阅读说明：本技术 一种铝电解槽阴极炭块局部破损修补方法 (Method for repairing local damage of cathode carbon block of aluminum electrolytic cell ) 是由 钱云超 杨永 杨军龙 周志昌 张文学 杜才德 黄荣钢 申太荣 王�锋 张荐 唐喜 于 2021-10-19 设计创作，主要内容包括：一种铝电解槽阴极炭块局部破损修补方法,在线从电解槽中提出破损的阳极,用直角钎子在铝电解槽阴极表面寻找并确定破损点；取打碎的镁砖堆放到破损点；取打碎的结壳块堆放到破损点镁砖上面；将粉状氧化铝堆放到结壳块上,全部覆盖修补料；电解槽通电,根据电解槽底的对应破损点位置的导电方钢温度上升梯度,对破损点导电方钢温度进行判定；当修补料在阴极炭块表面完全融化,均匀填补到破损点,化成为一个整体后,完成对阴极炭块的破损修补。本发明方法工艺简单、高效快捷、修补效果好。(A method for repairing local damage of cathode carbon blocks of an aluminum electrolytic cell comprises the steps of extracting damaged anodes from the electrolytic cell on line, and searching and determining damage points on the surface of the cathode of the aluminum electrolytic cell by using a right-angle brazing flux; taking and stacking the smashed magnesia bricks to a damaged point; taking the smashed crusting blocks and stacking the smashed crusting blocks on the magnesium bricks at the damaged points; stacking the powdery alumina on the crusting block, and completely covering the repair material; electrifying the electrolytic cell, and judging the temperature of the conductive square steel at the damaged point according to the temperature rising gradient of the conductive square steel at the position of the corresponding damaged point at the bottom of the electrolytic cell; and when the repair material is completely melted on the surface of the cathode carbon block, uniformly filling the repair material to the damaged point, and forming the cathode carbon block into a whole, completing the damage repair of the cathode carbon block. The method has the advantages of simple process, high efficiency, rapidness and good repairing effect.)

1. A method for repairing local damage of a cathode carbon block of an aluminum electrolytic cell is characterized by comprising the following repairing steps:

s1, in the operation process of an electrolytic cell, when the mass percentage of ferrosilicon in aluminum liquid in the electrolytic cell suddenly rises too fast or continuously rises during periodic analysis, measuring the temperatures of a furnace bottom, square steel and a heat dissipation hole of the electrolytic cell body, finding a corresponding anode at the suddenly rising too fast or continuously rising position, extracting the anode from the electrolytic cell, finding the position, the shape, the perimeter size and the damage depth of a damage point on the surface of a cathode of the aluminum electrolytic cell by using a right-angle drill rod, and determining the damage point;

s2, determining the position of a damaged point, stacking the smashed magnesia bricks to the damaged point of the cathode carbon block, wherein the stacking thickness is higher than the upper surface of the surrounding cathode carbon block;

s3, stacking the smashed crusting blocks on the magnesium bricks at the damage points of the cathode carbon blocks, wherein the crusting blocks are sediment materials cleaned from the electrolytic bath;

s4, stacking the powdery aluminum oxide on the crusting block, and completely covering the repairing material;

s5, electrifying the electrolytic cell, judging the temperature of the conductive square steel at the damaged point according to the temperature rising gradient of the conductive square steel at the position of the corresponding damaged point at the bottom of the electrolytic cell, and cutting off the welding part of the square steel head of the conductive square steel and the flexible connecting belt after repairing when the temperature of the conductive square steel is higher than 350 ℃ so as to prevent current from passing through the conductive square steel of the damaged cathode carbon block; when the temperature of the conductive square steel is less than 350 ℃, tracking the temperature after repairing, cutting off the welding part of the square steel head and the soft connecting belt if the temperature continuously rises, so that the current does not pass through the conductive square steel of the damaged cathode carbon block, and continuously tracking and measuring the temperature of the conductive square steel if the temperature drops;

and S6, when the repair material formed by mixing the magnesia bricks, the crusting blocks and the alumina is completely melted on the surface of the cathode carbon block, uniformly filling the repair material to the damaged points, and forming the cathode carbon block into a whole, completing the damage repair of the cathode carbon block.

2. The method for repairing the local damage of the cathode carbon block of the aluminum electrolysis cell as recited in claim 1, wherein the stacking thickness of the crushed magnesia bricks stacked to the damage point of the cathode carbon block is 9-11cm higher than the upper surface of the surrounding cathode carbon block.

