Characterization of the product of the thiosulfate process for desulfurization of flue gases

Journal Article · Sun May 01 04:00:00 EDT 1994 · Industrial and Engineering Chemistry Research; (United States)

DOI:https://doi.org/10.1021/ie00029a011· OSTI ID:7202322

Gadalla, A M; Gupta, A ^[1]

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1. Texas A M Univ., College Station, TX (United States). Chemical Engineering Dept.

X-ray diffraction, infrared spectroscopy, thermal analysis, scanning electron microscopy, and particle size analysis were used to characterize the product of the thiosulfate process. It was found to consist of a mixture of a solid solution of calcium sulfate in calcium sulfite hemihydrate, calcium sulfate dihydrate, and calcium carbonate. Reactions taking place on heating the byproduct were identified in oxidizing and reducing atmospheres. Pure calcium sulfite hemihydrate as well as solid solutions of CaSO[sub 4] in CaSO[sub 3] [center dot] (1/2)H[sub 2]O with different sulfate concentrations were synthesized in the laboratory. Thermal analyses of pure solid solutions proved that the higher the sulfate content, the higher is the dehydration temperature. Accordingly, taking SO[sub 4][sup 2[minus]] in solution increases the stability of the byproduct. Above the solubility limit, thermal analysis detected the formation of gypsum which precipitated as a second phase.

• OSTI ID: 7202322
• Journal Information: Industrial and Engineering Chemistry Research; (United States), Journal Name: Industrial and Engineering Chemistry Research; (United States) Vol. 33:5; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

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ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CALCIUM SULFATES
CARBON COMPOUNDS
CARBONATES
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CONTROL
DESULFURIZATION
FLUE GAS
FOSSIL-FUEL POWER PLANTS
GASEOUS WASTES
OXYGEN COMPOUNDS
POWER PLANTS
PROCESS CONTROL
SLUDGES
SULFATES
SULFUR COMPOUNDS
THERMAL POWER PLANTS
WASTE PRODUCT UTILIZATION
WASTES