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Geology of Ore Deposits

, Volume 56, Issue 7, pp 538–545 | Cite as

The thermodynamics of arsenates, selenites, and sulfates in the oxidation zone of sulfide ores: VIII. Field of thermal stability of synthetic analog of chalcomenite, its dehydration and dissociation

  • E. L. Fokina
  • E. V. Klimova
  • M. V. Charykova
  • V. G. Krivovichev
  • N. V. Platonova
  • V. V. Semenova
  • W. Depmeier
Article

Abstract

The objective of this paper is to study the thermal stability of the synthetic analog of chalcomenite, CuSeO3 · 2H2O, and its dehydration and dissociation, in an experimental context. The study has been carried out by a comprehensive application of thermogravimetry (TG), differential scanning calorimetry (DSC), and high-temperature X-ray diffraction at a temperature range of 25–600°C. It has been established that CuSeO3 · 2H2O dehydrates at 202–264°C in three stages corresponding to the formation of intermediate CuSeO3 · 2H2O and CuSeO3 · 1/3H2O hydrate phases. At 480–595°C anhydrous CuSeO3 breaks down into CuO and SeO2 via the formation of a Cu4O(SeO3)3 phase. Enthalpies of the reactions at each stage of the CuSeO3 · 2H2O dehydration and CuSeO3 dissociation have been determined and their kinetic analysis has been carried out.

Keywords

Differential Scanning Calorimetry Selenite Differential Scanning Calorimetry Curve Synthetic Analog Oxidation Zone 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Effenbergen, H., Die Kristallstrukturen von drei Modifikationen des Cu(SeO3), Ztschr. für Kristallographie, 1986, vol. 175, no. 1/2, pp. 61–72.CrossRefGoogle Scholar
  2. Friedel, C. and Sarasin, E., Reproduction de chalcomenite, Bull. Soc. Min., 1881, vol. 4, pp. 176–178.Google Scholar
  3. Freeman, E.S. and Carroll B., The application of thermoanalitical techniques to reaction kinetics. The thermogravimetric evalution of the kinetics of the decomposition of calcium oxalate monohydrate, J. Phys. Chem., 1958, vol. 62, pp. 394–397.CrossRefGoogle Scholar
  4. Gattow, G., Der Kristallstruktur von Cu2SeO3 · 2H2O (Chalcomenit), Acta Cryst., 1958, vol. 11, pp. 377–383.CrossRefGoogle Scholar
  5. Gmelins Handbuch der Anorganischen Chemie. System-nummer 60, Kupfer, 1958.Google Scholar
  6. Krivovichev, V.G. and Depmeier, W., Selenites and selenates: systems Se-S-H2O, Pb-Se-S-H2O, and U-Se-I-H2O, thermodynamic analysis and geological application, Zap. RMO, 2005, vol. 134, no. 4, pp. 1–14Google Scholar
  7. Krivovichev, V.G., Tarasevich, D.A., Charykova, M.V., et al. Thermodynamics of arsenates, selenites and sulfates in the oxidation zone of sulfide ores: V. Chalcomenite and its synthetic analog, properties and formation conditions, Geol. Ore Deposits, 2012, vol. 54, spec. issue 7 (Zapiski Russian Mineralogical Society), pp. 498–502.CrossRefGoogle Scholar
  8. Larrañaga, A., Mesa, J.L., Lezama, L., et al., Hydrothermal synthesis of Cu(SeO3) · 2H2O: structural characterization, thermal, spectroscopic, and magnetic studies, Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy, 2009, vol. 72, no. 2, pp. 356–360.CrossRefGoogle Scholar
  9. Robinson, P.D., Sen Gupta, P.K., Swihart, G.H., and Houk, L., Crystal structure, H positions, and the Se lone pair of synthetic chalcomenite, Cu(H2O)2[SeO3], Am. Miner., 1992, vol. 77, pp. 834–838.Google Scholar
  10. Vlaev, L.T., Genieva, S.D., and Gospodinov, G.G., Study of the crystallization fields of cobalt (II) selenites in the system CoSeO3-SeO2-H2O, J. Therm. Anal. Calorim., 2005, vol. 81, pp. 469–475.CrossRefGoogle Scholar
  11. Vlaev, L.T., Genieva, S.D., and Georgieva, V.G., Study of the crystallization fields of nickel(II) selenites in the system NiSeO3-SeO2-H2O, J. Therm. Anal. Calorim., 2006, vol. 86, pp. 449–456.CrossRefGoogle Scholar

Copyright information

© Pleiades Publishing, Ltd. 2014

Authors and Affiliations

  • E. L. Fokina
    • 1
  • E. V. Klimova
    • 1
  • M. V. Charykova
    • 1
  • V. G. Krivovichev
    • 1
  • N. V. Platonova
    • 1
  • V. V. Semenova
    • 1
  • W. Depmeier
    • 2
  1. 1.St. Petersburg State UniversitySt. PetersburgRussia
  2. 2.Institut für Geowissenschaften, Abt. Mineralogie-KristallographieUniversität KielKielGermany

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