Acta Metall. Sin.

The problems related to the product strength and fine particle content are the main tasks to be solved in sandy alumina production. Carbonization product, AI(OH)(3), was investigated through the application of additives to sodium aluminate liquors. A systematic study was made of the effects and mechanism of surfactants on product median diameter and attrition index quantitatively. It has been determined that some appropriate additive at certain concentration can significantly decrease the fine particle content, enhance the agglomeration process, and improve the product strength. For instance, additive CF2 at 200 mL/L increases the mean particle size by about 12 mum, decreases the content of particles with less 45 mum by 17% and the attrition index by 10% respectively. The crystal morphology indicates that the additives can accelerate the aggregation and inter-growth of crystal units, as a result, the product Al(OH)(3) presents a mosaic crystal structure close to global shape.The problems related to the product strength and fine particle content are the main tasks to be solved in sandy alumina production. Carbonization product, AI(OH)(3), was investigated through the application of additives to sodium aluminate liquors. A systematic study was made of the effects and mechanism of surfactants on product median diameter and attrition index quantitatively. It has been determined that some appropriate additive at certain concentration can significantly decrease the fine particle content, enhance the agglomeration process, and improve the product strength. For instance, additive CF2 at 200 mL/L increases the mean particle size by about 12 mum, decreases the content of particles with less 45 mum by 17% and the attrition index by 10% respectively. The crystal morphology indicates that the additives can accelerate the aggregation and inter-growth of crystal units, as a result, the product Al(OH)(3) presents a mosaic crystal structure close to global shape