Abstract: A method for treating produced gypsum and, in particular, a method for treating flue-gas desulfurization gypsum forms highly active, modifiable gypsum binders of high strength with simultaneously drying, deagglomerating and dehydrating. Pursuant to the invention, produced gypsum (flue-gas desulfurization gypsum), with a particle size ranging up to 200 .mu.m, to which 10% by weight of milled natural gypsum is optionally added, is dehydrated at a material temperature of 335.degree. to 363.degree. K. and at a pressure ranging from 2.5 to 8 kpa, the dehydration being concluded when anhydrite III constitutes 50% to 100% by weight.
Type:
Grant
Filed:
February 12, 1991
Date of Patent:
December 8, 1992
Assignee:
Ruedersdorfer Zement GmbH
Inventors:
Paul Clemens, Ellen Wanzura, Guenter Fietsch, Helmut Meyer, Detlef Kunze, Hans-Juergen Hartmann, Wolfgang Schnelle