Novel Dual Cycle Combined Aluminium Dross Stirrer and Pressing System

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Aluminium (Al) due to its properties is the 2nd most used metal after iron (C KrammerAlHandbook 1999).Al dross represents a residue from primary & secondary Al production. Drosses are classifiedaccording to their metal contents. White dross is higher metal Al content & is produced fromprimary & secondary Al smelters. Black dross has a lower metal content & is generatedduring Al recycling (secondary industry sector). White dross may contain from 15% to 70%recoverable metallic Al & it comprises a fine powder from skimming the molten Al. Blackdross typically contains a 15% or less aluminium with a mixture of Al oxides & slag. (HwangJ Y et al 2006).Apart from Al metal, dross may also contain other chemical compounds eg Al203, AIN,Al4C3, MgF2, NaAlCl4, S102 MgO. With total global Al production at 62m tonnes (withclose to 26m tonnes from recycled) increase to around 97m tonnes (39m from recycled)(Organisation of European Al Recycling Industry 2013) by 2020.Approximately, up to 4 million tonnes of white dross & more than a million tonnes of blackdross are reported throughout the world each year, & around 95% of this material is landfilled(Journal of Minerals & Materials 2012 Vol 5).The problem for Al industry is to develop a means of recovering as much molten liquid fromAl from the dross whilst still in the hot form (830°C-900°C) on removal from the furnace.Secondary recyclers are no longer providing acceptable value in dross recovery. Only about40% of the metal recovery is passed on to the customer & is now common practice. In the FarEast & BRIC Countries, secondary recycling services are often not available. Altek haveidentified a unique dual cycle stirring/pressing process which could dramatically increase thelevel of Aluminium recovery on site.