USA Process for preparing calcium sulfate ...
The process for preparing calcium sulfate anhydrite II by heating a flowable powder of flue gas gypsum moistened with less than 20% by weight, and preferably with from 7 to 17% by weight, of diluted sulfuric acid, wherein the sulfuric acid content is from to 7% by weight, and preferably 1 to 3% by weight of sulfuric acid, based on the total mixture, is carried out by that the total mixture ...