EFFECTS OF POWER ULTRASOUND ON PRECIPITATION PROCESS OF SODIUM ALUMINATE SOLUTIONS

摘要

Sodium aluminate solutions for alumina production have been ultrasound treated to enhance the seeded precipitation in a laboratory Bayer process. Higher precipitation ratio was found with ultrasound treated solutions than those without ultrasound. More new nuclei are observed on the surface of gibbsite from precipitation process with ultrasound. Particle size distribution of gibbsite varies with ultrasound power level and processing time. More fine fractions are found with ultrasound than without ultrasound. Ultrasound can improve the precipitation efficiency and promote growth of gibbsite.