Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 5, pp. 798−802.
Pleiades Publishing, Ltd., 2011.
Original Russian Text © D.G. Cherkasov, K.K. Il’in, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84, No. 5, pp. 768−772.
OF SYSTEMS AND PROCESSES
Salting out of Triethylamine from Aqueous Solutions
by Potassium Nitrate
D. G. Cherkasov and K. K. Il’in
Saratov State University, Saratov, Russia
Received July 22, 2010
Abstract—By visual-polythermal method in the range 5–25°C we studied phase equilibria and critical phenomena
in a ternary system potassium nitrate–water–triethylamine, where its component, binary liquid system, is stratiﬁ ed
at the lower critical solution temperature.
This study continues a research  of an effect of a salt
nature and temperature on liquid–liquid equilibrium in
ternary systems alkali metal nitrate–water–triethylamine,
where the liquid component, binary liquid system,
is stratiﬁ ed at the lower critical solution temperature
It was established  that introduction of sodium
nitrate in the binary system water–triethylamine leads
to a considerable decrease in its LCST and their mutual
solubility, i.e., salt possesses a salting-out effect. The
constructed isotherm of the system phase states conﬁ rmed
a developed generalized scheme of a topological
transformation of the phase diagrams of ternary systems
salt–binary solvent with the salting-out effect .
This study is aimed at a polythermal examination of
the phase equilibria and critical phenomena in the ternary
system potassium nitrate–water–triethylamine that has
not been studied.
The aim of the study is to reveal an effect of salt
possessing a larger cation size comparing to that of
sodium nitrate on critical parameters of the water–
triethylamine system and to conﬁ rm the scheme of the
topological transformation of the phase diagrams of
ternary systems .
Phase equilibria and critical phenomena in mixtures
of the components of the ternary system KNO
N were studied in the temperature range of
5–25°C using the same methods as that were described
in . The equilibrium of the liquid phases in the system
was set for an hour, and their equilibrium with the solid
), for 3 hours with continuous stirring
the mixture. The criterion for reaching the equilibrium
was the reproducibility of measurements of a transition
temperature of the phase states in the approach to it
from the lower and higher temperatures. The relative
error in determining the compositions of the mixtures
corresponding to points of phase transitions at selected
temperatures was ± 0.5–1.0%.
Water and triethylamine were prepared according
to  and potassium nitrate (chemically pure grades),
according to .
The binary systems components were characterized by
the following phase states. The H
N system is
stratiﬁ ed at LCST of 18.3°С . In the KNO
tem eutectic equilibrium occurs at –3.0°С. Its solid phases
are ice and potassium nitrate . This salt is of good solu-
bility in water and has a positive temperature coefﬁ cient
of solubility. The KNO
solubility in triethylamine has
not been studied, the carried out examination has revealed
that potassium nitrate is almost insoluble in it.
In the ternary system KNO
N we per-
formed polythermal examination of the mixture whose
compositions changed in ten sections of a concentration