PRODUCTION OF KAOLINITE WITH LOW CRYSTALLINITY

摘要

PURPOSE:To produce artificial kaolinite in which plasticity is maintained at high level with superior formation efficiency by carrying out hydrothermal synthesis treatment together with water by using the hydrate of amorphous calcium silicate and the strong acid salt of Al. CONSTITUTION:Hydrothermal synthesis treatment is carried out together with water by using, as raw materials, the hydrate of amorphous calcium silicate and the strong acid salt of Al, such as AlCl3, to obtain kaolinite powder. It is desirable to use, as the hydrate of amorphous calcium silicate, the one having a composition in which the atomic ratio of calcium to silicic acid is regulated to 0.1-2.0. Since the irregular tetrahedron layer of the amorphous Si can be utilized by using the hydrate of amorphous calcium silicate as raw material, kaolinite crystal formation is allowed to occur uniformly and simultaneously over the whole reaction system. Accordingly, sheet-like kaolinite reduced in crystallinity is formed.