in the same range as in altered oceanic crust and subducting sediments, demonstrating that the major amount remains in the subducting slab and is not released with fluids. However, moderate B loss is suggested by the light d11B values of phengite, chlorite and amphibole (6 ±4 ). As B fractionation is most effective at low temperatures, this light B isotope signature can be explained by low fluid losses from the shallow slab, which originally had a slightly positive average d11B value. Due to B isotope fractionation, the released (Li- and B-enriched) slab-fluids that correlate with a slabresidue with 6 ±4 , are positive reaching a d11B value of up to ~ +20 .In variably serpentinized peridotites, the serpentine polymorphs lizardite, chrysotile and polygonal serpentine together with minor brucite are preferentially distributed between textures or serpentine generations. Li, Be and B abundances are variable and serpentine minerals show an enrichment for Li and B but also a depletion for Li compared to depleted mantle values. Be contents in serpentine are low and similar to primary minerals olivine, orthopyroxene and clinopyroxene. These results demonstrate that serpentinization contributes to a general light element enrichment in the mantle wedge.Early serpentine textures have high Li abundances (up to 30 µg/g) compared to the later serpentine, B abundances are variable. The dominant polymorph is lizardite, which indicates relatively low fluid-rock ratios. Late (youngest) serpentine generations are dominated by chrysotile, which indicates high fluid-rock ratios during serpentinization. This serpentine has lower Li abundances and is relatively enriched in B. The varying fluid-rock ratios between serpentine generations are suggested to be the key to explaining the large range in d11B values of 14 to +24 found in serpentine. During early peridotite hydration, all fluid is completely consumed in small-scale serpentine areas and the averaging (~25 mm spot size) SIMS analyses reveal the positive B isotope signature of the slab-derived fluids. The negative d11B values in serpentine can be well explained by strong B fractionation between fluid and serpentine at the low temperature and neutral to basic pH.
Die zahlreichen Serpentinit-Vulkane auf dem Forearc der Izu-Bonin-Mariana (IBM) Subduktionszone sind die weltweit einzigen bekannten Fundorte, wo Serpentinite des Mantelkeils und Blauschiefer-fazielle metamafische Fragmente direkt beprobt werden können. Diese Fragmente wurden diapirisch in einer Fluid-Schlamm-Matrix niedriger Temperatur innerhalb dieser aktiven Subduktionszone aus einer Tiefe von >20 km unter dem Meeresboden, also direkt von der Platten-Mantel-Grenze, befördert. Am South Chamorro Seamount (ODP Leg 195), ~85 km entfernt vom Graben, liegt die Oberfläche der subduzierenden Platte bei ~27 km Tiefe, wo Temperaturen <350 °C herrschen, typisch für eine Blauschiefer-fazielle Sub-Forearc-Subduktionszonen-Umgebung.Dies ist die erste Studie, die hochauflösende Ergebnisse über die Verteilung leichter Elemente (Li, Be, B) und d11B in Gesteinen der metamafischen Platte und des serpentinisierten Mantels einer aktiven Subduktionszone vereint. Mobil in wässrigen Phasen und empfindlich als Tracer für Fluid-Quellen und -mobilisierung, liefern Li, Be und B in (Na-)Amphibol, Phengit, Chlorit und Serpentin a) Informationen, um die Entwässerung der subduzierenden mafischen ozeanischen Kruste in oberfläschen-nahen Regionen zu quantifizieren und b)Informationen über Fluid Infiltration in den Forearc-Mantel-Peridotiten auf Grund von Fluid-Transfer von der entwässernden Platte in den darüber liegenden Mantelkeil. Li-, Be- und B-Konzentrationen und B-Isotopenverhältnisse wurden mit dem Sekundär-Ionen-Massen-Spektrometer (SIMS) gemessen. Aufnahmen der Verteilung der leichten Elemente wurden mit dem Time-of-Flight SIMS(Flugzeitmassenspektrometer) erstellt. Mit dem Mikro-Raman wurden Serpentin Polymorphe und Brucit in den Serpentiniten bestimmt.Die feinkörnigen metamafischen Fragmente (<5mm) bestehen aus einer Vielzahl von Mineralparagenesen. Diese Paragenesen deuten auf eine Reihe von Ausgangsgesteinen hin, die mechanischer Vermengung und Metasomatose innerhalb einer Mélange-Zone