Characterization of Neogene marls from the Kert Basin (northeast Morocco): suitability for the ceramics industry

Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 379-392
Author(s):  
Hicham Nasri ◽  
Ali Azdimousa ◽  
Kamal El Hammouti ◽  
Abdelilah El Haddar ◽  
Meriam El Ouahabi
Keyword(s):  
Grain Size ◽  
Specific Surface ◽  
Cross Sections ◽  
Volcanic Ash ◽  
High Plasticity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Layers ◽  
Ceramics Industry

ABSTRACTThe Neogene marls from the lower Kert area (northeast Morocco) were characterized to evaluate their suitability for the ceramics industry. Two cross-sections involving all of the Neogene facies were studied on both banks of the Kert River. Grey and green marls occurring between sandstone and tuffs were characterized by mineralogical (X-ray diffraction) and physicochemical (grain size, Atterberg limits, X-ray fluorescence and specific surface area) analyses. The Neogene clays studied are mainly calcareous silty marls containing 13–20 wt.% calcite. They consist of quartz, calcite, feldspars, dolomite, illite, kaolinite, chlorite and 10–14 Å illite-vermiculite mixed layers. Cristobalite was detected only in the uppermost level of the green marls, and it originates from a volcanic ash of Messinian age. Trace amounts of siderite and rhodochrosite indicate reducing or locally oxidizing conditions during sedimentation or shortly thereafter. The marls have medium to high plasticity, making them optimal for extrusion. Raw Neogene marls are suitable for manufacturing structural clay products. More specific uses, such as hollow products, roofing tiles and masonry bricks, were supported by the geochemical results and grain-size distribution.

The Effect of Ethanol Solvent on Characterization of MAPbI3 Perovskite

2021 ◽  
Vol 1039 ◽  
pp. 307-312
Author(s):  
Mohammad Malik Abood ◽  
Osama Abdul Azeez Dakhil ◽  
Aref Saleh Baron
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Morphological Characteristics ◽  
X Ray Diffraction ◽  
Lead Iodide ◽  
X Ray ◽  
Diffraction Patterns ◽  
Photovoltaic Technologies ◽  
Perovskite Photovoltaic

Methyl ammonium lead iodide CH3NH3PbI3 Perovskite was synthesized by a new method mixing between one and two steps, in addition, the ethanol solvent was used to dissolve CH3NH3I and compared with isopropanol solvent. The characterizations of synthesized perovskite samples included the structural properties, morphological characteristics and optical properties. The intensity and orientation in X-ray diffraction patterns appear clearly in ethanol solvent while disappearing at a peak at 12o due to the speed reaction of perovskite in this solvent. Additionally, the ethanol solvent increasing the grain size of perovskite which homogeneity of the surface morphology. the ethanol solvent cause a decrease in the wavelength of absorbance edge in addition to an increase in the energy bandgap value. Keywords: Ethanol Solvent, Perovskite, Photovoltaic Technologies, X-ray diffraction.

Characterization of halloysite (North East Rif, Morocco): evaluation of its suitability for the ceramics industry

Clay Minerals ◽  
2018 ◽  
Vol 53 (1) ◽  
pp. 65-78 ◽  
Author(s):  
Abdelilah El Haddar ◽  
Elkhadir Gharibi ◽  
Ali Azdimousa ◽  
Nathalie Fagel ◽  
Iz-Eddine El Amrani El Hassani ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Fine Particles ◽  
High Plasticity ◽  
North East ◽  
Physico Chemical ◽  
Ceramics Industry ◽  
Tubular Crystals

