Gypsum is a highly demanded building material. The extraction of the raw material is increasing. Natural sources are diminishing. This is accompanied by interventions in nature. One solution: recycling gypsum-containing construction waste into new materials.

At MUEG Mitteldeutsche Umwelt- und Entsorgung GmbH, gypsum plasterboards that accumulates as construction waste are shredded and separated into three fractions with the help of a machine: cardboard remnants, gypsum granulate and gypsum powder. The gypsum components can then be further processed as recycled gypsum. The facility has the potential to recycle 350,000 tonnes of gypsum per year. This corresponds to about 4 percent of Germany's total annual demand.

To cover further demands, the Weimar Institute of Applied Construction Research gGmbH (IAB Weimar gGmBH) has developed a recycling plant in which construction waste can be processed into new building materials - including gypsum. In the system, mixtures of materials are shredded, scanned by cameras, and separated in a free-fall sorter.

This way, for example, bricks with adhering gypsum can be detected and sorted out through the scanning process. The brick-gypsum mixture is then pulverised and processed in a multi-stage process at high temperatures to produce a porous building material and gypsum powder. The aerated concrete produced from the brick waste is characterised by high strength combined with low weight as well as a high thermal insulation value.
Using renewable energy sources, the high energy demand for the process can also be covered in a climate-neutral way.

The rotary cement kiln plant at IAB Weimar gGmbH was funded by the European Regional Development Fund (ERDF) of the EU and the Free State of Thuringia.

Further information on IAB Weimar gGmbH: https://www.iab-weimar.de
Further information on MUEG Mitteldeutsche Umwelt- und Entsorgung GmbH: https://mueg.de/

On behalf of the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection