Wettable carbon cathode for aluminum electrolysis as well as preparation method and application thereof

Abstract

The invention belongs to the field of aluminum electrolysis, and particularly relates to a wettable carbon cathode for aluminum electrolysis. The wettable carbon cathode is an N-doped or N and P double-doped carbon material, and the carbon material is compounded in situ according to the mass ratio of graphite to a soft carbon material to a hard carbon material of 35-70: 15-25: 3-15; in the carboncathode, the molar ratio of elemental carbon to elemental nitrogen to elemental phosphorus is 76-99: 1-8: 0-6; and in the carbon cathode, the content of hybridized N in a six-membered carbon ring is not lower than 50% of the total N content, and the content of hybridized P in the six-membered carbon ring is not lower than 50% of the total P content. The invention further provides a preparation method and an application of the carbon cathode. Through large-scale atom doping, the wettability of the existing carbon cathode is improved under the condition of ensuring the electric conductivity; andmeanwhile, on the basis that the cost is effectively reduced, the problem that a TiB2 material serves as a wettable cathode is solved, and the application process of the wettable cathode is effectively promoted.

Description

Technical field: [0001] The invention relates to a cathode material for an aluminum electrolytic cell and a preparation method thereof, and belongs to the field of new cathode materials for an aluminum electrolytic cell and its preparation. Background technique: [0002] The Hall-Heroult method is the only industrial aluminum smelting method in the world today. In the current aluminum electrolysis industry, the cathode material not only plays the role of carrying current, but also bears the chemical erosion of the high-temperature electrolyte melt and the physical erosion of the aluminum liquid. The current tank has always used carbonaceous materials as the cathode material. The wettability of the surface of the carbon cathode material is extremely poor. In order to avoid the unstable electrode reaction caused by the exposure of the carbon cathode surface to the electrolyte, the current aluminum electrolytic cell usually retains molten metal aluminum with a thickness of abou...

AI Technical Summary

Problems solved by technology

However, the above-mentioned cathode materials more or less have the following deficiencies in the production and application process: such as poor wettability with molten aluminum, poor compactness, high brittleness, insufficient bonding with the matrix, poor thermal shock resistance or Uneven thermal expansion coefficient, high manufacturing cost, short life, etc. restrict TiB 2 Popularization and Application of Wettable Cathode

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