نتایج جستجو برای: pyrolusite
تعداد نتایج: 90 فیلتر نتایج به سال:
Mining, as defined by Stocks and Down is the ‘removal of minerals from their natural geological environment and their transport to the point of processing or use1’. As so defined mining has, in one form or another, been providing essential raw materials for tens of thousands of years. Although metal ores were first mined in southern Africa (south of 15°S) approximately 2 000 years ago, minerals...
Residual layers and lenses of the Borhan area (SE Mahabad, NW Iran) contain considerable volume of ferrite ores, which are surrounded by carbonate rocks of the Ruteh Formation of Permian age. Petrographic examinations show that these ores have polycyclic nature and allogenic origin and their evolution is largely affected by the diagenetic and epigenetic processes. Mineralogical studies reveal t...
The Beshgaz manganese-bearing veins are located in ~45 km northeast of Birdjand, South-Khorasan, and east of Iran. These veins with 0.1-1.5 m thickness and 4-7 m length are engulfed discordantly within Paleocene (Eocene-Oligocene) volcanic-pyroclastic rocks. The host of Mn-bearing veins are dacite to rhyo-dacite tuff, lapilli tuff with andesitic and andsi-basaltic fragments in shear zones. The...
Mn-based materials have been widely applied in the environmental catalysis field for their excellent redox properties. Here, three kinds of crystallite manganese oxides (pyrolusite, cryptomelane and todorokite) with different tunnel sizes (MnO(1 × 1), MnO(2 2), MnO(3 3)) were prepared by hydrothermal method, catalytic performance complete oxidation diesel vehicle exhaust tested. The highest act...
The Beshgaz manganese-bearing veins are located in ~45 km northeast of Birdjand, South-Khorasan, and east of Iran. These veins with 0.1-1.5 m thickness and 4-7 m length are engulfed discordantly within Paleocene (Eocene-Oligocene) volcanic-pyroclastic rocks. The host of Mn-bearing veins are dacite to rhyo-dacite tuff, lapilli tuff with andesitic and andsi-basaltic fragments in shear zones. The...
Sighter Induced Roll Magnetic Separation tests were conducted on a ferromanganese ore sample to determine the potential significantly upgrade Mn content and Mn:Fe ratio. The had ratio of 1.3 was comprised hematite, cryptomelane, pyrolusite, quartz, goethite braunite. Tests at 4.7, 2.3 1 mm top sizes revealed better separation Fe from sizes. This reflected liberation characteristics oxides both ...
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