中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 12 No. 6 December 2002 |
（1. College of Chemistry and Chemical Engineering, Lanzhou University,
Lanzhou 73000, China;
2. Colledge of Chemistry and Chemical Engineering, Central South University,
Changsha 410083, China）
Abstract:The effect of 20kHz ultrasound on alumina hydrate precipitation from seeded sodium aluminate solution was studied. Compared with alumina hydrate precipitation without treatment of ultrasound, the precipitation time is reduced from 30h to 15h when the precipitation ratio is 45% under 20kHz ultrasound. Furthermore, agglomeration is increased and the growth rate of alumina hydrate is increased under 20kHz ultrasound by comparing the crystal size distribution and the SEM photographs. As a result, the average size of alumina hydrate is increased by 3.7μm. The structure of product is not changed according to the results of X-ray powder deflection.
Key words: ultrasound; alumina hydrate; induction time; agglomeration; crystal growth
