scholarly journals CHEMICAL-MINERАLOGICAL CHARACTERIZATION OF BAUXITES FROM DIFFERENT DEPOSITS

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Gordana Оstojić ◽  
Dragica Lazić ◽  
Branko Škundrić ◽  
Jelena Penavin Škundrić ◽  
Slavica Sladojević ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Raw Materials ◽  
Mineralogical Composition ◽  
Chemical Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

From the aspect of their chemical and mineralogical composition, bauxites are very complex multicomponent raw materials. The paper presents the characterization of bauxite from several different deposits: Brazil, Milići, Čitluk and Kosovo. Chemical characteristics were determined by a combination of different analytical methods: gravimetry, potentiometric titration, atomic absorption spectroscopy (AAS) and UV-VIS spectrophotometry. Mineralogical composition was determined using X-ray diffraction and thermal analysis methods. Chemical and structural characterization is complemented by the results of scanning electron microscopy with EDX analysis. The information obtained was used for the assessment of the quality of investigated bauxites from the aspect of their application in the production of alumina.

Characterization of kaolin from Mankon, northwest Cameroon

Clay Minerals ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 563-577 ◽  
Author(s):  
A. Nzeukou Nzeugang ◽  
M. El Ouahabi ◽  
B. Aziwo ◽  
J.R. Mache ◽  
H.S. Mefire Mounton ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Raw Materials ◽  
Clay Fraction ◽  
Mineralogical Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Potential Applications ◽  
Kaolin Deposit ◽  
Scanning Electron

ABSTRACTA kaolin deposit from Mankon (northwest Cameroon) was prospected and studied for potential applications in ceramics. Six samples were investigated with X-ray diffraction (XRD), infrared (IR) spectroscopy and scanning electron microscopy (SEM) to determine the mineralogical composition and with X-ray fluorescence (XRF) to determine the chemical composition and properties for ceramic applications. The main minerals in the clays are kaolinite/halloysite and anatase associated with alunite, illite, gibbsite and maghemite. The kaolin samples have abundant organic matter (4–10%) and low absorption of methylene blue (0.2–2.5 meq/100 g), while SiO2 (33.28–56.31%) and Al2O3 (19.26–35.87%) are major oxides. The particle-size distribution derived from sieving and the hydrometer method indicates that 12–38% of the samples are in the <2 μm clay fraction. The clays have low to moderate plasticity (7–21%). One sample with K-feldspar and plagioclase displays the necessary properties for red ceramic products. SEM confirmed the occurence of halloysite in sample M9. The high kaolinite/halloysite content (64–97%), associated with low Fe2O3 content (0.5–1.4%) demonstrates that five samples are suitable raw materials for white firing industrial kaolin.

Synthesis and Characterization of Star-Like Copper Oxide (CuO) with Submicrometer Sizes

2012 ◽  
Vol 465 ◽  
pp. 186-191
Author(s):  
Shou Long Gong ◽  
Fang Lin Du
Keyword(s):  
Electron Microscopy ◽  
Synthesis And Characterization ◽  
Simple Liquid ◽  
Liquid Phase Deposition ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Star-like CuO with submicrometer sizes was fabricated via a simple liquid-phase deposition with the assistant of PVP and Na2MoO4. The as-prepared CuO have been characterized by X-ray diffraction(XRD) and scanning electron microscopy (SEM). The results showed that the as-prepared CuO owned monoclinic structure, the concentrations of PVP, Na2MoO4 and NaOH are very important to the morphology of CuO. The quality of PVP impacts the formation of thin flakes on the skeletons. Meanwhile, the growth of dendritic skeletons was depended on the addition of Na2MoO4, and the effect of NaOH is to control the dimension of CuO structure.

Darstellung und Charakterisierung des Silber(I,II,III)-oxidclathrates Ag7O8HCO3 / Synthesis and Characterization of the Silver(I,II,III) Oxide Clathrate Ag7O8HCO3

2000 ◽  
Vol 55 (9) ◽  
pp. 882-886 ◽  
Author(s):  
Martin Jansen ◽  
Sascha Vensky
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Magnetic Susceptibility ◽  
Solid State Nmr ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The silver(I,II,III) oxide clathrate Ag7O8HCO3 was synthesized by anodic oxidation of silver(I) in a suspension of Ag2CO3 in an aqueous AgF solution. The title compound was characterized by single crystal X-ray diffraction (cubic, Fm3̄m, a = 9.8085(3) Å, Z = 4), scanning electron microscopy, thermal analysis, IR spectroscopy, 1H-solid state-NMR and measurement of the magnetic susceptibility

Preparation and Properties of Sintering Brick from Iron Tailings

2012 ◽  
Vol 512-515 ◽  
pp. 1023-1027
Author(s):  
Ran Fang Zuo ◽  
Gao Xiang Du ◽  
Le Fu Mei ◽  
Wei Juan Guo ◽  
Jing Hui Liao
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Raw Materials ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Freeze Thaw ◽  
Scanning Electron

The main objective of this paper was to investigate the addition of iron tailing sintering brick production, in the presence of clay, coal refuses and bentonite. Mixtures containing raw materials of sintering brick and iron tailings were prepared at different proportions (up to 55 wt %), fired at 980°C. Freeze/thaw durability, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density and compressive strength of the fired samples. Their mechanical and microstructure properties were also investigated by differential thermal analysis (DTA/TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compressive strengths of the brick samples are higher than that required by the standards MU15 of GB5101-2003, up to 21.79Mpa with 40% iron tailings corresponding to its higher bulk density completely. Moreover, the results showed that it has such advantages as no lime blowing, uniform color, good freeze/thaw resistance and slight universal frost.