ABSTRACTA halloysite clay from Nador (NE Morocco) was studied to evaluate its suitability in the ceramics industry. A cross-section involving all the Messinian facies was performed in the Melilla Neogene basin, at the foot of the Gourougou volcano, to establish the origin of the halloysite and estimate its reserves. White layers of halloysite and red clays rich in smectite occurring in contact with basal-reef limestone were characterized by mineralogical (XRD, IR), textural (SEM) and physico-chemical analyses (grain-size, Atterberg limits, DTA/TG, XRF and specific surface area). Ceramic properties were evaluated for halloysite fired from 500 to 1100°C to evaluate technical processing for ceramic production.The halloysite clay consists of fine particles with a high plasticity and a large specific surface area. The XRD investigation revealed the presence of 7 Å non-hydrated halloysite along with gibbsite, alunite, K-feldspar and traces of smectite and illite.The presence of halloysite was confirmed from the characteristic IR bands at 3695 and 3618 cm−1and the predominance of tubular crystals observed in the SEM. The chemical analysis revealed high contents linked to the presence of Al-rich phases (gibbsite and alunite). DTA/TG and XRD results of fired clay samples proved the dehydroxylation of halloysite and a rearrangement of metakaolinite to form mullite and spinel at 975°C.The Moroccan halloysite might be suitable for refractory ceramic applications. However, addition of quartz sand might be necessary to avoid crack development during firing and to reduce the plasticity of raw halloysite and minimize shrinkage during sintering.

scholarly journals Mineralogical Study of Levels with Magnesian Clay Minerals in the Santos Basin, Aptian Pre-Salt Brazil

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 970
Author(s):  
Maurício Dias da Silva ◽  
Márcia Elisa Boscato Gomes ◽  
André Sampaio Mexias ◽  
Manuel Pozo ◽  
Susan Martins Drago ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Clay Fraction ◽  
Total Sample ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineralogical Study ◽  
Original Rock ◽  
Mixed Layers

The object of this study is magnesian clay minerals present in carbonate rocks of the post-rift phase of the pre-salt in the Santos Basin. These rocks developed in an Aptian-age alkaline lacustrine environment. This study summarizes the formation of clay minerals associated with different lithotypes in a range of 19 m and a depth of more than 5100 m. They were characterized from petrographic analysis by optical microscopy, X-ray diffraction (total sample and clay fraction), and modeling by Newmod®; and examined and analyzed by scanning electron microscopy. An approach based on identifying lithotypes and characterization of microsites allowed us to understand the occurrence of different clay minerals. Kerolite was the most abundant mineral in the sampled range. It occurs in lamellar aggregates under greater preservation of the original rock lamination and in association with spherulites and shrubs. The Stv/Ker mixed layers occurs in the same association, and formed finer unlaminated aggregates associated with the more intense dolomitization and silicification processes. Saponite occurs associated with detrital minerals forming clayey levels intercalated with microcrystalline carbonates. Fluids with a high Mg/Si and pH < 9 favor the precipitation of kerolite. The increase in pH during diagenesis may be responsible for the formation of Stv/Ker mixed layers.

Microcrystallinity in α-Si, Ge:H, F Alloys

1986 ◽  
Vol 70 ◽  
Author(s):  
D. S. Shen ◽  
J. Kolodzey ◽  
D. Slobodin ◽  
J. P. Conde ◽  
C. Lane ◽  
...  
Keyword(s):  
Grain Size ◽  
Cross Sections ◽  
Amorphous Alloys ◽  
Annealing Temperature ◽  
Substrate Surface ◽  
Columnar Structure ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Anneal

ABSTRACTMicrocrystalline inclusions in hydrogenated and fluorinated amorphous silicongermanium alloys, α-Si, Ge:H, F, were studied. Microcrystals grown during RF or DC glow discharge deposition from SiF4, GeF4 and H2 consist of either pure Si or Ge. Microcrystals produced by thermal annealing of initially amorphous alloys are either microcrystalline Ge or microcrystalline Si-Ge alloys depending on the annealing temperature. Values for the grain size were calculated from X-ray diffraction (XRD) and Raman spectra. The grain size of the “grown” microcrystal ranges from 8 to 60 nm. These grown grains exhibit preferential orientation of the (220) planes parallel to the substrate surface. Microcrystals produced by high-temperature anneal are randomly oriented. Scanning electron micrographs of as-grown samples show protruding platelets several 100 nm long and several 10 nm wide. Fractured cross sections exhibit columnar structure.

