scholarly journals High-efficiency leaching of valuable metals from saprolite laterite ore using pickling waste liquor for synthesis of spinel-type ferrites MFe2O4 with excellent magnetic properties

2020 ◽  
Author(s):  
Jian-ming Gao ◽  
Zongyuan Du ◽  
Shujia Ma ◽  
Fangqin Cheng ◽  
Peng Li
Keyword(s):  
Magnetic Properties ◽  
High Efficiency ◽  
Spinel Type ◽  
Waste Liquor ◽  
Valuable Metals ◽  
Laterite Ore

scholarly journals CoFe2O4-TiO2Hybrid Nanomaterials: Synthesis Approaches Based on the Oil-in-Water Microemulsion Reaction Method

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Arturo Adrián Rodríguez-Rodríguez ◽  
Sagrario Martínez-Montemayor ◽  
César Cutberto Leyva-Porras ◽  
Francisco Enrique Longoria-Rodríguez ◽  
Eduardo Martínez-Guerra ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Core ◽  
Hybrid Nanoparticles ◽  
Magnetic Domains ◽  
Spinel Type ◽  
Reaction Method ◽  
Light Region ◽  
Oil In Water ◽  
Vis Spectroscopy ◽  
Nanomaterials Synthesis

CoFe2O4nanoparticles decorated and wrapped with TiO2nanoparticles have been prepared by mixing well-dispersed CoFe2O4with amorphous TiO2(impregnation approach) and growing amorphous TiO2over the magnetic core (seed approach), respectively, followed by thermal treatment to achieve TiO2crystallinity. Synthesis strategies were based on the oil-in-water microemulsion reaction method. Thermally treated nanomaterials were characterized in terms of structure, morphology, and composition, to confirm hybrid nanoparticles formation and relate with the synthesis approaches; textural, optical, and magnetic properties were evaluated. X-ray diffraction revealed coexistence of cubic spinel-type CoFe2O4and tetragonal anatase TiO2. Electron microscopy images depicted crystalline nanoparticles (sizes below 25 nm), with homogeneous Ti distribution for the hybrid nanoparticles synthesized by seed approach. EDX microanalysis and ICP-AES corroborated established chemical composition. XPS evidenced chemical states, as well as TiO2predominance over CoFe2O4surface. According to BET measurements, the hybrid nanoparticles were mesoporous. UV-Vis spectroscopy showed optical response along the UV-visible light region. Magnetic properties suggested the breaking order of magnetic domains due to modification with TiO2, especially for mediated seed approach sample. The properties of the obtained hybrid nanoparticles were different in comparison with its individual components. The results highlight the usefulness of designed microemulsion approaches for the straightforward synthesis of CoFe2O4-TiO2nanostructured hybrids.

scholarly journals Technology for obtaining modified oil sorbents

2021 ◽  
Vol 82 (4) ◽  
pp. 247-253
Author(s):  
R. Mejri ◽  
Y. S. Peregudov ◽  
E. M. Gorbunova
Keyword(s):  
Magnetic Properties ◽  
High Efficiency ◽  
Low Cost ◽  
Oil Products ◽  
Solid Surfaces ◽  
Environmental Friendliness ◽  
Transmission Electron ◽  
Oil Sorbent ◽  
High Degree ◽  
Oil And Oil Products

Expediency of using natural glauconite material as a basis for the production of an environmentally friendly sorbent with hydrophobic and magnetic properties for liquidating oil and oil products spills mechanically and using a magnetic field has been substantiated and experimentally proved. Fractional, elemental and oxide compositions of the original mineral have been studied. The structure of glauconite fraction 0.045-0.1 mm has been investigated by transmission electron microscopy. It was found that the surface of the sample particles is heterogeneous with a large number of pores and cracks. Based on the experimental data, the optimal conditions for the production and use of powder and granular sorbents based on glauconite with specified properties were determined, at which a high degree of recovery (more than 90%) of oil with water and hard surfaces. The optimum temperature for obtaining a magnetic oil sorbent is 400 °C. The doses of stearic acid and iron (III) oxide were established at 5 wt. %, which provide hydrophobicity and magnetic properties to the synthesized sorbent. A high degree of oil (97%) and oil (98%) recovery when using a sorbent is achieved at a ratio of 1: 10 to sorbate. To eliminate oil and oil product spills, it is proposed to use granular ferromagnetic sorbents obtained by introducing carboxymethyl cellulose into the modified glauconite composition. oil and oil products granular sorbent increases in comparison with the original mineral by 1.2–2.2 times. Technological schemes for obtaining ferromagnetic hydrophobic and granular sorbents based on glauconite for collecting oil and oil products from water and solid surfaces have been developed. The synthesized sorbents are characterized by high efficiency, low cost, and environmental friendliness.

