| 摘要 |
PURPOSE: To enhance the resistivity against corrosions by high temperature gases by vacuum-forming a fire-resistant ceramic fiber together with an aqueous slurry of a ceramic binder and thermally treating the formed part to obtain a skeletal member, which is then fired at a high temperature after coated with alumina gel. CONSTITUTION: When the filter element (10) is prepared, a fire-resistant ceramic fiber with its diameter of 2 to 3μand length of 5 to 10 mm is pulled into a mold together with an aqueous slurry of a ceramic binder for vacuum-molding a part, which is then thermally treated for drying the binder to form a skelton member of the fire-resistant ceramic fiber. The skeletal member has an average pore dimension of larger than 40μ. The skelton member is then coated with a material selected from alumina gel, colloidal alumina and colloidal silica to reduce the average pore diameter to be 30 to 40μ. The skeletal member is heated at a temperature of about 925 to 1,260 deg.C for drying the coated material and for enhancing its resistivity against corrosions by high temperature gases. Its durability is thus enhanced.
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