Abstract
Black dross or salt slag is the slag that results from secondary aluminum melting, where aluminum alloys made with reclaimed or recycled aluminum are supplemented with prime aluminum as needed. The reclaimed metal feed can be from either industrial waste or postconsumer scrap, with the metal typically melted in a gas fired furnace with salt. The salt is added to flux the metal and forms a protective slag on top during melting. The resultant slag is an amalgam of salt, alloy, and partially or fully oxidized/nitrided metal. After removal of the liquid metal, the slag is further processed to remove any additional metal entrained within, after which any remaining slag/salt material is landfilled. Evergreen Alumina has a patented method to process this currently landfilled material and extract the soluble salt to return it to the secondary aluminum producer for use. The process also produces other feedstocks, including one that can be transformed into a high temperature resistant oxide-based refractory ceramic aggregate. This work will review the process and benefits of removing the slag/salt from landfill disposal and the potential properties and uses of a ceramic refractory aggregate output via this strategy.