Repair method for partial damage of cathode carbon block at the bottom of aluminum electrolytic cell

Abstract

The invention relates to a method for repairing a local damage to a cathode carbon block at the bottom of an aluminum electrolysis cell. The method comprises the following steps: finding out the position, shape, perimeter and damage depth of a damage point, and determining the damage point; selecting a repair-material-coating solid aluminum mold block cast by a casting mold having a shape most similar to that of the damage point, and filling the solid aluminum mold block into the damage point; and cutting off the part for welding a steel bar head and a flexible connection of a cathode carbon block at the damage point to enable electric current not to pass through the damaged cathode and the like. The method has the following advantages: overhaul of the entire lining of a cell accompanied with thorough shutdown of the cell is not needed, the repair time is short, the repair cost is low, and the influence on normal production is greatly reduced. Besides, the method effectively solves the technical problem of incomplete repair due to low density of magnesite in the aluminum electrolysis cell repair process; the method greatly decreases interference with the electrolysis cell, thereby ensuring efficient smooth running of the electrolysis cell; and the method greatly lowers the repair cost, improves the repair quality and prolongs the service life of the repair material.

Description

technical field [0001] The invention relates to a repair method for a damaged aluminum electrolytic tank, in particular to a repair method for partially damaged cathode carbon blocks at the bottom of an aluminum electrolytic tank. Background technique [0002] During the aluminum electrolysis production process, the cathode carbon block at the bottom of the aluminum electrolysis will be partially damaged. If the damaged position is found during normal production, it must be repaired in time. The existing aluminum electrolytic cell repair technology mainly adopts the overhaul of stopping the cell, that is, completely stopping the damaged cell and overhauling the lining of the cell. ), high overhaul cost (800,000 to 1,200,000 yuan for one overhaul of 200-300kA), and will also cause empty current consumption of series aluminum electrolysis production lines, greatly increasing power consumption costs. Some literatures propose to adopt the online repair method and add repair mat...

AI Technical Summary

Problems solved by technology

The existing aluminum electrolytic cell repair technology mainly adopts the overhaul of stopping the cell, that is, completely stopping the damaged cell and overhauling the lining of the cell. ), the cost of overhaul is high (200-300kA overhaul is 800-1.2 million yuan a time), and it will also cause a series of aluminum electrolysis production lines to lose current and greatly increase the cost of power consumption

Some literatures propose to adopt the online repair method and add repair materials scatteredly at the damaged position. Although this method does not stop the overhaul of the tank, the repair material cannot be filled to the damaged position quickly, and the excess repair material will be deposited on the cathode surface of the electrolytic cell. , the production of furnace bottom crusting will interfere with the material balance and energy balance of the electrolytic cell in severe cases, and affect the smooth operation of aluminum electrolysis production

In addition, the existing aluminum electrolytic cell repair basically uses magnesia and molten aluminum to fill the damage. During the repair process, because the density of magnesia is low, it will float and flow in the high-temperature molten electrolyte and molten aluminum, and the magnesium that enters the damaged point Less sand often leads to incomplete repair of damaged points

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