材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
20 巻, 213 号
選択された号の論文の22件中1~22を表示しています
  • 仲井 由宣
    1971 年 20 巻 213 号 p. 702-705
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
  • 高坂 彬夫, 遠藤 二男, 木村 義行
    1971 年 20 巻 213 号 p. 706-710
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    Kaolin minerals produced in Japan are mostly impure, containing such impurities as pyrite, iron oxide, free quartz, sericite and montmorillonite. For this reason attempts have been made to improve the quality of kaolin minerals in refining industries by removing the impurities as much as possible both chemically and physically.
    The centrifugal classification of domestically produced kaolin minerals was the object of our study performed by the wet method on an industrial scale as an important process in refining, and the following facts were confirmed as the result of the study.
    (1) The classification up to d50=4μ of overflow products is made easy by the use of a multiple small-sized liquid cyclone.
    (2) The classification up to d50=0.6μ of overflow products is made easy by centrifuging the material continuously, and the free quartz contained as impurities can be separated to some extent.
    It is recommended therefore that, when the centrifugal classification of kaolin minerals is to be processed by the wet method, while a cyclone, whether large-sized, medium-sized, or small-sized, or a multiple ultra small-sized liquid cyclone, will be used with much industrial advantage according to the range of particle sizes from coarse to microscopic fine, a centrifuge will as advantageously be used for the ultra-microscopic particles.
  • 青木 隆一, 湯沢 恩
    1971 年 20 巻 213 号 p. 711-714
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    Hereunder is presented the report of investigation made both theoretically and experimentally of the influence of the contact areas of particles on the effective thermal conductivity of the axially stressed packed bed.
    The contact areas of the particles were first related to the axial load, and to the axial load, then the thermal conductivity of the axially stressed packed bed has been related. The relation between the thermal conductivity of the axially stressed packed bed and the axial load has been shown as proportional.
    It has been experimentally examined by compressing the lead, steel and glass spheres in a cylindrical die and giving heat flow axially through this packed beds. The proportional relation between the thermal conductivity of the axially stressed packed bed and the axial load has been also observed. But there has been observed some difference between the theoretical and the experimental proportional constant.
    It is suggested that this apparent difference is due to the difference between the real contact areas and the theoretical contact areas of the stressed particles. Then the ratio of these two areas has been defined as the effective contact ratio of the stressed particles. So far as our experiments are concerned, the larger the particle diameter, the further reduced is this ratio of areas.
  • 田中 安彦, 高山 允良, 篠原 久
    1971 年 20 巻 213 号 p. 715-719
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The rotary dust collector used for this experiment is of a mechanical centrifugal type combined with a tangential entrance and an internal rotor so designed altogether as to arouse a vortex of air.
    Both the rotors of the radial-flow type and of the axial-flow type were compared with the cyclone of the conventional type with respect to their collection efficiency. The results of experimental study of their capacity for winnowing fly ash show that the axial-flow type rotor yields higher collection efficiency at lower inlet velocities than the conventional type cyclone, and that it has at higher inlet velocities much less detrimental effect than the radial-flow type rotor on its collection efficiency.
    Moreover in case the axial-flow type rotor with blades on the periphery is used, it is possible to formulate critical particulate diameter to sift the particles, though with simple assumptions, and that, if the overall collection efficiency is taken as equal to the cumulative-weight distribution of particles larger than the critical diameter among the dust collected in the collector, the predicted value of the collection capacity is found to be in good agreement with the experimental value.
    The relation of the results of the measurement of efficiency to the measured data concerning velocity distribution have also been briefly discussed.
  • 金庭 延慶, 池川 昭子
    1971 年 20 巻 213 号 p. 720-723
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    Molecular weight of poly-vinylpyrrolidone decreased by ball-milling in nitrogen, air or oxygen. After 420 hours of ball-milling, polyvinylpyrrolidone of molecular weight 9.6×105 degraded to about 2×104. Equation (1) was applied to the relation between -dM/dt and M.
    -dM/dt=KmMβ1{1-(Mt=∞/M)β2} (1)
    Numerical values of Km, β1 and β2 for the case of ball-milling in oxygen were the largest and those for the case of nitrogen were the smallest. Gel filtration of the sample suggested much probability in the way that, in nitrogen, the segment of the molecular weight below 105 was broken in order from the end of the polymer.
    Investigation of elemental analysis, Nestler's reaction and decomposition point of the sample showed partial change in chemical structure caused by ball-milling. Partial change in solid constitution caused by ball-milling was also suggested by the measurement of glass temperature.
