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Magnetite ultrafine particles/porous reduced graphene ...

Magnetite ultrafine particles/porous reduced graphene oxide in situ grown onto Ni 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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Synthesis of ultrafine AuPd bimetallic nanoparticles using ...

The magnetite-cored PPI dendrimer up to third generation was synthesized by a divergent method in our previous report. Bimetallic nanoparticles are more advantageous than monometallic nanoparticles in catalysis due to their synergistic effect between two metals, especially Au …

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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 …

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Improving roasting performance and consolidation of ...

For improving the strength of pellets made of ultrafine and super-high-grade magnetite concentrates, the influence of basicity (CaO/SiO2 ratio) on the roasting and consolidation of pellets was investigated. The results showed that with the basicity of pellets increasing from 0.09 to 0.60, the compressive strength of both preheated and roasted pellets …

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Some basic properties of granules from ore blends ...

Some basic properties of granules, including the granule size distribution, packed-bed permeability, and chemical composition of the adhering layer, were investigated in this study for four iron ore blends consisting of 5wt%, 25wt%, and 45wt% ultrafine magnetite and 25wt% ultrafine hematite concentrates. The effects of varying the sinter basicity (CaO/SiO2 mass …

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Constraining the magnetic properties of ultrafine- and ...

Ferritin-based ultrafine-grained magnetites can be taken as ideal sample for superparamagnetism study, because of (1) controllable and uniform grain size, (2) mono-dispersed, (3) lack of magnetic interaction, (4) good availability and (5) "ideal" SP behaviors at room temperature.

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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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Disappearance of long range spin-order in ultrafine ...

Ferromagnetic properties of ultrafine magnetite (Fe3O4) particles were examined by the ESR and the static magnetic susceptibility measurements. Ferromagnetic resonance became to be observed at the particle size larger than 3.4 nm. This finding suggests that the bulk-like ferromagnetic state cannot be formed in the particle less than 3.4 nm diameter for magnetite. …

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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, …

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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 …

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Recovery of ultrafine scheelite particles by magnetic ...

Ultrafine scheelite could flocculate with modified magnetite and then be recovered using magnetic separation. • EDLVO calculation illustrated electrostatic force and hydrophobic force caused the flocculation. Abstract Froth flotation has been proven to be the most efficient mineral processing technology for fine particles.

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Some basic properties of granules from ore blends ...

Some basic properties of granules, including the granule size distribution, packed-bed permeability, and chemical composition of the adhering layer, were investigated in this study for four iron ore blends consisting of 5wt%, 25wt%, and 45wt% ultrafine magnetite and 25wt% ultrafine hematite concentrates. The effects of varying the sinter basicity …

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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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Influence of a Prior Oxidation on the Reduction Behavior ...

The reduction behavior of raw and prior-oxidized magnetite iron ore ultra-fines with hydrogen was investigated. Reduction tests were conducted with a thermogravimetric analyzer in a temperature range from 873 K to 1098 K at 1.1 bar absolute, using hydrogen as reducing gas. The experimental results show that a prior oxidation of the magnetite has a …

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

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 process for high-efficiency cleaning of fine coal.

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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 magnetite 1–3. This suggests that in situ...

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Frontiers | Ultrafine Particle Recovery Using Thin ...

The selective recovery of ultrafine, <10 μm, particles remains a significant challenge in the minerals industry. Indeed, these particles often report to tailings impoundments, resulting in under-utilization of mined resources and the need for tailings dams. Recently, a technique has been developed offering the potential to selectively recover particles down to <1 μm in size.

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Hydrothermal preparation and characterization of …

Abstract 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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THE EFFECT OF MAGNETITE GRADE ON SEPARATION …

Coarse Medium Fine Ultrafine The percentage minus 45 microns for each grade is shown on the graph. MAGNETITE RHEOLOGY For a given medium density, magnetite rheology is defined by both settling rate and viscosity. Settling Rate A medium of the required density is made up by adding magnetite and water in the required ratio.

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LG's new 4K UltraFine OLED Pro monitor lineup features ...

2 The 2022 UltraFine OLED Pro lineup, which is designed with photographers, videographers and visual artists and mind, will come in a 32" version (32BP95E) and a 27" version (27BP95E). Despite their size difference, the two models will be identical, with 4K UHD (3840 x 2160 pixels) resolution, a 1,000,000:1 contrast ratio and a 1ms response time.

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Home | Lancaster University

nificant natural source of ultrafine magnetite. As with the soil magnetite, this bacterial magnetite is commonly substitution- free, but it frequently occurs in chains, occupies a narrow, biologically constrained, SD-grain-size range, and exhibits dis- tinctive hexagonal or teardrop shapesll. Lovely et al.13 have

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Ultrafine Magnetite Nanopowder: Synthesis ...

This paper proposes a straightforward air-aqueous oxidation of St3 steel wastes for mass production of pure ultrafine magnetite. The characterization of the obtained product has been made by X-ray fluorescence analysis, X-ray diffraction, impedance spectroscopy, low-temperature nitrogen absorption method, Möss spectroscopy and optical microscopy.

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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 …

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

Depending on culture conditions and bacterial forms (Vali et al., 2004), the respiration of iron-reducing bacteria based on solid Fe(III) mineral phases produces extracellular magnetite crystals (Lovley et al., 1987; Lovley, 1991; Coker et al., 2008) of ultrafine grains with diameters between 10 and 50 nm.

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Dextran coated ultrafine superparamagnetic iron oxide ...

Magnetite caused a decrease in fluorescence signal of DCFH, but it did not decrease fluorescence signal in the presence of the reactive oxygen species-inducer tert-butyl hydroperoxide (TBHP). In contrast, maghemite caused an increase in fluorescence, which was substantially reduced in the presence of the antioxidant N-acetyl cysteine.

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Computer-Aided Modeling, Simulation, and Exergy Analysis ...

A detailed study on dielec., magnetic, thermal, and optical properties of citric acid modified ultrafine superparamagnetic magnetite (Fe3O4) nanoparticles (Cit-USPMNs) was conducted. Water dispersible Cit-USPMNs were synthesized by modified co-pptn. technique. Hydrazine (N2H4) and sodium hydroxide were used as pptg. agents.