Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 9, pp. 1297−1306.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © N.V. Shul'ga, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 9, pp. 1377−1387.
AND INDUSTRIAL INORGANIC CHEMISTRY
Mechanical Activation and Reactivity
of Phosphate Raw Materials
N. V. Shul’ga
Institute of General and Inorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
Received February 14, 2012
Abstract—Effect of mechanical activation of phosphate raw materials on the main characteristics of their subse-
quent decomposition with an aqueous solution of a weak acid and a complexing agent was studied. It was shown
that, not being a versatile procedure, mechanical activation is rather efﬁ cient for well crystallized ﬂ uoroapatites,
whereas for “soft” phosphorites its application is inappropriate.
Despite all the presently encountered problems,
manufacturers of nitrogen and potassium fertilizers do
not suffer from shortage of raw materials. However,
prospects for supply of raw materials to plants producing
phosphate fertilizers are disturbing. Despite that the
key role of concentrates produced from ores from the
richest deposits in Russia, United States, China, and
North African countries is still preserved, involvement
of ordinary phosphorites into manufacture of phosphate
fertilizers, with development of a technology of their
production, is only a matter of time.
In development of small deposits situated near
agricultural regions, an acceptable variant of a particular
solution of the problem of providing farms with
phosphate fertilizers is by manufacture of mechanically
activated phosphor meal whose agrochemical efﬁ ciency
becomes several times higher upon a mill treatment .
Here, we cannot but agree with the authors of  in
that the technological progress in mechanochemistry is
only possible by carrying out appropriate fundamental
studies in this ﬁ eld.
A detailed study of processes occurring in mechani-
cal activation of phosphate raw materials is to a certain
extent hindered by the known procedure , which
does not envisage any “common system of coordinates”
making it possible to compare reactivities of samples
having different chemical compositions and to take into
account the effect of accompanying impurities on the
main chemical transformation in decomposition of a
complex solid-phase system with a solution of a weak
acid or a complexing agent. The method suggested 
for evaluating the chemical activity of phosphorites is
based on determining their degree of decomposition, α,
upon treatment with an extractive agent at a constant
l : s ratio. The thus found parameter α depends on the
phosphorus content of a sample, does not reﬂ ect the po-
sition of a liquid-solid extractive system at an instant
of time τ with respect to equilibrium, and gives no way
of comparing the types of behavior exhibited by sam-
ples of varied chemical composition and origin [4, 5].
Changing the methodological approach to evaluation of
the chemical activity of phosphate raw materials makes
it possible to recover phosphorus under identical condi-
tions and to evaluate the most important characteristics
of this process and the effect of side transformations on
its efﬁ ciency [4, 5]. This approach  was used to study
the effect of a mechanochemical activation on the reac-
tivity of phosphorites and apatites and to determine the
opportunities furnished by this method of their prepara-
tion for the next processing stage.
As objects of study served the phosphorite meal from