METHOD FOR OBTAINING PROTECTIVE COATINGS FOR BAKED ANODE BLOCKS OF ALUMINIUM ELECTROLYSERS Russian patent published in 2023 - IPC C25C3/12 C09D1/00 

FIELD: non-ferrous metallurgy.

SUBSTANCE: invention relates to the electrolytic production of aluminium, and can be used to protect the surface of baked carbon anode blocks of aluminium electrolysers to reduce non-technological losses associated with high-temperature oxidation. The method involves mixing crushed dispersed material with an aqueous solution of a water-soluble binder until a homogeneous composition is obtained to obtain a composition for obtaining a coating to protect carbon anode blocks of aluminium electrolysers from oxidative degradation, and applying the said composition, while industrial cryolite-alumina raw materials are used as crushed dispersed material, and as a water-soluble binder, a mixture of sodium and polyalkelene oxide derivatives of polymethylene naphthalene sulfonic acids and glycoside derivatives with a coke residue of at least 30 wt.% is used, while the phase composition of industrial cryolite-alumina raw materials is represented by the following compounds: Na₃AlF₆, Na₅Al₃F₁₄, α-Al₂O₃, CaF₂, Na₂Ca₃Al₂F₁₄ and K₂NaAlF₆, the main components of this composition are cryolite 80-90 wt.%, alumina 20-10 wt.% and a water-soluble binder, and the resulting composition on the prepared surface of the anode blocks with the formation of a layer of material that limits the access of oxygen and carbon dioxide of the electrolysis reaction medium to the material of the anode blocks.

EFFECT: protection for the baked carbon anodes of aluminium electrolysers from oxidative degradation and reduced penetration of unwanted impurities into the molten electrolyte.

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