SU452622A1 - Cathode Rod Aluminum Electrolyzer - Google Patents

Description

one

A cathode rod of an aluminum electrolysis cell is known, consisting of steel and graphite parts interconnected.

The proposed cathode rod of an aluminum electrolysis cell differs from that known in that the graphite part of the rod immersed in the electrolyte and located at the electrolyte-gas phase is covered with protective layers of silicon pyrocarbide with a thickness of up to 1.5 mm alu-minh nitride with thickness of 2 5-3.6 mm. This prevents leakage of electric current from the surface of the cathode rod and increases its service life,

The drawing shows the proposed cathode rod.

; The cathode rod consists of graphite, a part 1 and a steel part 2, which are interconnected, for example, by the method of soldering. The graphite part of the cathode rod immersed in electrolyte 3 and at the electrolyte – gas phase, running at the interface, is covered with a protective layer 4 of silicon pyro carbide up to 1.5 mm thick and protected

with a layer of aluminum nitride 5, 2.5-3.0 mm thick. The cathode rod is placed inside the annular anode 6 and immersed in the electrolyte and liquid aluminum 7, non-income somewhat up to the bottom 8 of the electrolyzer. The above laboratory tests of the described cathode rod showed that its service life before the destruction of the protective layer of aluminum nitride was 60-64 days, and before the destruction of the protective layer of pyrocarbide, 7O days. Since the deposition of a protective layer of pyrocarbide silicon is carried out at high temperatures and is known

: Difficulties; it is recommended to perform the restoration of the cathode rod after the destruction of only the protective upper layer of aluminum nitride, preventing the destruction of the protective layer of silicon pyrocarbide. In this case, the restoration of the destroyed protective layer of aluminum nitride is realized at room temperature by immersing the graphite part of the cathode rod in a solution of aluminum nitride.

or applying a protective layer of aluminum nitride on its surface while helping

brushes.

Subject invention

The cathode rod of an aluminum electrolysis cell, consisting of steel and graphite parts interconnected, is distinguished by the fact that, for the purpose of trans. preventing the leakage of electric current from the surface of the cathode rod and increasing its service life, the graphite part of the rod immersed in the electrolyte and located on the electrolyte – gas phase is covered with protective layers of pyro carbide silicon up to 1.5 mm thick and nitride aluminum thickness 2.5-3.0 mm.