The phase equilibria of ternary systems Li2SO4 + Na2SO4 + H2O and
Na2SO4 + K2SO4 + H2O at
303.2 K were investigated by using the isothermal dissolution method.
The solubility, density, and refractive index of the systems were
measured. There are two ternary invariant points and three crystallization
regions corresponding to Li2SO4·3Na2SO4·12H2O, Li2SO4·H2O, and Na2SO4·10H2O in the system Li2SO4 + Na2SO4 + H2O at 303.2 K. There are two ternary
invariant points and three crystallization regions corresponding to
Na2SO4·10H2O, Na2SO4·3K2SO4, and K2SO4 in the system Na2SO4 + K2SO4 + H2O at 303.2 K. By comparing the
phase diagrams of the ternary system Li2SO4 +
Na2SO4 + H2O at different temperatures,
one can find that the existence form of double salt changes from Li2SO4·3Na2SO4·12H2O to Li2SO4·Na2SO4. By comparing the phase diagrams of the ternary system Na2SO4 + K2SO4 + H2O at different temperatures, the double salt Na2SO4·3K2SO4 was not found at 273.2
K, while it was formed at 303.2 and 313.2 K. Meanwhile, the thermodynamic
data of these two systems at 303.2 K were fitted by the Pitzer–Simonson–Clegg
model, and the calculated values agree well with the experimental
values.
The isothermal dissolution method was applied for the
phase equilibria
experiment of the reciprocal quinary system Li+, K+, Rb+//Cl–, Borate-H2O at 323.2 K; the related density (ρ) of the system was measured
by the specific gravity bottle method experimentally, and the crystalloid
forms of the equilibrated solid phase were identified by the X-ray
diffraction method. Results show that the system belongs to a complex
type with the formation of solid solution [(K, Rb)Cl]; meanwhile,
six single salts, LiCl·H2O, KCl, RbCl, Li2B4O7·3H2O, K2B4O5(OH)4·2H2O, and RbB5O6(OH)4·2H2O, were also
formed at 323.2 K; no double salt was found in this system. The space
phase diagram consists of five quinary invariant points, fifteen isothermal
dissolution curves, and seven crystallization fields. The size of
the RbB5O6(OH)4·2H2O crystallization field is the largest among the coexisting salts
in the quinary system. Under the condition of RbB5O8 saturation, the crystallization field of Li2B4O7·3H2O occupied the largest crystallization
region, and salt RbCl had the smallest region.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.