A novel authigenic magnetite source for sedimentary …
Magnetite in marine sediments generally originates from detrital inputs from land or as an authigenic mineral that forms during diagenesis ... in such a sulfidic environment is puzzling and indicates that magnetite formation postdated most of the carbonate and pyrite formation at paleo-SMTZs, after the environment became …
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Magmatic immiscibility and the origin of magnetite …
The origin of magnetite-(apatite) iron deposits (MtAp) is one of the most contentious issues in ore geology with competing models that range from hydrothermal to magmatic processes. Here we report ...
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Limonite pseudomorphous after pyrite from York County.
Limonite pseudomorphous after pyrite from York County. PA. Edwin F. Holden. Edwin F. Holden State College, Pa. Search for other works by this author on: GSW. ... An oxygen and sulfur isotope study of skarn-type magnetite deposits of the Cornwall type, southeastern Pennsylvania Economic Geology. Archive; Current Issue; Online ISSN …
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Enhanced generation of reactive oxygen species by pyrite …
Fig. 1 c and d show the effects of solution pH on the reaction between pyrite and As(III). Increasing pH value from 3.0 to 7.0, the removal efficiency of As(III) by pyrite increased. At pH 3.0, 15.5% As(III) was oxidized to As(V) after 6 h reaction; however, the removal of total arsenic was negligible.
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Is Pyrite Magnetic? (+ Answers To Other Common Pyrite Questions)
Pyrite (aka "fool's gold" or "iron pyrite") is a metallic looking material with numerous applications. Its chemical formula is FeS 2, meaning that it is a compound made up of iron (Fe) and Sulphur (S).
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Hydrothermal sulfidation of biogenic magnetite produces …
In experiments with biogenic magnetite, no pyrite was observed after 7 days, irrespective of the presence of S⁰ (d–f). Dendritic-octahedral pyrite formed in experiments without OM but with the ...
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'Fool's gold' may be valuable after all | ScienceDaily
In a breakthrough new study, scientists and engineers have electrically transformed the abundant and low-cost non-magnetic material iron sulfide, also known …
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Pyrite in Magnetite
Pyrite In Magnetite - Color, Facts, Power, Mythology, History And Myths. The prominent aspect of black with gold in pyrite and magnetite makes it a jewel boulder that often recognized as Healer's Gold.
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Oxidation of pyrite in coal to magnetite
When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393–455 °C, pyrite (FeS 2) in coal is partially converted to magnetite (Fe 3 0 4).The maximum amount of Fe 3 0 4 formed during the time of heating corresponds to 5–20% of the total pyrite present, depending on the coal sample. The magnetite …
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The energetics and kinetics of uranyl reduction on pyrite, …
Interestingly, the second peak is only significant in pyrite and magnetite + U(VI) voltammograms after applied potential holds at −0.25 V, but the peak is clearly noticeable in all cyclic voltammograms for hematite. This result suggests that the rate of the disproportionation reaction is slowed by the pyrite and magnetite surface relative to ...
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Simultaneous removal of chromium(VI) and phosphate from …
The treatment of multi-component pollutants in wastewater is a challenge. In this work, a novel nanoscale magnetite/pyrite (Fe 3 O 4 /FeS 2) composite was successfully synthesized, characterized and applied in simultaneous removal of Cr(VI) and phosphate. Transmission electron microscopy, X-ray photoelectron spectroscopy, …
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Thermal decomposition and oxidation of pyrite with …
Pyrite is common in coal gangue formed in a reduced environment and has a significant influence on the recycling utilization of coal gangue. Four types of pyrite with different structures and morphologies, namely octahedral pyrite framboid, pentagonal dodecahedral pyrite framboid, irregular grain pyrite, and euhedral octahedral crystalline …
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Magnetite trace element characteristics and their use as a …
Since the pyrite paragenetically replaces pre-existing magnetite, care needs to be taken in interpreting pyrite chemical trends in isolation as many of the elemental trends mimic and reflect inheritance through scavenging of metals from early formed magnetite (e.g. Steadman and Large 2016), while several of the divergent trends can …
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Hydrothermal sulfidation of biogenic magnetite produces …
Here, we show that the hydrothermal sulfidation of abiogenic and biogenic magnetite (sulfide/iron = 4, 80 °C) yields pyrite with various distinct morphologies, …
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Sulfidation of nano-magnetite to pyrite: Implications for …
S 0 drives the sulfidation of magnetite to pyrite via the polysulfide pathway. • Pyrite growth after magnetite sulfidation proceeds via particle attachment. • Proxies and biosignatures in magnetite are likely altered or erased by sulfidation. • Hydrothermal pyrite may be a secondary product from magnetite sulfidation.
