From linear to circular economy: Story of the bottom ash

Incineration of municipal solid waste (MSW) with energy recovery is a key component of integrated waste management in the Czech Republic. In 2021, approximately 6 million tonnes of MSW were generated, with around 0.75 million tonnes processed annually in four operating waste-to-energy (WtE) plants. These facilities produce about 0.2 million tonnes of incineration bottom ash (IBA), which contains up to 13 wt.% ferrous and 3 wt.% non-ferrous metals. However, recovery of valuable metals remains limited due to the lack of advanced separation technologies. A detailed case study from the Prague WtE plant confirmed that most recoverable metals are found in particles >2 mm, accessible without intensive comminution. A full-scale metal recovery facility is planned, with expected commissioning in 2026/2027, and the potential to recover up to 2,500 tonnes of metals annually, saving approximately 15,000 tonnes CO₂-eq emissions. In 2021, a new legal framework enabled IBA utilization in road construction, under strict environmental and technical criteria. A pilot project using 1,000 tonnes of IBA demonstrated compliance and feasibility. These developments support broader IBA valorization, aligning with circular economy principles and national climate goals.