We propose to bracket the magnetite‐out and pyrrhotite‐in temperatures in shales and slates from Taiwan and the Pyrenees by using a combination of low‐temperature magnetic transitions and geothermometers. For T burial < 340°C, the magnetic assemblage is dominated by magnetite. Gradually with increasing burial temperature, the ...
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1 INTRODUCTION. The magnetic properties of the iron oxides and sulphides magnetite (Fe 3 O 4), hematite (αFe 2 O 3) and monoclinic 4C pyrrhotite (Fe 7 S 8) at above-ambient temperatures T govern their magnetic expression at depth in the Earth and other planets, fore example, Mars. They also determine the magnetic memory these minerals retain in the form of …
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Pyrrhotite Pyrrhotite, an iron sulfide mineral, is brassy yellow, opaque, and has metallic luster. It is found in small "hexagonal" crystals in the Franklin Marble, but most specimens consist of irregular grains, aggregates, or rounded, finger-like crystals or aggregates up to 5 cm in length by 1-2 cm wide, on which some planar features are present but commonly not definable as …
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Although pyrrhotite (iron sulfide) commonly occurs in Martian meteorites (Rochette et al. 2001), Dunlop and Arkani-Hamed (2005) favored magnetite over pyrrhotite because the saturation remanence ...
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The simultaneous solubilities of the minerals pyrite, pyrrhotite, magnetite, sphalerite, galena, gold, stibnite, bismuthinite, argentite, and molybdenite have been measured in 0 to 5 m NaCl solutions from 200 degrees to 350 degrees C at CO 2 partial pressures from 0.69 to 172 bars with oxygen and sulfur fugacities controlled by the pyrite-pyrrhotite-magnetite buffer.
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Pyrrhotite with Magnetite and Siderite Chiuzbaia, Baia Mare, Maramures Co., Romania Small Cabinet 7.5 x 7.5 x 4.0 cm (4 more images) SOLD. Details. PMRARE15-055 Native Gold in Quartz Vein with Scheelite, Dolomite, Pyrrhotite, and Arsenopyrite Mina Velha, Morro Velho, Nova Lima, Minas Gerais, Brazil Cabinet 9.0 x 6.0 x 5.5 cm
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Pyrrhotite is formed during low-grade metamorphism in marly carbonates (Carpenter, 1974, Rochette, 1987). Among other processes pyrrhotite can be formed at the expense of sedimentary magnetite and pyrrhotite (Crerar et al., 1978). This transformation may occur at. Acknowledgements. This project is funded by the German Research Council (DFG).
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Abstract. The non-stoichiometric compounds of iron sulphide named pyrrhotite (Fe1−xS) are often associated with pyrite (FeS2) in sulphidic ores and their waste products. The factors affecting pyrite and pyrrhotite oxidation are similar but the latter has received much less attention. As it is the case for pyrite, an increase in temperature ...
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The detrimental sulphur containing mineral is monoclinic pyrrhotite and its removal requires flotation. Previous published results related to pyrrhotite flotation from magnetite concentrate, e.g. on a magnetite deposit in Peru, only required the process to produce a final magnetite concentrate with a sulphur level below 0.4% w/w.
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A beautiful specimen of pyrrhotite from Russia! Flat, stacked crystals with a little magnetite! Size: 1 7/8 x 1 1/4 x 1 1/8 Weight: 3 oz. Thanks for looking! Hope your day is fantastic! I always combine shipping and refund excess shipping charges.
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Massive sulfide (9.3 cm across at its widest) with pyrrhotite, magnetite, and chalcopyrite (copper ore) from the Norilsk Mining District in Siberia, Russia. ----- This amazing piece of copper ore is from the Talnakh Copper-Nickel Deposit in Siberia. The rock is dominated by pyrrhotite (Fe(1-x)S - imperfect iron monosulfide), which is a washed-out brassy color, and …
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Pyrrhotite is a common bronze-coloured magnetic mineral consisting of ferrous sulphide in hexagonal crystalline form. It is also called magnetic pyrite, because the color is similar to pyrite and it is weakly magnetic. The magnetism decreases as the iron content increases, and troilite is non-magnetic. It commonly is found with pentlandite and ...
