ABSTRACT
The furnaces used for melting recycled aluminum generate three products. The first is the molten aluminum, which is cast or transferred to customers. The second is the off-gas, which will be discussed in the next chapter. The third is a semisolid skim removed from the melt surface. This skim, better known as dross, is a mixture of molten aluminum metal and various oxide and chloride compounds. Its composition depends on the choice of melting practice and the amount and composition of fluxes used. Regardless of composition, the processing of dross has always been important. Dross processing can (a) recover the valuable metal and salt content of the dross and (b) minimize the amount of waste material to be disposed of after treatment. The state of the art in dross treatment is much different than 20 years ago and is changing rapidly. This chapter will describe the choices available in dross treatment technology, and the factors determining whether one technology is favored over another.
