PRODUCTION OF LIGHTWEIGHT REFRACTORY

摘要

PROBLEM TO BE SOLVED: To raise the strength by removing bubbles on the surfaces of inorganic fibers in a dispersion containing the inorganic fibers and a boron nitride powder dispersed therein and then baking a molded product of the inorganic fibers and the boron nitride powder at a specific temperature. SOLUTION: This lightweight refractory is produced by dispersing and mixing preferably inorganic fibers with a boron nitride powder in water, carrying out vacuum defoaming, then vacuum forming the defoamed mixture, drying the formed compact and subsequently baking the formed compact at 1,300-1,400 deg.C. The inorganic fibers used are preferably obtained by adding alumina fibers as inorganic fibers for reinforcing to silica amorphous fibers as a main raw material. The vacuum degree when carrying out the vacuum defoaming after mixing the inorganic fiber suspension with the boron nitride suspension is preferably <=-600 mmHg. The resultant lightweight refractory is capable of improving the strength by >=10%. The formed compact obtained by the vacuum forming can be baked to afford the lightweight refractory having <=0.12 g/cm3 bulk density.