Method for greatly reducing horizontal current in aluminum liquid of aluminum electrolytic cell

Abstract

Disclosed is a cathode structure of an aluminum electrolysis cell, where a cathode steel bar is divided, along a height direction of the cathode steel bar from top to bottom, into at least two portions comprising an upper portion by a dividing seam in a segment close to an end portion of a cathode carbon block along the length direction, the cathode steel bar is connected to the cathode carbon block by an electric conductor in a segment in a middle part of the cathode carbon block which is not divided, the upper portion of the cathode steel bar that is close to the end portion of the cathode carbon block and is divided is connected to the cathode carbon block by an electric conductor, the other portions that are located below the upper portion is insulated from the cathode carbon block by using an insulator, and the dividing seam is filled with a dividing seam insulating material. Disclosed are also an aluminum electrolysis cell comprising the cathode structure and a method for lowering a horizontal current in an aluminum liquid. Through the present invention, the horizontal current in the aluminum liquid is greatly lowered, so that the distribution of cathode current becomes more even, the stability of the electrolysis cell is improved, the service life of the cell is prolonged, the energy consumption per ton of aluminum is effectively lowered, and a significant energy saving effect is achieved.

Description

technical field [0001] The invention relates to an aluminum electrolytic cell for producing primary aluminum by the Hall-Elu electrolytic method, especially the cathode structure of the aluminum electrolytic cell. Specifically, the invention relates to a method for greatly reducing the horizontal current in the aluminum liquid of the aluminum electrolytic cell. Background technique [0002] Metal aluminum is produced industrially by molten salt electrolysis, that is, electrolytically dissolving alumina in an electrolyte with molten cryolite as the main component. At present, the main method used is the Hall-Heroult electrolysis method. [0003] The direct equipment for the production of electrolytic aluminum is an electrolytic cell. The electrolytic cell is mainly composed of two parts, one part is the anode, usually made of carbon materials, and the other part is the cathode, which is made of carbon blocks and lining materials. [0004] The aluminum electrolytic cell is con...

AI Technical Summary

Problems solved by technology

In the electrolytic cell of this structure, there is a very big disadvantage in the cathode conductive structure: because the cathode steel rod and the cathode carbon block are placed horizontally in the same direction, a very large horizontal current is generated in the aluminum liquid, which is in line with the vertical magnetic field in the aluminum liquid The combined action produces electromagnetic force, which drives liquid aluminum to flow and fluctuate in the electrolytic cell. If the horizontal current in the electrolytic cell is too large and unevenly distributed, it will cause excessive fluctuations in the interface between the molten aluminum and the electrolyte, causing the electrolytic Slots create severe instabilities in production, reducing current efficiency

In addition, the horizontal current distribution in the aluminum liquid is unevenly distributed along the length direction of the cathode carbon block, so that the current density at the end of the cathode carbon block is the largest, thereby significantly accelerating the corrosion of the cathode carbon block here and reducing the life of the electrolytic cell

[0006] In order to improve the stability of the electrolytic cell, the usual practice is to strictly control the distribution of the vertical magnetic field in the molten aluminum in the design of the electrolytic cell, which not only increases the difficulty of the design of the cathode busbar, but also leads to complex cathode configuration, large amount of busbar, and increased investment

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