Process-based cost assessment of electrochemical metals recovery from municipal solid waste incineration ash

Municipal solid waste incineration (MSWI) ash, a byproduct of incineration with energy recovery from municipal solid waste (MSW) materials, is often disposed of in landfills despite containing valuable metals. Previous efforts to recover metals from MSW have faced processing challenges in achieving qualities high enough to retain market value. This work evaluates the economic feasibility of a metal recovery process capable of extracting high-purity metals and metal hydroxides via a combination of electrolytic refining, chemical precipitation, and onsite regeneration of reagents. We estimate cash flows and capital investment for a representative facility processing 40,000 metric tons of MSWI ash residues per year. Operating cash flows yield net revenues of up to $28/tonne ash, contingent on generous electricity pricing and the presence of copper, zinc, and magnesium in regional MSW. Discounted cash flow analysis demonstrates initial investment may be recovered within a payback period of 13 years despite a high cost high relative to contemporary resource recovery projects from MSWI ash. Findings show resource recovery from waste to be profitable over annual operation, yet in need of financial incentives such as credits or subsidies to reduce the burden of initial investment.