KINETICS OF REFRACTORY PHOSPHATE BINDER ACCUMULATION
I. I. Nemets,
Yu. N. Trepalina,
and V. M. Nartsev
Translated from Novye Ogneupory, No. 4, pp. 23 – 25, April, 2012.
Original article submitted November 25, 2011.
The effect of mechanochemical activation on component interaction is studied. Corundum is ground to an
identical fineness: together with H
solution, and also dry grinding followed by suspension. The chemical
reaction rate (formation of aluminum hydrophosphate) with different hydrodispersion synthesis methods is
due to a rapid increase in the number of active centers at the surface of a corundum grain during grinding and
combination with acid.
Keywords: mechanochemical activation, corundum, orthophosphoric acid, grinding, activation energy, re
An important task of contemporary ceramic materials
science is development of energy and resource saving tech-
nology for synthesizing new functional composites, with-
standing high temperature and corrosive media. These mate-
rials are extremely necessary for lining metallurgical fur-
naces, MHD-generators, plasmatrons, atomic reactors, etc.
The most promising base for preparing functional compos-
ites may be a mixture of phosphate binder with refractory ox-
, etc. [1 – 3]. By controlling the concentra-
tion and structure of nanostructures (colloidal particles, very
fine gel-like interlayers ), which form during synthesis, it
is possible not only to give material the required operating
properties, but also to reduce expenditure of energy and raw
material for its preparation.
The most widespread form of binder used in manufacture
of corundum and aluminosilicate objects, ramming mixes,
refractory concretes, and mortars, is orthophosphoric acid of
different concentration. Proceeding from published data, for
mation of nanostructures in a phosphate component proceeds
as a result of polycondensation:
12n – x
and therefore the main controlling parameters of composite
synthesis should be reagent concentration and reaction of
products, and also temperature of a reaction mixture .
Taking account of the inert nature and hardness of refrac-
tory oxides, in order to provide high composite strength,
which depends on contact strength between filler and binder,
mechanochemical action of a surface is rational for a refrac-
tory filler. The latter not only increases the proportion of con-
tacts, but also may intensify bond formation.
In composites prepared by traditional technology the
content is 3 – 5 wt.%, which causes ecological prob-
lems and reduces the thermal stability of such materials. In
contrast, a reduction in the proportion of P
in a composite
improves its operating properties and provides resource sav
Experience of controlling the properties of corundum
composites by introducing modifiers is presented in . The
ultimate strength of specimens after firing at 1000°C was
60 MPa, and after 20 thermal cycles of 1000°C – water, it
was 84 MPa.
The complexity of physicochemical processes and struc
ture formation of phosphate composites, and the limited
amount of data about the dependence of their properties on
material composition and production parameters for its prep
aration, require a detailed study of corundum surface activa
tion, the mechanism of bond formation and its behavior dur
ing synthesis, determination of rational parameters for com
posite preparation, and evaluation of the energy and resource
content of the technology. It is possible to study these pro
cesses comprehensively by means of kinetic studies. There
fore the aim of work is to study the kinetics of phosphate
binder accumulation, and also the energetics of mechano
chemical activation of filler in an H
Refractories and Industrial Ceramics Vol. 53, No. 2, July, 2012
1083-4877/12/05302-0115 © 2012 Springer Science+Business Media, Inc.
FGBOUVPO V. G. Shukov Belgorod State Technological Univer
sity, Belgorod, Russia.