Designing a Custom Metallurgical Flowsheet to Maximize Metal and Energy Recovery from E-waste Materials All the Way to Low Metallic Residues

Secondary recycling is gaining global attention due to stricter greenhouse gas targets, limited availability of high-grade material, and the drive to conserve copper and associated metals to avoid sending considerable amounts to landfill. Flowsheets in secondary recycling are mainly comprised of raw material preparation and management, metallurgical operation units, off-gas treatment systems, and product streams. This paper discusses process flowsheets and technology offerings across the full production chain suitable to process flexible raw material feeds ranging from high-value e-waste to low metallic content residues that can be integrated into an existing primary and/or secondary smelter or treated as a stand-alone process. Material management and sampling is an imperative component of this flowsheet to ensure a comprehensive mass balance and effective pretreatment prior to processing in metallurgical units. All components of the input material can be processed in a continuous or batch-wise operation with limited primary energy sources, often replaceable to a certain extent with secondary energy sources. The metallurgical process can be selected based on the type of recycled metal-containing material (both pyrometallurgy and hydrometallurgy) along with specific technology offerings (e.g., top-blown rotary converter, top submerged lance furnace). Off-gases produced can be further treated in post-combustion systems, heat recovery systems, and off-gas management systems. Flexible product streams include steam from a waste heat boiler to be used in local and district plant heating, electricity production, various copper containing products, as well as granulated slag and anode slimes.