scholarly journals Dehydroxylation and Structural Distortion of Kaolinite as a High-Temperature Sorbent in the Furnace

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 587 ◽  
Author(s):  
Cheng ◽  
Xing ◽  
Bu ◽  
Zhang ◽  
Piao ◽  
...  
Keyword(s):  
High Temperature ◽  
Structural Distortion ◽  
Hydroxyl Groups ◽  
Drop Tube ◽  
X Ray Diffraction ◽  
Exponential Factor ◽  
Adsorption Characteristics ◽  
Flash Calcination ◽  
Infrared Spectrometer

As a high-temperature sorbent, kaolinite undergoes the flash calcination process in the furnace resulting in the dehydroxylation and structural distortion, which are closely related to its heavy metal/alkali metal adsorption characteristics. We investigated the flash calcination of kaolinite by the experiments using a drop tube furnace and by the characterization of flash-calcined products using thermogravimetric-differential scanning calorimeter (TG-DSC), X-ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR)and nuclear magnetic resonance (NMR). There were three kinds of hydroxyl groups in kaolinite during flash calcination at 800–1300 °C, E-type (~50%, easy), D-type (~40%, difficult) and U-type (~10%, unable) according to the removal difficulty. The hydroxyl groups activation was believed to be the first step of the removal of E-type and D-type hydroxyl groups. The kinetics model of dehydroxylation groups at 900–1200 °C was established following Arrhenius equation with the activation energy of 140 kJ/mol and the pre-exponential factor of 1.32 × 106 s−1. At 800 °C, the removal of E-type hydroxyl groups resulted in the conversion of a part of VI-coordinated Al in kaolinite to V-coordinated Al and the production of meta-kaolinite. When the temperature rose up to 1200 °C, mullite was produced and a part of V-coordinated Al converted to IV-coordinated Al and VI-coordinated Al. Finally, the adsorption characteristics of kaolinite was discussed according to the results of dehydroxylation and structural distortion.

scholarly journals High-pressure synthesis and characterization of the non-centrosymmetric scandium borate ScB6O9(OH)3

2020 ◽  
Vol 75 (6-7) ◽  
pp. 597-603
Author(s):  
Birgit Fuchs ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Structure Solution ◽  
Temperature Experiment ◽  
Pressure Synthesis

AbstractThe non-centrosymmetric scandium borate ScB6O9(OH)3 was obtained through a high-pressure/high-temperature experiment at 6 GPa and 1473 K. Single-crystal X-ray diffraction revealed that the structure is isotypic to InB6O9(OH)3 containing borate triple layers separated by scandium layers. The compound crystallizes in the space group Fdd2 with the lattice parameters a = 38.935(4), b = 4.4136(4), and c = 7.6342(6) Å. Powder X-ray diffraction and vibrational spectroscopy were used to further characterize the compound and verify the proposed structure solution.

High pressure growth and characterization of SrCrO3 single crystal

2015 ◽  
Vol 29 (25n26) ◽  
pp. 1542025 ◽  
Author(s):  
L. P. Cao ◽  
L. Q. Pan ◽  
W. M. Li ◽  
X. C. Wang ◽  
Q. Q. Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Single Crystal ◽  
Perovskite Structure ◽  
Resistivity Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Measurement Results

Single crystal [Formula: see text] was prepared under high pressure and high temperature. Single crystal X-ray diffraction (XRD) result shows a cubic perovskite structure. The magnetic and resistivity measurement results indicate that [Formula: see text] is a paramagnetic semiconductor.

Synthesis and Characterization of Zn Nanoparticles by Using Hetero-Bicyclic Compound

2014 ◽  
Vol 938 ◽  
pp. 3-8
Author(s):  
V. Pushpanathan ◽  
D. Suresh Kumar
Keyword(s):  
Condensation Reaction ◽  
Energy Dispersive Spectrum ◽  
Hydroxyl Groups ◽  
Bicyclic Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Free Hydroxyl ◽  
Ft Ir ◽  
Esi Mass Spectrometry

The 1:1 condensation reaction between benzil and tris (hydroxymethyl) aminomethane in methanol yields a hetero bicyclic compound 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-aza-bicyclo [3.2.octan-2-ol. It was characterized by FT-IR, NMR (1H and 13C) spectroscopy and ESI mass spectrometry. The structure was conclusively determined by X-ray diffractrometric analysis. The structure shows a hetero bicyclic ring system. It consists of six membered morpholine and five membered oxazolidine rings with free hydroxyl groups. This bicyclic compound was used as a reducing and stabilizing agent to prepare zinc nanoparticles. The morphology and structure were characterized by field emission scanning electron microscope (FE-SEM), powder X-ray diffraction (XRD), and energy dispersive spectrum analysis (EDS).

