Circular economy strategy for mineral wool wastes : 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. At the same time, cities and regions offer opportunities to practice circular economy. 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 alkali activated concrete (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, Geographic Information System (GIS) was used to select the suitable location for establishing a mineral wool recycling plant, considering accessibility and transportation distance. Finally, using the life-cycle assessment (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 alkali-activated materials (AAMs). Recycling factories can be set up in Zug, Zurich, and Bern as a priority. The recycling of mineral wool can be seen as a practical application of the circular economy strategy in the framework of urban planning.