• Journal of Powder Materials
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• v.11 no.3
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• pp.202-209
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• 2004

In this study, nano-sized powder of Ni-ferrite was fabricated by spray pyrolysis process using the Fe-Ni complex waste acid solution generated during the shadow mask processing. The average particle size of the produced powder was below 100 nm. The effects of the reaction temperature, the inlet speed of solution and the air pressure on the properties of powder were studied. As the reaction temperature increased from 80$0^{\circ}C$ to 110$0^{\circ}C$, the average particle size of the powder increased from 40 nm to 100 nm, the fraction of the Ni-ferrite phase was also on the rise, and the surface area of the powder was greatly reduced. As the inlet speed of solution increased from 2 cc/min. to 10 cc/min., the average particle size of the powder greatly increased, and the fraction of the Ni-ferrite phase was on the rise. As the inlet speed of solution increased to 100 cc/min., the average particle size of the powder decreased slightly and the distribution of the particle size appeared more irregular. Along with the increase of the inlet speed of solution more than 10 cc/min., the fraction of the Ni-ferrite phase was decreased. As the air pressure increased up to 1 $kg/cm^2, the average particle size of the powder and the fraction of the Ni-ferrite phase was almost constant. In case of 3 $kg/cm^2 air pressure, the average particle size of the powder and the fraction of the Ni-ferrite phase remarkably decreased.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.45-45
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• 2003

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.1
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• pp.21-26
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• 2012

Microstructural and mechanical property were evaluated at the medium-sized HT9 (12Cr-1MoWV) forged steel which was considered as primary candidate for the fuel cladding in sodium-cooled fast reactor (SFR). Material was forged at $1170^{\circ}C$ after the induction melting to make round bar as 160mm diameter, 7000mm length then the radial distribution of microstructure as well as microhardness was evaluated. The results showed that overall microstructure exhibited as ferrite-martensite structure, where small amount (2~3%) of delta ferrite was formed throughout the specimen and maximum 15% of transformed ferrite was formed at the center, where it gradually decreased toward the radial direction. Sensitivity analysis of the cooling curve and Time-Temperature-Transformation (TTT) diagram revealed that formation of transformed ferrite could be avoided when the diameter was decreased down to 120mm.

• Advances in nano research
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• v.13 no.6
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• pp.527-543
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• 2022

A novel, green, versatile and magnetically retrievable BiFeO₃/CDR (Bismuth ferrite/coriander) nanocomposites were fabricated via simple wet chemical method utilizing in situ functionalized, cheap coriander seed powder (CDR 5%, 10%, 15% and 20 wt%) as a fuel to enhance the efficiency of pristine BiFeO₃. A comparative study was performed between BiFeO₃/CDR and BiFeO₃/CNT (Bismuth ferrite/carbon nanotubes) nanocomposites for the removal of various hazardous pollutants from waste water. The successful synthesis of the fabricated nanomaterials was monitored via FT-IR, Powder XRD, FE-SEM, CV, VSM, CHNS/O and XPS studies. The synthesized nanomaterials were employed for the oxidative degradation of Carbol fuchsin, Reactive black 5, Ciprofloxacin and Doxorubicin; adsorption of a pesticide malathion; and reduction studies for Para-nitrophenol (PNP). The fabricated nanomaterials (BiFeO₃/CDR) showcased excellent efficiency and comparable results with (BiFeO₃/CNT) for the removal of model pollutants. Moreover, synthesized green heterojunction was also testified for mixture of textile and pharmaceutical waste. Hence CDR can be utilized as a better alternative of CNTs.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.149-153
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• 2001

This paper describes on the fabrication of Fe-Co hydrophilic magnetic fluids from the waste pickling liquor of steel. By adding with HNO$_3$in the waste liquor oxidation is proceeded from Fe$^{3+}$ion at 6$0^{\circ}C$ with air blowing. Ultra-fine Co-ferrite particles with the mean particle size of 50 $\AA$ were produced at pH 12 after adjusting the ratio of Fe$^{3+}$Co$^{2+}$=7/3(wt%) and Fe-Co particles with the mean particle size of 94 $\AA$ were produced by reducing the Co-ferrite particle with H$_2$at the temperature of 50$0^{\circ}C$. After triple adsorption of oleic acid dodecyl benzene sulfonate(D.B.S.) and tetra methyl ammonium(T.M.A.) ions on the surface of Fe-Co particles Fe-Co hydrophilic magnetic fluid was produced by dispersing the Fe-Co particles in ethylene glycol solution. The magnetization of the Fe-Co hydrophilic magnetic fluid increased with increasing the Fe-Co concentration. The magnetic fluid containing 70% (g/cc) Fe-Co showed 73 emu/g in magnetization at the magnetic intensity of 10 kOe.kOe.e.

• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.454-457
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• 2011

We report the preparation of nanocrystalline cobalt ferrite, $CoFe_2O_4$, particles using recycled $Co_3O_4$ and their surface coating with silica using micro emulsion method. Firstly, the $Co_3O_4$ powders were separated from waste cemented carbide with acid-base chemical treatment. The cobalt ferrite nanoparticles with the size 10 nm are prepared by thermal decomposition method using recycled $Co_3O_4$. $SiO_2$ was coated onto the $CoFe_2O_4$ particles by the micro-emulsion method. The $SiO_2$-coated $CoFe_2O_4$ particles were studied their physical properties and characterized by X-ray diffraction (XRD), high resolution-transmission electron microscopy (TEM) analysis and CIE Lab value.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.54-61
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• 2019

In this study, a magnetic adsorbent was synthesized by growing ferrite nanoparticles substituted with metals (Me = Co, Mn, Ni) on zeolite 4A for the efficient separation of waste adsorbents present in the solution after the adsorption of Cu(II). The metal ferrite grown on the surface of zeolite was prepared by solvothermal synthesis. Characteristics of the magnetic adsorbent were analyzed by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and physical property measurement system (PPMS). The saturation magnetization of the A type zeolite coated with Co-ferrite (CFZC) was the highest at 5 emu/g and the Cu(II) adsorption performance was also excellent. The adsorption results of Cu(II) on CFZC were well fitted by the Langmuir model at 298 K. Also, the adsorption of Cu(II) on CFZC follows a pseudo-second order kinetic. The Gibbs free energy values (${\Delta}G^0$) ranging from -4.63 to -5.21 kJ/mol indicates that the Cu(II) adsorption is spontaneous in the temeprature range between 298 and 313 K.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.38-38
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• 2002

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.168.1-168
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• 2003

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.210.1-210
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• 2002