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  • 1 Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, China
  • | 2 Department of Chemical Engineering, Ningbo University of Technology, Ningbo 315016, China
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Abstract

The dehydration behaviors of FGD gypsums from three power plants were investigated at N2 atmosphere (autogenous and negligible partial pressure of water, ) in non-isothermal and isothermal condition. The dehydration of gypsum proceeded through one step, i.e., CaSO4·2H2O → γ-CaSO4 (γ-anhydrite) or two steps, i.e., CaSO4·2H2O → CaSO4·0.5H2O (hemihydrate) → γ-CaSO4 depending on temperature and . The discrepancies of three FGD gypsums on dehydration behavior were very likely due to the different crystalline characteristics (size and habit) and impurities, such as fly ash and limestone. Experimental data of non-isothermal analysis have been fitted with two ‘model-free’ kinetic methods and those of isothermal analysis have been fitted with Avrami and linear equation. The apparent empirical activation energies (Ea) suggest that the transition from gypsum to hemihydrate is mainly controlled by nucleation and growth mechanism, while the transition from gypsum to γ-anhydrite is mostly followed by phase boundary mechanism.

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  • SJR Hirsch-Index (2019): 87
  • SJR Quartile Score (2019): Q3 Condensed Matter Physics
  • SJR Quartile Score (2019): Q3 Physical and Theoretical Chemistry
  • Impact Factor (2018): 2.471
  • Scimago Journal Rank (2018): 0.634
  • SJR Hirsch-Index (2018): 78
  • SJR Quartile Score (2018): Q2 Condensed Matter Physics
  • SJR Quartile Score (2018): Q2 Physical and Theoretical Chemistry

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Journal of Thermal Analysis and Calorimetry
Language English
Size A4
Year of
Foundation
1969
Volumes
per Year
4
Issues
per Year
24
Founder Akadémiai Kiadó
Founder's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
Publisher Akadémiai Kiadó
Springer Nature Switzerland AG
Publisher's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
CH-6330 Cham, Switzerland Gewerbestrasse 11.
Responsible
Publisher
Chief Executive Officer, Akadémiai Kiadó
ISSN 1388-6150 (Print)
ISSN 1588-2926 (Online)

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