M�ssbauer effect and X-ray diffraction studies of synthetic iron bearing trioctahedral micas

1987 ◽  
Vol 14 (3) ◽  
pp. 276-280 ◽  
Author(s):  
Embaie Ferrow
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Iron Bearing

scholarly journals Genesis of langrial iron ore of hazara area, khyber pakhtunkhaw, parkistan

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Naghmah Haider ◽  
Sajjad Khan ◽  
Rehanul Haq Siddiqui ◽  
Shahid Iqbal ◽  
Nazar-Ul -Haq
Keyword(s):  
Iron Ore ◽  
High Energy ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Humid Climate ◽  
X Ray ◽  
High Silica ◽  
Depositional Setting ◽  
Iron Bearing ◽  
Ore Grade

The Iron Ore of Hazara area has been studied at seven locations for detail mineralogical and genesis investigations. Thick bedded iron ore have been observed between Kawagarh Formation and Hangu Formation i.e Cretaceous-Paleocene boundary. At the base of Hangu Formation variable thickness of these lateritic beds spread throughout the Hazara and Kohat-Potwar plateau. This hematite ore exists in the form of unconformity. X-Ray Diffraction technique (XRD), X-ray Fluorescence Spectrometry (XRF), detailed petroghraphic study and Scanning Electron Microscope (SEM) techniques indicated that iron bearing minerals  are hematite,  chamosite and  quartz, albite, clinochlore, illite-montmorillonite, kaolinite, calcite, dolomite and ankerite are the impurities present in these beds. The X-ray Fluorescence (XRF) results show that the total Fe2O3 ranges from 39 to 56% and it has high silica and alumina ratio is less than one. Beneficiation requires for significant increase in ore grade. The petroghraphic study revealed the presence of ooids fragments as nuclei of other ooids with limited clastic supply which indicate high energy shallow marine depositional setting under warm and humid climate. The overall results show that Langrial Iron ore is a low-grade iron ore and can be upgraded up to 62% by applying modern mining techniques to fulfill steel requirements of the country.

X-ray data on some calcium-iron-oxygen compounds

1967 ◽  
Vol 36 (278) ◽  
pp. 280-291 ◽  
Author(s):  
H. Hughes ◽  
P. Roos ◽  
D. C. Goldring
Keyword(s):  
Light Microscopy ◽  
Ferrous Iron ◽  
Incident Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Iron ◽  
Iron Bearing

SummarySynthetic mixtures of CaO and Fe2O3 fired in air at temperatures in the range 1180° C to 1240° C in some cases lost oxygen and formed ferrous-iron-bearing compounds. Samples after firing were examined by incident light microscopy and X-ray diffraction; new powder data are presented for the phases reported. In addition to α-Fe2O3, CaFe2O4, and Ca2Fe2O53. four distinct phases have been identified. These are and two forms of , described previously by Braun and Kwestroo (1960). The likely compositions of these phases are given.

Removal of Arsenic from Aqueous Solution by Aeromonas hydrophila

2017 ◽  
Vol 262 ◽  
pp. 647-650
Author(s):  
Laura Castro ◽  
M. Luisa Blázquez ◽  
Felisa González ◽  
Jesús Angel Muñoz ◽  
Antonio Ballester
Keyword(s):  
Environmental Problem ◽  
Iron Concentration ◽  
Arsenic Concentration ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Global Environmental ◽  
Co Precipitation ◽  
Removal Of Arsenic ◽  
Iron Bearing

Arsenic contamination is considered as a global environmental problem. This metalloid is known to be carcinogenic in some forms, and is mostly found in the environment as arsenate As (V) and arsenite As (III). Several chemical methods have been established for decontamination of arsenic from ground water including biological treatments. In the present work, the effect of the anaerobic bioreduction of soluble Fe (III) by the strain Aeromonashydrophila on arsenic immobilization has been investigated. The tolerance of this strain to arsenic concentration and the effect of the iron concentration in arsenic immobilization have been studied. The release of ferrous ion indicated the bioreduction of iron and promoted the subsequent arsenic co-precipitation, leading to the formation of various iron-bearing minerals. This precipitate has been observed and identified by Scanning Electron Microscopy and X-ray diffraction analysis as Fe3(AsO4)2(H2O)8.

