Circular economy model of cathode waste processing

The production of aluminium achieved significant step regarding energy efficiency while one of important waste stream remains untreated. Namely, waste, known as Spent Pot Lining (SPL) derives from each individual electrolytic cell, or more precisely from the material of the cathode electrode bath. The SPL stream contributes to about million tons per year of hazardous waste in the world’s smelters production. The carbonaceous content represents 60 % of the whole SPL mass and consists of a great part of graphite. This part of waste represents a great opportunity to harvest its usable material flows. Laboratory tests confirmed the inefficiency of onestep treatment separation of different impurities as needed. With the help of laboratory investigations, the possibilities of material utilization of SPL have been studied. Comprehensive aspects of preliminary inquiry allow placing a new model for the preparation of products that satisfy customer’s needs. This approach improves process economics and effectively close the loop of mass flow.