The theoretical maximum of mineral wool that could unlocked for exploitation is 2.5 Mt/year (the current formation rate) – that is also the amount of material, which strongly underexploited. Although this is only 0.2% of all CDW, it takes disproportionally large space due to low density and landfilling is getting increasingly expensive (expected cost will generally exceed 100 €/t of landfilled waste in the near future). Furthermore, the amount of mineral wool waste is expected to keep increasing worldwide, due to more stringent energy regulations: better insulation is one of the easiest ways to reduce the total environmental impact of buildings in cold and warm climates alike. The WOOL2LOOP project aimed to close this material loop by introducing novel technologies, adopting new concepts and value chain collaboration to CDW sorting, pre-treatment, and processing up to novel construction materials, such as:.
• pre-demolition audit
• on-site analysis with time-gated Raman spectroscopy and handheld XRF technology
• smart robotized demolition
• compression, baling, shredding, pre-processing milling technologies to achieve needed particle size
• alkali-activation (i.e. geopolymerization) technology to convert reactive silica and alumina of the mineral wool into new building material products.
The overall objective of the WOOL2LOOP project was and is still to divert mineral wool as CDW from landfilling and to develop its utilization into novel applications, meanwhile securing the access to sustainable, alternative, circular raw materials for the construction industry in the future.
A broad selection of products were produced in large-scale pilots from relatively low to high value products: precast concrete elements, pavement slabs, facade elements, acoustic panels, dry concrete, floor screed and 3D-printing equipment. Geographically consortium covered 9 countries within the EU and 14 partners from global large construction material producers, research institutes and innovative SME. Environmental, health, safety (EHS) and economic aspects were considered throughout the project. There is a strong business potential in the WOOL2LOOP concept, not only because of constantly increasing landfilling costs of mineral wool as economic driver for the project, construction material industry is more active than ever in adoption of alternative circular raw materials replacing CO2 -intensive binder systems like OPC. The key impacts of the project beyond academic outputs are 6 patent applications and industrial partners’ conviction to WOOL2LOOP circular concept. Product manufacturers are investing, investigating the concept up-scaling in their own industrial set-up as well testing and finalizing final recipes while also addressing learned (by today resolvable) challenges. The project started on 1st June 2019 and ended on 30th of November 2022.