EXPERIENCES WITH GAS SUSPENSION CALCINER ALUMINA

Venugopalan, T.A.

Hindustan Aluminium Corporation Limited (HINDALCO) has installed and commissioned the first ever GAS SUSPENSION CALCINER (GSC) for their Alumina Plant in July, 1986 with a rated nominal capacity of 850 MTPD Alumina. This has been done in the course of their modernization cum expansion programme of the facilities. The Calciner has been designed by Messrs F.L. Smidth & Co. A/S of Denmark and has replaced three conventional Rotary Kilns operating till then.

The comparative properties, both physical and chemical have been discussed for GSC vis a vis Rotary Kilns. Due to change in granulometry and lower Alpha content of the product the Plant's Smelter located at the same site has been experiencing operating problems due to hard crust formation. The problems are being studied and by doing certain modifications in the GSC it has been possible to achieve up to 15 per cent Alpha content against the original 3 to 5 per cent Alpha content. Crusting problems are being further evaluated for possible causes and solutions.