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Showing 1 to 20 of 61 for “"Pyrrhotite"”.
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Structure and Reactivity of Terrestrial and Extraterrestrial Pyrrhotite
Pyrrhotite (Fe1-xS) is a non-stoichiometric iron monosulfide common in terrestrial rocks, ore deposits, and many extraterrestrial materials. The non-stoichiometry due to metal vacancies relates to a variety of composition-dependent crystallographic superstructures, but little of the existing …
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Control of Surface Chemistry of Gold, Pyrite and Pyrrhotite
Removing pyrite from coal and pyrrhotite from pentlandite play a critical role in coal and nickel production, respectively, to meet the stringent restriction on SO2 emission. The present project investigates first the mechanism of xanthate adsorption on gold using Atomic Force Microscope (AFM), …
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On the selective flotation of pentlandite from pyrrhotite in Sheba's Ridge ores
… content in the BIC is comprised of pentlandite, pyrrhotite and chalcopyrite. Sheba's Ridge, one of the ore deposits found in the BIC, is exploited for its PGEs and PGMs. For typical PGE processing operations like the Merensky reef, the valuable PGEs and PGMs are associated with the base metal …
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The Low Temperature Surface Geochemistry And Kinetics Of Pyrrhotite Weathering: Influences On Acid Mine Drainage (amd)
… were conducted into the mechanisms of pyrrhotite oxidation and dissolution. Analysis of pyrrhotite (Fe{dollar}rmsb7Ssb8{dollar}) near surfaces (50A) identifies 32% Fe(III) and 68% Fe(II), both bonded to sulphide. These results show pyrrhotite has the stoichiometry …
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An integrated approach for the mitigation of acid rock drainage (ARD) associated with pyrrhotite in nickel deposits
… mechanisms in flotation to produce passivated pyrrhotite tailings. Passivation enables surface coating of the sulfide thus inhibiting attack by oxidising agents. Promotion of passivation of pyrrhotite during flotation to produce un-reactive tailings has not been explored to date. Polyethylene …
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Pyrite porphyroblast paragenesis at the Cherokee Mine, Ducktown, Tennessee
… The ore mineralogy at the mine is: hexagonal pyrrhotite (60%), pyrite (30%), chalcopyrite (4%), sphalerite (3 %), and magnetite (3 %) with minor galena, molybdenum, tetrahedrite, bismuth, ilmenite, and rutile. The ore body is interpreted to have been syngenetic and to have contained both …
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Kinetic Studies of Sulfide Mineral Oxidation and Xanthate Adsorption
… certain sulfide minerals, such as pyrite and pyrrhotite, are less desirable. Froth flotation is a commonly used separation technique, which requires the use of several reagents to float and depress different sulfide minerals. Xanthate, a thiol collector, has gained immense usage in sulfide …
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Sulfidation of synthetic biotites
… join phlogopite-annite and the composition of pyrrhotite. In an attempt to bracket the sulfide-silicate compositional pairs, three layers within a single capsule were used: 1) pyrite + Fe-rich biotite in the top, 2) sanidine + magnetite in the middle, and 3) troilite + Mg-rich biotite in the …
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Towards the development of an integrated modelling framework underpinned by mineralogy
… quartz) were determined in the third round and pyrrhotite and magnetite were calculated on the last round. Data validation for EMC was performed by comparing calculated mineral grades against the measured mineral grades obtained from QEMSCAN. The accuracy was determined by evaluating the R2 …
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An investigation into the process mineralogy of the Merensky reef at Northam Platinum Limited
… base metal sulphides (chalcopyrite, pentlandite, pyrrhotite and total sulphide) as well as through investigation of mass-water recoveries.
