scholarly journals Preliminary report on the application of portable x-ray flourescence equipment to the determination of iron and manganese in ores

1969 ◽  
Author(s):  
K V Godfrey
2012 ◽  
Vol 1480 ◽  
Author(s):  
Christina M. Gonzalez ◽  
Jason G. Parsons ◽  
Jeffrey Hernandez ◽  
Jorge L. Gardea-Torresdey

ABSTRACTIncreasing concentrations of selenium oxoanions in the environment are placing many animals at risk for reproduction failure and deformities. The understanding of binding mechanisms of selenium oxoanions to iron and manganese based oxide minerals could lead to enhanced understanding of selenium mobility in the environment. In this study, the binding mechanisms of selenium oxoanions, selenite and selenate, to non microwave-assisted and microwave-assisted synthetic Fe3O4, Mn3O4, and MnFe2O4 nanomaterials were investigated through the use of X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) spectroscopy studies revealed the oxidation state of selenite and selenate remains the same after binding occurs to all nanomaterials in pH 2, 4, or 6 environments. The binding modes of selenite and selenate were determined to be bidentate binuclear through use of Extended x-ray absorption fine structure (EXAFS) and were independent of nanomaterials, synthetic technique, and pH.


Author(s):  
D. Charny ◽  
O. Shevchenko ◽  
V. Nesterovskyi

Purpose. To determine composition and properties of iron-manganese crusts formed on grainy filtration load granules surface in the process of underground waters cleaning from Fe2+ and Mn2+, and to determine the application limits and perspective trends of the offered water preparation technology development, conditioned by the properties of these crusts. Method. For the analysis of physical and chemical properties of iron-manganese crusts analytical methods are used on the base of leaching and determination of iron and manganese content in solution and for more precise definition of crust qualitative composition an X-ray fluorescent photography spectrometry is used. For determination of crystalline structure an X-ray photography diffractometry was used, and the thickness of film was determined by mechanical micrometry. Processing of the received information and graphic interpretation of data is executed with application of LibreOffice Cacl, Gnumeric and PSPP software. Results. Determined physicochemical characteristics of iron-manganese crust formed on granules surface of grainy filtration load, the metrical sizes of film are determined: thickness and mass, analytically determined by lixiviating contents of iron and manganese in a crust. Manganites, that form a crust, are dispersion characterized; on some occasion considerable amount of roentgenoamorphous phase is formed, and in other - a crystalline form predominates as todorokite. In our opinion, it is determined by correlation of Mn/Fe concentrations in initial water. Results of crust measuring on the granules of filtration load on the water treatment station in town of Uzin is the following: thickness 0,518±0,209 mm; mass 0,0039±0,0004 g, manganese contents and total iron, accordingly, 115,59±4,33 mg/dm3 and 55,33±30,85 mg/dm3. Manganese and iron contents, which were lixiviated from the crusts of filtration load on the water treatment station in Chervona Sloboda village, accordingly: 55,067±10,946 mg/dm3; 100,476±4,284 mg/dm3. Scientific novelty. Firstly possibility of forming catalytic crust (film) from iron-manganese compositions on the filtration load surface is experimentally proved, among those compositions there are higher oxides of manganese in considerable volumes. Having determined their crystalline and chemical structure, it was proved that they provide the effective removal of iron and manganese over the norm contents from water and in a perspective can be used for the removal of a number of low valency cations among which the removal of Ñà2+ and Âr2+ is experimentally confirmed. Practical significance. Based on the known geobiochemical cycles of iron and manganese a new water treatment technology and also a new filter material with considerable potential of subsequent improvement and application are gotten, unlike classic technologies of manganese removal this method does not require bringing in additional reagents at Mn(II) → Mn(IV) oxidation.


1971 ◽  
Vol 20 (5) ◽  
pp. 601-606 ◽  
Author(s):  
Tetsuo MATSUMURA ◽  
Mitio TAKAHISA ◽  
Muneharu TAKIZAWA ◽  
Satoshi KITAMURA

1988 ◽  
Vol 3 (3) ◽  
pp. 552-556 ◽  
Author(s):  
Han-Ill Yoo ◽  
Harry L. Tuller

Electrical conductivity and thermoelectric power have been measured for a series of MnZn ferrites as functions of the oxygen partial pressure under high-temperature equilibrium conditions. The isothermal variation of both properties was successfully correlated to the onset of phase transitions at characteristic Po2's. The ferrite 0.482MnO-0.518Fe2O3 was examined in some detail to locate the stability fields of the metallic alloy of iron and manganese, manganowustite, the spinel ferrite, and the hematitelike phase, and to extract the appropriate free-energy data. The results confirmed by x-ray diffraction are in satisfactory agreement with literature data.


Author(s):  
H.J. Dudek

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S


Author(s):  
R. J. Narconis ◽  
G. L. Johnson

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.


Author(s):  
Allen Angel ◽  
Kathryn A. Jakes

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.


Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.


Author(s):  
Stuart McKernan ◽  
C. Barry Carter

The determination of the absolute polarity of a polar material is often crucial to the understanding of the defects which occur in such materials. Several methods exist by which this determination may be performed. In bulk, single-domain specimens, macroscopic techniques may be used, such as the different etching behavior, using the appropriate etchant, of surfaces with opposite polarity. X-ray measurements under conditions where Friedel’s law (which means that the intensity of reflections from planes of opposite polarity are indistinguishable) breaks down can also be used to determine the absolute polarity of bulk, single-domain specimens. On the microscopic scale, and particularly where antiphase boundaries (APBs), which separate regions of opposite polarity exist, electron microscopic techniques must be employed. Two techniques are commonly practised; the first [1], involves the dynamical interaction of hoLz lines which interfere constructively or destructively with the zero order reflection, depending on the crystal polarity. The crystal polarity can therefore be directly deduced from the relative intensity of these interactions.


Sign in / Sign up

Export Citation Format

Share Document