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magnetite ultrafine

The use of flotation to separate fine coal and ultrafine ...

@article{osti_110014, title = {The use of flotation to separate fine coal and ultrafine magnetite from dense-medium cyclone products}, author = {Polat, M and Klima, M S and Chander, S and Ahuja, G}, abstractNote = {A study was conducted to investigate the use of flotation in combination with dense-medium cycloning utilizing ultrafine ({minus}10 {micro}m) magnetite, as an integrated …

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Heavy media separation with dense Magnetite | LKAB Minerals®

Benefits of using Magnetite in dense medium separation. For many heavy media separation processes, the right slurry density can be reached with Magnetite. The particle density of our Magnetite is 5.1 t/m 3. Your benefits when using LKAB Minerals' Magnetite for media separation: Very pure: 99% Magnetite and 71.5% Fe. Low water absorption (<0.3%)

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(PDF) Formation of Ultra Fine-Grained Magnetite in Soils

The production of ultrafine-grained magnetite by magnetotactic bacteria in surficial aerobic sediments may contribute significantly to the natural remanent magnetism of sediments2-4.

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Constraining the magnetic properties of ultrafine- and ...

Four samples containing ultrafine- and fine-grained magnetite of magnetoferritins and magnetotactic bacteria cells were magnetically characterized at both room and low temperatures. Transmission electron microscopy analysis showed that the biometrically synthesized magnetoferritins (M-HFn) have magnetite cores with a mean size of 5.3 ± 1.2 nm inside protein shells, while …

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Magnetite pollution nanoparticles in the human brain | PNAS

Abstract. Biologically formed nanoparticles of the strongly magnetic mineral, magnetite, were first detected in the human brain over 20 y ago [Kirschvink JL, Kobayashi-Kirschvink A, Woodford BJ (1992) Proc Natl Acad Sci USA 89(16):7683–7687]. Magnetite can have potentially large impacts on the brain due to its unique combination of redox activity, surface charge, and strongly magnetic behavior.

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Microbial production of ultrafine-grained magnetite - The ...

Magnetite (Fe 3 O 4) is a mineral of great commercial value in that it is useful, e.g., in magnetic recording devices and as toner for plain paper copiers. Particularly desirable for these purposes is magnetite in ultrafine-grained (roughly 20-50 nanometers in diameter) form.

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Minerals | Free Full-Text | Selective Flocculation ...

Magnetite generally occurs as singular particles, such as those in micro-zones 1, 2, and 6, but some are also seen aggregated with gangue minerals, such as micro-zone 5.Ultrafine magnetite particles below 5 μm in size are commonly sighted, e.g., in micro-zones 1, 2, 3, and 4, and occasionally there are magnetite particles below 10 μm, e.g ...

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Protein assisted hydrothermal synthesis of ultrafine ...

A facile and green route is presented for mass production of oriented magnetite porous fibers (with >96% in yield), based on the protein assisted hydrothermal method in citric aqueous solution. The magnetite fibers are nearly cylindrical in shape, several ten micrometres in length and 120 nm in mean diameter. The whole single fibers are packed by the ultrafine Fe 3 O 4 nanoparticles with ...

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Magnetic properties of ultrafine magnetite particles and ...

Ultrafine magnetite particles of 4-10 nm were prepared in aqueous solutions of polyvinylalcohol (PVA) or PVA with partially exchanged carboxyl groups. The mode of agglomeration and dispersion of the particles were different depending on the properties of polymers in the solvent.

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Magnetite | Geology Wiki | Fandom

Magnetite is a rock mineral and one of the main iron ores, with the chemical formula Fe3O4. It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. It is the most magnetic of all the naturally-occurring minerals on Earth. Naturally-magnetized pieces of magnetite, called lodestone, will attract small pieces of ...

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Dextran Coated Ultrafine Superparamagnetic Iron Oxide ...

The distinct difference in the oxidative potential of maghemite and magnetite may be related to the oxidative state of the iron ions in the complex. In maghemite (Fe 2 O 3) iron ions are mostly Fe 3+, while in magnetite (Fe 3 O 4) they are a mixture of Fe 3+ and Fe 2+ with a Fe 2+ /Fe 3+ ratio of 0.435 (Table (Table1). 1).

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Fibrous Aggregation of Magnetite Nanoparticles Induced by ...

Chengliang Han, Weiping Cai, Wei Tang, Guozhong Wang, Changhao Liang, Protein assisted hydrothermal synthesis of ultrafine magnetite nanoparticle built-porous oriented fibers and their structurally enhanced adsorption to toxic chemicals in solution, Journal of Materials Chemistry, 10.1039/c1jm11048a, 21, 30, (11188), (2011).

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(PDF) Production of Nanocrystalline Magnetite for ...

