Aluminium Casting Furnace Energy Efficiency: Recent Improvements in Rio Tinto Aluminium Casthouses

In 2005, Rio Tinto Aluminium started an ambitious program to reduce casting furnace energy consumption in its casthouses. A major reduction step was reached in 2008 by implementing this energy efficiency program in all casthouses, focusing more specifically on the reduction of natural gas consumption (m3 of gas) and specific energy consumption (MJ/t of cast metal). In order to further reduce energy consumption, a new strategy was recently developed and is described in this paper.The main tool of this strategy is a standardized energy performance indicator. This indicator takes into account not only intrinsic furnace operating parameters such as burner efficiency and pressure control but also some specific production characteristics (casthouse layout, temperature of the potroom metal, mass of remelt and mass of alloying ingredients). This indicator allows to adequately compare energy performance between casthouses and to identify best practices and potential improvements. Some industrial applications of this tool are also presented.