scholarly journals Iron Oxalate Humboldtine Crystallization by Fungus Aspergillus niger

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1591
Author(s):  
Marina S. Zelenskaya ◽  
Alina R. Izatulina ◽  
Olga V. Frank-Kamenetskaya ◽  
Dmitry Y. Vlasov
Keyword(s):  
Aspergillus Niger ◽  
Solid Substrate ◽  
Oxidation States ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
Microscopic Fungus ◽  
X Ray ◽  
Iron Oxalate ◽  
Iron Bearing

Microfungi were able to alternate solid substrate in various environments and play a noticeable role in the formation of insoluble calcium oxalate crystals in subaerial biofilms on rock surfaces. The present work describes how iron oxalate dihydrate humboldtine is acquired under the influence of the acid-producing microscopic fungus Aspergillus niger on the surface of two iron- bearing mineral substrates in vitro. Pyrrhotite and siderite rocks, as well as the products of their alteration, were investigated using a complex of analytical methods, including powder X-ray diffraction, optical microscopy, scanning electron microscopy and EDX spectroscopy. The effect of the underlying rocks with different composition and solubility and different oxidation states of iron on Fe-oxalate crystallization and on the morphology of humboldtine crystals was shown. The mechanisms of humboldtine formation were discussed. The results obtained in vitro seem promising for using fungi in bioleaching iron and other metals from processed ores and for the development of environmentally friendly biotechnologies.

scholarly journals Evaluating and Enhancing Iron Removal via Filterable Iron Precipitates Formation during Coal-Waste Bioleaching

Eng ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 632-642
Author(s):  
Prasenjit Podder ◽  
Zongliang Zhang ◽  
Rick Q. Honaker ◽  
Michael L. Free ◽  
Prashant K. Sarswat
Keyword(s):  
Iron Removal ◽  
Coal Waste ◽  
X Ray Diffraction ◽  
Visual Minteq ◽  
Phase Purity ◽  
X Ray ◽  
Excess Iron ◽  
Favorable Conditions ◽  
Iron Bearing ◽  
Iron Precipitates

Iron removal via jarosite precipitate formation is a commonly used technique in various hydrometallurgical processes. Excess iron removal often becomes essential to an overall metal recovery circuit. This is particularly important to processes involving iron-bearing minerals. A technique, which involved the use of pyrite to generate acid for leaching, for iron removal is critical to enabling the process. Iron removal using CaO or similar reagents is expensive and often results in lost product. In the present study, various compounds that facilitate jarosite formation, namely Na2SO4, NH4OH, KCl, and KOH, were utilized and their effect in precipitation was observed. Visual Minteq assisted simulations were run in order to evaluate favorable conditions for iron removal. Morphology and elemental composition of precipitates were analyzed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, and the phase purity was identified using X-ray diffraction analysis.

Extracellular Iron-Sulfur Precipitates From Growth ofDesulfovibrio desulfuricans

1999 ◽  
Vol 590 ◽  
Author(s):  
Mark R. Antonio ◽  
Monica Lee Tischler ◽  
Dana Witzcak
Keyword(s):  
Ferrous Sulfate ◽  
Spectroscopic Data ◽  
Room Temperature ◽  
Average Distance ◽  
Basal Medium ◽  
X Ray Diffraction ◽  
X Ray ◽  
Iron Sulfur ◽  
X Ray Absorption ◽  
Iron Bearing

