CERAMIC MEMBRANE COMPRISING CERAMIC TAPES HAVING DIFFERENT PORE CHARACTERISTICS AND PRODUCTION METHOD THEREOF

摘要

PURPOSE: Provided is a method for producing ceramic membrane consisting of ceramic tapes including an intermediate and a support layer with a different pore characteristic by using at least two powders. CONSTITUTION: The ceramic membrane is produced by the following steps of: (i) preparing a ceramic slurry for a support layer(1,2,3) by mixing 100pts.wt. of two kinds of alumina powders having different sizes of 0.5-3micrometer(alumina (I)) and 20-25micrometer(alumina (II)), 0.2-0.8pts.wt. of dispersant, 15-30pts.wt. of water, 5-15pts.wt. of plasticizer and 5-20pts.wt. of binder, wherein less than 45micrometer of starch is optionally added to alumina powder(II) to be a weight ratio of alumina to starch of 7:3 - 9:1; (ii) preparing at least two ceramic slurries by changing the ratio of alumina (I) to alumina (II)+ starch of 0:10, 1:9, 2:8, 3:7, 4:6, 5:5, 6:4; (iii) preparing a ceramic slurry for an intermediate layer(4) by mixing 100pts.wt. of alumina (I), 0.2-0.8pts.wt. of dispersant, 15-30pts.wt. of water, 5-15pts.wt. of plasticizer and 5-20pts.wt. of binder; (iv) forming prepared slurries into ceramic tapes for the support layer(3-5mm thick) comprising at least two ceramic tapes having different pore characteristics and particle distributions, and the intermediate layer(100-500micrometer thick); (v) layering ceramic tapes for the support layer in order of pore size and then layering ceramic tape for the intermediate layer on a tube(or rod)-shaped gypsum mold, and warm isostatic pressing to bond layered ceramic tapes under pressure of 200-300kgf at 70-80deg.C; (vi) putting layered ceramic tapes on a tube-shaped refractory, the support of a ceramic membrane; (vii) sintering layered ceramic tapes by heating to 200, 300 and 500deg.C, and holding 1hr at each temperature to remove organic materials, heating to 1050-1150deg.C and holding for 2hrs to burn starch added in the support layer, and cooling slowly; (viii) removing the shrunken gypsum mold and trimming the joint of the tube, and sintering ceramic membrane product at 1500-1700deg.C and holding for 2hrs.