The, K., Boulanger, C., Tremblay, L., Clegg, R., Girouard, S. and Carruthers, A.

Stringent pollution regulations and the increasingly competitive nature of the market demand that fines generated during the alumina calcination operation must all be collected and used in an environmentally and economically acceptable manner. Alcan has successfully developed a process for recycling ESP dust to the potrooms. This paper describes the novel Alcan ESP dust micro-granulation technology(1), its concept and process, as well as fundamental chemical reaction involved. Results of tests on the production of ESP dust micro-granules on a semiindustrial scale and on the quality of these micro-granules with respect to calcination and electrolysis will be presented and discussed.