Friction reduction effect by acoustic pressure and surface vibration of ultrasonic was investigated. As a result, small particles are hardly affected by acoustic pressure. However, in case of large-sized particles, friction is decreased greatly by acoustic pressure. Moreover, the effect by surface vibration has relation to particle density. In short, this effect is enlarged with increasing of particle density. Finally, separation for particle size and material was tried by making use of difference in friction reduction. Results showed silica was divided according to each size, and iron could be picked up from particles which include titanium.

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In this article we introduce the apparatus we have successfully developed for performing various experiments with minimal quantity of material, which include grinding, dispersing, mixing, mechanical alloying, mechanochemical treatment and even scaling-up. This apparatus is capable of changing the powder operations by replacing the 3 types of folders. Therefore the single apparatus can carry out the various powder operations by itself and has made it possible to speed up the whole process of the experiment and product development as a result.

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Chemical vapor deposition （CVD） is generally employed to prepare thin films, whereas CVD can also prepare nano-particles by homogeneous nucleation in a gas phase or on support powder as catalyst. Although fluidized-bed CVD （FBCVD） has often been used to prepare particle/film on fluidized powder, the powder size of FBCVD is rather limited to several 10 to 100μm in diameter to fluidize powder in a gas phase. We have developed Rotary CVD （RCVD）, which has no limitation of powder size to deposit. Ni nano-particles a few nanometer in diameter were prepared on Al₂O₃, mesoporous silica and Zeorite powders by RCVD using Nickelocene precursor. Ni nano-particles were deposited inside mesoporous silica showing more than 6 times higher H₂ production by steam methane reforming reaction than that of conventional Ni catalyst.

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In order to obtain fine powder, dry dispersion and classification are used in the several industries. In this paper, firstly, the effect of liquid dispersion aids on dry dispersion of submicron metal powder was investigated. Measurements of dispersabilities of test powder with and without Diethylene glycol monomethyl ether （DEG） revealed that DEG improves the dispersability of metal powder by the factor of about three compared to the dispersability of metal powder without the aids. Through the observation of structure of metal powder after mixing it with DEG, the improvement in dispersability is due to the change in agglomerate structure from compact agglomerates to chain-like agglomerates. Secondary, our group has proposed a classifier equipped with a particle-trap ring at the exit of the classification zone to prevent the escape of large particles entrained by shortcut flow. The visualized swirl flow compares favorably with simulation results obtained by CFD.

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