MANUFACTURING AND EQUIPMENT
INTENSIFIED PRODUCTION OF FINE-GRAIN GRAPHITES
BASED ON NONFIRED COKE
N. A. Lobastov,
N. Yu. Beilina,
and A. N. Chernyavets
Translated from Novye Ogneupory, No. 5, pp. 12 – 14, May, 2006.
Original article submitted March 14, 2006.
A technology for intensified production of fine-grain graphites based on nonconducting, nonfired coke using
press-molded coke-pitch composites in a plastic state at temperatures close to the coke – semicoke transition
temperature is proposed. Two techniques for heating the press-powder: (i) by heat transfer from the hot matrix
wall and (ii) by use of a hot carrier gas to convey heat to suspended particles in a vortex chamber are consi
As is well known, the production of structural graphite
involves time-consuming technologies. Of these, firing is the
longest in duration, taking typically 350 h or even more.
Still, even this firing time may be insufficient for obtaining
high-strength graphite blocks of required dimensions. At
present, routes towards intensified production of fine-grain
structural graphites continues to be a major concern for tech
nologists. Research is focused on improving the raw materi
als used as well as on the updating of molding techniques
and heat treatment of graphite preforms.
Data have been reported
 on the intensification of
production of carbon materials by combining two processes
— pressing and firing. But these bear a direct relevance to
electroconducting carbon composites based on fired coke
which were heated by passing current through them. There is
further evidence for composites based on fired coke that
were directly heated under pressure . No data on
nonelectroconducting carbon composites based on non-fired
coke have been reported in the literature.
To intensify the production of structural graphite based
on non-fired coke, a method was developed by which coke
pitch composites were pressed in a plastic state at the pitch –
semicoke transition temperature followed by heat treatment
under pressure. This technique is a well-established one and
has found use for pelletizing coals
[3 – 5]. The high-tempe-
rature pressing technique has been applied in the production
of electrodes and carbon blocks
The object of study in this work was a coke pitch com
posite with a filler of particle size finer than 0.15 mm. The
press-powder had a binder of concentration 30 wt.%. Two
techniques for heating to temperatures close to the pitch –
semicoke transition temperature were used: (i) heating from
the hot matrix wall and (ii) heating the particles in a sus
pended state by the hot carrier gas. In the former technique,
the press-powder was heated at a rate of 4 K/min using a la
boratory heater at 450°C and holding at this temperature for
1 h. The press-powder was compacted into cylindrical pellets
of diameter and height 70 mm under a pressure of 20 MPa.
Next, the specimens were heated to 650 – 700°C using a ri
gidly fixed device that allowed the transmission of load to
the specimen without the need to apply additional load dur
ing shrinkage. This heat treatment technique makes it possi
ble to avoid decompaction of specimens relieved of the
pressing stress and increase their resistance to failure. The
Refractories and Industrial Ceramics Vol. 47, No. 3, 2006
1083-4877/06/4703-0149 © 2006 Springer Science+Business Media, Inc.
NIIgrafite State Unitary Enterprise (State Research Institute for
Graphite-Based Structural Materials), Moscow, Russia.
U.S. patent No. 2997744; France patent No. 1288272; Switzer
land patent No. 360678; U.S. patent No. 3268633; Great Britain
patent No. 1109625; U.S. patent No. 3284372; France patent
The New York Times magazine, as of December 6, 1957.
U.S. patent No. 3285372; France patent No. 1458296; U.S. patent
No. 3286003; Great Britain patent No. 1053883.