scholarly journals Magnetic Properties of Manganese-Zinc Soft Ferrite Ceramic for High Frequency Applications

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3173
Author(s):  
Lucian-Gabriel Petrescu ◽  
Maria-Cătălina Petrescu ◽  
Valentin Ioniță ◽  
Emil Cazacu ◽  
Cătălin-Daniel Constantinescu
Keyword(s):  
Magnetic Properties ◽  
High Frequency ◽  
High Efficiency ◽  
Magnetic Circuit ◽  
Hysteresis Loops ◽  
Vibrating Sample Magnetometer ◽  
Soft Magnetic ◽  
Mnzn Ferrite ◽  
Manganese Zinc ◽  
Soft Ferrite

A soft magnetic MnZn-type ferrite is considered for high frequency applications. First, the morphological, structural, and chemical composition of the material are presented and discussed. Subsequently, by using a vibrating sample magnetometer (VSM), the hysteresis loops are recorded. The open magnetic circuit measurements are corrected by employing demagnetization factors, and by taking into consideration the local magnetic susceptibility. Finally, the hysteresis losses are estimated by the Steinmetz approach, and the results are compared with available commercial information provided by selected MnZn ferrite manufacturers. Such materials are representative in planar inductor and transformer cores due to their typically low losses at high frequency, i.e., up to several MHz, in low-to-medium power applications and providing high efficiency of up to 97%–99%.

Effect of Antimony on the Structure, Texture and Magnetic Properties of High Efficiency Non-Oriented Electrical Steel

2012 ◽  
Vol 602-604 ◽  
pp. 435-440 ◽  
Author(s):  
Na Li ◽  
Li Xiang ◽  
Pei Zhao
Keyword(s):  
Magnetic Properties ◽  
Magnetic Flux ◽  
Flux Density ◽  
High Efficiency ◽  
Electrical Steel ◽  
Core Loss ◽  
Magnetic Flux Density ◽  
Antimony Content ◽  
The Core ◽  
Maximum Value

The effect of antimony on the structure, texture and magnetic properties of high efficiency non-oriented electrical steel were investigated. The results showed that antimony played an important role on inhibiting the grain growth and enhancing the fraction of favorable texture in the annealed steels. With the increase of antimony content, core loss of specimens monotonously increased and the magnetic flux density increased firstly and then decreased. The magnetic properties of specimen results showed that the magnetic flux density in the steel with 0.12% antimony reached the maximum value, while the core loss didn’t increase obviously. However, when the antimony content in steel reached 0.22%, the magnetic properties deteriorated significantly. This is maybe that the addition of antimony in steels inhibited the development of {111} texture content and increased the intensity of Goss and {100} texture on the grain boundary.

scholarly journals The Reduction Behavior of Ocean Manganese Nodules by Pyrolysis Technology Using Sawdust as the Reductant

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 850 ◽  
Author(s):  
Xiang-yi Deng ◽  
Dong-sheng He ◽  
Ru-an Chi ◽  
Chun-qiao Xiao ◽  
Jin-gang Hu
Keyword(s):  
Activation Energy ◽  
High Efficiency ◽  
Acid Leaching ◽  
Reduction Process ◽  
Reduction Reaction ◽  
Pyrolysis Process ◽  
Manganese Nodules ◽  
Valuable Metals ◽  
Shrinking Core ◽  
Isothermal Kinetic

Ocean manganese nodules, which contain abundant Cu, Co, Ni and Mn resources, were reduced using biomass (sawdust) pyrolysis technology. Valuable metals were further extracted by acid leaching after the reduction process with high efficiency. The effects of sawdust dosage, reduction temperature, and time were investigated to obtain optimal operating parameters. The extraction rates of Mn, Cu, Co, and Ni reached as high as 96.1%, 91.7%, 92.5%, and 94.4%, respectively. Results from TGA show that the main pyrolysis process of sawdust occurs at temperature range of 250–375 °C with a mass loss of 59%, releasing a large amount of volatile substances to reduce the ocean manganese nodules. The pyrolysis activation energy of sawdust was calculated to be 52.68 kJ∙mol−1 by the non-isothermal kinetic model. Additionally, the main reduction reaction behind the main sawdust pyrolysis process was identified by the comparison of the assumed and actual TG curve. The thermodynamic analysis showed that the high valence manganese minerals were gradually reduced to Mn2O3, Mn3O4, and MnO by CO generated from sawdust pyrolysis. The shrinking core model showed that the reduction process is controlled by the surface chemical reaction with activation energy of 45.5 kJ∙mol−1. The surface of reduced ore and acid leached residue exhibited a structure composed of relatively finer pores and rougher morphology than the raw ore.

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