2nd International Conference on Ultrafine Grained & Nanostructured Materials (UFGNSM) International Journal of Modern Physics: Conference Series Vol. 5 (2012) 771–783 World Scientific Publishing Company DOI: 10.1142/S20107 Production of Nanocrystalline Magnetite for Adsorption of Cr(VI) Ions by 18.206.13.133 on 06/13/20.

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Hydrothermal preparation and characterization of …

Ultrafine magnetite particles were prepared through a hydrothermal process at 130°–150°C from a solution of iron chloride and iron powder in the presence of urea. XRD and chemical analysis indicated that the product was magnetite. The size and morphology of the particles were studied by TEM.

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Synthesis and Characterization of Polypyrrole– Magnetite ...

The synthesis of colloidal polypyrrole-magnetite-silica nanocomposites is described. First, silica-coated magnetite particles were prepared by the aqueous deposition of silica onto ultrafine (5-20 nm) magnetite particles via controlled hydrolysis of sodium silicate. Then pyrrole was chemically polymerized using (NH 4 ) 2 S 2 O 8, H 2 O 2 /Fe 3 ...

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Solvent Extraction of Arsenic(V) with Dispersed Ultrafine ...

containing ultrafine magnetite and oleic acid, and a buffered aqueous solution of arsenic(V). When heptane containing 0.58 g/dm3 magnetite and 3.4 ×10–3 M of oleic acid was shaken with a buffered aqueous solution at pH 6, phase separation was insufficient. Oleic acid was thought to be responsible for the poor phase separation.

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Green synthesis of ultrafine super-paramagnetic magnetite ...

Abstract In this communication, environmental friendly and biocompatible ultrafine super-paramagnetic magnetite nanoparticles (USPMNs) ferro-fluid was prepared by modifying co-precipitation green itinerary under optimized conditions. Phase pattern of USPMNs was confirmed by X-ray diffraction (XRD). Particle size of USPMNs was also estimated using the Scherrer's formula which turned out to …

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Reverse flotation of ultrafine magnetic concentrate by ...

The results provide a reference for effective recovery of ultrafine magnetite. Materials and methods Pure minerals and reagents Pure magnetite, chlorite and quartz were sourced from Anshan, Huaheng, and Haicheng city in China, respectively. Magnetite, chlorite, and quartz were 98, 99, and 94% pure

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Minerals | Free Full-Text | Selective Flocculation ...

Simple magnetic separation for a certain magnetite mine with ultrafine disseminated lean ores has resulted in low performance, as the fine sizes and aggregation of ground mineral particles have caused inefficient recovery of the ultrafine minerals. In this study, we attempt to increase the apparent sizes of target mineral particles, and improve the separation indices, by using a multi-stage ...

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Identification and paleoclimatic significance of magnetite ...

In the famous Chinese Loess Plateau (CLP), weakly magnetic, windblown dust layers alternate with variably magnetic fossil soils, recording monsoonal variations through the last ∼3 My. The soils contain strongly magnetic iron oxides, formed in situ, the mineralogy and paleoclimatic significance of which are controversial. Reduction of iron to form Fe2+-bearing magnetite has been linked to ...

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Formation of ultrafine-grained magnetite in soils - NASA/ADS

The magnetic properties of certain soils indicate the widespread presence of ultrafine-grained magnetite, even where there is no detrital input of magnetite 1-3 . This suggests that in situformation of magnetite can occur under soil-forming conditions. Schwertmann and Taylor 4 have stated, however, that magnetite has not been found as a newly formed mineral in soils.

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Preparation of ultrafine magnetite and its oxygen ...

Ultrafine magnetite was prepared in aqueous solution by reflux method with ethylenediamine as precipitant. On partial substitution of ethylenediamine for distilled water in the solution, the crystallite was reduced in size linearly. Ethylenediamine worked as not only a …

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Frontiers | Ultrafine Magnetic Particles: A DIET-Proxy in ...

Magnetic particles formed by dissimilatory iron-reducing bacteria are typically ultrafine, as such generating mineral carriers with superparamagnetic properties, (e.g. ultrafine magnetite or greigite) from reducing Fe (III) minerals from background geological media.

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Ultrafine Grade Magnetite - Tasmania Mines Pty Ltd

The ultrafine grade magnetite is one of our most preferred coal wash grade magnetite products. Our coal wash products have a proven track record as a preferred choice for coal wash plants worldwide. Total Iron Fe Ferrous Iron Fe(2+) Nominal Range Magnetics Mean density. 68.40% min 20% min

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Effect of ultrafine powder of hematite and magnetite on ...

