An electrolytic process for repairing and restarting an aluminum electrolytic cell

Abstract

The invention relates to the technical field of electrolytic tanks, in particular to an electrolyzing technology for repair and restarting of an aluminum electrolytic tank. The electrolyzing technology comprises the following steps of S1, reducing of running indexes; S2, overhauling; S3, restarting; S4, adjusting of technical parameters to establish new heat balance; S5, cleaning. The electrolyzing technology for repair and restarting of the aluminum electrolytic tank has the advantages that after the heat-insulation material of the furnace surface is completely manufactured, the molecule ratio is adjusted to about 2.75, the fluidity of electrolyte is good, the anode current is uniformly distributed, the voltage fluctuation is reduced, the stability of the tank is enhanced, the settled crust at the furnace bottle is gradually melted, the series current is gradually increased back to 296KA to reach new heat balance, the voltage drop at the furnace bottom is reduced from 453V to 370V after the technical scheme is adopted, the fluctuation of tank voltage is basically eliminated, the long-time stable running is reached, and the electrolyzing temperature is stabilized to 905 DEG C for along time; the outstanding material characteristics and obvious progress are realized.

Description

technical field [0001] The invention relates to the technical field of electrolytic cells, in particular to an electrolytic process for repairing and restarting an aluminum electrolytic cell. Background technique [0002] Bauxite in Henan, Shanxi and other places is rich in lithium salts and potassium salts, and these lithium salts and potassium salts cannot be effectively removed during the process of converting aluminum ore into alumina. These lithium salts and potassium salts will be brought into the electrolyte of electrolytic aluminum along with the alumina, and gradually enrich in the electrolyte, with the concentration of lithium salts as high as 9-10%. As a result, the electrolysis temperature drops to 890-900°C, the viscosity of the electrolyte is high, the fluidity is poor, the ability to dissolve alumina drops sharply, and a large amount of precipitation and crusting occur at the bottom of the electrolytic tank. The bottom pressure drop of the electrolytic cell i...

AI Technical Summary

Problems solved by technology

As a result, the electrolysis temperature drops to 890-900°C, the viscosity of the electrolyte is high, the fluidity is poor, the ability to dissolve alumina drops sharply, and a large amount of precipitation and crusting occur at the bottom of the electrolytic tank

The bottom pressure drop of the electrolytic cell increases, the operation stability deteriorates, the current efficiency decreases, the power consumption per ton of aluminum rises sharply, and the production cost remains high. After the electrolytic cell has been in operation for a period of time, the anode plate needs to be replaced. The anode is slow to conduct electricity, and the uneven distribution of anode current causes many sick cells, low current efficiency, power consumption per ton of aluminum is as high as 14900kwh / t-Al, and the production cost remains high. Therefore, we propose a method of repairing and restarting the aluminum electrolytic cell electrolytic process