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Thermal Alteration of Pyrite to Pyrrhotite During Earthquakes: New
The magnetic signature of the sample at 770.44 m bsf appears to be dominated by pseudo-single-domain (PSD) magnetite (Figure S1); it is inferred to be a volcanic ash. There appears to be no slip surface present after close reexamination. Pyrrhotite is not identified as well.
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Surface Morphology and Structural Evolution of Magnetite …
The use of magnetite-based iron ore fines by means of fluidized bed technology has become a promising route to produce direct reduced iron. The significant influence of a prior oxidation treatment, which occurs in the preheating stage, on the subsequent fluidization and reduction behavior was observed in our previous study. As a …
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Trace element associations in magnetite and hydrothermal pyrite from
Trace element analysis of magnetite, pyrite and pyrrhotite was conducted following the methodology described by Steadman et al., 2013, Steadman et al., 2014. Laser ablation of magnetite and sulfides was conducted using a Coherent GeoPro 193 nm ArF laser, connected to a Varian 820 series ICP-MS housed at the Advanced Analytical …
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The effect of heat treatment on the magnetic properties of pyrite
The results of the magnetic separation of the pyrite samples are shown in Fig. 3.Initially the recovery in the magnetic fraction is very low, approximately 20% and remains so until 200 °C.Once the treatment temperature was 400 °C, the magnetic recovery increased considerably to 80%.This is where the first sign of the formation of new …
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The late diagenetic conversion of pyrite to magnetite by …
The geochemistry of late stage diagenetic replacement of pyrite by magnetite was investigated by laboratory experiments of pyrite dissolution and magnetite …
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Magnetite (mt)
Magnetite is typically altered to martite (hematite) by oxidation, initially favored by cleavage, following planes (111) but tending to extend later to the whole crystal (Fig. 78.7). It is also altered to maghemite. It can also be formed as a secondary product, for example by alteration of pyrrhotite, resulting in an aggregate of pyrite+magnetite.
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Replacement of pyrite framboids by magnetite in …
The first explanation involves a chemical remanent magnetization (CRM) acquired when new magnetic minerals (primarily magnetite) formed long after the formation of the …
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Hydrothermal sulfidation of biogenic magnetite …
After 35 days of incubation, pyrite was detected in experiments with biogenicmagnetite(noS 0 )usingµ-XRD(Fig. 1).Overall,µ-XRDreflections characteristic of pyrite are broader in the presence of ...
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The Mineral magnetite
Magnetite is best known for its property of being strongly attracted to magnets. Some forms of Magnetite from specific localities are in fact themselves magnets. Commonly known as Lodestone, this magnetic form of Magnetite is the only mineral that is a natural magnet. Due to the magnetism of Lodestone, small iron particles are often found ...
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Pseudomorphs
But Goethite does occur as a PSEUDOMORPH after Pyrite, and Pyrite does form cubic crystals. So, here is a list of PSEUDOMORPHS copied form Mr. Sinkankas' book: ... HEMATITE after MAGNETITE. GYPSUM after ANHYDRITE. GYPSUM after ARAGONITE. COPPER after CUPRITE. COPPER after AZURITE. COPPER after …
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The thermal transformation behavior and products of pyrite …
This may be the first report about nano-sized pseudomorph hematite after pyrite is heated, to the knowledge of the authors. As observed under SEM, the hematite nanoparticles were ∼ 50 nm in diameter and tightly arranged into aggregates, but melted and connected at higher temperatures. ... S/Fe = 2 in pyrite, but O/Fe in magnetite or …
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Magnetite : Properties, Occurrence, Formation, Deposits
Magnetite is rock mineral and one of the most important iron ore minerals with chemical formula is iron(II,III) oxide, Fe2+Fe3+2O4 .It also as the name magnetic minerals to attracted to a magnet. It is the most magnetic natural occuring minerals in the World. Small grains of magnetite occur in almost all igneous and metamorphic rocks.. …
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'Fool's gold' may be valuable after all | ScienceDaily
In a breakthrough new study, scientists and engineers have electrically transformed the abundant and low-cost non-magnetic material iron sulfide, also known as 'fool's gold' or pyrite, into a ...
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Rare and Critical Metals in Pyrite, Chalcopyrite, …
The geological setting of the Cenozoic magmatic rocks and related porphyry-type mineralization of the Vertiskos Unit (modified after [35,38,42,53,55,56]).
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Recycling of iron from red mud by magnetic separation after co-roasting
Based on these reports, a novel method to remove hematite from red mud has been proposed in this study. The flow-sheet diagram is shown in Fig. 1, hematite in red mud being transformed into magnetite with the help of pyrite, and then the resulting magnetite could be collected by magnetic separation.The treatment conditions, such as …
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