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Geochemistry International

, Volume 56, Issue 4, pp 397–401 | Cite as

Calorimetric Study of Natural Anapaite

  • L. P. Ogorodova
  • L. V. Melchakova
  • M. F. Vigasina
  • D. A. Ksenofontov
  • I. A. Bryzgalov
Short Communications

Abstract

The thermochemical study of natural hydrous calcium and iron phosphate, anapaite Ca2Fe(PO4)2 · 4H2O (Kerch iron ore deposit, Crimea, Russia), was carried out using high-temperature melt solution calorimetry with a Tian-Kalvet microcalorimeter. The enthalpy of formation of the mineral from elements was obtained to be Δ f Hel°(298.15 K) =–4812 ± 16 kJ/mol. The values of the standard entropy and the Gibbs energy of anapaite formation are S°(298.15 K) = 404.2 J/K mol and Δ f Gel°(298.15 K) =–4352 ± 16 kJ/mol, respectively.

Keywords

thermochemistry Calvet microcalorimetry enthalpy of formation anapaite 

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Copyright information

© Pleiades Publishing, Ltd. 2018

Authors and Affiliations

  • L. P. Ogorodova
    • 1
  • L. V. Melchakova
    • 1
  • M. F. Vigasina
    • 1
  • D. A. Ksenofontov
    • 1
  • I. A. Bryzgalov
    • 1
  1. 1.Geological FacultyMoscow State UniversityMoscowRussia

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