scholarly journals Ultrasonic Shaking of Glauconite Pellets with Diverse Reagents for a Comparison of Their K–Ar with Already Published Rb–Sr Results

Geosciences ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 439
Author(s):  
Norbert Clauer ◽  
Edward Keppens ◽  
I. Tonguç Uysal ◽  
Amélie Aubert
Keyword(s):  
Clay Material ◽  
Similar Data ◽  
X Ray Diffraction ◽  
Metallic Trace Elements ◽  
Three Samples ◽  
Isotopic Studies ◽  
Mineral Assemblages ◽  
Preparation Step ◽  
Mineral Compositions ◽  
Sr Method

A combined ultrasonic treatment, with de-ionized H2O, dilute HAc or dilute HCl, of three Mid-Miocene glauconite samples was applied to K–Ar date the different separates in order to compare the results with those obtained by the Rb–Sr method using the same three samples and that were analyzed strictly in the same way. Two aliquots yield opposite elemental and K–Ar trends, which suggests different initial mineral compositions for the various pellets. The K–Ar data of two untreated and leached L7 and L8 aliquots are almost within analytical uncertainty from 17.3 ± 0.6 Ma to 19.6 ± 0.7 Ma (2σ), while those of the third L10 sample are slightly higher at 22.1 ± 1.2 Ma (2σ). Comparatively, the earlier published Rb–Sr ages of the three untreated samples and of the leached aliquots gave similar data for the L7 aliquots by an isochron at 18.1 ± 3.1 (2σ) Ma and for the sample L8 by an isochron with an age of 19.6 ± 1.8 (2σ) Ma, while the untreated L10 aliquot yields a very high Rb–Sr date of 42.1 ± 1.6 (2σ) Ma. This untreated L10 glauconite fraction contains blödite, a Sr-rich carbonate that impacted the two isotopic systems differently. Generally, dilute HCl or HAc acids dissolve carbonates, sulfates, sulfites and oxides, while they do not affect the clay-type crystals such as glauconites. These soluble minerals can be identified indirectly, as here, by X-ray diffraction and the amounts of leached Na2O, CaO and Fe2O3 contents. Together with the leaching of some metallic trace elements, those of NaO confirm the leaching of metals and of blödite that are both hosted by the glauconite pellets. The occurrence of this Sr-enriched mineral explains the age differences of the non-treated aliquots and suggests a systematic leaching of any glauconite separate before isotope determination and, possibly, a comparison of the Rb–Sr and K–Ar results. Ultrasonic shaking appears appropriate for physical disaggregation of any contaminating grains that may remain hosted within the pellets, even after a preliminary H2O wash, which may dissolve and remove the soluble minerals but not the H2O-insoluble silicates. The K–Ar study completed here as a complement to a previous Rb–Sr study highlights, again, the importance of the preparation step in isotopic studies of glauconite-type and, by extension, of any clay material, as all occurring minerals can interfere in the final age determinations and, therefore, differently in the mineral assemblages. All those not in isotopic equilibrium need to be removed before analysis, including the soluble Sr or alkali-enriched ones.

scholarly journals Investigations of M3Al8O15:Eu3+,Dy3+ (M = Ba, Ca, Mg) phosphors

2016 ◽  
Vol 34 (2) ◽  
pp. 412-417
Author(s):  
Esra Öztürk
Keyword(s):  
Electron Microscopy ◽  
Solid State Reaction Method ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Three Samples ◽  
Scanning Electron ◽  
The Eu

AbstractIn this work, aluminate type phosphorescence materials were synthesized via the solid state reaction method and the photoluminescence (PL) properties, including excitation and emission bands, were investigated considering the effect of trace amounts of activator (Eu3+) and co-activator (Dy3+). The estimated thermal behavior of the samples at certain temperatures (> 1000 °C) during heat treatment was characterized by differential thermal analysis (DTA) and thermogravimetry (TG). The possible phase formation was characterized by X-ray diffraction (XRD). The morphological characterization of the samples was performed by scanning electron microscopy (SEM). The PL analysis of three samples showed maximum emission bands at around 610 nm, and additionally near 589 nm, 648 nm and 695 nm. The bands were attributed to typical transitions of the Eu3+ ions.

