Surface Of Ferrite Particles Research Articles

Increasing the high-frequency magnetic permeability of MnZn ferrite in polyaniline composites by incorporating silver

A hybrid composite containing 73vol% of MnZn ferrite, 21vol% of polyaniline, and 6vol% of silver is obtained by oxidative polymerization of aniline with silver nitrate in the presence of ferrite powder. The hybrid composite contains ferrite particles with a size of 40–80μm coated by an inhomogeneous layer of polyaniline in the conducting emeraldine form. Silver in the form of nano- and submicrometre -size particles is localized both on the surface of ferrite particles and in the bulk of polyaniline coating. The electrical and magnetic properties of the hybrid composite are investigated and compared with the properties of a composite with 71vol% of MnZn ferrite coated by a conducting polyaniline layer (29vol%). The hybrid composite containing silver exhibits an increase in the real and imaginary parts of the complex permeability in the radio-frequency band by more than one and a half times compared with those of the MnZn ferrite−polyaniline composite. The high-frequency permittivity of both composites is determined by the properties of core−shell structure: electric properties of shell as well as its composition and uniformity.

カドミウム含有廃液のフェライト化処理によって生成する スラッジの改質

Leached test was used to evaluate the safety of the ferrite sludge formed by the heat treatment after conventional or two-step treatment with pH adjustment of wastewater. Simultaneously, the concentrations of Cd and Fe ions in the treated water were measured before the leached test. The effect of the heat treatment on the concentrations of Cd (CCd) and Fe (CFe) in the elute was discussed by comparing the ferrite sludge formed without heat treatment. The CCd of ferrite sludge formed by the heat treatment with the two-step treatment was remarkably lower than that by conventional or two-step treatments in relation to Cd(OH)2 on the surface of ferrite particles. XPS measurement of the sludge formed by conventional and two-step treatments indicated the existence of Cd(OH)2 on the surface of ferrite particles. XPS measurement of the sludge formed by the heat treatment indicated no existence of Cd(OH)2 on the surface of ferrite particles. The measurement after Xe+ sputtering showed that the Cd(OH)2 is absent not only on the surface but also in the bulk of the particles formed by heat treatment. The heat treatment after two-step treatment stabilizes the sludge and is favorable for steady operation of the ferrite process, industrial utilization of the sludge and good quality of the treated water.

クエン酸共存下におけるニッケル含有廃液のフェライト化処理によって生成するスラッジの改質

Leached test was used to evaluate the safety of the ferrite sludge formed by conventional, two-step treatments and two-step treatments with pre-treatment by KMnO4. Simultaneously, the concentration of Ni, Fe and Mn ions in the treated water was measured before the leached test. The effect of pre-treatment on the concentration (C) of Ni, Fe and Mn in the elute was discussed by comparing the conventional and two-step treatments.The CNi and CMn of ferrite sludge formed by the two-step treatment with pre-treatment were remarkably lower than that by conventional and two-step treatments in relation to Ni(OH)2 on the surface of ferrite particles. However, the limit in the ability to treat heavy metals decreases in the wastewater containing citric acid. XPS measurement of the sludge formed by conventional and two-step treatment with pre-treatment indicated the existence of Ni(OH)2 on the surface of ferrite particles. The measurement after Xe+ sputtering showed that the Ni(OH)2 is present not only on the surface but also in the bulk of the particles formed by conventional treatment.The two-step treatment with pre-treatment stabilizes the sludge and is favorable for steady operation of the ferrite process, industrial utilization of the sludge and good quality of the treated water.

ニッケル含有廃液のフェライト化処理によって生成するスラッジの安定化

The saturated magnetization σ(emu·g-1) was measured for the ferrite sludge formed by two-step treatment with pH adjustment of wastewater containing nickel sulfate. Simultaneously, the concentration of nickel and iron ions in the treated water was measured. The effect of pH adjustment on the above parameters was quantitatively discussed by comparing the two different treatments: conventional and two-step treatments.The σ of ferrite sludge formed by the two-step treatment with pH adjustment was slightly larger than that by conventional and two-step treatments. XPS measurement of the sludge formed by conventional and two-step treatment with pH adjustment indicated the existence of Ni(OH)2 on the surface of ferrite particles. The measurement after Xe+ sputtering showed that the Ni(OH)2 is present not only on the surface but also in the bulk of the particles formed by conventional treatment. In leached test, the concentration of nickel ion in the elute was lower in order of conventional, two-step and two-step treatment with pH adjustment in relation to Ni(OH)2 on the surface of ferrite particles.The two-step treatment with pH adjustment stabilizes the sludge and is favorable for steady operation of the ferrite process, industrial utilization of the sludge and good quality of the treated water.