Production method for ceramic porous material

Abstract

To provide a method for producing a ceramic porous material which has a high strength, though it has a high porosity, and which is excellent in permeability without dust generation. In a ceramic porous material having a three-dimensional mesh-like skeleton structure with a large number of substantially spherical adjacent cells communicating with each other via communication holes, the crystal particle size at the rim of each communication hole in the skeleton structure is provided substantially equal to the crystal particle size in the other parts.

What is claimed is:  
     
         1 . A production method for a ceramic porous material comprising the steps of preparing a bubble-like slurry by mixing and whipping a ceramic powder, a liquid medium, a dispersing agent if necessary, a foaming agent and a gellation main agent, adding and mixing a gellation sub agent to the bubble-like slurry, pouring into a mold for obtaining a gellation product, drying the gellation product for having a compact having a three dimensional mesh-like skeleton structure with a large number of substantially spherical adjacent cells communicating with each other via communication holes, and sintering or fireing the compact directly, or temporarily baking (calcinating) the same before sintering or fireing for obtaining a sintered or fired product and then baking the same for obtaining a baked product, wherein the rim of each communication hole in the compact, the temporarily baked product or the sintered or fired product is eliminated mechanically.  
     
     
         2 . A production method for a ceramic porous material comprising the steps of preparing a bubble-like slurry by mixing and whipping a ceramic powder, a liquid medium, a dispersing agent (if necessary), a forming agent and a gellation main agent, adding and mixing a gellation sub agent to the bubble-like slurry, pouring into a mold for obtaining a gellation product, drying the gellation product for having a compact having a three dimensional mesh-like skeleton structure with a large number of substantially spherical adjacent cells communicating with each other via communication holes, and sintering or fireing the compact directly, or temporarily baking (calcinating) the same before sintering or fireing for obtaining a sintered or fired product, wherein the rim of each communication hole in the compact, the temporarily baked product or the sintered or fired product is eliminated chemically.  
     
     
         3 . A production method for a ceramic porous material comprising the steps of preparing a bubble-like slurry by mixing and whipping a ceramic powder, a liquid medium, a dispersing agent if necessary, a forming agent and a gellation main agent, adding and mixing a gellation subagent to the bubble-like slurry, pouring into a mold for obtaining a gellation product, drying the gellation product for having a compact having a three dimensional mesh-like skeleton structure with a large number of substantially spherical adjacent cells communicating with each other via communication holes, and sintering or fireing the compact directly, or temporarily baking (clcinating) the same before sintering or fireing for obtaining a sintered or fired product, wherein the evaporation-condensation mechanism with respect to the crystal particles at the rim of each communication hole is promoted during the sintering or fireing operation of the compact or the temporarily baked product, or the re-sintering or re-fireing operation of the sintered or fired product.