Method for repairing damage of cathode of prebaked anode aluminum electrolytic cell

Abstract

The invention discloses a method for repairing damage of a cathode of a prebaked anode aluminum electrolytic cell. The method for repairing damage of the cathode of the prebaked anode aluminum electrolytic cell comprises the steps that (1) a damage position of the prebaked anode aluminum electrolytic cell is determined; (2) an alumina repairing block is prepared, specifically, an alumina ball andaluminum liquid are arranged in a container, the alumina ball is immersed in the aluminum liquid, after cooling is conducted to the room temperature, a solid material is poured out reversely, and thealumina repairing block is obtained; and (3) repairing is conducted, specifically, after the alumina repairing block is arranged at the damage position, the upper surface of the alumina repairing block is covered with a shell face or a cell bottom precipitation block, and an anode is put in and maintained. According to the method for repairing damage of the cathode of the prebaked anode aluminum electrolytic cell, the alumina ball is adopted for replacing magnesia and made into an aluminum cake for repairing the broken cell, new impurities (such as magnesium elements) are not brought into thealuminum liquid in the repairing process, the service life is effectively prolonged by one and a half years or longer, and the repairing effect is more stable and lasting.

Description

technical field [0001] The invention specifically relates to a method for repairing damage to the cathode of a prebaked anode aluminum electrolytic cell. Background technique [0002] In 1888, the electrolysis method was applied to industrial aluminum smelting. The early electrolytic cells only had a few thousand amperes. After entering the 20th century, with the development of rectification technology, the current intensity of small pre-baked cells was improved, and self-baked anode electrolytic cells appeared at the same time. . In the 1960s, the current intensity of the small prebaked anode electrolyzer was increased to 50KA. After the 1970s, self-baked anode electrolyzers and prebaked anode electrolyzers were developed simultaneously, and the current intensity exceeded 100KA. Since the 1980s, the advantages of prebaked anode electrolyzers have gradually emerged. After 1990, prebaked anode electrolyzers have been fully promoted. After 2000, some self-baking anode elec...

AI Technical Summary

Problems solved by technology

[0005] However, the actual repair effect of this prior art is not ideal, and the extended service life is less than 1 year. The main problems are: (1) The main component of magnesia bricks is magnesium oxide, and the impurities are calcium oxide, silicon dioxide, iron oxide, etc. , a repair needs to add about 50 kg of magnesia bricks, which will increase the magnesium and silicon in the primary aluminum elements, which will have a great impact on the quality of primary aluminum; (2) magnesia is easily washed away in molten aluminum and is very It is difficult to have the conditions for roasting and sintering, and stable crystals cannot be formed. In addition, there are some sodium elements that are more active than magnesium in the molten aluminum, which will undergo replacement and reduction reactions with magnesium oxide in magnesia, and there is still dissolution in the magnesia and aluminum electrolytic system. Balance, the effect of the actual repair is not ideal

Images