Characterization of Clay from Vale do Mulembá - ES

2008 ◽  
Vol 591-593 ◽  
pp. 487-492 ◽  
Author(s):  
Monica Castoldi Borlini Gadioli ◽  
J.C.G. Correia ◽  
A. Caranassios
Keyword(s):  
Particle Size ◽  
Chemical Analysis ◽  
Thermal Analyses ◽  
The Other ◽  
High Plasticity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Characterization Studies ◽  
And Behavior

This work has for objective to characterize the clay from Vale do Mulembá-ES. The Vale do Mulembá is located in Joana D´Arc, Vitória in Espírito Santo State, Brazil. That clay is used in the production of the traditional clay pans of the State, what contributes to the economy of the area. The clay from Vale do Mulembá presents characteristics and behavior different from the other clays used for the production of clay pans. The characterization studies were carried out through chemical analysis, X-ray diffraction, particle size distribution, plasticity and thermal analyses (DTA, TGA). The results showed that the clay is typical kaolinitic, present relatively to the amount high of Al2O3 and high plasticity.

Mechano-Synthesis and Characterization of Fe-Co Based Nanocrystalline Magnetic Materials

2005 ◽  
Vol 475-479 ◽  
pp. 3567-3570
Author(s):  
M. Mujahid ◽  
S.H. Sim ◽  
J. Zhu
Keyword(s):  
Grain Size ◽  
Nanocrystalline Materials ◽  
Magnetic Behavior ◽  
Internal Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Additions ◽  
Co Alloys ◽  
Curie Temperatures

Nanostructured Fe-Co based alloys are believed to be good candidates for imparting improved magnetic behavior in terms of higher permeability, lower coercivity, reduced hysteresis loss and higher Curie temperatures. In the present work, Fe-Co alloys with Ni additions were prepared using mechanical alloying (MA). Grain size and internal strain in the MA powders was measured using X-ray diffraction. It has been shown that the grain size could be reduced down to less than 5 nm in these alloys. Nanocrystalline materials thus obtained were also evaluated for magnetic behavior and the influence of grain size and internal strain on the magnetic properties has been discussed.

Metallographic, Structural and Mechanical Characterization of a Low Density Fe-Mn-Al-C Steel Microalloyed with Ti/B in As-Cast and Homogenized Conditions

MRS Advances ◽  
2018 ◽  
Vol 3 (64) ◽  
pp. 3971-3978 ◽  
Author(s):  
O.E. Villanueva-Perez ◽  
I. Mejía ◽  
V. García-García ◽  
A. Bedolla-Jacuinde
Keyword(s):  
Grain Size ◽  
Mechanical Characterization ◽  
The Other ◽  
Low Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Other Hand ◽  
Average Grain Size ◽  
Cast Condition

ABSTRACTLow density (LD) steels have shown particular characteristics in terms of mechanical properties and microstructure, since they have high strength, high ductility and density reduction up to 18%. On the other hand, the addition of microalloying elements such as Ti and B generate hardening by solid solution and precipitation, as well as grain refinement effect. LD steels generate nano-sized kappa phase precipitated from the austenite matrix, and these advanced steels can reach strength and elongation up to 780 MPa and 60%, respectively. The main objective of this research work is the metallographic, structural and mechanical characterization of a LD steel microalloyed with Ti/B in as-cast and -homogenized conditions. For this purpose a Fe-27Mn-7Al-1.2C (%wt) LD steel microalloyed with Ti/B was melted in a vacuum-induction furnace and cast in metallic mold. LD-Ti/B steel samples were homogenized at 1100 °C during 20, 50, 100, 150 and 200 minutes followed by water quenching. Metallographic, structural and mechanical characterization was carried out by optical (LOM) and scanning electron (SEM) microscopy, X-ray diffraction (XRD) and microhardness Vickers testing (HV10), respectively. In general, results showed a typical dendritic microstructure with average grain size of 1256 μm in the as-cast condition. On the other hand, the as-homogenized condition showed an austenitic equiaxial microstructure with average grain size from 164 to 940 μm. Austenite, ferrite and kappa phases were detected by X-ray diffraction (XRD). Also, second-phase particles such as AlN, TiC and MnS were detected by LOM and SEM-EDS analysis. LD steel microalloyed with Ti/B exhibited the highest microhardness Vickers value (235 HV10) in the as-cast condition, whilst in the as-homogenized condition microhardness gradually decreases from 223 to 198 HV10 as holding time increases.

