Process and plant for a permanent storage of phosphogypsum

Abstract

A process and the related plant for the permanent deposition of phosphogypsum with simultaneous permanent carbon dioxide sequestration. This process includes a step (i) for decomposition calcium sulfate contained in the phosphogypsum with hydrogen to calcium oxide, sulfur dioxide and water at temperatures between 1.00° and 1.400° C. Thereby, a gas stream containing the sulfur dioxide and the water and a solid stream containing the produced calcium oxide result. In a further step (ii), production of sulfuric acid takes place by converting the sulfur dioxide contained in the gas stream obtained in step (i) to the acid. In step (iii), the calcium oxide contained in the solid stream is carbonized with carbon dioxide to a calcium carbonate at temperatures between 50° and 800° C. to obtain a solid material. Finally, the solid material obtained in step (iii) is deposited in a last step (iv).

Dependencies are inferred from the claim text.