DISMANTLING THE LINING OF AN ELECTROLYZER CATHODE UNIT
FOR ALUMINUM PRODUCTION USING HYDRAULIC PRESS EQUIPMENT
AND DIAMOND CUTTING TOOLS
Yu. V. Vasil’ev,
V. I. Kirko,
A. M. Petrov,
and E. N. Chichuk
Translated from Novye Ogneupory,No.10,pp.5–8,October 2009.
Original article submitted May 4, 2009.
Technology is considered for dismantling the lining of a aluminum electrolyzer cathode unit for major over
haul directly within the electrolyzer building. In order to accelerate breakdown of the lining and reduce the ef
fect of impact and vibration loads during dismantling on the neighbourhood during repair of the electrolyzer,
cathode dismantling is performed using hydraulic press equipment for impact-free breaking of materials using
diamond tools for cutting and boring. Acceleration of dismantling is achieved as a result of the use of hydrau
lic equipment making it possible to create within the electrolyzer cathode lining material local nonuniform
pressure distribution providing crack formation breaking the integrity of the lining.
Keywords: aluminum electrolyzer, cathode, dismantling, hydraulic press, diamond cutter.
FEATURES OF THE EFFECT OF VIBRATION
ON DISMANTLING OF AN ELECTROLYZER
CATHODE UNIT LINING ON THE LINING
OF NEIGHBORING ELECTROLYZERS
Dismantling of an electrolyzer cathode unit directly
within the electrolyzer building using dismantling machines
fitted with pneumatic and hydraulic hammers  is accom
panied by formation of additional vibratory dynamic action
over the background on neighboring electrolyzers. Accord
ing to estimates, the additional load on a neighbor with dis
mantling of an electrolyzer with a impact breaking scheme
for the cathode unit lining may exceed by a factor of
1.5 – 2.5 the overall background vibration load for the period
of its operation between repairs under natural conditions. As
a result of the impact action on a neighbor from the
electrolyzer being repaired is a worsening of their lining con
dition, that finally may lead to early shutdown of an
electrolyzer for major overhaul.
With an impact breaking scheme for a cathode unit of an
electrolyzer development of additional vibration and dy
namic loads in a neighboring electrolyzer is accompanied by
– an increase in crack formation as a result of additional
vibration on the lining;
– acceleration of diffusion and passage of molten alumi-
num within the cathode unit into the lining through cracks
– disturbance of molten aluminum stability accompa-
nied by excitation in the melt of surface vibrations at natural
frequencies leading to a change in electrolysis regimes.
With the use of pneumatic and hydraulic hammers, apart
from the main vibration frequency, determined by the natural
frequency of the hammer operation, that is within the range
F =6–15Hz, in the surrounding electrolyzer structures
there is excitation of a broad spectrum of vibrations whose
upper limit in order of value is estimated as
where V is movement velocity if the impact part of the ham
mer; d is the depth of penetration of the impact part of the
hammer into the material being broken. According to esti
mates of the upper limits of the vibration range F
, caused by
impact of a hammer, is 150 – 300 Hz.
When a hammer falls into a side, bottom of a bath or ag
glomerates having high strength, the range of frequencies ex
cited may be higher by one to two orders of magnitude.
However, since high-frequency vibrations are damped rap
idly during propagation, the main action on the neighboring
electrolyzers is low-frequency vibrations in the main fre
quency range of 150 – 300 Hz. This assumption is confirmed
by experiments which show that the main frequency range
Refractories and Industrial Ceramics Vol. 50, No. 5, 2009
1083-4877/09/5005-0321 © 2009 Springer Science+Business Media, Inc.
NTTs Innovation Technology, Siberian Federal University,
OAO RUSAL Krasnoyarsk, Krasnoyarsk, Russia.