Continuous hydrothermal synthesis method of alumina particles

摘要

PROBLEM TO BE SOLVED: To obtain fine alumina particles in a relatively short time. ;SOLUTION: Aluminum hydroxide or alumina hydrate and water or an aqueous solution of an alkali are made into a slurried state to give a slurry. The slurry and water are used, water is heated to a saturated steam temperature or higher than it and is supplied while pressurizing to a saturated steam pressure or lower than it. On the other hand, the slurry is supplied at a saturated steam temperature while pressurizing to the saturated steam pressure or higher than it. The slurry and the water are sprayed and mixed while adjusting the blending ratio so as not to make the mixture ≤ the saturated steam temperature. After the synthesis, a hydrothermal synthesis is carried out at a reaction part at a high temperature under high pressure conditions to continuously produce alumina particles. The high temperature and the high pressure conditions are ≥350°C and ≥50 kgf/cm² and the slurry concentration is 1-50 wt.%.;COPYRIGHT: (C)1999,JPO