The importance of mineralogy for a circular economy of the construction sector – examples from the ReMin funding initiative

One of the challenges on the way towards a more sustainable future is the transition from linear to circular economy (CE). The need to conserve and substitute primary raw materials wherever possible has driven research and development to study the potential of wastes and residues as important resources. The construction sector, in particular, has great potential to reduce parts of its high primary raw material demand by using mineral residues from various sources.In the presented funding initiative “ReMin” (“Ressourceneffiziente Kreislaufwirtschaft ─ Bauen und mineralische Stoffkreisläufe“) 16 research projects deal with resource efficient CE approaches. They aim to use construction and demolition wastes, metallurgical slags, incineration bottom ashes (IBA), mine tailings and other residues for the development of new construction materials. In this context, the investigation of the mineralogy and chemistry of the materials and processes is fundamentally important. Geoscientific aspects within the projects include e.g. the understanding of cement-clinker formation from thermally treated slags, the efficient separation of metallic and non-metallic particles in the fine fractions of IBA or mine tailings and the species and chemical bonding and behavior of heavy metals in waste streams. Other topics are the safe detection and separation of asbestos in mixed construction wastes and the investigation of the recycling potential of e.g. alternative gypsum sources. The accompanying research project “TReMin” with partners from CUTEC, Fraunhofer IWKS and BGR aims to support those research actions by networking and transfer of the results within and beyond ReMin and on a national and European level.