Crystallite size and microstrain: XRD line broadening analysis of AgSiN thin films

2019 ◽  
Vol 48 (6) ◽  
pp. 473-480 ◽  
Author(s):  
Umi Zalilah Mohamad Zaidi ◽  
A.R. Bushroa ◽  
Reza Rahbari Ghahnavyeh ◽  
Reza Mahmoodian
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Magnetron Sputtering ◽  
Crystallite Size ◽  
Approximation Method ◽  
Ti6al4v Alloy ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Content Type ◽  
Three Samples

Purpose This paper aims to determine the crystallite size and microstrain values of AgSiN thin films using potential approach called approximation method. This method can be used as a replacement for other determination methods such as Williamson-Hall (W-H) plot and Warren-Averbach analysis. Design/methodology/approach The monolayer AgSiN thin films on Ti6Al4V alloy were fabricated using magnetron sputtering technique. To evaluate the crystallite size and microstrain values, the thin films were deposited under different bias voltage (−75, −150 and −200 V). X-ray diffraction (XRD) broadening profile along with approximation method were used to determine the crystallite size and microstrain values. The reliability of the method was proved by comparing it with scanning electron microscopy graph and W-H plot method. The second parameters’ microstrain obtained was used to project the residual stress present in the thin films. Further discussion on the thin films was done by relating the residual stress with the adhesion strength and the thickness of the films. Findings XRD-approximation method results revealed that the crystallite size values obtained from the method were in a good agreement when it is compared with Scherer formula and W-H method. Meanwhile, the calculations for thin films corresponding residual stresses were correlated well with scratch adhesion critical loads with the lowest residual stress was noted for sample with lowest microstrain and has thickest thickness among the three samples. Practical implications The fabricated thin films were intended to be used in antibacterial applications. Originality/value Up to the knowledge from literature review, there are no reports on depositing AgSiN on Ti6Al4V alloy via magnetron sputtering to elucidate the crystallite size and microstrain properties using the approximation method.

Saponite, Corrensite and Chlorite-Saponite Mixed-Layers in the Sancerre-Couy Deep Drill-Hole (France)

Clay Minerals ◽  
1994 ◽  
Vol 29 (1) ◽  
pp. 47-61 ◽  
Author(s):  
D. Beaufort ◽  
A. Meunier
Keyword(s):  
Chemical Composition ◽  
Drill Hole ◽  
X Ray Diffraction ◽  
Parental Relationships ◽  
Clay Deposits ◽  
Fe Content ◽  
Three Samples ◽  
Structural Formulae ◽  
Layer Mineral ◽  
Mixed Layers

AbstractThe clay deposits in fractures of the metamorphic basement under the Paris Basin sedimentary formations at Sancerre-Couy (France) are composed of trioctahedral species which are exceptionally well crystallized. Three samples were chosen in order to study the chemical composition of 100% expandable saponite, 50% expandable corrensite and 10% expandable chlorite-saponite mixed-layer mineral C90–S10 Two sets of microchemical analyses were performed in order to determine the variations of the composition on large and small numbers of particles. X-ray diffraction (XRD) and Mössbauer spectrometry were performed on purified samples.The mathematical decomposition of Si, Al and Mg histograms established from microanalyses of a large number of crystals of saponite, corrensite and C90–S10 evidences bimodal populations. The total Fe content of the three species is unimodal whatever the chemical composition of the surrounding rock and the Fe2+/Fe3+ ratio. The structural formulae established from a large number of microanalyses of a few particles show that there are no parental relationships between saponite, corrensite and C90–S10. The expandable layer of corrensite is characterized by a high charge. It is proposed that the tetrahedral sheets adjacent to the brucitic sheet and the exchangeable interlayer in a 2 : 1 unit are identical in corrensite.

scholarly journals Identification of tetragonal and cubic structures of zirconia using synchrotron x-radiation source

