What is chemically real

REA plaster

REA plaster is gypsum, which is obtained from the exhaust gases of 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 mainly 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 FGD, the gypsum is of such high quality and purity and so low in pollutants[1][2]that apart from a few special applications (e.g. for medical purposes) it can largely or completely replace natural gypsum. 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.[2][3]

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 power plants that produce large quantities of FGD gypsum, the excess gypsum can be used, for example, to fill the remaining holes in the opencast mines from which the coal for the power plant comes.

Individual evidence

  1. ↑ German construction magazine DBZ 07/2006: Plasterboard in timber construction
  2. 2,02,1BUND for the environment and nature conservation: Arguments of the gypsum industry against the use of FGD gypsum at www.bund.net (accessed on September 10, 2009)
  3. ↑ 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 Management and Waste Act at www.umwelt.nrw.de