BitKOIN - CO2-reduced binding agent through thermochemical conversion of mineral wool waste combinations
01.03.2023 – 28.02.2026 (36 months)
In the course of the project RecyMin, the Montanuniversitaet of Leoben (MUL), Porr Umwelttechnik GmbH (PUT) and Lafarge Zementwerke GmbH (LAF) developed a technology concept for recycling mineral wool waste and experimentally confirmed individual process steps at component level.
The project showed that the recycling of mineral wool waste is the most promising option in the midterm, compared to investigated alternatives, i.e. until the landfill ban on 01.01.2027. At the same time, MUL and Graz University of Technology (TUG) developed a technology concept for the production of binders by combining various mineral wastes as part of the Upcycling Slag Binder project.
The motivation of BitKOIN is to combine the two technology concepts to develop the "Huettensand 2.0" and to proof the feasibility at system level. In this way, a recycling path for mineral wool waste and a substitute for GGBS can be developed. Which is of increasing importance since GGBS will no longer be produced in the future due to the decarbonization of the steel industry and the associated exit from the blast furnace route.
Contents and goals
The contents and objectives of BitKOIN are the functional verification of a concept for the production of "Huettensand 2.0" by thermochemical conditioning of mineral wool waste with other residual materials and the development of a binder. This is followed by a survey of the structural engineering approval requirements and an evaluation of the sustainability of the developed binding agent in comparison with the status quo and the impending scenario after the decarbonization of the steel industry.
In BitKOIN, samples of mineral wool waste and other mineral wastes, that are required as corrective substances to achieve the desired chemical composition, are first sampled and characterized chemically, mineralogically and physically and are additionally classified according to waste regulations. This is followed by impurity separation and mechanical conditioning of the materials to increase purity and density. The various materials are introduced in a large number of potential mixture variants as a raw material into an electrically heated melting process. The melt is granulated during cooling. The granules produced are characterized concerning their suitability as binder components, optimized by adapting the melting process and combined with other binder components to optimize resource consumption and efficiency. The environmental impact of the investigated scenarios will be analyzed by life cycle assessment and evaluated concerning their sustainability.
The results of BitKOIN shall enable the implementation of the landfill ban for mineral wool waste planned for 01.01.2027 by a recycling rate of mineral wool waste of 99 %. Selected residual material streams are to be returned to anthropogenic material cycles through an innovative recycling process, whereby pollutants are immobilized and hazard-relevant features are destroyed. Furthermore, a latent-hydraulic substitute for GGBS is being developed to reduce resource consumption by the Austrian binder industry and increase resource efficiency. The "Huettensand 2.0" developed in the project helps to reduce the CO2 emissions of the binder industry since no CO2 is released during its production due to electrical heating and the absence of carbon-based reducing agents, in contrast to GGBS production.
Dr. mont Philipp Sedlazeck
Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben
Partners of the project consortium
- IB Engineering GmbH
- Lafarge CTEC GmbH
- PORR Umwelttechnik GmbH
- Rohrdorfer Umwelttechnik GmbH
- Saint Gobain Austria GmbH
- Graz University of Technology