1991 ◽  
Vol 6 (6) ◽  
pp. 1287-1292 ◽  
Author(s):  
Ram Srinivasan ◽  
Robert J. De Angelis ◽  
Gene Ice ◽  
Burtron H. Davis
Keyword(s):  
Particle Size ◽  
Radiation Source ◽  
Sol Gel ◽  
Yttria Stabilized Zirconia ◽  
Tetragonal Structure ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Synchrotron Source ◽  
Three Samples

X-ray diffraction from a synchrotron source was employed in an attempt to identify the crystal structures in zirconia ceramics produced by the sol-gel method. The particles of chemically precipitated zirconia, after calcination below 600 °C, are very fine, and have a diffracting particle size in the range of 7–15 nm. As the tetragonal and cubic structures of zirconia have similar lattice parameters, it is difficult to distinguish between the two. The tetragonal structure can be identified only by the characteristic splittings of the Bragg profiles from the “c” index planes. However, these split Bragg peaks from the tetragonal phase in zirconia overlap with one another due to particle size broadening. In order to distinguish between the tetragonal and cubic structures of zirconia, three samples were studied using synchrotron radiation source. The results indicated that a sample containing 13 mol% yttria-stabilized zirconia possessed the cubic structure with a0 = 0.51420 ± 0.00012 nm. A sample containing 6.5 mol% yttria stabilized zirconia was found to consist of a cubic phase with a0 = 0.51430 ± 0.00008 nm. Finally, a sample which was precipitated from a pH 13.5 solution was observed to have the tetragonal structure with a0 = 0.51441 ± 0.00085 nm and c0 = 0.51902 ± 0.00086.

scholarly journals Characterization of Algerian kaolins for utilization as a raw material in electrical insulators

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 267-273
Author(s):  
M. Laraba
Keyword(s):  
Bending Strength ◽  
Dielectric Strength ◽  
Raw Material ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Electrical Insulator ◽  
X Ray ◽  
Three Samples ◽  
Porcelain Insulators

Abstract The aim of this investigation was to characterize three samples of kaolin (DD1, DD2 and DD3) collected from Djebel Debbagh deposit (East of Algeria) to be used in electrical porcelain insulators. Grain-size analysis, X-ray fluorescence, X-ray diffraction, scanning electron microscopy and thermal analysis (TG-DTA) were performed. Each sample was mixed with feldspar and silica to obtain three porcelain formulations. The obtained results indicated that the three kaolins were composed by kaolinite and halloysite with variable contents of MnO and Fe2O3 as associated impurities. It was found that the DD1 was the appropriate kaolin as raw material for making the high-voltage electrical insulator which had the highest electrical and mechanical properties (dielectric strength, bending strength and bulk density), while DD2 and DD3 were less suitable due to their lower properties caused by the presence of impurities which must be removed.

scholarly journals Transformation of Pb, Cd, and Zn Minerals Using Phosphates

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 342 ◽  
Author(s):  
Magdalena Andrunik ◽  
Magdalena Wołowiec ◽  
Daniel Wojnarski ◽  
Sylwia Zelek-Pogudz ◽  
Tomasz Bajda
Keyword(s):  
Sequential Extraction ◽  
Contaminated Soils ◽  
Heavy Metal Contamination ◽  
Cost Effective ◽  
X Ray Diffraction ◽  
Chemical Immobilization ◽  
Crystal Forms ◽  
Dissolved Carbon ◽  
Three Samples

