Metal recovery from municipal solid waste incineration fly ash as a tool of circular economy

Municipal solid waste contains metals in various amounts in many cases. The metals become part of municipal solid waste incineration fly ash and can be recovered. The article describes the role of recovered metals in the circular economy based on the analyses of metal recovery, the triple layered business model, and the SWOT analysis. Based on the results of the examination of the strengths, weaknesses, opportunities, and threats, setting them in the strengths-threats quadrant, the positive internal factors (quantified by +1.11) meet the negative factors in the environment (quantified by −0.62). The strength – heavy metal recovery, reduction of toxicity, risk reduction (due to lowering the toxicity), and re-use of process material, where possible, overcome the threats including the sorting of municipal waste in most countries, remediation of empty mines by filling with fly ash, soil, water and air contamination, land take, and social acceptance of the recycled materials for a successful recovery of metals from municipal solid waste incineration fly ash. Yet, not only the economic and environmental view is important but also the social aspect of metal. The circular representation of metal recovery is shown and the questions for the future are outlined.