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.

Geochemistry of halloysite-7Å formation from plagioclase in trachyandesite rocks from Limnos Island, Greece

Clay Minerals ◽  
2014 ◽  
Vol 49 (1) ◽  
pp. 75-89 ◽  
Author(s):  
D. Papoulis ◽  
S. Komarneni ◽  
D. Panagiotaras
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Analysis ◽  
Geochemical Data ◽  
X Ray Diffraction ◽  
Polarizing Microscopy ◽  
X Ray ◽  
Geochemical Evaluation ◽  
Scanning Electron ◽  
Southwest Part

AbstractTrachyandesite rocks, occurring over an area of about 1 km2in the southwest part of Limnos Island, Greece, are altered mainly to halloysite. The samples were collected and analysed by polarizing microscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and chemical analysis. The alteration of plagioclase to halloysite follows seven discrete stages that are described in detail. The geochemical evaluation of the data shows enrichment of the lightREE(LREE) over heavyREE(HREE) as expressed by the (La/Yb)n ratio. TheΣLREErange from 206.44 to 272.30, while the sum ofHREEvaries from 11.01 to 26.26. The (La/Yb)n ratio ranges from 9.72 to 27.64. Fractionation amongLREEexpressed as (La/Sm)n and between middleREE(MREE) andHREEis shown as (Tb/Yb)n ratios. The most altered rocks close to the fault zone have high (Tb/Yb)n ratios and low (La/Sm)n and Eu/Eu* ratios. Although mineralogy and clay mineral textures indicate hydrothermal genesis of halloysite, the geochemical data are not conclusive due to a secondary weathering effect.

Analyse des Stuckgipses der Abtei Villers / Analysis of Stucco from the Abbey of Villers

1997 ◽  
Vol 3 (4) ◽  
pp. 381-396
Author(s):  
S. Chandra ◽  
D. Van Gemert
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Analysis ◽  
Electron Spectroscopy ◽  
Natural Polymer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Abstract Interior plaster from the Abbot's Palace of the Abbey of Villers-la-Ville, Brabant Wallon province, Belgium has been investigated. It is done by using chemical analysis, x-ray diffraction analysis, scanning electron microscopy, energy dispersive electron spectroscopy, and transmission electron microscopy. It is found that the rendering was made with lime rich mortar and animal hairs. The sand used was very fine and the hairs were very short. The solid constituents and the hairs were uniformly dispersed, which could have been obtained by the addition of some other natural polymer, containing protein.

scholarly journals Quantitative Evaluation of Crystalline and Amorphous Phases in Clay-Based Cordierite Ceramic

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1122
Author(s):  
Zdeněk Klika ◽  
Marta Valášková ◽  
Lucie Bartoňová ◽  
Petra Maierová
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Analysis ◽  
Test Results ◽  
Mineral Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Cordierite Ceramic ◽  
Scanning Electron

An innovative chemical quantitative mineral analysis (CQMA) was successfully tested on a cordierite-based clay ceramic sample to quantify crystalline and amorphous components. The accuracy of this method was demonstrated on an added module to the CQMA program that used oxide formulas of amorphous phases obtained by energy dispersive X-ray spectroscopy (EDS) microprobe chemical analysis. This CQMA method was tested for three variants calculated using chemical analysis, i.e., X-ray diffraction (XRD) identification of crystalline (cordierite and enstatite) and amorphous phases by scanning electron microscopy (SEM)/EDS texture and microanalyses. The test results from CQMA suggest their application possibilities as well as the limits of their utilization.

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.

Sepiolite at a locality in the Keuper Marl of the Midlands

1956 ◽  
Vol 31 (235) ◽  
pp. 328-332 ◽  
Author(s):  
P. S. Keeling
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Chemical Analysis ◽  
Diffraction Data ◽  
Ferric Oxide ◽  
X Ray Diffraction ◽  
X Ray

SummarySepiolite has been identified in the Keuper Marl at a Midlands locality by X-ray diffraction data, electron microscopy, differential thermal analysis, and chemical analysis. It has been calculated that a sample representing 30 ft. thickness of clay may contain as much as 39 % sepiolite. Apart from sepiolite, the Keuper Marl in the area examined consists mainly of mica, quartz, calcite, and ferric oxide.

Zn-rich smectite from the Silver Coin Mine, Nevada, USA

Clay Minerals ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 417-430 ◽  
Author(s):  
S. Kaufhold ◽  
G. Färber ◽  
R. Dohrmann ◽  
K. Ufer ◽  
G. Grathoff
Keyword(s):  
Electron Microscopy ◽  
Ir Spectroscopy ◽  
Fine Fraction ◽  
Structural Formula ◽  
X Ray Diffraction ◽  
Geochemical Environment ◽  
X Ray ◽  
Silver Coin ◽  
Transmission Electron

AbstractMore than 100 minerals have been reported from the Silver Coin Mine, Nevada USA; five new minerals have been discovered here, due to the unusual geochemical environment. The present study reports on the investigation of a greenish clayey sample from the Silver Coin Mine. After the separation of a fine fraction to enrich the clay minerals, sauconite, a rare Zn-rich smectite, was found by X-ray diffraction (XRD) and was further characterized by differential thermal analysis (DTA), infrared (IR) spectroscopy and scanning electron microscopy (SEM). The Zn-rich smectite is accompanied by illite, minor kaolinite/halloysite and traces of gibbsite (as was indicated by the IR spectroscopy). The occurrence indicates an acidic environment probably caused by oxidation of sulfides.The determination of the structural formula, to further characterize the Zn-rich smectite, was difficult because of the multi-clay mineral assembly. However, different SEM-EDX (energy dispersive X-ray) approaches as well as transmission electron microscopy (TEM)-EDX analysis helped to characterize the smectite as Al-rich sauconite with some exchangeable K+.

