METHOD FOR PRODUCING SILICA SLEEVE FOR HEARTH ROLL

摘要

PURPOSE: A method of producing a silica sleeve for hearth roll using submicron-sized amorphous silica powders being more fine than fused silica is provided which imparts moldability to silica slurry and improves sintering. CONSTITUTION: A silica ceramic hearth roll which transfers steel strip at high temperatures continuously is prepared. Thus, their preparation method comprises producing water-based silica slurry by mixing fused silica powders and fumed silica particles in a proper ratio and dispersing in water, uniformly redispersing the silica slurry at a high pH by adjusting the pH of the silica slurry to above pH10, uniformly mixing silica slurry by adding with a pH reducing agent as a coagulant, pouring the free flowing slurry in a mold, drying, calcining, and sintering.