3. The method for repairing the local damage of the cathode carbon block of the aluminum electrolysis cell as claimed in claim 1 or 2, wherein the size of the broken magnesia brick blocks is 3-5 cm.

4. The method for repairing the local damage of the cathode carbon block of the aluminum electrolysis cell according to claim 1 or 2, wherein the stacking thickness of the crusted blocks stacked on the crushed magnesium bricks at the damage point of the cathode carbon block is 9-11cm higher than that of the crushed magnesium bricks.

5. The method for repairing the local damage of the cathode carbon block of the aluminum electrolytic cell as recited in claim 3, wherein the thickness of the piled crust breaking blocks piled on the broken magnesium bricks at the damage point of the cathode carbon block is 9-11cm higher than that of the broken magnesium bricks.

6. The method for repairing the local damage of the cathode carbon block of the aluminum electrolytic cell as claimed in claim 1 or 2, wherein the crusting block is heavy solid formed by alumina precipitated on the bottom of the furnace under the high temperature condition of more than 920 ℃, the main component is alpha-alumina, and the size of the crushed block of the crusting block is 3-5 cm.

7. The method for repairing the local damage of the cathode carbon block of the aluminum electrolytic cell as claimed in claim 3, wherein the crusting block is heavy solid gradually formed by alumina precipitated on the bottom of the furnace under the high temperature condition of more than 920 ℃, the main component is alpha-alumina, and the size of the crushed block of the crusting block is 3-5 cm.

8. The method for repairing the local damage of the cathode carbon block of the aluminum electrolytic cell as claimed in claim 4, wherein the crusting block is heavy solid gradually formed by alumina precipitated on the bottom of the furnace under the high temperature condition of more than 920 ℃, the main component is alpha-alumina, and the size of the crushed block of the crusting block is 3-5 cm.

Technical Field

The invention relates to the technical field of aluminum electrolysis cell cathode carbon block damage repair, in particular to a method for repairing local damage of a cathode carbon block in an aluminum electrolysis cell.

Background

In the process of aluminum electrolysis production, the aluminum electrolysis cathode carbon block can be partially damaged, and in the physical aspect, due to the factors of uneven thermal expansion and gravity pressure, the cathode thermal attraction is unevenly stressed, so that the cathode is physically extruded and damaged; in chemical aspects, the cathode is damaged in a consumable manner due to sodium permeation, aluminum carbide generated at the cathode, an electrocapillary phenomenon, aluminum, electrolyte and the like which permeate into the gaps of the cathode carbon block. If a damaged position is found in normal production, repair must be performed in a timely manner. The existing aluminum electrolysis cell repair mainly adopts on-line repair or cell stopping overhaul, wherein the on-line repair is to dispersedly add repair materials at damaged positions, although the method does not stop the cell overhaul, the repair materials can not be completely and rapidly filled to the damaged positions, and redundant repair materials can be deposited on the surface of an electrolytic cell cathode to interfere the material balance and the energy balance of the electrolytic cell and influence the stable operation of aluminum electrolysis production. The method affects the productivity and the yield of the series aluminum electrolysis cells, and has long overhaul period, high cost, no current consumption of the aluminum electrolysis production line and greatly increased power consumption cost. The concrete repairing method of the aluminum electrolytic cell comprises a magnesia brick method, an aluminum liquid-alumina method, a crushed material method and the like. In the magnesia brick method, as few magnesia bricks are arranged in the groove in the repairing process, the magnesia bricks are easy to melt and flow in high-temperature molten electrolyte and aluminum liquid, and few magnesia bricks are deposited at the position of a damaged point for a long time; the aluminum liquid-alumina method is not capable of precipitating at the position of a damaged point for a long time because aluminum is easy to melt and is mixed with aluminum water; the crushed material block method has small density, can float and flow in high-temperature molten electrolyte and aluminum liquid, and has less crushed material blocks entering the position of a damaged point. In conclusion, the existing methods often result in the defect of incomplete repair of the damaged point.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for repairing the local damage of the cathode carbon block of the aluminum electrolytic cell, which has the advantages of simple process, high efficiency, rapidness and good repairing effect.