Thick PLZT Films Grown by Sol-gel for Optical Device Applications

1998 ◽  
Vol 541 ◽  
Author(s):  
M. Linnik ◽  
O. Wilson ◽  
A. Christou
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Phase Modulator ◽  
X Ray Diffraction ◽  
X Ray ◽  
Device Applications ◽  
Gel Technique ◽  
Scanning Electron

AbstractThe preparation and characterization of thick PLZT films for spatial phase modulator applications are reported. Films were fabricated on LSCO/LAO substrates by a sol-gel technique using multiple heat-treatment parameters. The crystal quality of PLZT 9/65/35 films was investigated by X-ray diffraction and scanning electron microscopy.

Preparation and Characterization of Fibri-Form Silica from Short Chrysotile Fibers by Mix-Roasting

2014 ◽  
Vol 809-810 ◽  
pp. 313-318
Author(s):  
Peng Cheng Song ◽  
Tong Jiang Peng ◽  
Hong Juan Sun ◽  
Yu Cao Yu
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fluorescence Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fibrous Morphology ◽  
Ft Ir ◽  
Scanning Electron

Fibri-form silica was extracted from short chrysotile fibers by mix-roasting with ammonium bisulfate. The fibri-form silica were characterized by X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), thermogravimetry and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and N2 adsorption isotherms. The results show that the fibri-form silica with disordered crystalline structure, but also in fibrous morphology. The surface area and pore volume of fibri-form silica are 181.66 m2/ g and 0.44 cc/ g, respectively. The structure of fibri-form silica is stable, no phase transformed from 50 to 1200 oC.

Synthesis and Stability of the Strontium Cobaltite Thermally Treated in Air

2019 ◽  
Vol 70 (9) ◽  
pp. 3330-3334
Author(s):  
Alina Melinescu ◽  
Georgeta Velciu ◽  
Virgil Marinescu ◽  
Cristian Hornoiu ◽  
Maria Preda
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Raw Materials ◽  
Stoichiometric Ratio ◽  
Chemical Transformations ◽  
Vitreous Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

This paper reports, the studies on chemical transformations at thermal treatment of a mixture of SrCO3 and Co3O4 corresponding to stoichiometric ratio of SrCoO3 compound. The mixture of raw materials was prepared by mechanical activation. Thermal analysis, X-ray diffraction and scanning electron microscopy were used for these studies. It was found that SrCoO3 forms at 930oC but is not stable and turn immediately into Sr2Co2O5 by eliminating of oxygen. This compound, Sr2Co2O5, is unstable and by increasing of the temperature decomposes in Sr3Co2O6 and cobalt oxide. At temperatures above the 1250oC, the samples melt and Sr3Co2O6 crystallizes from vitreous phase by cooling.

Green Synthesis and Characterization of Hydroxyapatite from Fish Scale Biowaste

2014 ◽  
Vol 695 ◽  
pp. 235-238 ◽  
Author(s):  
Jamali Sukaimi ◽  
Sofiah Hamzah ◽  
Mohd Sabri Mohd Ghazali
Keyword(s):  
Electron Microscopy ◽  
Synthesis And Characterization ◽  
Fish Scale ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Different Temperatures ◽  
Scanning Electron

The present study was undertaken to study the effect of calcinate temperature on characteristics of hydroxyapatite synthesized from the fish scale (FHAp). The FHAp calcined at different temperatures starting from 100 up to 300 °C. The structures of FHAP were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The analytical results show that the FHAp quality increased as the calcin temperature increased. The FHAp displayed excellent characteristics in term of particle size, morphology and properties and crystalinity after calcined at 300 °C, FHAp 300. From this study, it founded that 300 °C is the lowest calcin temperature could be applied to synthesize high quality of HAp from fish scale biowaste.

Synthesis and Structural Characterization of La0.8Sr0.2MO3 (M=Mn, Fe, Co and Cr) Solid Ionic Material for Catalyst Application

2016 ◽  
Vol 840 ◽  
pp. 48-51
Author(s):  
Muhammad Nor Azri Aziz ◽  
Johar Banjuraizah ◽  
Shing Fhan Khor ◽  
Zainal Arifin Ahmad
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Raw Materials ◽  
Solid State Reaction Method ◽  
Cold Isostatic Pressing ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Scanning Electron

La0.8Sr0.2MO3+δ, (M=Mn, Fe, Cr, Co) ceramics were prepared by using solid state reaction method. All raw materials were mixed and ground using mortar. Homogenized powders were calcined at 900°C for three hour followed by grounding and uniaxial pressed at 100MPa. Compacted pellets were further pressed using cold isostatic pressing machine at 2600kg/m.s and sintered at 1300°C with heating rate 5°C/min for 4 hour. Crystal structure and phase transformation of sintered samples were obtained using X-ray diffraction. Density and porosity are measured by using Archimedes principle. The morphology of sintered samples is observed using scanning electron microscopy, while elemental analysis using the EDX.

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