A novel method for processing sodium reduction skimming station residue

Abstract

The aluminium industry often faces financially conflicting challenges where costs are under increasing pressure but more stringent environmental constraints and customer specifications are imposed. Increasingly, smelters are resorting to treatment of aluminium in crucible technologies to reduce alkali and in particular sodium content in the hot metal prior to delivery to the casthouse. The consequence of this process is a residue or skimming waste that can be costly to process and/or dispose of and typically involves some form of landfill. This paper describes how, faced with a large and growing stockpile of skimming waste, Emirates Aluminium (EMAL, also known as EGA A1 Taweelah) used the existing plant to process 100 % of the skimming waste on site with no additional off-site disposal or treatment.