Method for producing a cordierite body

Claim 1

A method for producing a cordierite body comprising the sequential steps of: (1) preparing a first batch material having an average particle diameter of from about 1 to about 50 microns consisting essentially in weight percent of 33.98 to 42.05% kaolin mineral particles, 14.74 to 18.24% raw talc particles, 14.74 to 18.25% fired talc particles produced by delaminating pulverized, layered raw talc along (001) Plane into plate-shaped particles then firing said plate-shaped particles, and at least one of aluminum hydroxide or alumina, the batch material having substantially the same composition ratio as the theoretical composition ratio for cordierite; (2) adding to the batch material prepared in step (1) from about 1 to about 20 weight percent of preformed cordierite particles having substantially the same composition as that of the batch material and having an average particle diameter of from about 1 to about 50 microns, said preformed cordierite particles being prepared by mixing together and kneading a second batch material, consisting essentially of kaolin mineral particles, raw talc particles and at least one of aluminum hydroxide or alumina, into a slurry, forming said slurry into a formed body, drying and firing the formed body to form synthetic cordierite, then pulverizing the synthetic cordierite into cordierite particles; (3) mixing and kneading the batch material and preformed cordierite particles together to form a slurry; (4) anisostatically forming said batch into a formed body of the desired shape; and (5) drying and firing said formed body, the resulting cordierite body having a coefficient of thermal expansion which is nearly equal and is ≦15.0×10 -7 /°C. in the range of 25° to 1,000° C. in all directions.

Claim 2

A method for producing a cordierite body comprising the sequential steps of: (1) preparing a first batch material having an average particle diameter of from about 1 to about 50 microns consisting essentially in weight percent of 33.98 to 42.05% kaolin mineral particles, 14.74 to 18.24% raw talc particles, 14.74 to 18.25% fired talc particles produced by delaminating pulverized, layered raw talc along (001) Plane into plate-shaped particles then firing said plate-shaped particles, and at least one of aluminum hydroxide or alumina, the batch material having substantially the same composition ratio as the theoretical composition ratio for cordierite; (2) adding to the batch material prepared in step (1) from about 1 to about 20 weight percent of preformed cordierite particles having substantially the same composition as that of the batch material and having an average particle diameter of from about 1 to about 50 microns, said preformed cordierite particles being prepared by mixing together and kneading a second batch material, consisting essentially of kaolin mineral particles, raw talc particles and at least one of aluminum hydroxide or alumina, into a slurry, forming said slurry into a formed body, drying and firing the formed body to form synthetic cordierite, then pulverizing the synthetic cordierite into cordierite particles; (3) mixing and kneading the batch material and preformed cordierite particles together to form a slurry; (4) anisostatically forming said batch into a formed body of the desired shape; and (5) drying and firing said formed body, the resulting cordierite body having a coefficient of thermal expansion which is nearly equal and is ≦15.0×10 -7 /°C. in the range of 25° to 1,000° C. in all directions.