ABSTRACTWe have examined extracellular iron-bearing precipitates resulting from the growth ofDesulfovibrio desuyfuricansin a basal medium with lactate as the carbon source and ferrous sulfate. Black precipitates were obtained whenD. desulfuricanswas grown with an excess of FeSO4. WhenD. desulfuricanswas grown under conditions with low amounts of FeSO4, brown precipitates were obtained. The precipitates were characterized by iron K-edge XAFS (x-ray absorption fine structure),57Fe Mössbauer-effect spectroscopy, and powder x-ray diffraction. Both were noncrystalline and nonmagnetic (at room temperature) solids containing high-spin Fe(III). The spectroscopic data for the black precipitates indicate the formation of an iron-sulfur phase with 6 nearest S neighbors about Fe at an average distance of 2.24(1) Å, whereas the brown precipitates are an iron-oxygen-sulfur phase with 6 nearest O neighbors about Fe at an average distance of 1.95(1) Å.

scholarly journals The crystal structures of Fe-bearing MgCO3 sp 2- and sp 3-carbonates at 98 GPa from single-crystal X-ray diffraction using synchrotron radiation

2020 ◽  
Vol 76 (5) ◽  
pp. 715-719 ◽  
Author(s):  
Stella Chariton ◽  
Maxim Bykov ◽  
Elena Bykova ◽  
Egor Koemets ◽  
Timofey Fedotenko ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Single Crystal ◽  
Structure Prediction ◽  
Structural Data ◽  
X Ray Diffraction ◽  
Model Calculations ◽  
X Ray ◽  
Laser Heated ◽  
Iron Bearing

The crystal structure of MgCO3-II has long been discussed in the literature where DFT-based model calculations predict a pressure-induced transition of the carbon atom from the sp 2 to the sp 3 type of bonding. We have now determined the crystal structure of iron-bearing MgCO3-II based on single-crystal X-ray diffraction measurements using synchrotron radiation. We laser-heated a synthetic (Mg0.85Fe0.15)CO3 single crystal at 2500 K and 98 GPa and observed the formation of a monoclinic phase with composition (Mg2.53Fe0.47)C3O9 in the space group C2/m that contains tetrahedrally coordinated carbon, where CO4 4− tetrahedra are linked by corner-sharing oxygen atoms to form three-membered C3O9 6− ring anions. The crystal structure of (Mg0.85Fe0.15)CO3 (magnesium iron carbonate) at 98 GPa and 300 K is reported here as well. In comparison with previous structure-prediction calculations and powder X-ray diffraction data, our structural data provide reliable information from experiments regarding atomic positions, bond lengths, and bond angles.

scholarly journals Genesis of langrial iron ore of hazara area, khyber pakhtunkhaw, parkistan

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Naghmah Haider1 ◽  
Sajjad Khan1 ◽  
Rehanul Haq Siddiqui2 ◽  
Shahid Iqbal3 ◽  
Nazar-Ul -Haq1
Keyword(s):  
Iron Ore ◽  
High Energy ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Humid Climate ◽  
X Ray ◽  
High Silica ◽  
Depositional Setting ◽  
Iron Bearing ◽  
Ore Grade

The Iron Ore of Hazara area has been studied at seven locations for detail mineralogical and genesis investigations. Thick bedded iron ore have been observed between Kawagarh Formation and Hangu Formation i.e Cretaceous-Paleocene boundary. At the base of Hangu Formation variable thickness of these lateritic beds spread throughout the Hazara and Kohat-Potwar plateau. This hematite ore exists in the form of unconformity. X-Ray Diffraction technique (XRD), X-ray Fluorescence Spectrometry (XRF), detailed petroghraphic study and Scanning Electron Microscope (SEM) techniques indicated that iron bearing minerals  are hematite,  chamosite and  quartz, albite, clinochlore, illite-montmorillonite, kaolinite, calcite, dolomite and ankerite are the impurities present in these beds. The X-ray Fluorescence (XRF) results show that the total Fe2O3 ranges from 39 to 56% and it has high silica and alumina ratio is less than one. Beneficiation requires for significant increase in ore grade. The petroghraphic study revealed the presence of ooids fragments as nuclei of other ooids with limited clastic supply which indicate high energy shallow marine depositional setting under warm and humid climate. The overall results show that Langrial Iron ore is a low-grade iron ore and can be upgraded up to 62% by applying modern mining techniques to fulfill steel requirements of the country.

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