NEW TWO-STAGE CALCINATION TECHNOLOGY

Ilievski D

Alcoa has been investigating and developing technologies for reducing energy consumption and GHG emissions in alumina refining. This paper reports the development of a novel two-stage calcination technology that has the potential to reduce plant energy consumption by up to ~ 1.1 GJ/t and potentially allows the recovery of an additional 0.4 t of condensate per t of SGA processed.

The two-stage calcination technology is a variation of the pressure calcination technology developed by Alcoa in the 1980s [1] and has a number of significant advantages over its predecessor. The paper discusses the results from pilot test work, flow sheet modelling and preliminary design.