N2 - Effect of ultrafine powder of Hematite and Magnetite on granulation characteristics of iron oxide was investigated by mixing and exterior coating granulation. The results obtained are follows: (1) In the case of Hematite Ore H, particle diameter of granule is increase with increasing the amount of fine powder in both mixing granulation and ...

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Formation of ultrafine-grained magnetite in soils | Nature

The magnetic properties of certain soils indicate the widespread presence of ultrafine-grained magnetite, even where there is no detrital input of magnetite1–3. This suggests that in ...

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Structure and magnetic properties of ultrafine ...

The glycol assisted co-precipitation was used as the synthesis method of tin-doped magnetite. • The XPS and Möss spectra confirm the existence of only Sn 4+ ions in magnetite structure.. Ultrafine Fe 3 O 4:Sn 4+ NPs have high saturation magnetization equal to 49.7 emu/g.. The very low coercivity equaled 13.29 Oe was correlated with superparamagnetic behavior.

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Morphological and magnetic features of Ru(III) doped ...

Magnetite nanoparticles constitute a class of nanoparticles which is easily manipulated using a magnetic field. Magnetite nanoparticles doped with ruthenium (Ru) ions [RuxFe(3-x)O4] were synthesized via co-precipitation method where 0.0 ≤ x ≤ 0.5 with step 0.1. The obtained nanopowder was investigated via x-ray diffraction, FTIR, FESEM. It was shown that …

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(PDF) Ultrafine magnetite nanopowder: synthesis ...

Ultrafine magnetite nanopowder: synthesis, characterization, and preliminary use as filler of polymethylmethacrylate nanocomposites. Download. Related Papers. Approaches to synthesis and characterization of spherical and anisometric metal oxide magnetic nanomaterials. By Davide Peddis.

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Classification of Ultrafine Magnetite and its Effect on ...

Two grades of magnetite were used for this series of tests. Type-I was an ultrafine magnetite with a top size of 15 µm, which was supplied by the Pea Ridge Iron Ore Company. Type-II was coarser (43% < 15µm) and was prepared by dry screening conventional (90% <45 µm) magnetite …

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Ultrafine-grained magnetite in deep-sea sediments ...

A new extraction technique now permits ultrafine magnetite crystals to be separated from a variety of deep-sea sediments. Morphologic characterization of these particles with transmission electron microscopy reveals the presence of several distinct crystal types, some of which closely resemble those formed by the magnetotactic bacteria.

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(PDF) Selective Flocculation Enhanced Magnetic Separation ...

aggregated with gangue minerals, such as micro-zone 5.Ultrafine magnetite particles below 5 μ m in size are commonly sighted, e.g., in micro-zones 1, 2, 3, and 4, and occasionally there are magnetite

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Ultrafine Magnetite Nanopowder: Synthesis ...

Magnetite ultrafine particles/porous reduced graphene oxide in situ grown onto Ni foam as a binder-free electrode for supercapacitors Y. Mao, B. Zhou and S. Peng, RSC Adv., 2020, 10, 20753 DOI: 10.1039/D0RA03724A

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Department of Electrochemical Power Engineering and Chemistry

Pure ultrafine magnetite from carbon steel wastes // Materials Today: Proceedings: 3rd ISE Satellite Student Regional Symposium on Electrochemistry in Ukraine – Promising Materials and Processes in Applied Electrochemistry-2018, 18th April, 2018, Ukraine (special issue) / Edited by V. Barsukov, V. Khomenko, O. Linyucheva, Yu. Borysenko.

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Water as the Solvent in the Stober Process for Forming ...

DOE PAGES Journal Article: Water as the Solvent in the Stober Process for Forming Ultrafine Silica Shells on Magnetite Nanoparticles

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MAGNETITE TO MAGHEMITE TRANSFORMATION IN …

ultrafine magnetite powders in the light of the present results. The conversion experiments make it probable that a partially oxidized ultrafine magnetite powder is actually a mixture of fully oxidized (y-Fe,03) particles together with stoichiometric Fe304 particles. The alternative possibility that the particles are a uniformly ...

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Magnetite - Wikipedia

Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe 3 O 4.It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. It is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of ...

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Microbial production of ultrafine-grained magnetite by ...

TEM observation revealed aggregates of small crystals of ultrafine magnetite which ranged in size from about 2 to 4 nanometers. Magnetic property by SQUID analysis showed the magnetite nanoparticles demonstrate superparamagnetic behavior. As a result, the method of the present study can be used to produce magnetite efficiently using inexpensive ...

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Improving roasting performance and consolidation of ...

: Basicity, Consolidation, Ultrafine and super-high-grade magnetite concentrate, Fired pellet, Compressive strength, Liquid phase Abstract :For improving the strength of pellets made of ultrafine and super-high-grade magnetite concentrates, the influence of basicity (CaO/SiO 2 ratio) on the roasting and consolidation of ...

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