نتایج جستجو برای: chromite

تعداد نتایج: 697  

2018
Ramadan Abdelaziz Yasser Abd El-Rahman Sophie Wilhelm

Chromite is widely distributed in the east and southeast of Afghanistan, especially in Logar Province. Chromite mineralization is podiform-type and is hosted in the stratigraphically lowest ultramafic rocks of the Logar Ophiolite Complex. This ophiolite complex represents a remnant of an early Cretaceous oceanic crust that was thrusted over a late Permian to Mid-Jurassic platform-type sequence ...

2018
Dawei Yu

This paper describes an innovative process for the production of ferrochromium alloy via segregation reduction of chromite at 1300 ◦C in the presence of calcium chloride. Both charcoal and petroleum coke were used as the reductant. Individual polycrystalline ferrochrome carbide particles were produced, with their particle size and shape resembling that of the starting carbon particles. Interact...

2017
Hua Liu Shenghui Guo Jinhui Peng Duan Yu Libo Zhang Linqing Dai

In the present investigation, the oxidizing roasting process of chromite with sodium carbonate to prepare potassium dichromate crystals was studied in the microwave field with air, by heating the chromite and sodium carbonate. The chromite and sodium carbonate heated separately at 1000 ◦C in the microwave oven (frequency: 2.45 GHz; power 1.5 kW) in order to study the microwave absorption proper...

2015
Takako Satsukawa William L. Griffin Sandra Piazolo Suzanne Y. O’Reilly

Investigations of the Mantle Transition Zone (MTZ; 410-660 km deep) by deformation experiments and geophysical methods suggest that the MTZ has distinct rheological properties, but their exact cause is still unclear due to the lack of natural samples. Here we present the first direct evidence for crystal-plastic deformation by dislocation creep in the MTZ using a chromitite from the Luobusa per...

2017
Farshad Beshkar Sahar Zinatloo-Ajabshir Samira Bagheri Masoud Salavati-Niasari

Highly photocatalytically active copper chromite nanostructured material were prepared via a novel simple hydrothermal reaction between [Cu(en)2(H2O)2]Cl2 and [Cr(en)3]Cl3.3H2O at low temperature, without adding any pH regulator or external capping agent. The as-synthesized nanostructured copper chromite was analyzed by transmission electron microscopy (TEM), UV-vis diffuse reflectance spectros...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2003
Ming Chen Jinfu Shu Ho-kwang Mao Xiande Xie Russell J Hemley

A high-pressure polymorph of chromite, the first natural sample with the calcium ferrite structure, has been discovered in the shock veins of the Suizhou meteorite. Synchrotron x-ray diffraction analyses reveal an orthorhombic CaFe2O4-type (CF) structure. The unit-cell parameters are a = 8.954(7) A, b = 2.986(2) A, c = 9.891(7) A, V = 264.5(4) A3 (Z = 4) with space group Pnma. The new phase has...

2011
Magnus Ivarsson Curt Broman Nils G Holm

Chromite is a mineral with low solubility and is thus resistant to dissolution. The exception is when manganese oxides are available, since they are the only known naturally occurring oxidants for chromite. In the presence of Mn(IV) oxides, Cr(III) will oxidise to Cr(VI), which is more soluble than Cr(III), and thus easier to be removed. Here we report of chromite phenocrysts that are replaced ...

2011
P.V.S RAJU R.K.W MERKLE

The occurrence of rhythmic layering of chromite and host serpentinites in the deformed layered igneous complexes has been noticed in the Nuggihalli schist belt (NSB) in the western Dharwar craton, Karnataka, South India. For this study, the chromitite rock samples were collected from Jambur, Tagadur, Bhakatarhalli, Ranganbetta and Byrapur in the NSB. Petrography and ore microscopic studies on c...

2011
Ram Prasad Pratichi Singh

In this review article various applications and preparation methods of copper chromite catalysts have been discussed. While discussing it is concluded that copper chromite is a versatile catalyst which not only catalyses numerous processes of commercial importance and national program related to defence and space research but also finds applications in the most concerned problem worldwide i.e. ...

2016
Federica Zaccarini Arifudin Idrus Giorgio Garuti Raymond M. Coveney

Several chromite deposits located in the in the South and Southeast Arms of Sulawesi, Indonesia, have been investigated by electron microprobe. According to the variation of the Cr# = Cr/(Cr + Fe3+), the chromite composition varies from Cr-rich to Al-rich. Small platinum-group minerals (PGM), 1–10 μm in size, occur in the chromitites. The most abundant PGM is laurite, which has been found inclu...

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