    Equation (2) was applied to the first 150 hours of ball-milling, where S is the surface area of the sample.
    dS/dt=k1·exp(-k2·S) (2)
    Parameter k1 was large for the case of ball-milling in an oxygen-containing atmosphere, similar to that of Km in Equation (1).
  • 古茂田 暸三, 西 泰英
    1971 年 20 巻 213 号 p. 724-727
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The continuous thermal decomposition of solid particles are often carried out in a rotary kiln. Fractional decomposition of a given sample may be estimated upon the appropriate mathematical expressions based on a hypothetical model of the reactor system.
    Hereunder is given a brief statement of an iterative and stepwise method which has been adopted in calculation of the overall conversion of the thermal decomposition of lead carbonate particles flowing through a rotary cylinder. In framing the mathematical expressions to estimate the overall conversion of the sample, two items have been taken into consideration, a hypothetical model of the reactor system in which the reactor is assumed as consisting of a number of differential elements on one hand, and on the other, the temperature profile and residence time distribution of the sample in the cylinder. The rate of thermal decomposition obtained by the isothermal batch decomposition runs has also been utilized as data in the present estimation of the fractional decomposition. During the calculation procedure in the present study, the effect of partial pressure of carbon dioxide in the reactor has constantly been taken into account. The experiments were conducted to verify the above mentioned estimation of the overall eonversion of the material. The comparison of the estimated overall conversion of lead carbonate particles in the cylinder with the result of its experiments amply shows that the above mentioned method is an effective approach to the estimation of the said overall conversion. The detailed process of the calculation and estimation will, however, be deferred to a separate paper.
  • 貞広 嘉和
    1971 年 20 巻 213 号 p. 728-731
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The crystallite dimension and the lattice distortion of the ground NiO and ZnO powder were measured by X-ray diffraction method, and the effects of dry ballmilling on the catalitic activation energy of the NiO and ZnO powder were studied by the catalitic decomposition of H2O2.
    The following results have been obtained:
    (1) During the grinding process, the catalitic activation energy of the NiO powder increased as the crystallite dimension decreased. It decreased as the crystallite dimension remained as it was. This phenomenon shows that the stoichiometric anion rich surface layer exfoliates as the crystallite dimension decreases, but that it remains intact as the crystallite dimension remains unchanged.
    (2) The frequency factor of the N1O powder shows the same behavior as that of activation energy by the change in the crystallite dimension. This shows that the density of active center on the surface of the paricle increases exceedingly by removal of the surface layer.
    (3) The catalitic activation energy of the ZnO powder decreases as the crystallite dimension decreases, and increases as the crystallite dimension increases. This behavior is different from that of NiO. It seems that the difference is due to the difference of p type semiconductor (NiO) from n type semiconductor (ZnO).
  • 宇津木 弘, 西村 成興, 高平 二朗, 加藤 守孝
    1971 年 20 巻 213 号 p. 732-736
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    Lyophilic zinc powder has been prepared by subjecting zinc powder to reaction with n-butanol under high temperature and high pressure. By the microanalysis of the surface-treated zinc powder, by observation through electron microscope, and by dissolution of the zinc-rich paint film into dil. HCl, adsorption of argon at 77°K, and also by the fact that, though the surface-treated samples cannot be suspended into water, they can into organic solvent, it is found that only the surface properties of the powder are made lyophilic, causing no change to any fundamental properties of the powder, e. g. the surface area, pore structure or any chemical properties. This surface-treatment of zinc powder is understood as esterification of the acidic group of the surface oxide of zinc powder with n-butanol. The zinc-rich paint of the surface-treated zinc powder is found better dispersed in the vehicle than that of untreated native zinc powder. On the contrary, the dry film of the paint prepared from the surface-treated zinc powder proves more easily breakable than that prepared from the untreated native kind.
  • 宇津木 弘, 西村 成興
    1971 年 20 巻 213 号 p. 737-741
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The surface properties of the surface-treated oxide powders were investigated by means of the heat of immersion in water, benzene and in n-heptane, of the samples which were confirmed to be lyophilic by the fact that they tended to disperse into organic medium of the immiscibly mixed media like benzene and water, and of which the surface-radicals were also confirmed. Increasing the length of carbon chain of surface radicals, the heat of immersion in water shows decrease, whereas the immersion in benzene or in n-heptane shows increase. On the surface-treated samples, the heat of immersion in n-heptane is larger than in water, whilst the heat of immersion in water is larger than that in n-heptane on native oxides. In this way it would be possible to determine whether the sample is hydrophilia or lyophilia by comparing the heat of immersion whether it is in water or in n-heptane, except the sample treated by the ethanol. In the case of the sample treated by ethanol, it may be caused by the entropy term that the sample is lyophilic whilst the heat of immersion in water is larger than that in n-heptane. In connection with this, it is much more advisable to use the free energy of immersion than to use its heats in order to determine the surface properties.
