Anti-oxidation coating for carbon anodes in aluminum electrolysis

Abstract

The invention relates to a technology for preventing high-temperature oxidation of carbon anodes during aluminum electrolysis production, specifically to an anti-oxidation coating for carbon anodes in aluminum electrolysis. The coating comprises, by weight, 30-40% of alumina powder, 10-20% of sodium fluoride, 10-20% of aluminium fluoride, 1.0-5.0% of a complex anti-oxidant, 10-15% of a binder, 2-5% of a suspending agent and the rest of a solvent. The high-temperature anti-oxidation coating can effectively raise oxidation resistance of carbon anodes at high temperature, has an effect of resisting corrosion of cryolite slag to the coating, effectively reduces carbon anode consumption in aluminum electrolysis production, prolongs service life of carbon anodes, saves consumption cost of carbon anodes, decreases discharge of gas generated by high-temperature oxidation-combustion of carbon anodes, and obviously improves the working environment.

Description

technical field [0001] The invention relates to a technology for preventing high-temperature oxidation of carbon anodes in the production process of electrolytic aluminum, in particular to a high-temperature anti-oxidation coating for electrolytic aluminum carbon anodes. Background technique [0002] Aluminum is a metal element with huge reserves and wide distribution in the earth's crust, accounting for about 7.5% in the earth's crust, more than the sum of all other non-ferrous metals. As early as 1854, the French chemist Deville mixed bauxite, charcoal, and salt, fed chlorine gas and heated to obtain a double salt, and then melted the double salt with excess sodium to obtain metal aluminum. In 1886, Hauer in the United States and Hylander in France independently produced metal aluminum by electrolyzing a mixture of molten bauxite and cryolite, which laid the foundation for today's large-scale production of aluminum. Due to the rapid development of the power generation ind...

AI Technical Summary

Problems solved by technology

The root cause is that although some have better anti-oxidation performance, some impurities are introduced into the liquid electrolyte or pure aluminum water to pollute the purity of pure aluminum; while some have better anti-oxidation performance, but the anti-oxidation The corrosion ability of fluoride ions is poor, because cryolite is a strong corrosive agent, the coating is corroded at high temperature and flows completely, and loses its protective effect prematurely

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