PHOSPHOGYPSUM AS A RAW MATERIAL FOR THE PRODUCTION OF SO₂ AND LIME IN CIRCULATING FLUIDIZED BEDS

Abstract

The primary objective of this research is to investigate the possibility of producing sulfur dioxide and lime from phosphogypsum (PG) in a circulating fluidized bed (CFB) on a pilot scale. Thermal decomposition of PG was conducted in a CFB using anthracite as the reducing agent and fuel at temperatures in the range 900–1100°C. The gaseous decomposition products, which mainly consist of sulfur dioxide, were analyzed using a gas analyzer and X-ray diffraction. The results indicate that the reaction conditions required to produce sulfur dioxide and lime are an air flow rate of 94 m³/h, a temperature of 1100°C, and a PG consumption rate of 120 kg/h. Under optimal conditions, the maximum concentration of sulfur dioxide in the flue gas reached 8.2% (vol. %), and the maximum CaO concentration in the phospholime reached 62.57% (wt. %).

Keywords:

• Anthracite
• Circulating fluidized bed
• Phosphogypsum
• Thermal decomposition

Notes

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