EFFECTIVE METHOD FOR PREPARING UNIFORM CARBON FILLER
FOR STRUCTURAL GRAPHITES WITH IMPROVED OPERATING LIFE
N. A. Lobastov,
A. N. Chernyavets,
and N. Yu. Beilina
Translated from Novye Ogneupory, No. 1, pp. 14 – 18, January, 2010.
Original article submitted April 28, 2009.
A method is proposed for preparing a new form of filler NUDOL (Lobastov uniformly dispersed carbon filler)
for structural graphites, on whose basis materials are prepared with improved operating life at the level of the
best domestic and world examples. All of the production operations are inexpensive and may be entirely ac
complished under existing enterprise conditions on available equipment. With further development of the
technology for preparing filler and graphite based upon it may be possible to prepare materials with properties
and productive life exceeding the world level.
Keywords: NUDOL (Lobastov uniformly dispersed carbon filler), structural graphite, surfactant, self-adhesion.
Structural graphites are used in various branches of tech-
nology, and also in objects operating under wear conditions
with action of a high-temperature gas atmosphere, moving
liquids, etc. The main requirement for these graphites, apart
from providing the required structural strength, are structural
uniformity, that is built up from the uniformity of graphite
components: graphite from coke filler and pitch binder
graphite. By property uniformity for material from graphite
filler, binder and graphite based upon them, we understand
little scatter, that is determined by the coefficient of variation
(ratio of mean square deviation to average value of moni
tored physicomechanical properties).
In order to prepare structural graphites a filler made from
calcined and uncalcined cokes is used. Use of uncalcined
coke is connected with a requirement for preparing high-
strength and high-density graphite. Uncalcined coke may be
distinguished by considerable instability, i.e. nonuniformity
of initial properties. For pitch coke the apparent density for
input monitoring of even one supply batch may vary from
1050 to 1480 kg/m
, apparent density from 1840 to
, and electrical resistance from 530 to 1085 mW·m
. For calcined pitch coke with an ultimate strength in com
pression of 6.35 MPa, the coefficient of variation is 50.3%,
very high scatter, apparently connected with presence of re
sidual cracks that occur during coke formation. For pitch
coke with increased porosity from 18.5 to 29.0% the appar
ent density decreases from 1.66 to 1.48 g/cm
. For oil coke
with a reduction in porosity from 62 to 37% the ultimate
strength in compression increases from 1.5 to 8.0 MPa [2,
p. 67], and after firing with a ultimate strength in compres-
sion of 5.44 MPa the coefficient of variation is 15.6% .
The yield of volatiles from coke of different batches may
vary from 1.2 to 7.0 wt.%. Depending on the yield of volatile
substances there is a change in the ultimate strength in com-
pression for finished performs, and also the dynamic elastic
It has been established  that the dynamic elasticity
modulus and yield of volatiles depends on filler preparation
temperature (Fig. 1). The change in yield for finished per
forms and ultimate strength in compression with an increase
in yield of volatile substances in coke filler are provided be
Yield of volatile
substances, % ...................... 1.75 2.80 3.60 4.25 5.05 5.90
Output of finished
performs, %......................... 100 95 85 70 35 0
in compression, MPa .......... 63.0 82.5 102.0 120.0 140.0 163.0
Therefore the original uncalcined coke should be consid
ered as an inhomogeneous mixture consisting of carbon par
ticles with different structural resistance (Fig. 2) caused by
nonuniformity of the filler of pitch coke composition and
graphite based upon it . There is published information
about methods for improving coke filler homogeneity as a
Refractories and Industrial Ceramics Vol. 51, No. 1, 2010
1083-4877/10/5101-0014 © 2010 Springer Science+Business Media, Inc.
Proc. International Conference of Refractory Workers and Metal
lurgists (Moscow 23 – 24 April, 2009).
FGUP NIIgrafit, Moscow, Russia.