Metastable Phase Equilibrium of the Quaternary System Na+, Rb+, Mg2+//Cl–-H2O at 298.2 K
- 25 Downloads
The component solubilities, densities and refractive indices of the quaternary system Na+, Rb+, Mg2+//Cl–-H2O at 298.2 K were measured using an isothermal evaporation method. Based on the gathered data, a metastable phase diagram, a water content diagram, and a density/refractive index vs. composition diagram were constructed. The results show that this system is of a complex type with a double salt rubidium carnallite (RbCl·MgCl2·6H2O) formed at 298.2 K. Double salt rubidium carnallite, whose component point locates in its own crystallization zone in the dry salt phase diagram, belongs to congruent double salt at 298.2 K. Accompanied by the double salt that was formed, there are two invariant points in the phase diagram that cosaturated with three salts and an equilibrated solution. The cosaturated salts for the two invariant points are MgCl2·6H2O+RbCl·MgCl2·6H2O+ NaCl and NaCl+RbCl+RbCl·MgCl2·6H2O, respectively. Both invariant points are commensurate invariant points in the evaporation process, and the two invariant points are evaporative dry points. The sizes of the crystalline regions of the salts are in the order of NaCl>RbCl>RbCl·MgCl2·6H2O>MgCl2·6H2O.
KeywordsMetastable phase equilibrium Rubidium carnallitite Quaternary system
Unable to display preview. Download preview PDF.
- Zhang S. H., Xinjiang Nonferrous Metals, 1998, 2, 43Google Scholar
- Lin Y. T., Chen S. L., J. Salt Lake Res., 2008, 16, 1Google Scholar
- Yang J. H., Xu Y. X., Hou X. D., Deng X. L., Li B. Y., Liu Z. M., Specifications for Salt-lake, Salt Mineral Exploration(DZ/T 0212-2002), Geological Publishing House, Beijing, 2003 Google Scholar
- Jin Z. M., Zhou H. N., Wang L. S., Chem. J. Chinese Universities, 2002, 23(4), 690Google Scholar
- Jin Z. M., Zhou H. N., Wang L. S., Chem. J. Chinese Universities, 2001, 22(4), 634Google Scholar
- Zeng Y., Yin H. A., Tang M. L., Feng X. X., Chem. J. Chinese Universities, 2003, 24(6), 968Google Scholar
- Chen H. Y., Chen H., Chemical Reagent-General Method for the Determination of Density(GB/T 611-2006), China Standards Press, Beijing, 2006 Google Scholar
- Institute of Qinghai Salt-Lake of Chinese Academy of Sciences, Analytical Methods of Brines and Salts, 2nd Ed., Academic Press, Beijing, 1988 Google Scholar
- Ye X. S., Zhang S. Y., Li H. J., Li W., Wu Z. J., Spectrosc. Spect. Anal., 2009, 29, 833Google Scholar