IMPROVEMENT IN THE QUALITY OF SELF-FIRING ANODES
OF ALUMINUM ELECTROLYZERS AND OTHER CARBON ARTICLES
A. N. Chernyavets,
N. Yu. Beilina,
N. A. Lobastov,
B. G. Ostronov,
and I. A. Bubnenkov
Translated from Novye Ogneupory, No. 8, pp. 37 – 40, August 2007.
Original article submitted March 17, 2007.
An effective method is demonstrated for improving the quality of carbon materials and graphite, whose artic
les are used extensively in different branches of the national economy. This method with use of the “nudel pro
cess” includes preparation of a strong and compact filler. The low temperature for filler preparation (550°C)
provides a synchronous nature for its shrinkage with the binder during subsequent heat treatment, which re
duces to a minimum structural defects for the final material, and as a consequence, it considerably increases
the physicomechanical and operating properties similar to the properties of normal high quality materials, and
the level of quality for the latter is achieved by repeated production cycles of impregnation of coal tar me
dium-temperature pitch, i.e. firing. The operational properties of articles made from the material exceeds the
similar properties of articles made from traditional materials. The marked production advantages of the sug-
gested version for carbon material using the nudel process are a significant reduction in the time of graphite
preparation, a reduction of discharge into the atmosphere of cancerous substances (pitch vapors) and carbon
dust; reduced gas flow rate, electric power, spilled materials, and other material expenditures.
In various branches of the national economy there is ex-
tensive use of carbon materials and articles made from them:
fired and self-firing anodes for aluminum electrolyzers,
electrodes of ore heating and steel pouring furnaces, crucibles
for melting various metals and alloys, furnace heaters for dif
ferent purposes, etc. Production of carbon materials, for example
graphite grade GMZ, is accomplished by a production
scheme illustrated in Fig. 1. an increase in their density and
strength is achieved as a result of using additional production
operations of impregnation with medium-temperature coal
tar pitch followed by firing. However, use of additional opera
tions markedly increases the duration of production of car
bon materials and graphites, and also their cost, but it avoids
considerable nonuniformity of billet properties. This leads to
a delay in the development of new fields of contemporary
In order to create new carbon materials, in particular
self-firing anodes for aluminum electrolyzers with increased
uniformity and operating stability, we have used experience
accumulated in developing articles for special technology
and other forms of articles made from structural graphite.
On the basis of previous experience new specifications have
been formulated for the filler: to have a uniform macro
structure with low defectiveness (porosity, cracking); to ex
hibit high adhesion to the binder; to have the optimum struc-
ture depending preparation temperature; to exhibit a good ca-
pacity to graphitize (with a requirement of performing a ma-
terial graphitizing operation).
Proceeding from these requirements for preparing a
strong anode or graphite with increased operating stability, it
Refractories and Industrial Ceramics Vol. 48, No. 4, 2007
1083-4877/07/4804-0268 © 2007 Springer Science+Business Media, Inc.
Federal State Unitary Enterprise (FGUP) NIIgrafit, Russia.
Cooling, homogenising mix
in a mixer
Graphitization of billets
Fig. 1. Layout of production for graphite grade GMZ.