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Iron-magnesium amphiboles: synthesis and stability with respect to temperature, pressure, oxygen fugacity, and sulfur frugacity
… been determined between Fe-Mg amphiboles and pyrrhotites in the presence of excess magnetite and quartz at 2 kbar, and 650°, 675°, 700°, and 725°C. This assemblage represents the simultaneous equilibria: amphibole + O₂ -> magnetite + quartz + H₂O (1) amphibole + S₂ -> pyrrhotite + quartz + H₂O …
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Characterization of pentlandite-bearing quartz veins of Kambalda, Western Australia
… quartz veins with pentlandite intergrown with pyrrhotite and gangue minerals such as quartz, feldspar and biotite. Pentlandite, co-genetic pyrrhotite and gangue minerals formed by precipitation from metamorphic fluids. Mineralization Style IV represents fractured or brecciated quartz veins with …
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Mechanisms governing the growth, reactivity and stability of iron sulfides
… of three case studies on the stable Fe-S phases pyrrhotite (Fe₁-xS) and pyrite (FeS₂) to identify the elementary corrosion mechanisms and their kinetic parameters. Pyrrhotite is of interest because the off-stoichiometry of this phase leads to relatively rapid bulk processes such as diffusion; …
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Ore mineralogy and paragenesis of a portion of the Great Gossan Lead district, Virginia
… Ore mineralogy is dominated by hexagonal pyrrhotite with minor amounts of sphalerite and chalcopyrite. All other phases--galena, arsenopyrite, pyrite, cubanite, mackinawite, tetrahedrite, stannite, and native bismuth--are disseminated throughout the ores. Pyrite is locally common as …
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ΜΕΛΕΤΗ ΜΑΓΝΗΤΟΑΝΤΙΣΤΑΣΗΣ ΣΕ ΜΟΝΟΚΡΥΣΤΑΛΛΟΥΣ FE7S8
… SEMICONDUCTORS AND SPECIALLY IN PYRRHOTITE FE7S8 CUT FROM NATURAL SINGLE CRYSTALS (WITH ORIENTATIONS B C AND B// FROM 88 TO 607K. BEYOND THE NEEL POINT TN 600K AND FOR MAGNETIC FIELDS B FROM 0 TO 7 KG. A MAGNETORESISTANCE OF THE ORDER OF 10-3 WHICH IS ALWAYS NEGATIVE FOR SMALL B …
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Paleomagnetic and mineral magnetic studies of zinc-lead ore deposits in the Metaline (Washington state, USA) and Midlands (Ireland) ore fields
… by pseudosingle (PSD) to single domain (SD) pyrrhotite that records a primary chemical remanent magnetization (CRM) in ore and a secondary ChRM in host specimens. Furthermore, the paleomagnetic Middle Jurassic age suggests an epigenetic origin for ore formation of the Zn-Pb mineralization at …
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Laboratory Electrical DC Resistivity of Serpentinite, Graphite, Oxide and Sulfide Minerals
… graphite, hematite, ilmenite, magnetite, pyrite, pyrrhotite and serpentinite was assessed using a Cryogen-Free Measurement System (CFMS) over a temperature range of 10K-300K. The objective of this work is to contribute to radar and Ground Penetrating Radar sensing data interpretation as electrical …
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The role of nitrogen on the flotation performance of a complex sulphide ore
… the ore; chalcopyrite (Cu), pentlandite (Ni) and pyrrhotite (Fe, as an approximate representative since Fe occurs in pyrrhotite, chalcopyrite, pentlandite as well as nonsulphide gangue). Secondly, to develop an understanding of the mechanisms of nitrogen addition on the relevant sub processes and …
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Synthesis of Cadmium, Lead and Iron Sulfide Thin Films and Nanoparticles
… Furthermore, optically active greigite and pyrrhotite-iron sulfide nanoparticles were prepared by simply varying the temperature of the hot solvent. Pyrrhotite-Fe1-XS sensor device showed interesting performance when tested for humidity and different nitrogenous gases such NO2 and NH3. The …
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A Comparison of Geochemistry, Carbonate Mineralogy, and Argillic Alteration between the Dome Prospect and the Main Au Resource of the Donlin Creek Project in Southwest Alaska
… arsenopyrite on porous pyrite-marcasite ± pyrrhotite grain boundaries, mainly in the resource area, demonstrates the late timing of the precious-metal minerals compared to the base-metal mineral assemblage. The base-metal district is noted for …
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