Mineralogical and chemical heterogeneity of three standard clay mineral samples

Clay Minerals ◽  
1996 ◽  
Vol 31 (3) ◽  
pp. 417-422 ◽  
Author(s):  
H. M. Köster
Keyword(s):  
Particle Size ◽  
Chemical Analysis ◽  
Clay Mineral ◽  
Chemical Heterogeneity ◽  
X Ray Diffraction ◽  
Accessory Minerals ◽  
Size Fractions ◽  
X Ray ◽  
Compositional Variations

AbstractMineralogical and chemical heterogeneity within three standard clay mineral samples have been identified by X-ray diffraction and chemical analysis of various size-fractions. This heterogeneity is partly attributed to accessory minerals, but mostly to structural and compositional variations in the 2:1 layer minerals of different particle size in the same specimen.

Microdomains in BaFeO3-y (0.35 < y < 0.50)

1990 ◽  
Vol 48 (4) ◽  
pp. 780-781
Author(s):  
M. Vallet-Regí ◽  
M. Parras ◽  
J.M. González-Calbet ◽  
J.C. Grenier
Keyword(s):  
Electron Diffraction ◽  
Chemical Analysis ◽  
Monoclinic Phase ◽  
Orthorhombic Phase ◽  
Total Iron ◽  
Zone Axis ◽  
Electron Micrograph ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Variations

BaFeO3-y compositions (0.35<y<0.50) have been investigated by means of electron diffraction and microscopy to resolve contradictory results from powder X-ray diffraction data.The samples were obtained by annealing BaFeO2.56 for 48 h. in the temperature range from 980°C to 1050°C . Total iron and barium in the samples were determined using chemical analysis and gravimetric methods, respectively.In the BaFeO3-y system, according to the electron diffraction and microscopy results, the nonstoichiometry is accommodated in different ways as a function of the composition (y):In the domain between BaFeO2.5+δBaFeO2.54, compositional variations are accommodated through the formation of microdomains. Fig. la shows the ED pattern of the BaFeO2.52 material along thezone axis. The corresponding electron micrograph is seen in Fig. 1b. Several domains corresponding to the monoclinic BaFeO2.50 phase, intergrow with domains of the orthorhombic phase. According to that, the ED pattern of Fig. 1a, can be interpreted as formed by the superposition of three types of diffraction maxima : Very strong spots corresponding to a cubic perovskite, a set of maxima due to the superposition of three domains of the monoclinic phase along [100]m and a series of maxima corresponding to three domains corresponding to the orthorhombic phase along the [100]o.

An Electron Microscopy study of the BaxLa1-xFeO3-x/2 (1/2≤x≤2/3) system

1990 ◽  
Vol 48 (4) ◽  
pp. 608-609
Author(s):  
M. Parras ◽  
J.M. González-Calbet ◽  
M. Vallet-Regí ◽  
J.C. Grenier
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Chemical Analysis ◽  
Analysis Data ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Variations ◽  
Perovskite Unit Cell

In a previous paper we have shown that compositional variations in BaxLa1-xFeO3-y materials prepared in air. are accommodated in a different way than in other perovskite-related ferrites probably due to the bigger size of barium.When oxidated BaxLa1-xFe3+,4+O3-y samples in the 1/2 ≤ x ≤ 2/3 range, are reduced by annealing at 1100°C for 24h. in flowing Ar-5%H2, all iron,as deduced from chemical analysis data, is found in the III state oxidation. Powder X-ray diffraction data in this range (La1/2Ba1/2FeO2.75-La1/3Ba2/3FeO2.67) can be indexed on the basis of a single cubic perovskite unit cell (ac ≃ 3.95Å)In order to elucidate the way in which anionic vacancies are accommodated in these solids an electron diffraction (ED) and microscopy study was performed, similar results being obtained in both La1/2Ba1/2 FeO2.75 and La1/3Ba2/3FeO2.67samples.

