Abstract
Using thermal analysis, we have constructed the phase diagram of the crystalline hydrate system Na2CO3 · 10H2O-Na2S2O3 · 5H2O, which has been shown to have eutectic phase relationships. The eutectic composition is 27 wt % Na2CO3 · 10H2O + 73 wt % Na2S2O3 · 5H2O, and the eutectic temperature is T e = −0.92°C. We have determined the enthalpy of fusion of the alloys in this system and evaluated the activities of their components both at the liquidus temperatures and in metastable regions. The composition dependences of the above thermodynamic characteristics are shown to correlate with each other and to have extreme values at the eutectic composition. The results obtained lead us to recommend the eutectic mixture of the crystalline hydrates in this system as a heat storage material.
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References
Hörmansdörfer, G., EEC Patent EP 0 402 304 B1, 1996.
Bank, D.H., Soukhojak, A.N. and Sehanobish, K., US Patent Application 20120216981, 2012.
Kimura Hiroshi and Kai Junjiro, US Patent Application 06/343,767, 1982.
Chalk, C.D. and Hayman, C., US Patent 4 619 778.
Yamasita Kadzuo, Jpn. Patent 621 161 756, Kakai Tokke Koho, 1989, no. 3(3), pp. 593–594.
Van Hook, H., US Patent 4 603 003, 1986.
Kimura Hiroshi, Nucleation of molten Na2S2O3 · 5H2O and some other similar hydrates. A thermodynamic observation, Ind. Eng. Chem. Fundam., 1980, vol. 19, no. 3, pp. 251–253.
Aleksandrov, V.D., Sobol’, O.V., and Savenkov, M.V., Precrystallization supercooling in the system watersodium thiosulfate pentahydrate, Fiz. Khim. Tverd. Tila, 2007, vol. 8, no. 4, pp. 771–775.
Aleksandrov, V.D. and Sobolev, O.Yu., Na2CO3 · 10H2O crystallization from H2O-Na2CO3 solutions, Fiz. Khim. Tverd. Tila, 2011, vol. 12, no. 2, pp. 407–410.
Aleksandrov, V.D., Sobolev, A.Yu., and Sobol’, O.V., Phase diagram of the crystalline hydrate system Na2CO3 · 10H2O-Na2SO4 · 10H2O, Ukr. Khim. Zh., 2012, vol. 78, no. 2, pp. 88–93.
Stromberg, A.G. and Semchenko, D.P., Fizicheskaya khimiya (Physical Chemistry), Moscow: Vysshaya Shkola, 2001.
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Original Russian Text © V.D. Aleksandrov, A.Yu. Sobolev, 2014, published in Neorganicheskie Materialy, 2014, Vol. 50, No. 7, pp. 739–744.
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Aleksandrov, V.D., Sobolev, A.Y. Phase diagram of the Na2CO3 · 10H2O-Na2S2O3 · 5H2O system. Inorg Mater 50, 686–690 (2014). https://doi.org/10.1134/S0020168514070012
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DOI: https://doi.org/10.1134/S0020168514070012