scholarly journals In situ characterization of the effects of Nb and Sn on the anatase–rutile transition in TiO2 nanotubes using high-temperature X-ray diffraction

2014 ◽  
Vol 307 ◽  
pp. 372-381 ◽  
Author(s):  
Nathália C. Verissimo ◽  
Alessandra Cremasco ◽  
Christiane A. Rodrigues ◽  
Rodnei Bertazzoli ◽  
Rubens Caram
Keyword(s):  
High Temperature ◽  
Tio2 Nanotubes ◽  
X Ray Diffraction ◽  
In Situ Characterization ◽  
X Ray

scholarly journals Characterization of magnetic biochar amended with silicon dioxide prepared at high temperature calcination

2016 ◽  
Vol 34 (3) ◽  
pp. 597-604 ◽  
Author(s):  
Shams Ali Baig ◽  
Zimo Lou ◽  
Malik T. Hayat ◽  
Ruiqi Fu ◽  
Yu Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Silicon Dioxide ◽  
Environmental Remediation ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Magnetic Biochar ◽  
Ft Ir ◽  
High Temperature Calcination

AbstractCalcination is considered to increase the hardness of composite material and prevent its breakage for the effective applications in environmental remediation. In this study, magnetic biochar amended with silicon dioxide was calcined at high temperature under nitrogen environment and characterized using various techniques. X-ray diffraction (XRD) analysis revealed elimination of Fe3O4 peaks under nitrogen calcination and formation of Fe3Si and iron as major constituents of magnetic biochar-SiO2 composite, which demonstrated its superparamagnetic behavior (>80 A2·kg−1) comparable to magnetic biochar. Thermogravimetric analysis (TGA) revealed that both calcined samples generated higher residual mass (>96 %) and demonstrated better thermal stability. The presence of various bands in Fourier transform infrared spectroscopy (FT-IR) was more obvious and the elimination of H–O–H bonding was observed at high temperature calcination. In addition, scanning electron microscopy (SEM) images revealed certain morphological variation among the samples and the presence of more prominent internal and external pores, which then judged the surface area and pore volume of samples. Findings from this study suggests that the selective calcination process could cause useful changes in the material composites and can be effectively employed in environmental remediation measures.

Synthesis and structural characterization of Li3Y(BO3)2

2017 ◽  
Vol 72 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Sebastian Bräuchle ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Boric Acid ◽  
Structural Characterization ◽  
Diffraction Data ◽  
Lithium Carbonate ◽  
X Ray Diffraction ◽  
X Ray

AbstractLi3Y(BO3)2 was prepared by high-temperature solid state synthesis at 900°C in a platinum crucible from lithium carbonate, boric acid, and yttrium(III) oxide. The compound crystallizes monoclinically in the space group P21/c (no. 14) (Z=4) isotypically to Li3Gd(BO3)2. The structure was refined from single-crystal X-ray diffraction data: a=8.616(3), b=6.416(3), c=10.014(2) Å, β=116.6(2)°, V=494.9(3) Å3, R1=0.0211, and wR2=0.0378 for all data. The crystal structure of Li3Y(BO3)2 consists of [Y2O14] dinuclear units, which are interconnected to each other by planar B(1)O3 groups and LiO4 tetrahedra via common edges and corners along the a axis.

Synthesis and characterization of a silylated Brazilian clay mineral surface

2014 ◽  
Vol 68 (7) ◽  
Author(s):  
Márcia Silva ◽  
Saloana Gomes ◽  
Maria Fonseca ◽  
Kaline Sousa ◽  
José Espínola ◽  
...  
Keyword(s):  
Clay Mineral ◽  
Solid State Nmr ◽  
Textural Properties ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Diffraction Patterns ◽  
Trimethoxy Silane

AbstractClay mineral containing kaolinite, illite and montmorillonite was organofunctionalized with silylating agents: (3-aminopropyl)triethoxysilane, 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane and (3-mercaptopropyl)trimethoxy-silane, to yield three hybrids labelled Clay1, Clay2 and Clay3, respectively. These solids were characterized using elemental analysis, thermogravimetry, X-ray diffractometry, infrared spectroscopy, scanning electron micrograph, and 29Si and 27Al solid state NMR. Immobilized quantities of the organic groups were 0.66 mmol g−1, 0.48 mmol g−1 and 0.88 mmol g−1 for Clayx (x = 1–3), respectively. X-ray diffraction patterns confirmed the immobilization of silanes onto the surface without changes in the textural properties of the clay mineral as noted from the SEM images. Spectroscopic measurements were in agreement with the covalent bonding between the silanes and the hydroxyl groups deposited on the surface. The new hybrids were utilized as adsorbents of cobalt in aqueous solution, with retention values of 0.78 mmol g−1, 1.1 mmol g−1 and 0.70 mmol g−1 for Clayx (x = 1–3), respectively.

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