Manufacture of ammonium sulfate fertilizer from FGD-gypsum. Technical report, March 1--May 31, 1995

Goal is to assess technical and economic feasibility for producing fertilizer-grade ammonium sulfate from gypsum produced in limestone flue gas desulfurization (FGD). This is the 1st year of a 2-year program among Illinois State Geological Survey, University of Illinois (Urbana-Champaign), Allied-Signal, Marketing Chem. Process Inc., Henry Fertilizer, Illinois Power Co., and Central Illinois Public Services. In previous quarter, chemistry and process conditions were reviewed and a reactor system set up and used to conduct laboratory tests. FGD-gypsum from Abbott power plant was used. The scrubber, a Chiyoda Thoroughbred 121 FGD, produced a filter cake (98.36% gypsum and < 0.01% CaSO{sub 3}). Conversion of FGD- gypsum to ammonium sulfate was tested at 60-70{degree}C for 5-6 hr. Yield up to 82% and purity up to 95% were achieved for the ammonium sulfate production. During this quarter, more bench-scale experiments including a mass balance analysis were conducted; a yield up to 83% and up to 99% purity were achieved. A literature survey was completed and a preliminary process flow sheet was developed. Economics of the process is being estimated