EVALUATION OF THE PHASE AND DIMENSIONAL HETEROGENEITY
OF THE QUARTZ COMPONENT OF RAW MATERIAL AND HCBS
A. V. Cherevatova,
I. V. Zhernovskii,
and V. V. Nelyubova
Translated from Novye Ogneupory, No. 8, pp. 59 – 60, August 2010.
Original article submitted October 1, 2009.
Experience is given for the application of x-ray total profile quantitative phase analysis for a comparative
study of the quartz component of raw material and HCBS based on it. It is detected that the quartz component
of silica-containing raw material is a heterogeneous phase and dimensional composition, represented by a-
Keywords: mechanochemical activation, highly concentrated ceramic binder suspensions (HCBS), a- and
b-modifications, system phase composition, Rietveld method.
It is well known  that grinding, connected directly
with mechanochemical activation of a solid phase surface of
a system, promotes an increase in its internal energy and an
increase in reaction capacity. During fine grinding of mineral
particles they are subject to marked non-hydrostatic stresses
. We have made an assumption that during preparation of
highly concentrated ceramic binder suspensions (HCBS)
there are qualitative and quantitative changes in the phase
composition of a system in the direction of greater activity.
In order to confirm this hypothesis comparative analysis
is necessary for quantitative and qualitative mineralogical
characteristics of a starting raw material and a finished prod
uct. An x-ray analysis method was used in order to estimate
values of the sizes of crystallites of the original raw material
and a quartz base HCBS of silica composition. The possibil
ity of determining dimensions of the field of coherent scat
tering (FCS) (minimum crystallite dimensions) using x-ray
diffraction emerges from the dependence of the half-width of
the profile (its angular width over half of the height) of a re
flection on the value of the FCS. The x-ray patterns of
nanodispersed material (NDM) were obtained in a DRON-4
diffractometer using Cu-anode radiation (Ni-filter for weak
ening b-components of radiation). The scanning step was
0.05° and the duration of measuring intensity at scanning
points was 0.02 sec.
The relative intensity of reflections and angular position
of their maxima corresponding to low-temperature quartz.
However, a typical feature was detected for the x-ray patterns
obtained (Fig. 1), i.e. asymmetry of the x-ray reflection pro
file and their low-angle field. The most contradictory expla-
nation of this fact was the assumption of presence within the
HCBS quartz composition alongside the low-temperature
modification of b-quartz close to it in crystallographic struc-
ture a high-temperature phase of a-quartz (Fig. 2). It should
be noted that presence of phases, similar to a-quartz has
been noted in  during dispersion of quartz specimens.
The solution of this problem (with superimposition of re-
flections of different phases for one diffraction profile) is
only possible with the use of calculation approaches based
on the Rietveld method [4, 5]. On the basis of this method,
also called total profile, lies the procedure of minimizing the
difference between experimental and calculated diffraction
spectra. The latter is considered proceeding from the model
of a crystalline structure of substances, comprising a
polycomponent material. Necessary conditions for the use of
Refractories and Industrial Ceramics Vol. 51, No. 4, 2010
1083-4877/10/5104-0310 © 2010 Springer Science+Business Media, Inc.
Belgorod State Technological University, Belgorod, Russia.
Fig. 1. HCBS specimen x-ray pattern.