Mullite Porous Ceramic Prepared By Andalusite

Mullite porous ceramic has good high temperature mechanical properties andvolume stabilization, been used as insulating material in high temperature kilnindustry. Due to the low thermal conductivity, it can reduce the thermal losses,improve efficiency and save cost. It has an important research significance to be asinsulating material.Mullite porous ceramic has been prepared using andalusite and industrialaluminum hydroxide as raw materials with pore-forming agent. Its porous diameter isequality, apparent density is low and mechanics properties is good though sinteringprocess.In order to gain high porosity and low defects, had compared with differentpore-forming agent. The phase and microstructure at different sintering temperatureand ratio of gain mullite were analyzed by XRD and SEM methods. Based on all this,had studied on density and strength, to increase the property of mullite porousceramic.The results show that the sintering temperature of mullitratoin is above1400℃and the addition amount of andalusite and alumina is80:20. Compared with PVC andEPS by means of orthogonal test, found that pore-forming agent addition amount isthe most important influencing factors of mullite porous ceramic, and the poreinducing effect of the latter is better than that of the frost. When sintering temperatureis1450℃, pore-forming agent is5wt%and the mass ratio of andalusite to alumina is80:20, the apparent density is0.52g/cm~3, porosity is84%and bending strength is0.36MPa.A further study on the binder, high-temperature binder addition amount is40~50wt%, CMC addition amount is10wt%, PVA addition amount is about20wt%.By means of orthogonal test:the more binder, the more porosity of porous ceramic;and the smaller particle size of pore-forming agent, the better pore structure andstrength. EPS grain size less than0.600mm as pore-forming agent, the mass ratio ofandalusite to alumina is80:20, can be prepared of mullite porous ceramic with goodperformance. When sintering temperature is1450℃, pore-forming agent is9wt%, theapparent density is0.52g/cm~3, porosity is83%and bending strength is1.54MPa,thermal shock resistance is4.