Journal of the Society of Powder Technology, Japan
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
Volume 28, Issue 12
Displaying 1-8 of 8 articles from this issue
  • Characteristics of the Particle Size Distribution of the Ground Product
    Yoko HASHI, Mamoru SENNA
    1991 Volume 28 Issue 12 Pages 732-737
    Published: December 10, 1991
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    Particle size distributions of CaCO3 ground by an agitation-beads mill were analyzed. A horizontal type mill equipped with perforated discs was used. Calcium carbonate was put into the mill with water to give 10% slurry, and the CaCO3 was ground under various conditions. Particle size distribution was approximated by a mono or bimodal-logarithmic normal distribution. Geometric mean and standard deviation of the smaller particle size group were determined only by the energy consumption. The bimodal distribution with the undesired larger particle fraction, FL, appeared when the degree of media filling was small. The fraction FL, depended on the residence time of the specimen but not on energy consumption.
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  • Relationship between the Media Flow Pattern and the Grinding Efficiency
    Yoko HASHI, Mamoru SENNA
    1991 Volume 28 Issue 12 Pages 738-744
    Published: December 10, 1991
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    The relationship between the media flow pattern and the particle size distribution of CaCO3 ground by an agitation-beads mill was examined. Fractionated alumina beads between 1.7 and 2.0mm were used as grinding media. Longitudinal and cross-sectional flow patterns of the grinding media in a grinding vessel of an agitation-beads mill were observed. The mill was equipped with perforated, non-perforated or pin-discs. Several types of inhomogeneously distributed flow patterns were observed under certain operating conditions. Appearance of each pattern was determined by the media filling degree or viscosity of the fluid. The fraction of the larger particle, FL, did not depend on the energy consumption. FL, decreased with decreasing irregular segregated flow of the grinding media and increasing residence time of the specimen.
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  • Jai Koo PARK, Yasuhiko OKANO, Toshio INOUE
    1991 Volume 28 Issue 12 Pages 745-750
    Published: December 10, 1991
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    Experimental investigation into the compressive comminution characteristics of raw materials was carried out under various conditions with a single particle or particle bed comminution apparatus. The fracture mechanics of this system are discussed from several aspects such as; (i) particle fracture analysis with loaddisplacement diagrams, (ii) size distribution properties of the progeny particles, (iii) increment of specific surface area, and (iv) energy utilization.
    It was found that the energy utilization is improved by the application of lower input energy i. e., by moderate compressive force, lower bed thickness and larger initial particle size. It could also be shown that the relationship between input energy and increment of surface area depends greatly upon the property of the raw materials.
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  • Toyokazu YOKOYAMA, Yoshiki TANIYAMA, Genji JIMBO, Qian-Qiu ZHAO
    1991 Volume 28 Issue 12 Pages 751-758
    Published: December 10, 1991
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    The limit of in-water grinding of silica sand by a planetary ball mill, which gives a much higher grinding rate than tumbling ball mills, was investigated from the viewpoint of mechanical grinding conditions. The grinding limit and subsequent negative grinding were confirmed in the in-water grinding. To do this, the product fineness was evaluated on the basis of size analysis by the laser scattering-diffraction method. As a result of a series of experiments, it was found that the grinding equilibrium size, defined as the minimum particle size determined by the size analysis, decreased as the ball size, ball density or mill's rotation was reduced. The grinding equilibrium size was well correlated with the maximum force exerting on a single ball in the mill pot within the experimental range.
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  • Kanji OTSUKA
    1991 Volume 28 Issue 12 Pages 759-764
    Published: December 10, 1991
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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  • Zenji MATSUMOTO, Teruo FUKUI
    1991 Volume 28 Issue 12 Pages 765-770
    Published: December 10, 1991
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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  • 1991 Volume 28 Issue 12 Pages 781-793
    Published: December 10, 1991
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
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  • 1991 Volume 28 Issue 12 Pages 794-797
    Published: December 10, 1991
    Released on J-STAGE: April 30, 2010
    JOURNAL FREE ACCESS
    Download PDF (5898K)
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