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Montalti (1994) systematically investigated pyrrhotite floatability using ethyl xanthate. The pyrrhotite sample was from North Bend, Washington and was analyzed by XRD to be only one phase β-Fe 1−x S (Fe 47.0% and S 32.6%) having hexagonal crystal structure with some impurities (C 1.45% and Zn 4.64%). The zeta potential of this pyrrhotite sample was …
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Pyrrhotite is an iron sulfide mineral with the formula Fe (1-x) S (x = 0 to 0.2). It is a nonstoichiometric variant of FeS, the mineral known as troilite.Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is weakly magnetic.The magnetism decreases as the iron content increases, and troilite is non-magnetic. [page needed]
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The U.S. Department of Energy's Office of Scientific and Technical Information
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The variation of iron in Pyrrhotite's structure is also responsible for more than one crystal symmetry type, allowing it to form in both hexagonal and monoclinic symmetries. Multiple crystal symmetries should technically classify Pyrrhotite as a mineral group rather than a single mineral, but a sub-classification is rarely made due to polytypes appearing similar and perhaps even …
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Pyrrhotite with Magnetite and Siderite Chiuzbaia, Baia Mare, Maramures Co., Romania Small Cabinet, 7.5 x 7.5 x 4.0 cm Ex. Kay Robertson SOLD. SUPERB and classic, this Pyrrhotite is from an old locale in Romania. The main crystal is complete all around and gracefully elongated, and it has an excellent, antique bronze patina. It rises a full 5 cm ...
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Request PDF | Flotation of pyrrhotite to produce magnetite concentrates with a sulphur level below 0.05% w/w | Northland Resources is developing several magnetite mineral resources in northern Europe.
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Heating Pyrrhotite at 320 degrees C. will destroy its magnetism. Heating in the presence of Oxygen (no water) will have the following reaction equation (balanced) ; 3FeS + 5O2 = Fe3O4 + 3SO2 This is the process that used to be used at INCO in Sudbury, Ontario, Canada to convert FeS to Magnetite, which was then pelletized and sold as Iron Ore.
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THE MINERAL PYRRHOTITE. Chemistry: Fe 1-x S (x=0 to x=0.2), Iron Sulfide. Class: Sulfides and Sulfosalts. Group: Nickeline. Uses: mineral specimens and as an ore of sulfur and iron. Specimens. Pyrrhotite has some unusual characteristics. First, it has an unusual formula. The amount of sulfur does vary by roughly 20% or 50 to 55 atoms of sulfur ...
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The analysis results in Table 3 and Table 4 show that it was of high purity with minor impurities in pyrrhotite and magnetite. The lumps of pyrrhotite and magnetite were crushed and ground to a particle size less than 74 µm in a ceramic ball mill. The powder of −74 µm was further ground to −2 µm for zeta potential and FTIR experimental ...
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During burial of clay-rich sediments, magnetic minerals, just as other minerals, are continuously produced, altered, and dissolved. In shales, from early burial to anchi-metamorphism (Tburial< 250°C), magnetite is the main magnetic mineral. In slates, it is known that the dual breakdown of magnetite and pyrite trigger the formation of pyrrhotite for burial temperature close to 300°C ...
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the chemically pure, hexa-octahedral magnetite particles association with pyrrhotite. Hence, the products generated by the thermal decomposition of siderite and pyrite provide strong evidence for the inorganic formation of magnetite and pyrrhotite in Martian meteorite ALH84001 (Figure 1). Figure 1: Magnesium composition of the original, natural ...
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It is proposed that a substantial fraction of the magnetite, at least, resulted from the oxidation of troilite. Pyrrhotite is expected as a direct consequence of magnetite formation through this reaction. During thermomagnetic experiments on troilite, magnetite formation was observed at temperatures as low as 373 K, provided that the oxygen fugacity was held in the magnetite …
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The difference between pyrrhotite and magnetite is that "pyrrhotite" is a weakly magnetic ferrous sulfide mineral, FeS and "magnetite" is a magnetic mineral, Fe3O4, one of the primary ores of iron. It has also been called lodestone. Tags: magnetite, pyrrhotite What is the difference between Organogenesis and Morphogenesis?
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Pyrrhotite is superficially like pyrite in appearance and chemistry, but they are different minerals. Pyrrhotite has a metallic luster, a brownish-brassy or bronzish color, a black streak, no cleavage, and is magnetic. What's particularly distinctive about pyrrhotite is that it is variably magnetic.
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Recovery of pyrrhotite and magnetite from tailings of Norilsk disseminated sulfide ores Download PDF. Download PDF. ... A. A. Bikbov, A. M. Komlev, et al., "Final treatment of magnetite concentrates in a separator with a traveling magnetic field," in: Features of Concentration of Finely Disseminated Ores of Ferrous Metals [in Russian], Nedra ...
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Pyrrhotite from Dal'negorsk, Primorskiy Kray, Russia. Pyrrhotite is an unusual iron sulfide mineral in the niccolite group with up to 20% variable amounts of iron and or sulfur. Pyrrhotite is also called magnetic pyrite because the color is similar to pyrite and it is weakly magnetic. The magnetism increases as the iron content decreases.
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Pyrrhotite-pentlandite-chalcopyrite-magnetite from the Precambrian of Ontario, Canada. (SDSMT 86, South Dakota School of Mines and Technology, Museum of Geology, Rapid City, South Dakota, USA) Silvery-bronze = pyrrhotite ~Whitish-brassy = pentlandite Yellow brassy gold = chalcopyrite Black = magnetite A mineral is a naturally-occurring, solid, …
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