Heavy metal contamination in soils has become one of the most critical environmental issues. The most efficient in-situ remediation technique is chemical immobilization that uses cost-effective soil amendments such as phosphate compounds to decrease Pb, Cd and Zn accessibility in the contaminated soils. The present study examined the effectiveness of KH2PO4 in immobilizing Pb, Cd and Zn in three samples of contaminated soils collected from ZGH “Bolesław” (Mining and Smelting Plant “Bolesław”). Effectiveness was evaluated using the following methods: a toxicity characteristic leaching procedure (TCLP)-based experiment, sequential extraction, X-ray diffraction analyses (XRD), and scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS). The most efficient percentage reduction of total leachable metal concentration assessed by TCLP was observed for lead (50%–80%), and the least reduction was observed for zinc (1%–17%). The most effective immobilization of stable compounds assessed by sequential extraction was noted for lead, while the weakest immobilization was noted for cadmium. New insoluble mineral phases were identified by SEM-EDS analysis. Cd, Zn, and Pb formed new stable mineral substances with phosphates. The predominant crystal forms were dripstones and groups of needles, which were easily formed by dissolved carbon rock surfaces containing zinc ions. The alkaline nature of the soil and a large number of carbonates mainly influenced the formation of new structures.

Clay mineral evidence for low-grade Caledonian and Variscan metamorphism in south-western Dyfed, south Wales

1980 ◽  
Vol 43 (331) ◽  
pp. 857-863 ◽  
Author(s):  
D. Robinson ◽  
R. A. Nicholls ◽  
L. J. Thomas
Keyword(s):  
Lower Cambrian ◽  
Volatile Matter ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Illite Crystallinity ◽  
X Ray ◽  
South Wales ◽  
Mineral Assemblages ◽  
Variscan Metamorphism ◽  
Pelitic Rocks

SummaryIllite crystallinity determinations on Palaeozoic pelitic rocks, whose stratigraphic range runs from Lower Cambrian to Westphalian, indicate that anchimetamorphism has affected both the Lower and Upper Palaeozoic sequences. Two metamorphic episodes are in evidence, with the earlier, Caledonian, being of slightly higher grade. The higher anchizone crystallinity values are recorded from the Fishguard area in which mineral assemblages of the prehnite-pumpellyite facies have recently been recognized in basic igneous rocks. The later metamorphic episode has affected rocks to the south of the Variscan front. Here crystallinity values are low anchizone but some straddle the boundary with the diagenetic state. The Pembroke coalfield lies in this southern area and has coals largely of anthracite rank with volatile matter contents of between 10.1 and 5% Grade of metamorphism as indicated by crystallinity and by coal rank data from the Pembroke coalfield shows anomalous results to that described from the main South Wales coalfield. A neo-formed 2M illite from the Variscan spaced cleavage is described with analytical and X-ray diffraction data.

Two-step mode of clay formation in the extensional basins: Cambrian–Ordovician clastic rocks of the Antalya unit, SW Turkey

Clay Minerals ◽  
2017 ◽  
Vol 52 (3) ◽  
pp. 365-389 ◽  
Author(s):  
Ö. Bozkaya ◽  
H. Yalçin ◽  
P.A. Schroeder
Keyword(s):  
Spatial Relations ◽  
White Mica ◽  
Chemical Characteristics ◽  
Burial History ◽  
X Ray Diffraction ◽  
X Ray ◽  
Clastic Rocks ◽  
Sw Turkey ◽  
Mineral Assemblages ◽  
Clay Formation

AbstractOrdovician clastic rocks of the Antalya unit in SW Turkey bear mineralogical/geochemical evidence of Triassic extensional rift timing and spatial relations. The crystal chemistry of the phyllosilicate assemblages (illite, chlorite, kaolinite, mixed-layer illite-smectite, chlorite-vermiculite and chlorite-smectite) is consistent with the rock experiencing a multi-generational burial history. The appearance of kaolinite and illite-smectite-bearing rocks in the Antalya unit is characteristic of diagenetic-anchimetamorphic conditions and is of higher grade than their anchi-epizonal equivalents in other regions of the Tauride belt. Illites and chlorites are of both detrital and authigenic origin, whereas I-S and kaolinites are authigenic. Detrital micas have been altered to chlorite and K-white mica stacks in which relicts suggest the chlorites were derived from detrital biotites. The broad X-ray diffraction illite peaks show that they are composed both of illite and illite-smectite. Na,K-mica and paragonite occur within the chlorite-mica stacks as replacements of muscovite, probably driven by Na-rich solutions. The authigenic clays were formed within the microporous matrix and the interplanar spaces of {001} planes of chlorite-mica stacks, with textures independent of the bedding and foliation planes of the rocks. The authigenic chlorites exhibit higher Si and Fe and lower Mg contents than their detrital counterparts. Authigenic chlorite thermometry indicates rift-related temperatures of 50–150°C, whereas pre-rift detrital chlorites formed at temperatures of  >200°C. Authigenic illite and illite-smectite are phengitic in composition and contain more Si, Mg, Fe and Ca and less Al and K than detrital K-white micas. The textural, mineralogical and chemical characteristics support the hypothesis that the mineral assemblages were a result of a two-step mode of formation with diagenetic overprints of previously anchizonal rocks in extensional basin conditions.

