Online minor repair method for 300/380KA large-scale prebake cells

Abstract

The invention discloses an online minor repair method for 300 / 380KA large-scale prebake cells. The method comprises the following steps of: when lining damage or red furnace or furnace leakage occursat the side part of a prebake cell, pulling out an anode carbon block at a leakage point in time without stopping the cell; encircling the periphery of the leakage point by molten aluminum and liquidelectrolyte through a mixture of electrolyte and aluminum oxide; cooling the outer side of the cell shell leakage point of the prebake cell via blowing by using compressed air; when the temperature islower than 150 DEG C, starting to clean the inner side of the leakage point to ensure that the bottom is flat and the vertical face is straight; cleaning the residual materials, cooling via blowing by using compressed air, when the temperature is reduced to 100 DEG C, paving a thickener and carrying out compaction, constructing an anode carbon block at the top of the thickener, and tamping aluminum oxide between the lateral anode carbon block and the cell shell; after the repair, carrying out baking for 24, and mounting the pulled anode carbon block. According to the method, rapid repair is carried out in a shortest time without stopping the cell, so that large-area molten aluminum leakage caused by untimely processing is prevented from thrusting buses around the cell and then influencingthe safe operation of electrolytic series.

Description

technical field [0001] The invention relates to a maintenance method for an aluminum electrolysis electrolytic cell, in particular to an online minor repair method for a 300 / 380KA large prebaked cell. Background technique [0002] In the production process of aluminum electrolysis, there are many reasons for the damage of the lining of the electrolytic cell. For example, the temperature gradient is too large during the firing start-up and operation of the aluminum electrolytic cell, and the tank temperature is unstable, which causes the internal stress of the cathode lining to locally generate cracks and fall off. The thermal expansion and contraction of the cathode carbon block do not match the expansion after heating; the current distribution is uneven; the metal sodium forms a stable intercalation compound with the cathode carbon lining through the interface reaction, because its lattice is larger than the carbon lattice size. The local expansion of the lining generates i...

AI Technical Summary

Problems solved by technology

[0002] In the production process of aluminum electrolysis, there are many reasons for the damage of the lining of the electrolytic cell. For example, the temperature gradient is too large during the firing start-up and operation of the aluminum electrolytic cell, and the tank temperature is unstable, which causes the internal stress of the cathode lining to locally generate cracks and fall off. The thermal expansion and contraction of the cathode carbon block do not match the expansion after heating; the current distribution is uneven; the metal sodium forms a stable intercalation compound with the cathode carbon lining through the interface reaction, because its lattice is larger than the carbon lattice size. The local expansion of the lining generates internal stress, which leads to damage to the carbon lining of the cathode; at high temperature, metal aluminum and carbon are formed by the interaction, resulting in chemical and electrochemical corrosion, which damages the carbon lining of the cathode, etc. But the shutdown repair is too big a loss for the enterprise

Images