Porous ceramics have many excellent properties, including high-temperature resistance, chemical resistance, and high porosity. They are widely used in filtration and separation, catalyst carriers, and pollution control. Among them, porous Cordierite ceramics, due to their very low thermal expansion coefficient and excellent thermal shock resistance, can be used under harsh conditions and have become commonly used catalyst carrier materials. Let's learn about the preparation methods and applications of Cordierite porous ceramics!

　　Properties of Cordierite Porous Ceramics

　　Cordierite crystals exhibit anisotropic thermal expansion, with negative values in the c-axis direction and positive values in the a-axis direction. Thus, the c-axis direction exhibits negative expansion, resulting in very small overall thermal expansion. Therefore, porous ceramics prepared using Cordierite have good properties such as low Cordierite thermal expansion coefficient, chemical stability, and dielectric characteristics, while also exhibiting low density, high permeability, corrosion resistance, high-temperature resistance, and good thermal insulation.

　　Method for Manufacturing Porous Cordierite Ceramics

　　 Cordierite The main characteristic of porous ceramics is their porous nature, and the key and difficulty in their preparation is the formation of their porous structure. According to the specific use and performance requirements of porous ceramic materials, the current preparation methods for Cordierite porous ceramics include particle deposition, foaming, extrusion molding, pore-forming agent addition, organic foam impregnation, sol-gel, and gel casting.

　　1. Preparation of Cordierite Porous Ceramics by Pore-Forming Agent Addition Method

　　Introducing the corresponding pore-forming agent to prepare Cordierite porous ceramics is a simple preparation method. The preparation process involves adding an appropriate amount of pore-forming agent to the ceramic green body. Because the pore-forming agent occupies a certain space in the green body, after sintering, the pore-forming agent leaves the matrix to form pores inside the green body, resulting in Cordierite porous ceramics. Commonly used pore-forming agents in the preparation of Cordierite porous ceramics include graphite, starch, polystyrene microspheres, carbon black, polypropylene plastic particles, wood chips, rice bran, etc.

　　The advantages of the pore-forming agent addition method for preparing porous ceramics are its simple preparation process, convenient operation, and the ability to prepare porous ceramics with complex shapes and various pore structures. The disadvantages are that it is difficult to ensure the uniform distribution of the pore-forming agent in the raw material during mixing, resulting in poor uniformity of pore distribution in the product, low porosity, and difficulty in ensuring the stability of product performance.

　　2. Preparation of Cordierite Porous Ceramics by Extrusion Molding

　　The process characteristics of preparing Cordierite porous ceramics by extrusion molding are the use of pre-designed porous metal grinding wheels to form pores. Generally, the prepared plastic green body is placed in an extruder, molded using a grinding wheel with a honeycomb grid structure, dried, and sintered to obtain Cordierite porous ceramics with certain looseness and pore size distribution.

　　3. Preparation of Cordierite Porous Ceramics by Foaming Method

　　The preparation of Cordierite by foaming involves adding a certain amount of foaming agent during the ceramic preparation process. Commonly used foaming agents include organic and inorganic foaming agents. During the dough processing, the foaming agent forms a certain amount of volatile gas, producing a certain amount of foam. After drying and calcination, porous ceramics with a certain looseness can be obtained. Cordierite Porous ceramics.