A hydrothermal clay mineral assemblage at the Late Proterozoic unconformity in the Buenos Aires Complex – La Tinta Formation, Barker area, Tandilia Ranges (Argentina)

Clay Minerals ◽  
2010 ◽  
Vol 45 (2) ◽  
pp. 209-224 ◽  
Author(s):  
J. C. Martínez ◽  
J. A. Dristas ◽  
H.-J. Massonne ◽  
T. Theye
Keyword(s):  
Clay Mineral ◽  
White Mica ◽  
X Ray Diffraction ◽  
Aluminium Phosphate ◽  
X Ray ◽  
Late Proterozoic ◽  
Eu Anomaly ◽  
Rapid Changes ◽  
Mineral Assemblages ◽  
First Time

AbstractA general alteration pattern of two transitional clay mineral assemblages was determined by petrography and X-ray diffractometry studies at the Tandilia Late Proterozoic unconformity zone, around the Barker locality: (1) K-white mica + chlorite + calcite ± anatase-rutile ± secondary quartz (farther from the unconformity) and (2) pyrophyllite + K-white mica + Ti-rich hematite ± aluminium phosphate-sulphate minerals ± tourmaline ± anatase-rutile (closer to the unconformity). The local occurrence of Na in K-white micas and K-Na in pyrophyllite is described for the first time. Possible interlayering with intermediate K-Na mica and paragonite is indicated by detailed X-ray diffraction analyses. A negative Eu anomaly (Eu/Eu* = 0.24), strongly positive Eu anomaly (Eu/Eu* =11.7) and positive Ce anomaly characterized rapid changes from an unaltered basement to the most altered basement and sedimentary rocks at the unconformity. Aluminium phosphate-sulphate minerals dominate patterns of LREE. A model of hydrothermal alteration comparable to that of unconformity-related uranium deposits is presented.

Fusibility Characteristics of Slag from Fluidized-Bed Gasification of Jincheng Anthracite

2013 ◽  
Vol 805-806 ◽  
pp. 1317-1320
Author(s):  
Feng Hai Li ◽  
Zhen Zhu Li ◽  
Ming Jie Ma ◽  
Jie Jie Huang ◽  
Yi Tian Fang
Keyword(s):  
Fluidized Bed ◽  
Slag Formation ◽  
X Ray Diffraction ◽  
Fusion Temperature ◽  
X Ray ◽  
Base Content ◽  
Ash Fusion Temperature ◽  
Total Base ◽  
Mineral Compositions ◽  
Distribution Plate

To investigate fusibility characteristics of slag from Jincheng Anthracite (JC) pressurized ash agglomerate fluidized bed (AFB) gasification of Jincheng Anthracite (JC), the slag samples were examined by an ash fusion temperature (AFT) analyzer, scanning electron microscope (SEM), and X-ray diffraction (XRD). The results show that the AFTs of three kinds of slag are lower than that of JC greatly, and the AFTs of three kinds of slag decrease from the slag formed that on the central tube (SC) to distribution plate (SD) to inner face (SI), as a result of the increase of total base content and the differences in their mineral compositions accordingly. Not all slag during AFB gasification are composed of molten mineral matters. This can be explained that the phenomena that the slag formation during fluidized-bed gasification when the operating temperature is below the AFTs of coal.

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