Synthesis, Thermal and X-Ray Investigations of the High-Temperature Phase of Copper(I) Cyanide

2003 ◽  
Vol 58 (1) ◽  
pp. 155-158 ◽  
Author(s):  
Olaf Reckeweg ◽  
Cora Lind ◽  
Arndt Simon ◽  
J. Salvo
Keyword(s):  
High Temperature ◽  
Ir Spectroscopy ◽  
Chemical Analysis ◽  
Rietveld Refinement ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray

Abstract CuCN was investigated by chemical analysis, IR spectroscopy and powder X-ray diffraction. A high-temperature phase of CuCN was identified and structurally characterized by Rietveld refinement. HT-CuCN is isotypic to AgCN (R3m (No. 166), Z = 3, a = 597.109(8), c = 484.33(5) pm, Cu (3a), C/N (6c), z = 0.3915(10) at 77 K) with head-tail disorder of the cyanide anions.

Synthesis, characterization and morphotropic transitions in a family of M[(UO2)(CH3COO)3](H2O)n (M=Na, K, Rb, Cs; n=0–1.0) compounds

2020 ◽  
Vol 235 (3) ◽  
pp. 95-103
Author(s):  
Ilya V. Kornyakov ◽  
Sophia A. Kalashnikova ◽  
Vladislav V. Gurzhiy ◽  
Sergey N. Britvin ◽  
Elena V. Belova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ir Spectroscopy ◽  
Chemical Analysis ◽  
Structural Transformations ◽  
Experimental Investigations ◽  
Crystal Chemical ◽  
X Ray Diffraction ◽  
Crystal Chemical Analysis ◽  
X Ray ◽  
Space Groups

AbstractExperimental investigations of crystallization in a family of uranyl triacetate compounds with Na, K, Rb and Cs were performed. The crystal structures of two novel Cs- and Rb-bearing tri(acetato)uranylates were solved, and the content of H2O molecules in the crystal structure of K-bearing uranyl triacetate was refined. Synthesized compounds were analyzed using IR spectroscopy and single-crystal X-ray diffraction. Crystal chemical analysis of the M[(UO2)(CH3COO)3](H2O)n family (M = Na, K, Rb, Cs; n = 0–1.0) reveals the sequence of structural transformations depending on the size of alkali cation resulting in the symmetry reduction from cubic P 213 (for Na), through tetragonal I 41/a (for K and Rb) to triclinic P 1̅ space groups (for Cs), which is in accordance with the principle of morphotropism, suggested by Paul von Groth, founder of the Zeitschrift für Krystallographie journal, in 1870.

scholarly journals Textural patterns, mineralogy, and chemistry of sandstone-related Calçadinha chalcedony (Piauí, Brazil)

2016 ◽  
Vol 46 (3) ◽  
pp. 395-409
Author(s):  
Marcondes Lima da Costa ◽  
Quézia da Silva Alencar ◽  
Erico Rodrigues Gomes ◽  
Henrique Diniz Faria de Almeida ◽  
Sarise Kamanda de Oliveira
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Trace Elements ◽  
Chemical Analysis ◽  
Energy Dispersive Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Geological Evolution ◽  
Scanning Electron ◽  
Parnaíba Basin

ABSTRACT: Paleozoic sandstones of the Parnaíba Basin, in addition to hosting opal deposits, also have occurrences of chalcedonies with potential for mineral and ornamental handicrafts, in addition to assisting the understanding of the geological evolution of the basin. However, the chalcedonies were not investigated yet, and this study intended to fulfill this gap by the investigation of the chalcedonies of Calçadinha in Piauí. Fieldwork, microtexturals analysis, X-ray diffraction and scanning electron microscopy with energy dispersive spectrometry, chemical analysis, and gemological assessments were developed. Four distinct types of chalcedonies have been distinguished. They stand out for their well distribution of Fe and Mn dendrites, which involves opal nodules, and contains microcavities with well-formed microcrystalline quartz, nontronite, and palygorskite. The mesoscopic features of these chalcedonies and cabochon and free forms cutting show potential for use in mineral crafts and semi-jewels. As expected, the chalcedonies are dominated by high contents of SiO2, besides the low and variable contents of Al2O3, Fe2O3, MgO, and TiO2. Among trace elements that show high Ba contents, bound in barite, seem also to be a geochemical signature of the country sandstones in Parnaíba basin. These chalcedonies were formed during the partial solubilization of SiO2 of sandstones, which was promoted during their tectonic formation in faults and fractures zones.

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