Photoluminescence and Physical Properties of the Nano-Zn2SiO4:Mn Phosphor Powder under the Nitrogen Atmosphere

2014 ◽  
Vol 602-603 ◽  
pp. 1009-1012
Author(s):  
Fann Wei Yang ◽  
Chien Min Cheng ◽  
Kai Huang Chen
Keyword(s):  
Grain Size ◽  
Grain Shape ◽  
Nitrogen Atmosphere ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
Phosphor Powder ◽  
Sintering Atmosphere ◽  
X Ray ◽  
The Subject

The subject of this work was to study the photoluminescence characteristics of nanoZnO and SiO2powders into Zn2SiO4phosphor, and to achieve better control on grain size and grain shape than traditional powder. The manganese elements were used to replace Zn2SiO4defects and to achieve better control on grain size and grain shape than traditional powder. With different sintering atmosphere conditions, the effect of the photoluminescence intensity due to sintering temperature and the concentration of activator were be discussed by the X-Ray diffraction, SEM and TEM were utilized in the characterization of phase purity and microstructure of phosphor particles.

Synthesis and Luminescent Property of Nanocrystalline Phosphors via Solvothermal Processes

2006 ◽  
Vol 988 ◽  
Author(s):  
Chien-Yuen Tung ◽  
Shyue-Ming Chang ◽  
Teng-Ming Chen
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Luminescent Property ◽  
Commercial Product ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
Emulsion Method ◽  
X Ray ◽  
The Poor

AbstractWe have synthesized a series of nanocrysatlline (5±3 nm in diameter) and submicrom ZnS:Ag,Al phosphors with various dopant compositions via a newly developed emulsion method. The X-ray diffraction (XRD), EDS, SEM, and TEM were utilized in the characterization of phase purity and microstructure of phosphor particles. Photoluminescence (PL) and cathodoluminescence (CL) spectra were also utilized to characterize the optical properties of blue-emitting phosphor. The CL intensity of submicron ZnS:Ag,Al phosphor was found to be weaker than that of corresponding commercial product, which was attributed to the poor crystallinity and small grain size. In this article we described the synthesis of ZnS:Ag,Al nanophosphor with emphasis on the correlation between spectroscopic features and the microstructure.

scholarly journals Magnetic Characterization in the Rayleigh Region of Nanocrystalline Magnetic Cores

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2278 ◽  
Author(s):  
Mikel Osinalde ◽  
Pablo Infante ◽  
Lurdes Domínguez ◽  
Juan Blanco ◽  
Alexander Chizhik ◽  
...  
Keyword(s):  
Grain Size ◽  
Nanocrystalline Structure ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
Magnetic Characterization ◽  
X Ray ◽  
Magnetic Cores ◽  
Precursor Alloy

We report on the structural and magnetic characterization of two nanocrystalline Finemet-type magnetic cores. The nanocrystalline structure developed after annealing the amorphous precursor alloy at 550 °C for 30 and 60 min of annealing time. Structural analysis carried out by means of X-ray diffraction providing useful information on the grain size mean and partial volume of the nanocrystalline phase. The magnetic characterization was focused mainly in the Rayleigh region which, influenced by the intergranular coupling, was found to be more efficient in the sample treated for a longer time with a finer nanocrystalline structure.

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