Online repair method of large pre-baking tank

Abstract

The invention aims at discloses an online repair method of a large pre-baking tank. Compared with the prior art, during runout of an electrolytic tank, an anode carbon block on the leaking tank portion is rapidly pulled out, an electrolyte and aluminum oxide are mixed to isolate the area, a mixture is tamped, and molten aluminum and the electrolyte are prevented from leaking out; rapid repair canbe achieved within the shortest time under the condition of production without shutting down the tank, and the situation that the molten aluminum leaks by a large area, the generatrix around the tankis cut off, and safety operation of series electrolytic tanks is influenced is avoided; and construction is simple, operation is easy, the repair cost is saved, and the aim of the method is achieved.

Description

technical field [0001] The invention relates to a repairing method, in particular to an online repairing method for a large prebaked tank suitable for an electrolytic tank. 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 and operation of the aluminum electrolytic cell, and the temperature of the cell is unstable, which makes the internal stress of the cathode lining locally and cracks appear. Falling 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 embedded compound with the cathode carbon lining through the interface reaction, and the cathode carbon is caused by its crystal lattice larger than the carbon lattice size. The local expansion of the inner lining produces ...

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 and operation of the aluminum electrolytic cell, and the temperature of the cell is unstable, which makes the internal stress of the cathode lining locally and cracks appear. Falling 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 embedded compound with the cathode carbon lining through the interface reaction, and the cathode carbon is caused by its crystal lattice larger than the carbon lattice size. The local expansion of the inner lining produces internal stress, which leads to damage to the carbon lining of the cathode; at high temperature, metal aluminum reacts with carbon to produce chemical and electrochemical corrosion, which damages the carbon lining of the cathode, etc., but for the side leakage of the electrolytic cell It is too much loss for the enterprise to stop the furnace for repair

[0003] First, there is unbalanced settlement, and the settlement of the side B of the aluminum outlet of the electrolytic cell is more serious. The aluminum liquid and electrolyte in the tank tilt toward the aluminum outlet B to squeeze the corner block and the adjustment block of B, causing the insulation failure of the tank body, and the corner block and the tank The shell is connected and conductive, and the side block at the corner breaks down, which damages the tank shell and causes damage

[0004] The second is that there is less crusting on the side wall of the cathode inner chamber of the large prebaked tank. On the upper edge of the artificial leg, the silicon nitride combined with silicon carbide side block at the interface between the aluminum liquid and the electrolyte liquid is seriously corroded, which leads to an increase in the early damaged tank and makes the electrolytic Shortened service life of the tank