Effect of Mechanically Activated Seeds on the Agglomeration Process of Supersaturated Sodium Aluminate Liquors

摘要

Crystal seeds of gibbsite are added into supersaturated sodium aluminate liquors to enhance the precipitation process. The effect of normal seeds and mechanically activated seeds on the agglomeration process was investigated contrastively. Results show that the precipitation ratio of supersaturated sodium aluminate liquors is 6.8% higher, and the agglomeration ratio of gibbsite particles is 1.4 higher with the addition of mechanically activated seeds in the seeded agglomeration process. As the agglomerates of mechanically activated seeds have irregular shape and high activity, they may probably turn into gibbsite particles with more satisfactory size and intensity by further crystal growth. Investigations show that mechanically activated seeds own larger specific surface area and solid-liquid interface with sodium aluminate liquors because of their smaller particle size. And they have more new fracture planes of high activity and more lattice distortion. As a result, seeded agglomeration process can be enhanced with the addition of mechanically activated seeds.