Structure Characterization of Sulfate and Oxysulfate Phases Formed During Sulfuric Acid Digestion of Ilmenites

1996 ◽  
Vol 49 (7) ◽  
pp. 801 ◽  
Author(s):  
IE Grey ◽  
MR Lanyon ◽  
R Stranger
Keyword(s):  
Sulfuric Acid ◽  
Rietveld Method ◽  
Three Dimensional ◽  
Structure Characterization ◽  
Acid Digestion ◽  
X Ray Diffraction ◽  
Titanium Sulfate ◽  
Structural Relationships ◽  
Concentrated Sulfuric Acid

Laboratory digestion of natural and upgraded ilmenites with concentrated sulfuric acid has been carried out under conditions simulating the sulfate-route pigment process. X-Ray diffraction studies on the solid digestion cakes led to the characterization of a number of different iron titanium sulfate and oxysulfate compounds, whose formation was dependent on the ilmenite composition and digestion conditions. Two different sulfate phases were identified, with structures related to those for Fe2(SO4)3 and H2O[ Zr (HPO4)2]. Four different iron titanium oxysulfates , ( Fe,Ti )(O,OH)SO4, were identified as major digestion products, three having structures related to those for β-NbOPO4, GeOHPO4 and lazulite , Mg[AlOHPO4], and the fourth being a new struture type. The structures of the oxysulfate phases were refined by the Rietveld method. Both the sulfates and the oxysulfates have three-dimensional framework structures formed by corner linking of ( Ti,Fe )O6 octahedra and SO4 tetrahedra, and containing channels or interlayer regions that can be occupied by cations such as H3O+ and Fe2+. The different structures have many features in common. Their structural relationships are discussed and mechanisms are proposed for the phase transformations encountered in the digestion studies.

Quantitative Characterization of Hydration of Cement Pastes by Rietveld Phase Analysis and Thermoanalysis

2013 ◽  
Vol 539 ◽  
pp. 19-24 ◽  
Author(s):  
Yong Qi Wei ◽  
Wu Yao
Keyword(s):  
Phase Analysis ◽  
Cement Paste ◽  
Rietveld Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Quantitative Characterization ◽  
Cement Pastes ◽  
Hydration Mechanism ◽  
Spot Check

The quantitative characterization of hydration of cement pastes has always been one of focuses of researchers’ attention. Rietveld phase analysis (RPA), a combination of quantitative X-ray diffraction (QXRD) and the Rietveld method, supplies a tool of an enormous potential for that. Although a few of related researches were conducted by RPA, the reported attention was not paid to the neat cement paste with a low w/c ratio. Therefore, this work aimed at the quantitative study on hydration of such a cement paste chiefly by this method, meanwhile, cooperated with the hyphenated technique of thermogravimetry with differential scanning calorimetry (TG-DSC), as a spot check. Results indicated that RPA was a reliable method in quantitatively characterizing hydration of cement pastes, and gave a clear decription of evolution of all main crystal phases in cement pastes; and that the evolution of monosulphate(Afm_12) was also able to be tracked quantitatively. This will help to understand better the hydration mechanism of cement pastes, as well as to investigate quantitatively effects of mineral and chemical admixtures on hydration of composite cementitious systems.

Characterization of New Inorganic- Organic Hybrid Compounds: (C6H10N2).Cl2 (I), [C6H10N2]2ZnCl4 (II): Crystal Structure, Hirschfield Surface, IR and NMR spectroscopy Analysis.

2021 ◽  
Author(s):  
nejeh hannachi ◽  
faouzi hlel
Keyword(s):  
Nmr Spectroscopy ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Absorption Bands ◽  
Monoclinic System ◽  
Xrd Pattern ◽  
Organic Hybrid ◽  
C Nmr

Abstract Two new organic-inorganic hybrid materials, (C6H10N2).Cl2 (I) and [C6H10N2]2ZnCl4 (II), have been synthesized by hydrothermal method and characterized by single-crystal X-ray diffraction and XRD pattern investigations. These two compounds are crystallized in the monoclinic system; C2/c space group. In the both structures, the anionic-cationic entities are interconnected by hydrogen bonding contacts and p-p Interaction forming three-dimensional networks. Intermolecular interactions were investigated by Hirshfeld surfaces and the contacts of the four different chloride atoms in (II) were compared. The vibrational absorption bands were identified by infrared spectroscopy. These compounds were also investigated by solid state 13C NMR spectroscopy.

scholarly journals Structural characterization of quaternary selenites of tungsten(VI), A 2W3SeO12 (A = NH4, Cs, Rb, K or Tl)

2021 ◽  
Vol 77 (4) ◽  
pp. 406-411
Author(s):  
Vineela Balisetty ◽  
Kanamaluru Vidyasagar
Keyword(s):  
Three Dimensional ◽  
Spectroscopic Studies ◽  
Solid State Reactions ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
Compound K ◽  
Three Dimensional Structure ◽  
Thermal And Spectroscopic Studies ◽  
Anionic Framework

