Environmentally friendly and economical: recycling management in practice
Together with our partner company Otto Dörner, Xella Technologie- und Forschungsgesellschaft has started a project to reuse aerated concrete residues from mixed construction waste for the renewed production of aerated concrete.
At Otto Dörner, the demolition material delivered from the construction sites is first crushed and processed and sorted in a multi-stage process. So-called impurities are separated from the aerated concrete using a wide variety of processes. This also includes the sink-swim separation process, which is characterised by a high degree of selectivity compared to other density sorting processes. In the water bath, substances with a higher density than water sink to the ground. Substances with a lower density, such as wood, plastics or cellular concrete, remain on the surface and are separated with rakes. The final sorting and thus the provision of pure aerated concrete, which from a chemical-mineralogical point of view is equivalent to aerated concrete flour from freshly produced aerated concrete, is finally carried out by hand on the reading belt. The remaining pure aerated concrete can then be returned to the production process. Other possible uses include preparation as cat litter or as a binding agent for oil or other chemical liquids. Thus, recycling management is not a theoretical term for us, but already integrated into our work processes. Aerated concrete residues from factories, construction sites or even demolition material can be returned to production or new products in various ways. But in the future we will continue to work on developing new possibilities and procedures for the avoidance of waste and the recyclability of aerated concrete residues.