ESP DUST AGGLOMERATION PILOT PLANT

Clegg, R.L., Boily, H., Boulanger, C., and Parent, L.

ESP dust is normally less than 20 µm. This size fraction in metallurgical alumina has been shown to contribute to dust emissions at smelters, particularly in wet-scrubbed smelters. Some smelters have also claimed an increase in electric current efficiency from a reduction in %-20 µm in their alumina feed. A process was developed in the laboratories of Alcan International Ltd. in Jonquière to granulate ESP dust. Using this process 25 t of granules were used as a portion of the feed in a flash calciner and in a smelter pot. These tests were successful, but the process equipment used was inadequate for a full scale, fully automated production of ESP dust granules. This paper describes the development of a fully automated, prototype agglomeration unit at Alcan's Vaudreuil Works' alumina Calcination Centre.