“RUSAL Engineering and Technological Center” LLC, Bratsk, Russia

S. I. Nozhko, Head of the Electrolysis Department, e-mail: Semen.Nozhko@rambler.com

“RUSAL Bratsk” JSC, Bratsk, Russia

O. Yu. Sukhov, Manager of the Electrolysis Board

There are several points of view on limiting stage of intensity of a currant increasing on electrolyzers of the second generation: gashydrodinamical process on electrolyzer; bad heat sink; magneto-hydrodynamic instability. During the research were determinate three probable reasons of anode lamination: anode overheating because of the fall of anode column or the fall of anode relative to the flange; common level of the technological discipline during the operations on the anode; geometrical form of anodic pin.

Anode overheating

Dynamics of the anode lamination connected with metal level in electrolyzer. According to the research decreasing of metal level for 1 cm leads to increasing of the anode lamination till 50%.

Common level of the technological discipline

In whole discipline level during the operation on anode is high enough. For minimization of human factor influence were carried out some measures, for example, doing all the operations on anode in day-shift and transfer to two-level scheme of anodic pins placement. In winter there is seasonal increasing of anode lamination because of the difficulty taking place during the technological operation of cutting through (rumming) of the anode peripheral part. This problem must be solved by carrying out additional measures.

Geometrical form of anodic pin

For determination of influence of geometrical form on anode lamination carried out some research. As a result was determined that during the replacement of anodic pin its steel part untwists. That leads to a mechanical force on the anode and appearance of macro- and micro splits which leads to anode lamination. Consequently, for increasing of electrolyzer efficiency it is necessary to not allow critical corrosion of the steel part of anodic pin. The critical mass of corrosion of anode pin composes 15 kg.

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