MANUFACTURING AND EQUIPMENT
NEW TYPES OF BOTTOM BLOCKS AVAILABLE
FROM THE NOVOSIBIRSK ELECTRODE PLANT JOINT-STOCK CO.
AND THEIR PERFORMANCE CHARACTERISTICS
A. N. Seleznev,
V. V. Ochkov,
V. I. Pirogov,
L. S. Kotova,
Yu. F. Gnedin,
S. A. Kokhanovskii,
and A. Yu. Vinogradov
Translated from Novye Ogneupory, No. 9, pp. 19 – 22, September, 2004.
Original article submitted March 3, 2004.
New materials based on electrocalcinated anthracite, gas-calcined anthracite, and artificial graphite (from pe-
troleum coke) have been developed for production of bottom blocks for aluminum electrolyzers at the NovEP
JSC. Performance characteristics of the newly-developed materials (density, porosity, compressive and bend-
ing strength, elasticity modulus, heat conductivity, resistivity, coefficient of linear thermal expansion and ash
content) are discussed and compared to those recommended by DIN international standards.
The bottom blocks serve as heavy-duty engineering com-
ponents of the electrolysis bath in the production of alumi-
num, and for this reason stringent requirements are placed on
their performance characteristics. These are controlled by
adding anthracite and artificial graphite in the proper propor
tion to the mixture. The Novosibirsk Electrode Plant Joint-
Stock Co. is a manufacturer of bottom blocks based on
electrocalcined anthracite (ECA), gas-calcined anthracite
(GCA), and mechanically machined blocks with different
content of artificial graphite.
The basic raw materials in the production of bottom
blocks are: thermoanthracite (GCA and ECA) — filler; artifi
cial graphite AG (under typical conditions at an electrode
plant, produced by the scheme molding – calcination –
graphitization) — filler; coal-tar pitch — binder.
The raw material for thermoanthracite was anthracite
commercially available from Sibantratsit JSC (Gorlovka coal
field). Electrocalcined anthracite was prepared using an
IÉT-10 electrocalcinator at 1800°C, gas-calcinated anthracite
was prepared using a rotary kiln at 1300°C, and artificial
graphite was prepared from petroleum coke with a sulfur
content of up to 1.5% at a graphitization temperature not be-
low 2500°C. Relevant characteristics of the raw materials are
given in Table 1. Consumer requests (Russian Aluminum
Management (RAM) JSC, SUAL-Holding JSC) for the qua
lity of bottom blocks are listed in Table 2.
The bottom blocks at the NovEP JSC were manufactured
by the extrusion method under a pressing load of 6300 tons.
To improve the technology of bottom block production, com
mercial specimens containing 40% AG + 60% GCA and 50,
60, 80% AG + 50, 40, 20% ECA were prepared and tested at
the NovEP JSC using domestic and international standards;
relevant results are given in Table 3.
One will note the methodological difference in domestic
and international testing techniques. According to TU
Refractories and Industrial Ceramics Vol. 45, No. 6, 2004
1083-4877/04/4506-0412 © 2004 Springer Science+Business Media, Inc.
Novosibirsk Electrode Plant (NovEP) Joint-Stock Co., Novosi
TABLE 1. Properties of Raw Materials (average values given)
mW × m, not
not higher than
ECA 750 2.7 1.83 0.1
GCA 1000 2.9 1.74 0.2
AG 100 0.2 2.21 0.1