Results 121 to 130 of about 728 (154)

Influence of manganese on iron oxyhydroxides and oxides formed in aqueous solution

Corrosion Science, 2008
Abstract Structural analysis techniques such as X-ray diffraction and anomalous X-ray scattering were used for characterizing the influence of manganese on iron oxyhydroxides and oxides formed from green rust (GR) in an aqueous solution. The results showed that the formation of Fe 3 O 4 was enhanced by the addition of manganese ions during the ...
Katsuya Inoue, Masato Okui, Masahiko Tanaka, Kozo Shinoda, Shigeru Suzuki, Yoshio Waseda   +5 more
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Spectral and chemical studies of iron and manganese oxyhydroxides in laterite developed on ultramafic rocks

Resource Geology, 2021
AbstractIron (Fe) oxyhydroxides (goethite and hematite) and manganese (Mn)‐oxyhydroxides (lithiophorite, asbolane, lithiophorite‐asbolane intermediate) are typically fine‐grained and poorly crystalline in nature, and as such are difficult to identify by conventional X‐ray powder diffraction.
Carmela Alen J. Tupaz, Yasushi Watanabe, Kenzo Sanematsu, Takuya Echigo   +3 more
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Template-free low temperature hydrothermal synthesis and characterization of rod-shaped manganese oxyhydroxides and manganese oxides

Nanotechnology, 2006
Single-crystalline MnOOH (γ-MnOOH) and MnO2 nanorods (β-MnO2 and α-MnO2) were synthesized by redox reaction of a mixture of KMnO4 and Mn(CH3COO)2 at various pH levels at a temperature range of 120–180 °C. The products were characterized by powder x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Raman and infra-red spectroscopy, field ...
Jeyagowry T Sampanthar, Jian Dou, Gan Geok Joo, Effendi Widjaja, Low Qui Hui Eunice   +4 more
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Detailed mineralogy and petrology of manganese oxyhydroxide deposits of the Imini district (Morocco)

Mineralium Deposita, 2015
Manganese ore in the Cenomanian-Turonian dolostone of the Imini district (south of the High Atlas, Morocco) displays a high Mn content due to the occurrence of pyrolusite, cryptomelane, hollandite sensu stricto, coronadite, romanechite, and lithiophorite.
A. Dekoninck, A. Bernard, J. Barbarand, B. Saint-Bezar, Y. Missenard, R. Lepretre, O. Saddiqi, J. Yans   +7 more
openaire   +2 more sources

In situ collection of diagenetic iron and manganese oxyhydroxides from natural sediments

Nature, 1989
IRON and manganese oxyhydroxides are constituents of natural aquatic systems and are thought to play a predominant role in the cycling of toxic trace elements in both marine and fresh-water sediments. Because of their dilution in the sediment matrix (typically 0.1–3.0% dry weight) and because no adequate separation technique was available until now ...
Nelson Belzile, Richard R. De Vitre, André Tessier   +2 more
openaire   +1 more source

Improving the oxygen evolution performance of iron–manganese oxyhydroxides by Cr doping

Chemical Communications
Cr doping into iron–manganese oxyhydroxides increases the active sites, accelerates charge transfer, and lowers the energy barrier, thus promoting the OER.
Jiayang Yu, Tianmi Tang, Jingqi Guan, Yupeng Guo   +3 more
openaire   +2 more sources

Kinetic and Thermodynamic Characterization of the Cobalt and Manganese Oxyhydroxide Cores Formed in Horse Spleen Ferritin

Inorganic Chemistry, 2005
Horse spleen ferritin (HoSF) containing 800-1500 cobalt or 250-1200 manganese atoms as Co(O)OH and Mn(O)OH mineral cores within the HoSF interior (Co-HoSF and Mn-HoSF) was synthesized, and the chemical reactivity, kinetics of reduction, and the reduction potentials were measured.
Bo, Zhang, John N, Harb, Robert C, Davis, Jae-Woo, Kim, Sang-Hyon, Chu, Sang, Choi, Tim, Miller, Gerald D, Watt   +7 more
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Geochemistry and crystallochemistry of oceanic hydrothermal manganese oxyhydroxides showing Mn-Cu association

Geochimica et Cosmochimica Acta, 1989
Hydrothermal iron and manganese oxides have been found in association with sulfides dredged on the E.P.R. near 7{degree}N. The Mn phase, mainly a 10-7 {angstrom} phyllomanganate, presents a very important enrichment in Cu (up to 30% as weight of oxide). The Fe phase, mainly hydro-goethite, has a very low content of metals of economic interest.
Pierre Stouff, Jacques Boulègue
openaire   +1 more source

Formation of manganese oxyhydroxides on the Dead Sea coast by alteration of Mn-enriched carbonates

Hydrobiologia, 1993
Manganese enriched carbonates preferentially accumulate in near-shore, shallow water sediments of the Dead Sea. These carbonates are formed by coprecipitation of Mn with authigenic aragonite, as well as by direct precipitation of Mn-carbonate from the pore water of the shallow sediments.
Aminadav Nishri, Arie Nissenbaum
openaire   +1 more source

The High-Grade Imini Manganese District—Karst-Hosted Deposits of Mn Oxides and Oxyhydroxides

2016
For more than 80 years of mining the economically important Imini district has been the main producer of manganese in Morocco. Three stratabound manganiferous orebodies in the district are hosted in a 10-m-thick Cenomanian-Turonian dolostone that records the effects of laterally extensive dissolution and epigenetic processes.
Dekoninck, Augustin, Leprêtre, Rémi, Saddiqi, Omar, Barbarand, Jocelyn, Yans, Johan   +4 more
openaire   +1 more source