  • 三輪 茂雄, 田坂 和彦
    1971 年 20 巻 213 号 p. 742-747
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    For the measurement of particle density, many types of devices have hitherto been proposed. Among them the air pycnometer method is found superior to the immersion-into-liquid method in that the measurement technique by the former is simpler, and in that it is applicable to soluble powders. There is drawback, however, in that it does not yield exact duplicate value.
    The air pycnometer method can be classified into four types, i. e. there can be twofold classification into the constant volume method and the variable volume method, of twofold classification into the compressing method and the expansion method, as follows:
    The constant volume method of the compressing method
    The variable volume method of the compressing method
    The constant volume method of the expansion method
    The variable volume method of the expansion method
    These four types of methods were applied to the measurement of several kinds of samples of powdered materials, in which newly designed apparatuses were used, and the results were compared with the measurement made with the immersion-into-liquid method.
    It is concluded that the compressing method of constant volume has been found most preferable as possible of being easily constructed, and as yielding duplicate value, if measurement is made of the material at larger ratio of its sample volume to its total volume.
  • 佐藤 建, 吉沢 達夫, 伊吹 順章
    1971 年 20 巻 213 号 p. 748-753
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    Hereunder is given a brief report of investigation that was made of Cl-doped CdSe powders, with particular reference to that metal being nonlinear in its current-voltage curve. In view of the hypothesis if the said current-voltage relation is dependent on the particle size, microscopic observation of CdSe under electron beams was performed, and it has been concluded as its result that the nonlinearity of the material has originated in the areas where the particles come in contact with one another, as will be confirmed by the similar case with interparticle contact in spherical crystals.
    The experiments that were carried out within the temperature region between 123°K and 293 °K show that the current-voltage relation is best expressed as proportional to the product of terms A and B as below.
    A: its dependence on temperature
    B: its dependence on voltage
    Concerning the causes of the nonlinear current-voltage characteristics there are five things that can be considered as possible factors as follows.
    (1) The space-charge limited current
    (2) The thermal breakdown
    (3) The avalanche breakdown
    (4) The thermal current
    (5) The tunneling
    Of these five potential causes, the last, (5), will best explain the results of the experiments, though it is not known yet what sort of barriar the electron current must tunnel through.
  • 林 尚孝
    1971 年 20 巻 213 号 p. 754-757
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    It is well known that each value of the angle of repose is variable according to the kind of measurements, besides it is variable according to the size of the apparatus even by using the same measurement (Scale effect). The author has been able to explain the cause of the scale effect by means of the stochastic method.
    At first measurements of the angle of repose (Table I) were compared with each other and the conclusion is that the tilting box test is the best measurement to find out the 3 factors which effect the value of the angle of repose. The 3 factors are the size of the apparatus, bulk density (Table II) and the velocity of formation (Fig. 1). So the tilting box test has been used in these experiments.
    Values of the angle of repose (Using sand as material) are accompanied by great fluctuation (Table III). As the size of the box is smaller, the fluctuation becomes greater. It becomes clear that the fluctuation of values depends on the Weibull distribution (Fig. 4). The scale effect is divided between two factors, the horizontal length of the box (Fig. 3) and the tilting length of the box, and they are explained by 2 parameters of the Weibull distribution (Table IV).
    The same result has been got by using not only sand but glass balls. So it is considered that the stochastic method may be useful for the research of the other various physical properties of powdered and graunlar materials, not restricted to the angle of repose.
  • 真鍋 秀幸, 鈴木 章, 松下 博一
    1971 年 20 巻 213 号 p. 758-761
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    Hereunder is presented the report of investigation of the process of compressing powder bed. A method to analyze the stress-strain curves obtained at upper and lower punch was introduced in the compressional process. Pile of thin homogeneous layers was assumed for the powder bed, and so the exponential strain distribution in it also. The calculated results contain a stress-strain curve for thin homogeneous layer and heterogeneity index (H.I.) which represents the difference of strain between the layers.
    The applicability of the analytic method was shown to be reasonable. The calculated results of stress-strain curves for various powders coincide with the curves experimentally obtained for the thin bed after the repeated compression. The calculated stress distribution in the powder bed agreed well with the estimated values.
    The change of H.I. with stress is characteristic of the powder used and has its maximum plateau. The shape of H.I. change was similar to that of stress-relaxation rate for corn starch, and similar to that of Janssen's constant for sucrose.
