Composite ceramic materials as a pulverization medium and for working parts of a pulverizer

A pulverizer comprising:

• at least one of a working part of the pulverizer or a container of the pulverizer having a Vickers hardness (Hv) of at least 1300kgf/mm.sup.2 (12.75 GPa), and
• a pulverizing medium whose Vickers hardness (Hv) is 100-600 kgf/mm.sup.2 (1-6 GPa) lower than that of the Vickers hardness of at least one of the working part or the container.

A sintered composite ceramic material comprising a crystalline aluminium oxide material and a crystalline zirconium oxide material, said crystalline aluminium oxide material is present in an amount of from 60-85 wt. %, and said crystalline zirconium material is present in an amount of 15-40 wt. %, based on the total weight of the composite ceramic material, and said crystalline zirconium oxide material contains additionally at least one of Y.sub.2 O.sub.3 or CeO.sub.2 in an amount of 0.1-5 mol % based on the total zirconium oxide material.

An agitating member suitable for use in a media agitating pulverizer, wherein at least an outer shell of said agitating member comprises a ceramic composite material comprising at least 50 weight percent of a crystalline aluminum oxide material, based on the total weight of the ceramic composite material, and 15-40 weight percent of a crystalline zirconium oxide material, based on the total weight of the ceramic composite material, wherein said crystalline zirconium oxide material contains additionally at least one of Y.sub.2 O.sub.3 or CeO.sub.2 in an amount of 0.1-2 mol %, based on the total amount of said crystalline zirconium oxides in said ceramic composite material.

A container member suitable suitable for use in a media agitating pulverizer, wherein at least an inner liner of said container member comprises a ceramic composite material comprising at least 50 weight percent of a crystalline aluminum oxide material, based on the total weight of the ceramic composite material, and 15-40 weight percent of a crystalline zirconium oxide material, based on the total weight of the ceramic composite material, wherein said crystalline zirconium oxide material contains additionally at least one of Y.sub.2 O.sub.3 or CeO.sub.2 in an amount of 0.1-2 mol %, based on the total amount of said crystalline zirconium oxides in said ceramic composite material.

A method of pulverizing a product, comprising the steps of:

• selecting an agitating member of which at least an outer shell comprises a ceramic composite material comprising at least 50 weight percent of a crystalline aluminum oxide material, based on the total weight of the ceramic composite material, and 15-40 weight percent of a crystalline zirconium oxide material, based on the total weight of the ceramic composite material, wherein said crystalline zirconium oxide material contains additionally at least one of Y.sub.2 O.sub.3 or CeO.sub.2 in an amount of 0.1-2 mol %, based on the total amount of said crystalline zirconium oxides in said ceramic composite material;
• and
• (2) agitating the product in the presence of said agitating member so as to pulverize said product.

A method of pulverizing a product, comprising the steps of:

• (1) selecting a container member of which at least an inner liner comprises a ceramic composite material comprising at least 50 weight percent of a crystalline aluminum oxide material, based on the total weight of the ceramic composite material, and 15-40 weight percent of a crystalline zirconium oxide material, based on the total weight of the ceramic composite material, wherein said crystalline zirconium oxide material contains additionally at least one of Y.sub.2 O.sub.3 or CeO.sub.2 in an amount of 0.1-2 mol %, based on the total amount of said crystalline zirconium oxides in said ceramic composite material;
• and
• (2) agitating the product in the presence of said container member to pulverize said product.

A method of pulverizing a product, comprising the steps of:

• (1) selecting a pulverizer comprising a container, a pulverizing medium within the container and optionally at least one working part associated with the pulverizer and within the container, wherein at least one of an outer shell of the working part of the pulverizer, an outer shell of the pulverizing medium and an inner lining if the container is formed from a ceramic composite material comprising at least 50 weight percent of a crystalline aluminum oxide material, based on the total weight of the ceramic composite material, and 15-40 weight percent of a crystalline zirconium oxide material, based on the total weight of the ceramic composite material, wherein said crystalline zirconium oxide material contains additionally at least one Y.sub.2 O.sub.3 or CeO.sub.2 in an amount of 0.1-2 mol %, based on the total amount of said crystalline zirconium oxides in said ceramic composite material;
• and
• (2) agitating the product in the presence of said pulverizing medium within said pulverizer to pulverize said product.

A method of pulverizing a product, comprising the steps of:

• (1) selecting a pulverizer comprising a working part and a container, at least one said working part and container having a Vickers hardness (Hv) of at least 1300 kgf/mm.sup.2 (12.75 GPa), and a pulverizing medium whose Vickers hardness (Hv) is 100-600 kgf/mm.sup.2 (1-6 GPa) lower than the Vickers hardness of at least one of the working part and the container;
• and
• (2) agitating the product in said pulverizer to pulverize said product.