Advertisement

Russian Journal of Inorganic Chemistry

, Volume 62, Issue 6, pp 843–853 | Cite as

Na2SO4–NaCl–H2O system with a binary homogeneous critical point: Phase equilibria at 475–520°C and to 130 MPa

  • M. A. Urusova
  • V. M. Valyashko
Physicochemical Analysis of Inorganic Systems

Abstract

Phase equilibria were studied at temperatures 475–520°C and a pressure to 130 MPa in the ternary system Na2SO4–NaCl–H2O with boundary binary subsystems of two types. In type 1 subsystems (the NaCl–H2O subsystem in this work), there are no critical phenomena in saturated solutions. Type 2 subsystems (the Na2SO4–H2O subsystem in this work) have terminal critical points p (G = L – \({S_{N{a_2}S{O_4}}}\)) and Q (L1 = L2\({S_{N{a_2}S{O_4}}}\)). It was shown that the ternary system contains two regions of three-phase equilibria ((G–L–S) and (L1–L2–S)), divided by a two-phase fluid region (F – \({S_{N{a_2}S{O_4}}}\)), and two types of monovariant critical curves ((G = L – \({S_{N{a_2}S{O_4}}}\)) and (L1 = L2\({S_{N{a_2}S{O_4}}}\))). With increasing temperature, these three-phase regions approach each other until the two-phase fluid equilibrium vanishes and the monovariant critical curves meet at a binary homogeneous critical point (G = L–S ⇔ L1 = L2\({S_{N{a_2}S{O_4}}}\)) at a maximal temperature of ~495°C and a pressure of ~75 MPa.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    M. I. Ravich, Water–Salt Systems at Elevated Temperatures and Pressures (Nauka, Moscow, 1974) [in Russian].Google Scholar
  2. 2.
    V. M. Valyashko, Phase Equilibria and Properties of Hydrothermal Systems (IONKh AN SSSR, Moscow, 1990) [in Russian].Google Scholar
  3. 3.
    M. A. Urusova and V. M. Valyashko, Russ. J. Inorg. Chem. 54, 759 (2009).CrossRefGoogle Scholar
  4. 4.
    V. M. Valyashko and M. A. Urusova, Sverkhkrit. Flyuidy Teor. Prakt. 5 (2), 28 (2010).Google Scholar
  5. 5.
    M. A. Urusova and V. M. Valyashko, Russ. J. Inorg. Chem. 56, 430 (2011).CrossRefGoogle Scholar
  6. 6.
    M. A. Urusova and V. M. Valyashko, Russ. J. Inorg. Chem. 50, 1754 (2005).Google Scholar
  7. 7.
    M. A. Urusova and V. M. Valyashko, Russ. J. Inorg. Chem. 53, 604 (2008).CrossRefGoogle Scholar
  8. 8.
    M. A. Urusova, V. M. Valyashko, and I. M. Grigor’ev, Russ. J. Inorg. Chem. 52, 405 (2007).CrossRefGoogle Scholar
  9. 9.
    M. A. Urusova, S. V. Makaev, E. V. Maleeva, et al., Sverkhkrit. Flyuidy Teor. Prakt. 6 (2), 92 (2011).Google Scholar
  10. 10.
    M. A. Urusova and V. M. Valyashko, Russ. J. Inorg. Chem. 60, 230 (2015).CrossRefGoogle Scholar
  11. 11.
    M. A. Urusova and V. M. Valyashko, Russ. J. Inorg. Chem. 60, 1275 (2015).CrossRefGoogle Scholar
  12. 12.
    M. A. Urusova, Zh. Neorg. Khim. 19, 828 (1974).Google Scholar

Copyright information

© Pleiades Publishing, Ltd. 2017

Authors and Affiliations

  1. 1.Kurnakov Institute of General and Inorganic ChemistryRussian Academy of SciencesMoscowRussia

Personalised recommendations