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.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

New Coordination Compounds of Fe(III) with Organic Ligands

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Complex Compounds ◽  
Organic Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Chemical Analysis ◽  
Structural Formulae ◽  
Paramagnetic Properties

In this paper the synthesis and the study of some complex compounds of Fe(III) with ligands derived from: 2-(4-chloro-phenylsulfanyl)-1-(2-hydroxy-3,5-diiodo-phenyl)-ethanone (HL1), 1-(3,5-dibromo-2-hydroxy-phenyl)-2-phenylsulfanyl-ethanone(HL2), and 2-(4-chloro-phenylsulfanyl)-1-(3,5-dibromo-2-hydroxy-phenyl)-ethanone (HL3) is presented. The characterization of these complexes is based on method as: the elemental chemical analysis, IR and ESR spectroscopy, M�ssbauer, the thermogravimetric analysis and X-ray diffraction. Study of the IR and chemical analysis has evidenced that the precipitates form are a complexes and the combination ratio of M:L is 1:2. The central atoms of Fe(III) presented paramagnetic properties and a octaedric hybridization. Starting from this precipitation reactions, a method for the gravimetric determination of Fe(III) with this organic ligands has been possible. Based on the experimental data on literature indications, the structural formulae of the complex compounds are assigned.

Hydrolytic products of Fe(III) after oxidation of Fe(II) by chlorate

1982 ◽  
Vol 47 (4) ◽  
pp. 1069-1077 ◽  
Author(s):  
Karel Mádlo ◽  
František Hanousek ◽  
Antonín Petřina ◽  
Jaroslav Tláskal
Keyword(s):  
Electron Microscopy ◽  
Ir Spectroscopy ◽  
Chemical Analysis ◽  
Ferrous Sulphate ◽  
Reaction Medium ◽  
Potassium Chlorate ◽  
X Ray Diffraction ◽  
X Ray

Ferrous sulphate was oxidized by potassium chlorate in the pH region 2-7 and at temperatures ranging from 298.1 to 323.1 K and various hydrolytic products of Fe(III) were separated and indentified. The separated solid ferric products were analyzed using a combination of the chemical analysis, IR spectroscopy, X-ray diffraction, and electron microscopy. The following substances were found as major components of the products: Fe2O3.n H2O ("ferric gel"), Fe2O3.n H2O with bound SO2-4 ions ("sulphogel"), α-FeO(OH), γ-FeO(OH) and Fe3O4. Their amount depends particularly on the pH temperature of the reaction medium.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

scholarly journals Synthesis of magnesium carbonate hydrate from natural talc

2020 ◽  
Vol 18 (1) ◽  
pp. 951-961
Author(s):  
Qiuju Chen ◽  
Tao Hui ◽  
Hongjuan Sun ◽  
Tongjiang Peng ◽  
Wenjin Ding
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Crystal Growth ◽  
Crystal Morphology ◽  
Magnesium Carbonate ◽  
Organic Additives ◽  
X Ray Diffraction ◽  
Morphological Transformation ◽  
X Ray ◽  
Carbonation Process

AbstractVarious morphologies of magnesium carbonate hydrate had been synthesized without using any organic additives by carefully adjusting the reaction temperature and time during the talc carbonation process. At lower temperatures, magnesium carbonate hydrate was prone to display needle-like morphology. With the further increase of the carbonation temperature, the sheet-like crystallites became the preferred morphology, and at higher aging temperatures, these crystallites tended to assemble into layer-like structures with diverse morphologies, such as rose-like particles and nest-like structure. The reaction time had no effect on the crystal morphology, but it affected the particle size and situation of the crystal growth. X-Ray diffraction results showed that these various morphologies were closely related to their crystal structure and compositions. The needle-like magnesium carbonate hydrate had a formula of MgCO3·3H2O, whereas with the morphological transformation from needle-like to sheet-like, rose-like, and nest-like structure, their corresponding compositions also changed from MgCO3·3H2O to 4MgCO3·Mg(OH)2·8H2O, 4MgCO3·Mg(OH)2·5H2O, and 4MgCO3·Mg(OH)2·4H2O.

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