scholarly journals Quantitative phase analysis of iron ore concentrates

2002 ◽  
Vol 55 (4) ◽  
pp. 263-266 ◽  
Author(s):  
Geraldo Magela da Costa ◽  
Valdirene Gonzaga de Resende ◽  
Norberto Magno Toríbio

The quantification of goethite, magnetite, martite and specularite in iron ores was successfully achieved by a combination of wet chemical analysis and x-ray diffraction. It was found that the intensity of the goethite (111) peak is constant for a certain sample provided that the same sample holder is used. Calibration curves with a linear behavior have been derived using the areas of the above mentioned peak and the amounts of goethite obtained by Mössbauer spectroscopy and optical microscopy. In addition, the integral width of the hematite (012) line broadens linearly as the amount of martite increases, thus allowing an estimation of the amounts of martite and specularite.

2014 ◽  
Vol 633 ◽  
pp. 443-446
Author(s):  
Kai Li ◽  
Hai Jian Li ◽  
Ping Wu

This paper studied the problems met in the quantitative analysis of synthetic Mullite phase,which was based on the analysis of various typical Mullite composite scheme. A method of quantitative analysis of Mullite phase (excluding amorphous phase SiO2) by use X-ray diffraction was discussed. The error of the analysis can be verified by chemical analysis of Al2O3 content. The method can effectively improve the accuracy of quantitative analysis of the Mullite phase, the error analysis is less than 3%. The error range can meet the accuracy requirement of Mullite content in the production.Studies show that this method is preliminarily solved how to quantitative the content of mullite phase by X-ray diffraction method .


1991 ◽  
Vol 35 (B) ◽  
pp. 1147-1155 ◽  
Author(s):  
K. Yamada ◽  
H. Kohno ◽  
T. Arai

AbstractThe problem of background radiation in X-ray fluorescence trace element analysis of fused-glass iron ore samples is addressed. A first-order model of coherent and Comptcn scattering with primary absorption is presented and used to correct measurements. Overlap coefficients for elements in iron ores are presented. The importance of these corrections is demonstrated. The accuracy achieved with X-ray measurements after background corrections compares well with the accuracy of chemical analysis.


2017 ◽  
Vol 371 ◽  
pp. 117-120 ◽  
Author(s):  
Andrey N. Dmitriev ◽  
G.Yu. Vitkina ◽  
R.V. Petukhov ◽  
L.A. Ovchinnikova

The chemical composition of pellets of various basicity from pig iron ore materials is described. The metallurgical characteristics (reducibility, strength, softening and melting temperatures) is analyzed. The micro X-ray diffraction phase analysis is made. Also the sinter of various basicity from titaniferous raw materials is investigated.


Clay Minerals ◽  
1983 ◽  
Vol 18 (1) ◽  
pp. 77-88 ◽  
Author(s):  
A. Fontanaud ◽  
A. Meunier

AbstractWeathering products of a serpentinized Iherzolite were investigated using optical microscopy, X-ray diffraction, infrared spectroscopy, and electron microprobe and wet-chemical analysis methods. The original mineral assemblage of the rock was chrysotile-enstatite-diopside-picotite-magnetite-calcite. Rock porosity governed the types of chemical microsystems from which the clay minerals were derived. These microsystems were grouped into three types. (1) Grain microcracks and grain boundaries. These were the earliest manifestations of weathering. Only pyroxenes were affected and transformed into talc + iron oxides. (2) Plasma zones in which the rock structure was preserved. The talc + oxide and chrysotile were both altered into a saponitic mineral. Picotite was oxidized to oxipicotite. (3) Fissure zones. In the argillized zones the rock was restructured. Saponite was altered to nontronite + magnesium silicate gel. Talc was also transformed to the same gel. Fissures were often filled with clay cutans and some were edged with iron oxides. Mineral facies in the different zones have been plotted in Si-R2-R3 coordinates.


Author(s):  
M. Vallet-Regí ◽  
M. Parras ◽  
J.M. González-Calbet ◽  
J.C. Grenier

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.


2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  

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.


1982 ◽  
Vol 47 (4) ◽  
pp. 1069-1077 ◽  
Author(s):  
Karel Mádlo ◽  
František Hanousek ◽  
Antonín Petřina ◽  
Jaroslav Tláskal

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.


1994 ◽  
Vol 58 (391) ◽  
pp. 307-314 ◽  
Author(s):  
Mizuhiko Akizuki ◽  
Hirotugu Nisidoh ◽  
Yasuhiro Kudoh ◽  
Tomohiro Watanabe ◽  
Kazuo Kurata

AbstractA study of apatite crystals from the Asio mine, Japan, showed sectoral texture related to the growth of the crystal, and with optically biaxial properties within the sectors. Wet chemical analysis gave a composition Ca5(PO4)3(F0.64,OH0.38,Cl0.01)1.03 for the specimen.Additional diffraction spots were not observed in precession and oscillation X-ray photographs and electron diffraction photographs. Since the internal textures correlate with the surface growth features, it is suggested that the internal textures and the unusual optical properties were produced during nonequilibrium crystal growth. The fluorine/hydroxyl sites in hexagonal apatite are symmetrically equivalent in the solid crystal but, at a growth surface, this equivalence may be lost, resulting in a reduction of crystal symmetry. Heating of the apatite to about 850°C results in the almost complete disappearance of the optical anomalies due to disordering, which may be related to the loss of hydroxyl from the crystal.


1994 ◽  
Vol 27 (5) ◽  
pp. 716-722 ◽  
Author(s):  
H. Wang

The influences of step size and scanning speed on the shape of a single X-ray diffraction (XRD) peak are analyzed quantitatively. For this purpose, it is assumed that XRD peak shapes are a mixture of Cauchy and Gauss curves. Six equations are established for the calculation of position, maximum intensity and full width at half-maximum (FWHM) errors caused by step size and two for the FWHM errors caused by counting statistics. The ratio of step size to FWHM is proposed as the shape-perfect coefficient of the XRD peak. From these equations and the relationship between the FWHM and the integral width of a peak based on the pseudo-Voigt function or Voigt function, three basic elements of a single symmetric XRD peak (peak position, maximum intensity and FWHM) can be refined. The optimum step size and scanning time can also be set from them.


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