Preparation Of Mesh Porous Ceramics From Organic Precursor By Soaking Method

The porous ceramics has the advantages of low density, high penetration coefficient, corrosion resistance, good heat insulation performance, thermostable and long service life etc. It is one kind of new functional materials. Now the applications of porous ceramics have been spreading the fields of metallurgy, chemical industry, energy, environmental protection, biology and so on. It is receiving more and more attentions by researchers.The organic template body soaking method is the economical and practical method of preparing the mesh porous ceramics. According to the different applications and requirements, the mesh porous ceramic materials with different properties can be obtained, which are usually made of cordierite, mullite, alumina, carborundum and so on. They are often limited in the applications because of the relative higher cost. In this work, the much abundant and cheaper natural materials such as porcelain stone, kaoline, feldspar were chosen for the production of mesh porous ceramics.Firstly, the TG-DSC thermal analysis on the organic precursor was carried out for designing the reasonable burning schedule. The optimized compositions of the mesh porous ceramics are porcelain stone 50%,feldspar 25%,calcspar 13%,dolomite 12%,and additional steatite 7% and bentonite 3%. Then, the soaking technology from organic precursor was investigated. The factors influencing the slurry loading in the foam were analyzed and the soaking parameters were optimized. In order to increase the capacity of catalyst on carrier, more pores on surface of biscuit body can be prepared by mixing colophony soap and slurry.Using the mixture solution of NaOH and polyacrylamide to manipulate the organic precursor body can obviously improve the quantity of slurry loading on the precursor, and the best concentrations of NaOH and polyacrylamide are 3mol/L and 2/l respectively. The solid concentration, additives and the relative roller space are the important factors affecting the performance of mesh porous ceramics, and the optimized value of the solid content and the relative roller distance (l/h) are 73wt% and 4.16 respectively. The slurry loaded in the foam increases with the increase of CMC content, and the best value is located at 0.5%, which can improve the viscosity and fluidity of slurry.More pores on the surface of green body were obtained by mixing colophony soap with slurry so as to prepare the carriers with larger specific surface area and catalyst capacity. The final mesh porous ceramics with higher ratio of specific surface area were prepared by using the foam slurry in 17.3% concentration for two times, and the filtrating efficiency for coal smoking increased 10% by the porous ceramics carrier.