| 摘要 |
PROBLEM TO BE SOLVED: To obtain a material suitable as a filler for resin, coating material and paper by treating a granular hydrous aluminosilicate material produced by a flash firing with a leaching agent to leach aluminum. SOLUTION: The hydrous alumino silicate material may consist of, for example, a candite and/or smectite type clay material. A material containing at least 90 wt.% kaolin is preferably used as the aluminosilicate material. The heating rate for the particles in the flash firing is controlled to raise the temp. of the material at least >=5×10<3> deg.C/sec. The max. temp. in the flash firing range 500 deg.C to 950 deg.C. The leaching agent is selected from among inorg. acids, org. acids and aluminum chelating agents such as EDTA, and preferably 1M to 3M sulfuric acid is used. The leaching process is carried out within 30 to 100 deg.C temp. range. The granular product obtd. by leaching is separated and then cleaned in water.
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