  • 松居 国夫, 関口 岳男, 五十畑 仁, 宮田 憲一, 本間 裕, 塚越 雅樹
    1971 年 20 巻 213 号 p. 762-766
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The authors discuss in the present paper about the compaction energy of“the powdery layers”, when the statically compressive load is appllied to the powdery layers in a steel mortal, and then carry on investigations on the relationship between the compaction energy and the tensile splitting strength of the cylindrically combined“powdery layers”.
    In this paper, the authors will advance a proposal that the compaction energy is equal to the area under a connecting link between the intersections of hysteresis curves as shown in Fig. 1.
    The tensile splitting strength of“the powdery layers”is directly proportional to the compaction energy per unit volume. The proportional constant is to be decided by the characteristic values of grindability CEI. The authors have derived Eq. (19) as the basic relation between the tensile splitting strength and the loading condition.
  • 神保 元二, 浅川 貞雄, 桜井 伍朗
    1971 年 20 巻 213 号 p. 767-772
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The relationship between the solid surface produced and the required energy in the vibration of ball milling has been obtained by direct measurement of the torque value of the mill shaft. There the real Rittinger number, ηr0' and the differential Rittinger number ηr(=ds/dE) are defined, and the relationship between them is found experimentally as follows.
    ηr0r=aSnw
    And it is proved that this equation, which is for the first time proposed in this report as a fundamental equation of size reduction, includes Rittinger's equation and also Tanaka's equation.
    Though the values of ηr0 are affected by several grinding conditions, they have close connection with Bond's work index, Wi. The values of n have not been precisely obtained in this experiment, but they are known to come in the range of 1-3.
    The boundary of the region is also showed, in which the above mentioned relation can be found, and out of this boundary, the S-shaped grinding curves have been observed as Rose has pointed out in the vibration of the milling.
  • 内海 良治, 上田 康
    1971 年 20 巻 213 号 p. 773-775
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The phenomena of gravity flow of bulk solid has hitherto been investigated through the flow in a hopper or a rotary cylinder, but the flow in such a device is complicated too much to clarify the flow characteristics of bulk solid precisely.
    As it is considered that an inclined open channel for observing the flow of bulk solid is relatively simple, the flow behavior of grains of rapeseed was studied within an inclined open channel.
    The channel is made of a transparent acryl plate of 5mm in thickness, into size 940mm in length, 50mm in width, and 80mm in depth. Barnyard millet was mixed into the rapeseeds as tracer in the ratio of one to twenty-five (1 to 25).
    A photographic observation of the channel was carried out by means of a stroboscope in three directions within the range of 530∼580mm from the inlet of the channel. The slope of the channel was set at 23.0°, 27.5°, 31.5°, or 35.5°.
    The velocity distribution curve obtained through the side wall was nearly linear except in the neighbourhood of the bottom. When the slope of the channel was 23.0°, the distribution curve showed the shape of the letter S. This is considered to be due to the fact that the slope of the channel was smaller than the angle of repose, 24.5°, of the specimen.
    The velocity of the flow at the surface and that at the bottom showed the maximum value in the middle part of the channel as it was the case with viscous fluid, and the boundary layer was developed near the side wall. The distribution curves were approximately quadratic.
    Regarding the distribution curve of the side wall as a line, the flow rate and average velocity can be calculated on the basis of the velocity distribution curves of surface and bottom and the area of cross section of granular layers, and the average velocity has been found as about 80% of the maximum velocity.
    The average porosity in flowing has been estimated upon the calculated value of the flow rate and the measured value of the mass flow rate, and has been found as smaller than the porosity of the sphere model in the cubic arrangement.
  • 荒川 正文, 西野 操
    1971 年 20 巻 213 号 p. 776-780
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The powder bed in a vibrating state of various graphite of different particle sizes have been experimentally studied with respect to their relation between their fluidity and structure. The structure of powder bed in a vibrating state has been discussed on the bases of variation of electric resistance of powder bed with the vibration intensity, since the electric resistance is related to the packing structure of particles in the bed. The fluidity measurements were made with a rotary type viscometer. A slight increase of electric resistance of the powder bed has occurred with increase in amplitude of vibration. Further increase in vibration results in rapid increase of electric resistance. During this stage, the slopes of amplitude-electric resistance plot increases in proportion to the particle size of the powder.
    As amplitude of vibration increases further, the net drag force exceeds the gravitational force on the particles, and the increase of electric resistance is slow. The change in fluidity with vibration shows the same tendency to the amplitude-electric resistance plots. These relations between the amplitude and electric resistance or fluidity of powder bed are similar to the change found in the relation of temperature vs. specific volume in glass transition of various materials. In the region where the vibration force exceeds the gravitational force acting on particles, the relation between the change of electric resistance due to the vibration and the fluidity of powder bed can be expressed in the following equation:
    φ=aexp(-bRo/Rx)
    where φ stands for fluidity, Ro and Rx for the electric resistance of powder bed in fixed-bed and in vibrating state, and a, b as constant and b is related to the particle sizes of the powder.
