The purification of raw iron oxide obtained from iron precipitation of the Zinc leach residue using the recrystallization method with Na₂B₄O₇ flux and magnetic properties of Mn_0.95Zn_0.05Fe₂O₄ synthesized from resultant iron oxide has been investigated.
The main purposes of present study are to decrease the heating temperature as much as possible for reduction of the purifing energy cost, and to examine effects of decrease in heating temperature on iron oxide morphology and removal of Zn, S, As, and effect of iron oxide purity on magnetic properties of Mn_0.95Zn_0.05Fe₂O₄ synthesized from resultant iron oxide.
The main results obtained as follow:
(1) Morphology of purified iron oxide is returned gradually from hexagon crystals pseudoparticles of original raw material as heating temperature is decreased.
(2) From removal of Zn, S and As, heating temperature is possible to decrease from 1573K to 1273K.
(3) Purity and magnetic properties of iron oxide have nearly no influence on magnetic properties of synthesised Mn_0.95Zn_0.05Fe₂O₄ ferrite.

抄録全体を表示

Three Dimensional Printing (3DP^TM) is an outstanding method for fabricating complex 3D-shaped parts, that cannot be obtained by the conventional methods such as dry press, sheet stack, tape casting, and so on. In order to accomplish green part retrieval from ceramic powder-bed, it is indispensable to study redispersion technology. For the purpose, the effects of redispersion on Al₂O₃, SiO₂, TiO₂, and MR2 ceramic powder beds were investigated with special reference to the molecular weight and concentration of various poly ethylene glycol (PEG) as organic dispersants. Furthermore, redispersion phenomena were discussed in terms of chemical potential and osmotic pressure between powder bed and solvent. The experimental results were estimated with Flory-Huggins and van't Hoff theories. Under the appropriate redispersing conditions, it is emphasized that different types of electronics parts were obtained at the same time in one powder bed eventually.

抄録全体を表示

Sintering experiments were conducted in order to suppress the formation of large pores existed in the assimilated parts of sinter produced using pisolitic limonite ores. Modeled pseudo-particles, which consisted of coarse iron ore particle as cores and fine mixture of hematite ore and limestone as shell layer, were used in the present experiments. CaO concentration of shell fine was varied in three levels, i. e. 10, 20 and 30 mass% and ratio of shell fine was varied in two levels, i. e. 30 and 50 mass%. CaO concentration and ratio of shell fine were regarded as indices of apparent viscosity and volume of melt formed during heating. The influence of CaO concentration and the ratio of shell fine on the behavior of large pore formation during heating were examined by a microscopic observation. The mean diameter and area fraction of pores existed in the assimilated part of specimen were also measured. The results obtained were as follows:
1) With increasing CaO concentration and the ratio of shell fine, the area fraction and number of pore were decreased; the suppression of the large pore formation was achieved.
2) The decrease in both of the area fraction and number of pore depend on the lowering apparent viscosity and increasing volume of melt formed during heating.
3) The lowering apparent viscosity of melt is more effective to suppress the formation of large pore than increasing volume of melt.
4) It is clear that the suppressive effect is resulted from the promotion of coalescence of bubbles due to the lowering apparent viscosity of melt formed during heating.

抄録全体を表示

This paper analyzes spectral reflectance information in order to understand color features. Twenty-three-color image data are taken by using a monochrome CCD (Charge Coupled Device) camera through three filters: X, Y and Z filters on condition that the range of illumination is 10001x to 110001x at every 10001x, and that a lens opening is eight types. Digital number (luminous intensity) in image data is much related to both brilliance and illumination at data acquisition. The relation between spectral reflectance information and brilliance will help extract the difference of colors. Based on the measurements and the resulting relations, we propose a color distinction approach due to fuzzy reasoning. The reliability of the proposed approach is demonstrated in an experiment using the color image data that taken in a XYZ space.

抄録全体を表示

The dioxin from the garbage incineration is one of the most serious environmental problems in recent years. There is a method using slaked lime (Ca (OH) ₂) as one of the dioxin preventive methods, reacting in the present garbage incineration and removing the chlorine in combustion exhaust gas. The formation mechanism of specific surface in the slaked lime powder generated by reaction from quicklime is not sufficiently elucidated up to now.
In this paper, the formation mechanism of surface is fundamentally and experimentally discussed. As the result, it is fundamentally pointed out that the alkyl chain length of the added alcohol and, at the same time, the alcohol concentration in solution play predominant roles in the formation of surface of the slaked lime powder.

抄録全体を表示