Slide Background
Slide Background

ON AGGLOMERATION OF ALUMINA CALCINATION FINES

Hall, J. Barton, T. Robson, B.

There is an increasing focus by industry on improving the handleability of alumina fines. Agglomeration is recognised as a means to improve fines handling by dramatically improving flowability and de-dusting. The success of agglomeration depends on the "bridge" between the particles being compatible with both the particles to be agglomerated and the process for which the agglomerates are intended.

This paper describes the use of two binding systems - inorganic and organic - to achieve the agglomeration of alumina fines in a spray drying process. In both cases 7mm alumina particles were agglomerated to a product size in the range 50-150mm. The inorganic system, incorporating 5% binder addition, provided good attrition resistance, control over agglomerate size, acceptable surface area and a-alumina properties. The organic system provided acceptable handling characteristics, in terms of attrition resistance and flowability time, at binder levels below 1.5%.

In operations with less stringent requirements on granule strength, the binder level may be reduced futher. The two binding systems have since been patented.