POROUS MULLITE MATERIAL

PURPOSE:To obtain the subject porous material having fine pore size and sharp pore size distribution by preparing a sintered ceramics containing mullite as a main constituent phase and added with a specific metal oxide and dissolving the matrix of the material with an aqueous solution of an alkali. CONSTITUTION:The sintered ceramic material to be used as a raw material of the subject mullite material contains a mullite composed of 35-63wt.% of SiO2 and 60-32wt.% of mullite (in terms of oxide) as a main constituent phase and is added with one or more metallic components selected from 1-10wt.% of TiO2, Fe2O3, CoO, CuO and ZnO and 0.2-2wt.% of B2O3. The matrix of the sintered ceramic material is dissolved with an aqueous solution of an alkali (e.g. aqueous solution of sodium hydroxide) to obtain the objective porous mullite material. Since the raw material is added with a metal effective to accelerate the growth and development of acicular or columnar crystal of mullite, the sintered product contains developed acicular crystal of mullite and the dissolution treatment can be quickly performed. The obtained porous material is suitable as various filters, catalyst carriers, etc.