Journal of the Society of Powder Technology, Japan
Online ISSN : 1883-7239
Print ISSN : 0386-6157
ISSN-L : 0386-6157
Search
Advanced search
OR
Browse
Search
Volume 31, Issue 4
Displaying 1-5 of 5 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • Some Proposals for a Wet Grinding Process for Ceramic Raw Materials
    Nobuyoshi ASAI, Tsunemi SUGIE, Shigeki TOYAMA
    1994 Volume 31 Issue 4 Pages 236-240
    Published: April 10, 1994
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.31.236
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The problem of contamination has become the centre of interest in the technique for the preparation of a high-purity powder, especially the milling process of the starting powder in high performance ceramics. In this report, the increasing tendencies in the amount of impurity in TiO2 powder during wet alumina ball milling are described.
    The results obtained are summarized as follows:
    (1) Impurity (intermixture into the ground TiO2 powder), caused by wear of the grinding ball and the mill liner, was mainly included in the finer size range of the ground productt in the initial grinding stage. Also, the size of intermixture was distributed widely throughout the full size range of the ground product in the final grinding stage.
    (2) The intermixture concentration was influenced considerably by the viscosity and the specific gravity of the slurry.
    (3) The size of the wear debris was distributed into a finer size range of the ground product. Then, in the closed circuit wet milling process, it was estimated that the impurity was concentrated in the fine grinding product that was collected by the classifier.
    View full abstract
    Download PDF (521K)
  • Rheological Behavior of Highly Filled Ceramic Suspensions
    Hachiro NAKAMARU, Yasushi TAWARA, Yoichi NAGASE
    1994 Volume 31 Issue 4 Pages 241-247
    Published: April 10, 1994
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.31.241
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Viscoelastic properties of highly filled suspensions (HFS) of ceramic powders-bentonite, kaolin, alumina and titania-mixed with various binders were tested by means of the mono-axial compression method. The rheological properties of HFS before and at rupture were: Strains at rupture, εR, were independent of concentration and were in the range, 0.1 to 0.2, for every combination of powders and binders. Rupture strengths, σR, were highly dependent on solid concentration and varied with powders and binder combinations. A binder, HPMC, gave adhesiveness and softness to the HFS, and did not show complete rupture. The CMC gave the most brittle nature to the HFS. In addition, thixotropic hardening was observed for long time loading with every sample. Burgers' model in which the time dependency term was introduced into the Maxwell part was presented to simulate the rheological behavior of HFS. Finally, the effect of binders was quantitatively estimated.
    View full abstract
    Download PDF (749K)
  • Measurements of the Tortuosity Factor and Surface Diffusivity in Liquid-Filled Pores
    Chikao ARAI, Hiroyuki MARUYAMA, Noriko NAKAGAWA, Kazutoshi HIOKI, Seij ...
    1994 Volume 31 Issue 4 Pages 248-255
    Published: April 10, 1994
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.31.248
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The method of determining the liquid phase surface diffusivity based on the parallel diffusion model was presented. The model can be described in the form with two parameters, X and Y. X is defined as the ratio of the porosity to the tortuosity factor as a parameter of the adsorbant, and Y is the ratio of surface diffusivity, Ds to diffusivity, DL of the solute in a solution. It was shown that an objective function to identify the model with an experimental adsorption rate has a minimum value on a line with respect to X and Y, in contrast to the results of having a minimum value at a point in several papers.
    The tortuosity factor was measured using methanol as a solvent to inhibit the contribution of surface diffusion. For the measurement of surface diffusivity aqueous solutions were used, then the diffusivity was evaluated from both the tortuosity factor and the line decided by the objective function. The diffusivities and amount of equilibrium adsorbed, qe were correlated by the form,
    DS/DL=αqeβ, where α and β are experimental coefficients.
    View full abstract
    Download PDF (890K)
  • On the Functions of Organic Binders in Ceramic Forming
    Hachiro NAKAMARU, Masahiro HACHIYA, Yoichi NAGASE
    1994 Volume 31 Issue 4 Pages 256-258
    Published: April 10, 1994
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.31.256
    JOURNAL FREE ACCESS
    Download PDF (263K)
  • [title in Japanese]
    Shigehisa ENDO
    1994 Volume 31 Issue 4 Pages 269-272
    Published: April 10, 1994
    Released on J-STAGE: April 30, 2010
    DOIhttps://doi.org/10.4164/sptj.31.269
    JOURNAL FREE ACCESS
    Download PDF (2343K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top