RU2225900C2 - Method for increasing electric current intensity in set of cells for producing aluminum - Google Patents

Abstract

FIELD: nonferrous metallurgy, possibly production of aluminum by electrolysis at reconstruction of cells during their major repairs. SUBSTANCE: method comprises steps of parallel connecting movable makeup apparatuses to each reconstructed cell or to group of cells while arranging said apparatuses just near reconstructed cells; increasing electric current intensity in reconstructed cell or in group of reconstructed cells before complete reconstruction of all cells of set by 1 - 10 kA. EFFECT: less loss of metal and electric energy at changing operational mode of cells to mode with increased electric current intensity. 2 cl, 1 dwg, 1 ex

Description

The invention relates to the field of non-ferrous metallurgy and can be used in the production of aluminum by electrolysis.

There is a method of increasing the current strength of electrolyzers included in the electrolysis series, consisting in the fact that additional current is supplied to one cell by parallel connection of an auxiliary power source to increase the current strength on this cell. This is done if it is necessary to change the technological modes of operation of the electrolyzer, for example, when conducting technological research on the electrolyzer (Japanese patent 3-998).

This method does not solve the problems of increasing the current strength of the entire series of electrolyzers. In addition, it is known from practice that additional power sources are located at the converter substation, and it is necessary to lay busbars up to 500 m long outside the electrolysis casing, which requires significant capital costs and electrical safety.

It is known that in order to increase the current strength of an electrolysis series, it is necessary to reconstruct all of the series electrolysers. To reconstruct the electrolyzer for a large current strength, it must be disconnected from the series current and make the necessary changes in the design of the anode and cathode. (Belyaev A.I. et al. Electrometallurgy of aluminum. - M., 1953, p. 320).

Reconstruction of a series of electrolyzers is carried out by stopping the entire series or reconstruction of electrolyzers during their overhaul.

The simultaneous reconstruction of all electrolyzers of the series to work with increased current strength leads to large economic losses due to the cessation of metal production. The disadvantage of reconstructing individual electrolyzers during their overhaul is the impossibility of increasing the current strength on reconstructed electrolyzers, because an increase in the current strength of the entire series of electrolyzers will lead to a decrease in the performance of the electrodes that have not yet been reconstructed.

If each reconstructed electrolyzer will operate at a current less than the optimum value for which it is designed, it will be necessary to compensate for the lack of power (heat) by increasing the voltage of the electrolyzer, which will not be spent on aluminum production, but on the need to maintain the minimum temperature of the electrolyte in the electrolyzer. In this case, aluminum output will be 10-15% lower and electricity consumption will increase by 25-30%.

There is a method of increasing the current strength on an electrolytic cell or a group of electrolytic cells, in which mobile make-up devices are connected in parallel with reconstructed electrolytic cells in a series of series-connected electrolytic cells (the operation of the unit designed by the Irkutsk branch of VAMI, drawing No. 766046, 1970, is described in ed. St. USSR No. 514918, C 25 C 3/16, 1976).

An object of the invention is the transfer of a series of electrolyzers to work with increased amperage, in which reconstructed and non-reconstructed electrolyzers operate with optimal current load.

The technical result of the invention is to reduce the loss of metal and electricity when transferring the series to work with increased amperage.

The technical result is achieved by the fact that in the method of increasing the current strength in a series of electrolyzers to produce aluminum during the reconstruction of electrolyzers during their overhaul, including the parallel connection of mobile make-up devices to each reconstructed electrolyzer or group of electrolyzers, mobile make-up devices are located in the immediate vicinity of the reconstructed electrolyzers , and the increase in current strength on the reconstructed electrolyzer or group of electrolyzers lead to the complete reconstruction of electrolyzers series.

Make-up current is supplied in the range of 1-10 kA.

The drawing shows a diagram of a series of electrolysis.

An example of the method.

It is required to reconstruct 80 electrolyzers of the electrolysis series, operating at a current strength of 80 kA. After reconstruction, the series current will be increased to 90 kA, i.e. 10 kA.

In a series of electrolyzers, according to the overhaul plan, electrolyzers 1 and 2 were to be turned off. Simultaneously with these electrolyzers, electrolysers 3, 4 and 5 were unscheduledly switched off, on which the anode and cathode would be upgraded to transfer to work at a current strength of 90 kA. After the overhaul and modernization are completed, electrolyzers 1-5 are included in the series, and a make-up unit 6 is connected to them in parallel, which feeds these electrolyzers with an additional current of 10 kA. Then they do the same with the next group of electrolyzers.

After the reconstruction of all electrolyzers of the series, the make-up units are turned off and the series current is increased to 90 kA.

EFFECT: invention will reduce metal losses and reduce energy losses when transferring series electrolyzers to work with increased current strength.

Claims (2)

1. A method of increasing the current strength in a series of electrolyzers for aluminum during the reconstruction of electrolyzers during their overhaul, including the parallel connection of mobile make-up devices to each reconstructed electrolyzer or group of electrolyzers, characterized in that the mobile make-up devices are located in the immediate vicinity of the reconstructed electrolyzers, and an increase in current strength on a reconstructed electrolyzer or a group of electrolyzers is carried out until complete Traction of all electrolyzers of the series. 2. The method according to claim 1, characterized in that the current strength is increased by 1-10 kA.

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