The quaternary A 2W3SeO12 (A = NH4, Cs, Rb, K or Tl) selenites have been prepared in the form of single crystals by hydrothermal and novel solid-state reactions. They were characterized by X-ray diffraction, thermal and spectroscopic studies. All of them have a hexagonal tungsten oxide (HTO) related [W3SeO12]2− anionic framework with pyramidally coordinated Se4+ ions. The known A 2W3SeO12 (A = NH4, Cs or Rb) compounds are isostructural with the Cs2W3TeO12 compound and have a non-centrosymmetric layered structure containing intra-layer Se—O bonds. The new compound K2W3SeO12(α) is isostructural with the K2W3TeO12 compound and has a centrosymmetric three-dimensional structure containing interlayer Se—O bonds. It is inferred that the new Tl2W3SeO12 compound has the same three-dimensional structure as K2W3SeO12(α).

scholarly journals Rietveld Method Applied for Triacylglycerol Polymorphism Analysis

2014 ◽  
Vol 70 (a1) ◽  
pp. C1764-C1764
Author(s):  
Guilherme Calligaris ◽  
Ana Paula Ribeiro ◽  
Adenilson dos Santos ◽  
Lisandro Cardoso
Keyword(s):  
Rietveld Method ◽  
Rietveld Analysis ◽  
Polymorphic Form ◽  
Polymorphism Analysis ◽  
X Ray Diffraction ◽  
Full Characterization ◽  
Β Phase ◽  
Lack Of Information ◽  
Refinement Method

The characterization of the fat components becomes very useful in the formulation of shortening, margarines and fatty products due to their unique properties of plasticity, texture, solubility and aeration. The qualitative analysis obtained by X-ray diffraction (XRD) can be further improved in order to fulfill the lack of information on the triacylglycerol (TAG) in the hardfat systems aiming a complete polymorph characterization. In this work, as an attempt to quantify the distinct β and β' TAG polymorphs, XRD was combined with Rietveld refinement method and applied to two types of samples: mixtures (M) and blended hardfats (B) samples involving fully hydrogenated of soybean (FHSO) and palm (FHPO) oils. M-samples were prepared with linear concentrations of FHSO (β) and FHPO (β') and their Rietveld analysis have provided the expected content trend through the involved polymorphic phases with a very good agreement (~5%). This result validates the Rietveld method applicability on this kind of materials. The Rietveld method applied for B-samples has shown that β' polymorphic form prevails over the β-form, even for samples originally prepared with FHSO (β)/FHPO (β') = 60/40 ratio (see figure). This result indicates the influence of the seeding process (earlier crystallization of β' phase). This first quantitative approach for blended samples represents a very useful contribution towards the full characterization of fats.

Structure Characterization of Sintered CaO-Al2O3-SiO2 Glass-Ceramic Reinforced with Spodumene

2013 ◽  
Vol 834-836 ◽  
pp. 309-314
Author(s):  
Zi Fan Xiao ◽  
Jin Shu Cheng ◽  
Jun Xie
Keyword(s):  
Glass Ceramic ◽  
Energy Dispersive Spectrometry ◽  
Crystal Size ◽  
Bending Strength ◽  
Glass Ceramics ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray

A glass-ceramic belonging to the CaO-Al2O3-SiO2(CAS) system with different composition of spodumene and doping the Li2O with amount between 0~2.5 % (mass fraction) were prepared by onestage heat treatment, under sintering and crystallization temperature at 1120 °C for two hours. In this paper, differential thermal analysis, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and bending strength test were employed to investigate the microstructure and properties of all samples. β-wollastonite crystals were identified as the major crystalline phases, and increasing Li2O was found to be benefit for the crystallization and tiny crystalline phases remelting, resulting in the content of major crystalline phases increased first and then decreased with increasing the expense of spodumene. Meanwhile, the crystal size can be positively related with the content of Li2O. The preferable admixed dosage of spodumene can be obtained, besides the strength of glass-ceramics can be more than 90 MPa.

scholarly journals Synthesis, Spectral, Structural and Thermal Characterization of Inorganic Crystal: Phenyl Trimethylammonium Tetrachlorocobaltate

2019 ◽  
Vol 31 (8) ◽  
pp. 1779-1784
Author(s):  
V. Mohanraj ◽  
R. Pavithra ◽  
M. Thenmozhi ◽  
R. Umarani
Keyword(s):  
Three Dimensional ◽  
Thermal Characterization ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
Evaporation Technique ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
Ft Ir Spectroscopy

Phenyl trimethylammonium tetrachlorocobaltate, crystals were grown by slow evaporation technique. The crystal was bright, transparent. The three dimensional structure of the phenyl trimethylammonium tetrachlorocobaltate was obtained from single crystal X-ray diffraction studies. The molecule belongs to monoclinic crystal system with C2/c space group. The presence of functional groups and modes of vibrations were identified by FT-IR spectroscopy. 1H NMR spectroscopy was also used to characterise the compound and the thermal stability of the crystal was established by TGA/DT analysis. This work undergoes phase transition which makes the study interesting.

