IMPROVED BAUXITE RESIDUE SETTLER PERFORMANCE AT WORSLEY ALUMINA

Kahane, R.B. and McRae, C.

Western Australian alumina producers use bauxite from the Darling Scarp which has low extractable alumina content by world standards and consequently contend with a bauxite residue to product ratio of approximately 2:1.

Add to this the fact that the Worsley production rate has increased by 65% over the last six years without major capital upgrade of the bauxite residue settling equipment, and it becomes clear that major improvements in residue handling technology have been achieved.

The ability to handle this increase in bauxite residue has been due to better understanding of feedwell flow patterns, improved computer control loops, the use of new generation flocculants and innovative development of their applications while always adhering to basic mixing, shearing and flocculation rules.

This paper describes the use at Worsley of new flocculants, improved settler process control and the feedwell flow pattern determination.