Anti-corrosion and anti-oxidation coating material for electrolytic aluminum anode steel claw and preparation method of anti-corrosion and anti-oxidation coating material

Abstract

The invention discloses an anti-corrosion and anti-oxidation coating material for an electrolytic aluminum anode steel claw and a preparation method of the anti-corrosion and anti-oxidation coating material, and the anti-corrosion and anti-oxidation coating material comprises the following raw materials in percentage by mass: 40-70% of alpha-Al2O3, 0-30% of gamma-Al2O3 (preferably 5-30%), 2-7% of aluminum silicate fiber and 20-30% of water glass. Various aluminum oxides are used in the raw materials of the anti-corrosion and anti-oxidation coating material for the electrolytic aluminum anode steel claw to the maximum extent, only a small amount of aluminum oxides are contained, other elements can be prevented from entering an electrolyte, and therefore the influence on the quality of an aluminum product is avoided. The coating material is compact in structure, the permeation amount of corrosive gas can be reduced, the corrosion rate of an electrode can be obviously reduced, the corrosion resistance is high, and the wear resistance is good. The coating material disclosed by the invention is enhanced in ductility, suitable for a high-temperature environment, and not easy to crack and fall off when being used in the high-temperature environment.

Description

technical field [0001] The invention relates to the technical field of electrolytic aluminum, in particular to an anti-corrosion and anti-oxidation coating material for electrolytic aluminum anode steel claws and a preparation method thereof. Background technique [0002] The production of electrolytic aluminum in modern industry mainly adopts the cryolite-alumina molten salt electrolysis method, that is, the carbon body is used as the anode (since the carbon body is connected to one end of the steel claw, and the other end of the steel claw is connected to the DC power supply, Therefore, it is commonly known as "anode steel claw"), using molten cryolite as the electrolyte, using the molten metal aluminum dissolved in the electrolyte as the cathode, and passing direct current to the two poles. Electrochemical reaction is carried out to obtain metallic aluminum products. [0003] Only the carbon body part of the anode steel claw is in contact with the electrolyte, and the st...

AI Technical Summary

Problems solved by technology

[0009] The formulas of the protective coatings for electrolytic aluminum anodes disclosed above are all more complicated, and in addition to aluminum elements, also contain a large amount of other elements in the raw materials, although the electrodes can be protected from corrosion, they will be released into the electrolyte (melted ice crystals) The introduction of other elements may have adverse effects on the quality of aluminum products (such as the introduction of other impurities, the increase in the amount of impurities leads to a decrease in the purity of aluminum products)

[0010] In addition, the anode protective coating formulations disclosed in prior art 2-5 all contain organic matter (such as acrylic emulsion, glycerin in prior art 2; hydroxyphosphazene resin, organic adhesion promoter in prior art 5) And / or cement components (such as kaolin in prior art 3; binder CA (calcium aluminate) cement in prior art 4), the heat resistance of organic matter generally does not exceed 450 ° C, and it is easy to decompose and volatilize when heated, making the coating The protective function of the anode steel claws is lost due to the formation of channels in the middle; cement is a hydraulic adhesive, which will lose water and lose strength at high temperatures. Even refractory cement cannot withstand high temperatures above 900 ° C. These adhesives and binders will be lost at high temperatures. Strength, so that the coating powder, can not play the role of effective protection of the electrode, and further deteriorate the quality of aluminum products