Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 3, pp. 553−561.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
S.A. Mazunin, V.L. Chechulin, S.A. Frolova, N.S. Kistanova, 2010, published in Khimicheskaya Promyshlennost’, 2009, Vol. 87, No. 1,
TECHNOLOGY OF ORGANIC
AND INORGANIC CHEMISTRY
Technology of Obtaining of Potassium Dihydrophosphate
in the System with Salting-Out
S. A. Mazunin, V. L. Chechulin, S. A. Frolova, and N. S. Kistanova
Perm State University, Perm, Russia
Received September 3, 2009
Abstract—The technology of producing of potassium dihydrophosphate (and potassium metaphosphate) mineral
fertilizer in multicomponent system with salting-out is described; this technology is the result of investigation of
multicomponent system K
O, diagrams of the system condition and technological
scheme are given; theoretical estimation of useful product yield agrees with experimental data.
Technologies of fertilizers production with the
high concentration of minerals present the interest
regarding the reduction of their power consumption
and simpliﬁ cation of apparatus and processing. The
technology of obtaining potassium dihydrophosphate
and metaphosphate, high concentration fertilizers, are
described; summary concentration of useful components
O in anhydrous salts is: KH
100%. Potassium metaphosphate
is a high-performance, practically nonhygroscopic
and noncaking fertilizer, nontoxic for seeds . The
main idea of creation of the described and similar to
these technologies consists in multicomponent system
of conditions for salting-out of the useful component;
diethylammonium chloride is used as a salting-out
agent. In described production method the potassium
dihydrophosphate is obtained at once in crystalline form
and with a high yield.
2. METHODOLOGICAL FEATURES
OF THE INVESTIGATION
The main method of study of solubility in
multicomponent water-salt systems was prognostic
method (modiﬁ ed method of residues) [2, 3]. The main
point of modiﬁ cation was in use of the fact that the
composition of reaction mass same as the residue, lies on
the same straight line, which connects the compositions
of saturated solution and equilibrium solid phase.
Plotting on a diagram the compositions of saturated
solution and initial reaction mixture, connecting them
with a straight line and prolonging this line to crossing
with coordinate axes, we determine the composition of
equilibrium solid phase without analysis of the residue.
The same operation is performed by mathematic
calculations according to elaborated program.
The key point of this method is the choice of
composition of initial reaction mixture on the basis of
composition of equilibrium liquid phase and optimal
ratio of presumed solid phases; therefore this method
can be called “prognostic”.
The optimal composition of initial reaction mixture
should comply with the following conditions:
(1) To be in the studied phase area of the system.
(2) During the process of thermostating the system
should separate into liquid and solid phases in amount
which would allow to mix the mass (15−30% of solid
substances) and to calculate the composition of solid
(3) Amounts of solid phases should be approximately