Elemental sulfur recovery from FGD gypsum and calcium cyclic utilization in coal-fired power plants

• Published in: Journal of thermal analysis and calorimetry Vol. 147; no. 24; pp. 14115 - 14121
• Main Authors: Tan, Hongbin, Ye, Min, Su, Xuemei, Ma, Xiaoling, Dong, Faqin, Yang, Feihua
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2022; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Aqueous solutions; Calcite; Calcite crystals; Calcium sulfides; Carbon dioxide; Carbonates; Chemistry; Chemistry and Materials Science; Coal-fired power plants; Electric power-plants; Flue gas; Gypsum; Hydrogen sulfide; Inorganic Chemistry; Irregular particles; Limestone; Measurement Science and Instrumentation; Oxidation; Physical Chemistry; Polymer Sciences; Power plants; Roasting; Sulfur; Hydrogen sulfide; Elemental sulfur; Cyclic utilization; FGD gypsum; Calcium sulfide
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-022-11724-7

Flue gas desulfurization (FGD) gypsum mainly contains gypsum, which comes from the FGD by using lime or limestone. The effects of calcining temperature and time on calcium sulfide preparation were explored. The gypsum completely decomposed into calcium sulfide by calcining at 900 °C for 30 min. The effect of time on CaS and CO 2 reaction were also explored in aqueous solution. The main phase was calcite phase after reaction 6  h, with nearly cubic particles and 1–2 µm in diameter, which calcite can be reused in FGD process. Hydrogen sulfide was produced when CaS reacted with CO 2 . And then, irregular particle and pellets of elemental sulfur, with 0.5–5 μm in diameter, were obtained by the H 2 S oxidation in Fe(III) chelate solution.