SCIENTIFIC RESEARCH AND DEVELOPMENT
NANODISPERSED SILICA AND SOME ASPECTS OF NANOTECHNOLOGY
IN THE FIELD OF SILICATE MATERIALS SCIENCE. PART 3
Yu. E. Pivinskii
Translated from Novye Ogneupory, No. 1, pp. 32 – 43, January 2008.
Original article submitted October 14, 2007.
On the example of highly concentrated binding suspensions (HCBS) of fuzed quartz the effect of their
concentration with wet grinding is specified governing the content of nanoparticles in a system. On the basis
of the limiting concentration of HCBS (C
= 0.82) castings are prepared with a nanoporous structure.
As applied to the technology of different silicate materials theoretical aspects are specified connected with
preparation and control of colloid-chemistry and rheological properties of nano-containing dispersed systems
for their preparation.
CONCENTRATION OF HCBS AS A FACTOR
DETERMINING NANOPARTICLE CONTENT
In preparing and studying numerous types of HCBS it
has been established that in the field of concentrations
approaching critical there is a sharp change in properties
both of suspensions and castings based on them. For
example, with an increase in quartz glass suspension con-
centration by 5% in the range C
= 0.70 – 0.75, P
ases by 25 – 30% (rel.), but s
increases by a factor of
1.5 – 2.0. As C
increases further the intensity of the change
in properties increases. Analysis of this feature has shown
that dependences of the change in HCBS properties on their
concentration should be considered from the position of the
volumetric solid to liquid ratio (SLR) that is the ratio in a
system of volume fractions of solid C
and liquid C
i.e. SLR = C
As follows from Fig. 1, in the field of high values of C
the SLR indices increase more markedly than in the field of
low values. For example, with an increase in C
from 0.7 to
0.8 (i.e. by 14%) the value of SLR increases by 71% (from
2.33 to 4.00).
In publication  in order to establish regularities in the
change in properties of suspensions and castings based on
them in relation to SLR index a study was made of fuzed quartz
suspensions prepared both in an industrial mill (C
and in a 50-liter laboratory vessel (C
< 0.77). Here the grain
size composition was about the same (< 5 mm 28 – 35%,
>50 mm 3 – 10%) and pH (5.5 – 6.0), but the temperature
differed markedly (~90°C in the industrial mill and 65°C in
the laboratory). Thus, in the range of change of C
limits 0.68 – 0.77 or SLR within the limits 2.12 – 3.34 the
dependence of fuzed quartz suspension phase composition
(volume concentration of solid phase C
, kinetically free C
and bonded C
of a dispersed medium), critical concentra
and casting porosity P
on SLR index were
studied (Fig. 2). As SLR increases there is a reduction in the
system of both kinetically free and bonded liquid. Here a
rectilinear dependence of index C
on SLR is noted.
Refractories and Industrial Ceramics Vol. 49, No. 1, 2008
1083-4877/08/4901-0038 © 2008 Springer Science+Business Media, Inc.
Parts 1 and 2 of the article have been published in the journal
Ogneupory Nos. 11 and 12 for 2007.
OOO NVF KERAMBET-OGNEUPOR, Russia.
Fig. 1. Interconnection between indices of volume concentration