in erstaunlich niedriger Tiefe ausgesetzt waren. Minerale wie Chlorit, Na- und Ca-Amphibol, Phengit, Epidot und Na-Pyroxen in Paragenese mit Pumpellyit entsprechen Blauschiefer-faziellen Bedingungen in ~27 km Tiefe (bei ~300 °C). Die hauptsächlichen Li-, Be- und B-Träger sind Phengit > Chlorit + Amphibol. Abgeschätzte Gesamtgesteins-Konzentrationen leichter Elemente liegen im Bereich alterierter ozeanischer Kruste und subduzierender Sedimente; dies zeigt, dass der größte Teil der leichten Elemente in der subduzierenden Platte verbleibt und nicht mit Fluiden abgegeben wird. Jedoch deuten die leichten d11B Werte von Phengit, Chlorite und Amphibol (6 ±4 ) auf einen mäßigen B-Verlust hin. Da B-Isotopen-Fraktionierung bei niedrigen Temperaturen am stärksten ist, kann dieser negative d11B Wert durch Fluid-Verlust von der Platte in niedriger Tiefe erklärt werden, welche einen im Mittel leicht positiven d11B Ausgangswert hatte. Aufgrund von B-Isotopen-Fraktionierung haben die von der subduzierenden Platte freigesetzten (Li- und B-reichen) Fluide, die mit einem Residuum mit 6 ±4 d11B korrelieren, eine positive Isotopie von bis zu ~ +20 .In den unterschiedlich stark serpentinisierten Peridotiten sind die Serpentin Polymorphe Lizardit, Chrysotil und polygonaler Serpentin zusammen mit wenig Brucit unterschiedlich zwischen Texturen und Serpentin-Generationen verteilt. Li-, Be- und B-Häufigkeiten sind variabel und Serpentin Minerale zeigen sowohl An- als auch Abreicherung an Li und Anreicherung in B im Vergleich zum verarmten Mantel. Be Konzentrationen sind niedrig und ähnlich wie in Primärmineralen Olivin, Orthopyroxen und Klinopyroxen. Diese Ergebnisse zeigen, dass Serpentinisierung zu einer allgemeinen Anreicherung leichter Elemente im Mantelkeil führt.Frühe Serpentin Texturen haben hohe Li Konzentrationen (bis zu 30 µg/g) im Vergleich zu spät gebildetem Serpentin, die B Gehalte sind variabel. Das dominierende Polymorph ist Lizardit, was auf ein relativ niedriges Fluid-Gesteins-Verhältnis hinweist. Späte (also junge) Serpentin-Generationen sind von Chrysotil dominiert, was auf ein hohes Fluid-Gesteins-Verhältnis während der Serpentinisierung hinweist. Dieser Serpentin has niedrige Li-Konzentrationen und ist relativ mit B angereichert. Die wechselnden Fluid-Gesteins-Verhältnisse zwischen Serpentin-Generationen sind die naheliegenste Erklärung für die große Spannweite der d11B Werte von 14 bis +24 in Serpentin. Während früher Hydratisierung des Peridotits wird das Fluid komplett in kleinräumigen Serpentin-Bereichen aufgezehrt; somit weisen die SIMS Analysen, bei einer Messpunktgröße von ~25 mm, eine im Mittel positive B-Isotopie des von der subduzierenden Platte kommenden Fluids hin. Die negativen d11B Werte im Serpentin können durch starke B-Isotopen-Fraktionierung zwischen Fluid und Serpentin bei niedriger Temperatur und neutralem bis basischem pH-Wert erklärt werden.
U članku su prikazana tri ulomka kamenih sjekira s gradine
Monkodonja, za koje je obavljena petrografska analiza.
Prikazani su načini analize i dobiveni rezultati o vrsti i porijeklu
kamena. Sirovine ...za njihovu izradu - žad, serpentinit i metadijabaz
- potječu iz različitih izvora. Ti su materijali najčešće
u uporabi kroz mlađi neolitik i eneolitik, a na Monkodonji je
njihovo korištenje datirano još barem kroz prvu polovicu 2.
tisućljeća pr. n. e.
U ovom radu istraživan je serpentinit s nalazišta na Banovini u Hrvatskoj. U toj mineralnoj sirovini prevladavajući mineral je antigorit. Dilatacijska krivulja ukazuje da je prva kontrakcija uzorka ...uzrokovana dehidratacijom antigorita na približno 660°C. Nasuprot tome, na drugu kontrakciju uzorka koja počinje pri približno 860°C utječe stvaranje olivina. Morfologija serpentinita prije i poslije termičke obradbe promatrana je optičkim mikroskopom. Izgled serpentinita prije termičke obradbe karakteriziran je uključcima olivina kao primarnog minerala zaostalog u procesu serpentinizacije. Izgled serpentinita poslije termičke obradbe promijenio se uslijed eliminacije vode. Prvo termički obrađen te potom mljeven serpentinit ima bolje karakteristike od prvo mljevenog, a potom termički obrađenog serpentinita.
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