Journal of Thermal Analysis and Calorimetry

, Volume 80, Issue 3, pp 655–658 | Cite as

Monitoring of the evolved gases in apatite-ammonium sulfate thermal reactions

  • Kaia Tõnsuaadu
  • J. Pelt
  • Maria Borissova


Thermal reactions in natural fluorapatite or fluorcarbonate apatite and ammonium sulfate mixtures with mole ratio 1:4 at calcination up to 500°C were studied by simultaneous thermogravimetry and FTIR analysis of the evolved gases. The composition of natural apatite has little impact on the release of NH3. Upon the evolution of NH3 nitrous oxides were found in minor amounts. The release of SO2 at temperatures above 400°C is more intensive and occurs at lower temperatures in the case of fluorapatite than of carbonate containing apatites. Evolution of CO2 starts at 250°C with maximum at 350-360°C.

FTIR evolved gas analysis apatite CO2 N2O (NH4)2SO4 NH3 SO2 


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Copyright information

© Springer-Verlag/Akadémiai Kiadó 2005

Authors and Affiliations

  • Kaia Tõnsuaadu
    • 1
  • J. Pelt
    • 2
  • Maria Borissova
    • 3
  1. 1.Tallinn University of Technology
  2. 2.Tartu Observatory
  3. 3.Tallinn University of Technology

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