Synthesis and Characterization of the Manganese Pyroarsenate Mn2As2O7 · 2H2O

2001 ◽  
Vol 56 (4-5) ◽  
pp. 359-363 ◽  
Author(s):  
N. Stock ◽  
G. D. Stucky ◽  
A. K. Cheetham
Keyword(s):  
Three Dimensional ◽  
Spectroscopic Studies ◽  
Mean Value ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Raman Spectroscopic ◽  
Distorted Octahedral ◽  
Ir And Raman ◽  
Hydrothermal Methods

Abstract The manganese pyroarsenate hydrate, Mn2As2O7 · 2 H2O, has been obtained as a single phase product using hydrothermal methods and the structure has been determined by single crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group P21/n with a = 6.6576(4), b = 14.555(1), c = 7.8147(5) Å, β = 94.935(1)°, V = 754.46(8) Å3 and Z = 4. The manganese ions are each coordinated to five oxygen atoms and a water molecule in a distorted octahedral arrangement. Edge-sharing MnO6 octahedra form chains which are connected to a three-dimensional framework by As2O74- ions. The pyroarsenate anion, which attains a nearly eclipsed conformation, has a mean As-O distance for the terminal As-O bonds of 1.669(2) Å, while for the bridging oxygen atom a mean value of 1.757(2) Å is observed. Magnetic susceptibility measurements indicate the presence of high-spin Mn2+ ions. Thermogravimetric as well as IR and Raman spectroscopic studies of Mn2As2O7 · 2 H2O are presented.

scholarly journals Synthesis of Silver Nanoparticles Using Muntingia Calabura L. Leaf Extract as Bioreductor and Applied as Glucose Nanosensor

2018 ◽  
Vol 34 (6) ◽  
pp. 3088-3094 ◽  
Author(s):  
Abdul Wahid Wahab ◽  
Abdul Karim ◽  
Nursiah La Nafie ◽  
Nurafni Nurafni ◽  
I. Wayan Sutapa
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Reduction Method ◽  
Measurement Range ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Muntingia Calabura

Silver nanoparticles have been synthesized by reduction method using extract of Muntingia calabura L. leaf a bioreductor. The process of silver nanoparticles formation was monitored by UV-Vis method. The results showed that the absorbance values increased according to the increase of reaction time. Maximum absorption of silver nanoparticle was obtained at a wavelength of 41-421 nm. The size of silver nanoparticles was determined using a PSA (Particle Size Analyzer) with a particle size distribution of 97.04 nm. The functional groups compound that contribute in the synthesis was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). Morphology of the silver nanoparticles was observed by an Scanning Electron Microscope instrument and the structure characterization of the compounds were analyzed using X-Ray Diffraction. The glucose nanosensor based on silver nanoparticles have the measurement range of 1 mM - 4 mM with the regretion (R2) is 0,9516, the detection limit of sensor is 3,2595 mM, the sensitivity of sensor is 2,0794 A. mM-1. mM-2.

Template Assisted Growth of Zinc Oxide-Based Nanowires and Piezoelectric Properties

2013 ◽  
Vol 829 ◽  
pp. 757-761 ◽  
Author(s):  
Nooshin Sadat Ayati ◽  
Elahe Akbari ◽  
Seyed Pirooz Marashi ◽  
Shahyar Saramad
Keyword(s):  
Zinc Oxide ◽  
Zinc Nitrate ◽  
Zno Nanowires ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Contact Mode ◽  
Oxide Nanowires ◽  
Nitrate Precursor ◽  
Potentiostatic Electrodeposition

In this paper, we report on the synthesis of ZnO nanowires via templated electrochemical deposition. ZnO nanowire arrays were fabricated by potentiostatic electrodeposition in track-etched polycarbonate (PC) membrane. The electrolyte was aqueous solution containing zinc nitrate precursor. The electrodeposition process involves the electroreduction of nitrate ions to alter the local pH and precipitation of the metal oxide within the pores. The morphology analysis and structure characterization of the ZnO nanowires were carried out using conventional scanning electron microscopy (SEM) and X-Ray diffraction. To check the piezoelectric characteristics of the zinc oxide nanowires, the AFM microscope is used in contact mode. The scanned area was 5µm*5µm and the affected force was 30nN. In result of scanning each nanowire with conductive AFM tip in contact mode, a current peak which had a width smaller than topography peak was fabricated. This is due to semi-conductivity and piezoelectricity characteristics of Nanowires.

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