Ngk Insulators, Inc.

Ngk Adrec Co., Ltd.

Akito Higuchi

Tsuneo Komiyama

Osamu Yamakawa

Tetsuhiro Honjo

Takashi Harada

Yoshiyuki Kasai

Yukinari Shibagaki

Hiroyuki Hotta

A non-settling refractory mortar is provided, which includes 100 mass % of a ceramic powder such as cordierite, mullite, alumina, or silicon carbide, 0.5 to 1.5 mass % of a clay mineral, and a colloidal oxide solution, in which the Ca content in the total solid component is defined at 0.01 to 0.5 mass % as converted to oxide so as to be provided with a thixotropic property. As a result, the coating performance is not lowered if stored for a long period after kneading, the dimension change rate after coating is small, and cracks or gaps are not formed on the coat surface. The median diameter of ceramic powder is preferred to be 10 to 50 &#x3bc;m, and in order to reduce the dimension change rate after coating, the content of particles of 0.1 to 5 &#x3bc;m in ceramic powder is desired to be 1 to 20%.

Non-settling refractory mortar

A monolithic refractory material is provided by a method including the steps of kneading cordierite powder having a median diameter in a range of 10 to 50 &#x3bc;m, and having a sharp mountain-like particle size distribution in which the content of particles smaller than 10 &#x3bc;m is 1% or more to 36% or less, the content of particles ranging from 10 &#x3bc;m or more to 50 &#x3bc;m or less is 50% or more to 75% or less, and the content of particles of 51 &#x3bc;m or more is 1% or more to 14% or less, and a solvent including water and alumina sol or silica sol solution.

Monolithic refractory material having low expansibility, high strength, and crack extension resistance

A refractory mortar cured material is formed in the surface or joint portions of a ceramic refractory material, such as fire bricks used in the lining of melting furnace or firing furnace used at high temperature, and includes ceramic particles with an inorganic binder having silanol group that are kneaded together with water. The kneaded mortar is applied on the surface of a ceramic base material. The average particle size of ceramic particles in the refractory mortar is 10 to 50 &#x3bc;m, and the difference between the 90% particle size and the 10% particle size is 10 &#x3bc;m or more to 60 &#x3bc;m or less. The average pore size of the refractory mortar cured material is 5 to 25 &#x3bc;m, and the width of pore size distribution is 20 to 80 &#x3bc;m, so that the cracks are suppressed. In addition, the bulk density is 0.9 to 1.5 g/cm.

Refractory mortar cured material

A ceramic honeycomb structure has an open frontal area of 50% to 85%, a porosity of 0.1% to 10%, and a proportion of the volume of pores of 1 &mgr;m or larger in diameter, in total pore volume, of 20% or more; a regenerative thermal oxidizer using the ceramic honeycomb structure. The ceramic honeycomb structure has a small porosity and, therefore, has a sufficient heat accumulation capacity and hardly causes floating by gas pressure; has controlled pore diameters and, therefore, hardly shows adsorption of VOC or the like, or rupture; and has controlled contraction and, therefore, has a large GSA.

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Kani, Japan

Akito Higuchi