PRODUCTION OF DENSE CORDIERITE CERAMIC MATERIAL

摘要

PROBLEM TO BE SOLVED: To industrially produce a dense cordierite ceramic material having high performance. SOLUTION: A compounded material essentially comprising high-quality particulate kaoline or clay with elutriation (called as elutriation kaoline hereinafter) containing kaolinite or halloysite by >=90wt.% in a dry state and submicron fine particles of magnesium compd. which is thermally decomposed to produce MgO at <=850 deg.C is prepared. The compounding ratio of the kaoline to the magnesium compd. is so that the molar ratio of MgO to Al2 O3 in the chemical compsn. after calcining ranges from 0.8 to 1.2. Moreover, these components are preliminarily and sufficiently dispersed and mixed so that most of the MgO makes amorphous solid solution with the thermally decomposed kaoline before silicate is crystallized in the heat treatment. The compounded material is molded, or calcined at <=900 deg.C to obtain a powder and compacted. Then the material is calcined to obtain a high-performance dense cordierite ceramic material.