A curved anode for reducing the probability of anode effect and its production method

Abstract

The invention relates to a curved-surface anode capable of decreasing anode effect occurrence probability and a production method. The curved-surface anode is structurally characterized in that an edge position on the lower side of the anode is in the shape of a convex curved surface, a large surface of the anode and the bottom surface of the anode are through by the aid of the convex curved surface, and the end of the anode is a convex curved surface with a gradually-changeable radius and through with the bottom surface. The anode of the structure is used in an electrolytic bath to enable gas to move to the edge along the anode bottom, and the gas can be smoothly discharged from the end and the large surface of the anode under the guidance action of an arc edge so that the anode effect occurrence probability is decreased. Additionally, a gas film can be dispelled with the aid of flowing electrolyte so that anode effect is reduced. 0.5-1.5% of current efficiency of the electrolytic bath can be improved by the whole curved-surface anode, time for gas bubbles in enrichment on the surface of the anode is shortened, corrosion of anode gas to an anode body is reduced, ineffective consumption of the anode is lowered, and carbon consumption of each ton of the aluminum anodes can be reduced by about 5kg. During production of the curved-surface anode, about 5-10kg of paste is saved for each ton of the curved-surface anodes, and raw material consumption is reduced by about 0.6-2.5%.

Description

technical field [0001] The invention relates to a production technology of an anode structure for aluminum electrolysis, in particular to a curved anode and a production method for reducing the occurrence probability of an anode effect. Background technique [0002] The anode effect is a unique phenomenon in molten salt electrolysis, and the performance of electrolytic aluminum production is the most obvious. The harmfulness of the anode effect in aluminum electrolysis production is not only manifested in the harm to production, but also extremely serious harm to the ecological environment. When When the anode effect occurs, the voltage of the electrolyzer rises sharply, reaching 20-50V, sometimes even higher. Its occurrence has a great impact on the entire electrolysis series, reducing the current efficiency, affecting various technical indicators of electrolysis, reducing the output and quality of aluminum, and destroying the stable power supply of the entire electrolysis ...

AI Technical Summary

Problems solved by technology

Its occurrence has a great impact on the entire electrolysis series, reducing the current efficiency, affecting various technical indicators of electrolysis, reducing the output and quality of aluminum, and destroying the stable power supply of the entire electrolysis series

The mechanism of the anode effect has not yet been ascertained, but the "anode process change theory" can better explain the mechanism of the anode effect. This view believes that the occurrence of the anode effect is due to the electrolysis process. The oxygen-containing ions in the electrolyte gradually decrease. When it reaches a certain level, fluorine precipitates and reacts with the anode carbon to form carbon fluoride. When the carbon fluoride decomposes, fine carbon particles are precipitated, and these carbon particles are attached to the surface of the anode. On the surface, it prevents the contact between the electrolyte and the anode, so that the electrolyte cannot wet the anode well, just like water cannot wet the oiled surface, so that a poorly conductive gas film is formed between the electrolyte and the anode, and the anode overvoltage increases. anode effect

The usual treatment methods are: use effect rods (wooden sticks) to extinguish, or reduce the anode, increase the amount of aluminum oxide, to achieve the purpose of extinguishing the anode effect. Although these treatment methods are effective, there are always certain limitations, such as treatment Not timely enough, consumes a certain amount of materials, etc.

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