Circular economy strategy for mineral wool waste - potential secondary raw material for Alkali Activated Materials (AAMs)

Abstract

By recycling and reusing materials to close the resource cycle and move towards a circular economy, waste can be significantly reduced. As the main source of waste in the EU, the construction industry needs to both improve the recycling rate and find alternatives with a lower carbon footprint. Mineral wool waste is often considered non-recyclable, but the disposal of landfill will no longer be suitable in the medium to long term. At the same time, mineral wool can react with the alkaline activator to generate AA concrete, which can be used as a substitute for cement concrete. This study is conducted on building typology to track mineral wool from individual building levels in Swiss dwellings over time and space. Afterward, GIS was used to select the suitable location for establishing a mineral wool recycling plant, considering accessibility and transportation distance. Finally, using the LCA framework, emissions are calculated through the production phase. The results revealed that the mineral wool stock shows an increasing trend from 2020 to 2035, and can provide a stable supply. In addition, using mineral wool waste to produce AA concrete can effectively reduce CO2 emissions. Therefore, mineral wool waste has the potential to become raw material for AAMs. Recycling factories can be set up in Zug, Zurich, and Bern as a priority.