    These results will point to the fact that the varying process in the moving structure of powder bed, which is due to the vibration, consists of two different packing structures based on the motion of the particles.
  • 西野 操, 荒川 正文
    1971 年 20 巻 213 号 p. 781-785
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    In order to investigate the effect of water on the cohesion of powder, the experiments were made with a system composed of powder, water and non polar liquid in which a very small amount of water is soluble. Benzen was chosen as such liquid, and spherical glass powders with four kinds of particle sizes (12.4μ∼144μ) were used. In these systems, the adsorption weight of water, sedimentation volumes and angles of repose were measured.
    In a typical adsorption isotherm, the adsorption weight reached a certain value (point A), and was kept on at this value until another point (B) is reached beyond which it began to increase with a steep slope. In the range of lower concentration of water in benzene than that at B, the sedimentation volume and the angle of repose did not vary with water concentration for the powder of large particle size, and they increased slowly for the smaller one. But when the adsorbed water content approached that at B, the sedimentation volumes and the angles of repose increased sharply, and then decreased with much larger content of water. Representing the adsorption isotherms in the form of adsorption weight per unit surface area of particles, the isotherm curves roughly coincided in the range between A and B. The adsorption weight in this form was 20∼30×10-8g/cm2 and corresponded to the thickness of 20∼30Å for the adsorbed layer.
    On the basis of the above results, it was considered that the water was uniformly adsorbed on the surfaces of particles first, and then was condensed at the contact points between the particles and formed the water bridges. The adsorbed water layer made the surface of particle more hydrophylic and these particles became easy to flocculate each other in such a non polar medium as benzene. The cohesiveness due to the above mechanism was considered to have been influensed by the particle size.
    On the other hand, it is widely accepted theoretically that the attractive force due to the liquid bridge between the two spherical particles decreases with increase in the volume of the liquid. These sedimentation volumes were plotted in terms of the mean vloume of bridge water at a contact point, which were calculated from the experimental data of sedimentation volume and adsorption of water. It is found that the curves show the same tendency as the theoretical one for the attractive force versus the volume of the bridge water.
  • 棚田 成紀, 松本 和興, 榎本 三郎
    1971 年 20 巻 213 号 p. 786-789
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    Hereunder is given a report of experimental studies that have been performed of the adsorption of argon and pyridine, using magnesium silicate specimens prepared respectively by coprecipitation and by hydrothermal treatment. The heat of adsorption of argon have been obtained from adsorption isotherms at -196° and -191°C. The initial heats of adsorption of argon on two kinds of magnesium silicate specimens were about 6kcal/mole and 4kcal/mole, respectively. The gradual fall, on the isosteric heat curve against coverage was observed at an early stage of adsorption on the sample through the hydrothermal treatment, but the secondary peak after the gradual fall appeared in the heat curve on the sample through the coprecipitation method. The specific surface area vs. SiO2/MgO did not agree with the amount of the acid point vs. SiO2/MgO which was obtained by the adsorption of pyridine.
    These facts reveal the fact that both kinds of magnesium silicate specimens have heterogeneous surfaces.
    The amount of the acid point on the sample prepared by the hydrothermal treatment was less than that on the coprecipitated sample.
    It is concluded that the surface of the magnesium silicate specimens subjected to hydrothermal treatment has smaller amount of acid points, but these acid points are stronger than those on the surface of coprecipitated specimens.
  • 宇津木 弘
    1971 年 20 巻 213 号 p. 790-794
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
    The flow curve of suspension with thixotropy was investigated through the calculation of the flow equation derived on the basis of the absolute reaction rate theory. On this basis, the following experimental trends were qualitatively well-explained, where (1) the structure of the grease deformed by application of shear showed no remarkable recovery even after the grease was kept at standstill without shear, or even under such condition as to make the grease mobile by the heat, (2) the experimental scanning of the flow curves of the hysteresis loop on the equilibrium flow curve showed either the increasing or the decreasing rate of the shear in their shapes.
  • 1971 年 20 巻 213 号 p. 795-801
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
  • 高圧下の金属の塑性 (その2)
    西原 正夫, 藤田 達
    1971 年 20 巻 213 号 p. 802-808
    発行日: 1971/06/15
    公開日: 2009/08/20
    ジャーナル フリー
feedback
Top