oxidation of pyrite in coal to magnetite

Method for oxidation of pyrite in coal to magnetite and low ...

A method for increasing the magnetization of pyrite-containing pulverized coal comprises heating the coal in an atmosphere of inert gas, desirably nitrogen, containing 3 to 60 torr, preferably 12 to 16 torr, partial pressure of air to a temperature in the range 390° to 455° C., desirably 400° to 410° C., for a time sufficient, preferably 2 minutes to 2 hours, for converting enough pyrite to magnetite to allow separation of at least 50% by weight of the pyrite from the coal in a low ...

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Nanominerals and nanoparticles in feed coal and bottom ash ...

4/27/2010 · Iron oxides (mainly hematite and magnetite) are the main bottom ash products of the oxidation of pyrite, sometimes via intermediate pyrrhotite formation. The presence of iron oxide nanocrystals mixed with silicate glass particles emphasises the complexity of coal and bottom ash micromineralogy.

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Iron Pyrite - Uses & Applications | African Pegmatite

Iron pyrite is a naturally pure and hugely useful ore of iron, finding applications in areas as diverse as photovoltaic cells, brake pads and as a glass colourant. African Pegmatite is a leading supplier of iron pyrite, with the ability to provide the material in a range of grind sizes suited to any operational need.

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Anaerobic, Nitrate-Dependent Oxidation of Pyrite ...

Pyrite is a key mineral in the global biogeochemical cycles of sulfur and iron, yet its anaerobic microbial oxidation has eluded geochemists and microbiologists for decades. Recent reports indicated that anaerobic oxidation of pyrite is occurring, but the mechanism remains unclear. Here, we provide evidence for the capability of Thiobacillus denitrificans to anaerobically oxidize a putatively ...

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Pyrite in Magnetite - Healing Properties, Color, Power ...

What is magnetite in magnetite?

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Magnetite Ore Coal Processing, Magnetite Separation Coal ...

Coal is dewatered after washing for efficient transport and use. Find Out More. The use of DMS magnetite is the most efficient technique for coal preparation and processing available. The DMS magnetite particles allow for greater control and a wider range of separation gravities.

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sg of magnetite in coal mine

Magnetite & Lodestone | Mineral Photos, Uses, Properties. Clean coal particles float and those contaminated with pyrite (a sulfide mineral with a high specific gravity) sink into the high-density slurry. ... Gold - An important metal for thousands of years - uses, prospecting, mining, production. Read more

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CBD-152. Expansion of Pyritic Shales - NRC-IRC

Pyrite oxidation reactions also produce sulphuric acid, reportedly a major pollutant of fresh water streams receiving drainage water from shale beds disturbed by coal mining operations. Pyrite weathering, however, can also be beneficial, as in the recovery of metals such as copper and uranium by the "dump" or "heap" leaching process.

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MECHANISMS OF PYRITE OXIDATION TO NON-SLAGGING SPECIES ...

Sep 01, 2002 · Abstract A project was undertaken to characterize the oxidation of iron pyrite to the non-slagging species magnetite during pulverized coal combustion. The work was aimed at defining the pyrite transformations responsible for the higher slagging propensity of staged, low-NO {sub x} pulverized coal combustor burners.

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Pyrite Passivation by Triethylenetetramine: An ...

The potential of triethylenetetramine (TETA) to inhibit the oxidation of pyrite in H2SO4 solution had been investigated by using the open-circuit potential (OCP), cyclic voltammetry (CV), potentiodynamic polarization, and electrochemical impedance (EIS), respectively. Experimental results indicate that TETA is an efficient coating agent in preventing the oxidation of ...

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PDF The mechanisms of pyrite oxidation and leaching: A ...

A.P.Chandra,A.R.Gerson/SurfaceScienceReports65(2010)293-315 295 Table 1 Restpotentialofsomecommonsulfidemineralsdeterminedunderstandard conditions.

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Limonite - Wikipedia

Limonite (/ ˈ l aɪ m ə n aɪ t /) is an iron ore consisting of a mixture of hydrated iron(III) oxide-hydroxides in varying composition. The generic formula is frequently written as FeO(OH)· n H 2 O, although this is not entirely accurate as the ratio of oxide to hydroxide can vary quite widely. Limonite is one of the three principal iron ores, the others being hematite and magnetite, and ...

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PDF Investigating the Oxidation Phenomena of Magnetite Pellet

The oxidation fraction or the degree of oxidation orf the magnetite pellets exposed to different isothermal temperatures and different O 2 content in oxidizing gas with respect to time is shown in Fig. 2. The oxidation continuously increases with time under the giventhermal and gaseous atmosphere.

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Magnetite Uses - Education - Micrex Development Corp

Using magnets, magnetite can be easily recovered from the waste and coal streams and then re-used in the coal separation circuit. Recyling the magnetite provides a cost saving to the operator, and is an environmentally conscious method of utilizing this valuable resource.

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Oxidation of Pyrite - SCHOENLAUB - 1969 - Journal of the ...

The decomposition of pyrite was investigated in a thermo‐balance. In neutral or reducing gases it decomposes between 550° and 700°C to volatile sulfur and ferrous sulfide. In oxygen it oxidizes in tw...

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PDF Thermal Behavior of Pyrite in the CO and N Atmosphere for ...

These factors allow pyrite to transform into hematite, magnetite and/or pyrrhotite12. The phase changes promoted by thermal treatment of pyrite up to 800 ºC substantially increase its magnetization. These changes include the formation of magnetic phases such as pyrrhotite. In the thermal decomposition process, pyrite

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PDF Frequency Distribution of the pH of Coal-Mine Drainage in ...

presence of calcareous minerals; acid produced by pyrite oxidation is neutralized. The pH values in the acidic mode result from pyrite oxidation and imply a deficiency of calcareous minerals and the absence of carbonate buffering. The oxidation of only a small quantity of pyrite can acidify pure water (0.012 g·L-1 FeS 2 produces pH~4 and 20 mg ...

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Oxidation of pyrite in coal to magnetite - USGS

When bituminous coal is heated in an inert atmosphere (He) containing small amounts of oxygen at 393-455 ??C, pyrite (FeS2) in coal is partially converted to magnetite (Fe304). The maximum amount of Fe304 formed during the time of heating corresponds to 5-20% of the total pyrite present, depending on the coal sample.

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magnetic separation pyrite

Also, the pyrite is not stable in air during the microwave pretreatment process. Due to the porosity of fine coal, when it is placed in air, oxidation reaction occurs between a small amount of oxygen and coal pyrite. This is the reason for the decrease in the specific magnetic susceptibility and the weakening of the magnetic behavior of fine coal.

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Coal cleaning by froth flotation - Iowa State University

Floatability of Coal and Pyrite 30 Flotation Characteristics of Iowa Coal 32 Variables of Coal Flotation 34 Particle size 34 Flotation reagents 36 Pulp density 38 Pulp pH 39 Agitator speed 39 Separation of Pyrite from Coal 40 Wet oxidation pretreatment 41 Ultrasonic vibration 44 Chemical comminution 46 Micro-bubble flotation 48 Kinetics of Coal ...

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