REA plaster
FGD gypsum is gypsum obtained from the exhaust gases from flue gas desulphurisation systems (abbreviation “REA”). The sulfur dioxide contained in the exhaust gases reacts with additionally added limestone to form gypsum.
The gypsum obtained in this way is chemically identical to the naturally occurring gypsum (natural gypsum) . Like natural gypsum, it is primarily used in the gypsum and cement industries to manufacture building materials such as gypsum plaster , plasterboard or gypsum screed . Further areas of application are as fertilizers , soil improvers and for the production of hemihydrate or anhydride .
In modern FGDs, the gypsum is of such high quality and purity and so little pollutant that it can largely or completely replace natural gypsum with the exception of a few special applications (e.g. for medical purposes). This reduces the need to mine the natural gypsum in quarries . Since such a quarry always means an intervention in potentially valuable ecosystems, this reduction is desirable from the point of view of nature conservation.
In the industrialized nations today, FGD gypsum sometimes occurs in quantities that are above demand, so that surpluses have to be disposed of as waste despite the good quality . In lignite-fired power plants that produce large quantities of FGD gypsum, the excess gypsum can be used, for example, to fill open -cast mine holes from which the coal for the power plant comes.
In future - after the coal phase out - REA gypsum will be replaced by natural gypsum.
Individual evidence
- ↑ German construction magazine DBZ 07/2006: Gypsum boards in timber construction ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ a b BUND for Environment and Nature Conservation: Arguments of the gypsum industry against the use of FGD gypsum on www.bund.net (accessed on September 10, 2009).
- ↑ Ministry for the Environment and Nature Conservation, Agriculture and Consumer Protection of the State of North Rhine-Westphalia: Agreement (...) on the legal treatment of (...) FGD gypsum against the background of the Recycling and Waste Management Act at www.umwelt.nrw.de ( Memento des Originals dated December 14, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 732 kB).
