低白色度石灰石粒子への炭酸カルシウム被覆による 高白色度化  [in Japanese] Preparation of Limestone Particles with High Value of Whiteness Parameter by Coating with Calcium Carbonate  [in Japanese]

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Author(s)

    • 栗和田 穆 KURIWADA Atsushi
    • 東京大学大学院工学系研究科地球システム工学専攻 The University of Tokyo, Department of Geosystem Engineering, Graduate School of Engineering
    • 定木 淳 SADAKI Jun
    • 東京大学大学院工学系研究科地球システム工学専攻 The University of Tokyo, Department of Geosystem Engineering, Graduate School of Engineering
    • 藤田 豊久 FUJITA Toyohisa
    • 東京大学大学院工学系研究科地球システム工学専攻 The University of Tokyo, Department of Geosystem Engineering, Graduate School of Engineering

Abstract

Calcium carbonate powder with high value of whiteness parameter is widely used in various industrial applications such as paper, plastics, glass etc. The value of the whiteness parameter of the powder mainly depends on the whiteness of limestone used as raw material. White limestone is formed through lithological re-crystallization by geological thermal-metamorphism, thus, the reserves of white limestone are limited and regionally maldistributed in Japan. In turn, the production of calcium carbonate products with the high whiteness is viable only in some areas.<br> The native carbon (eg. graphite) as well as sulfide and oxides species, blamed for giving the ordinary limestone a gray color, are not easy to be removed from limestone particles. With this in mind the authors are putting forward a process for production of white calcium carbonate by using ordinary gray colored limestone found in many areas throughout Japan. The process is carried out in two steps:<br> 1. reducing the coloring substances, contained in limestone particles, by heating.<br> 2. covering the surface of limestone particles, mainly calcite, with crystallized white calcium carbonate.<br> The experimental results point out that the whiteness of calcium carbonate particles is considerably increased by using this method, suggesting that the ordinary gray colored limestone can be used to produce high whiteness calcium carbonate products.<br>

Journal

  • Resources Processing

    Resources Processing 54(3), 128-138, 2007

    The Resources Processing Society of Japan

Codes

  • NII Article ID (NAID)
    130000103585
  • NII NACSIS-CAT ID (NCID)
    AA11907992
  • Text Lang
    JPN
  • ISSN
    1348-6012
  • NDL Article ID
    8940311
  • NDL Call No.
    Z17-275
  • Data Source
    NDL  J-STAGE 
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