The technical scheme adopted by the invention is as follows:

a method for repairing local damage of a cathode carbon block of an aluminum electrolytic cell comprises the following repairing steps:

s1, in the operation process of an electrolytic cell, when the mass percentage of ferrosilicon in aluminum liquid in the electrolytic cell suddenly rises too fast or continuously rises during periodic analysis, measuring the temperatures of a furnace bottom, square steel and a heat dissipation hole of the electrolytic cell body, finding a corresponding anode at the suddenly rising too fast or continuously rising position, extracting the anode from the electrolytic cell, finding the position, the shape, the perimeter size and the damage depth of a damage point on the surface of a cathode of the aluminum electrolytic cell by using a right-angle drill rod, and determining the damage point;

s2, determining the position of a damaged point, stacking broken magnesia bricks with the size of 3-5cm to the damaged point of the cathode carbon block, wherein the stacking thickness of the broken magnesia bricks is 9-11cm higher than the upper surface of the surrounding cathode carbon block;

and S3, stacking crusting blocks with the crushed size of 3-5cm on the magnesium bricks at the damaged points of the cathode carbon blocks, wherein the stacking thickness of the crusting blocks is 9-11cm higher than that of the crushed magnesium bricks. The crusting block is a heavy solid formed by alumina gradually under the condition of long-term high temperature cleaned from an old electrolytic cell, and the main component of the crusting block is alpha-alumina;

s4, stacking the powdery aluminum oxide on the crusting block, and completely covering the repairing material;

s5, electrifying the electrolytic cell, judging the temperature of the conductive square steel at the damaged point according to the temperature rising gradient of the conductive square steel at the position of the corresponding damaged point at the bottom of the electrolytic cell, and cutting off the welding part of the square steel head of the conductive square steel and the flexible connecting belt after repairing when the temperature of the conductive square steel is higher than 350 ℃ so as to prevent current from passing through the conductive square steel of the damaged cathode carbon block; when the temperature of the conductive square steel is less than 350 ℃, tracking the temperature after repairing, cutting off the welding part of the square steel head and the soft connecting belt if the temperature continuously rises, so that the current does not pass through the conductive square steel of the damaged cathode carbon block, and continuously tracking and measuring the temperature of the conductive square steel if the temperature drops;

and S6, when the repair material formed by mixing the magnesia bricks, the crusting blocks and the alumina is completely melted on the surface of the cathode carbon block, uniformly filling the repair material to the damaged points, and forming the cathode carbon block into a whole, completing the damage repair of the cathode carbon block.

Compared with the prior art, the invention has the following beneficial effects:

(1) the method only needs to carry out local online operation repairing on the damaged part of the cathode carbon block of the aluminum electrolytic cell, has simple repairing process, short repairing time, low cost, high efficiency, rapidness and good repairing effect, and reduces the influence on production to the maximum extent.

(2) The method effectively solves the technical problems that the magnesium bricks are less and the long-time sedimentation repair is difficult to realize and the aluminum liquid-aluminum oxide and crushed aggregates are easy to melt in the repair process of the damaged points of the cathode carbon blocks of the aluminum electrolytic cell. By utilizing the mode of combining the crusting block and the magnesia brick, the melting of the magnesia brick in high-temperature molten electrolyte and aluminum liquid is effectively controlled under the action of the crusting block, and the problem that a repair object is easy to melt is effectively solved.

(3) The crust block is a byproduct in the production of the electrolytic cell and needs to be cleaned regularly, and the invention recycles the crust block, can reduce the repair cost and the interference of other impurities, and plays a role in ensuring the improvement of the product quality.

Drawings

FIG. 1 is a schematic view of a repair cell.

Detailed Description

The invention is described in further detail below with reference to the figures and examples.

FIG. 1 shows a method for repairing local damage of cathode carbon block of aluminum electrolysis cell. The aluminum electrolytic cell in the prior art comprises a cell body 1, an anode 2, a cathode carbon block 3, conductive square steel 4, a soft connecting belt 5, electrolyte 10 and molten aluminum 11. When the cathode carbon block is found to be partially damaged, the cathode carbon block is repaired. The repairing steps are as follows:

s1, in the operation process of the electrolytic cell, the mass percent of ferrosilicon in aluminum liquid in the cell suddenly rises too fast or continuously rises during periodic analysis, the temperatures of the furnace bottom, square steel and heat dissipation holes of the cell body are measured, an anode which is approximately corresponding to the suddenly rising too fast or continuously rising position is found, an anode 2 above a cathode damage position is lifted out of the electrolytic cell 1, and the position, the shape, the perimeter size and the damage depth of a damage point are manually found on the surface of a cathode carbon block of the aluminum electrolytic cell by using a right-angle drill rod, so that the damage point is determined.

S2, manually operating, determining the position of a damaged point, taking broken magnesium bricks 7 (namely broken magnesium bricks) and stacking the broken magnesium bricks to the damaged point 6 of the cathode carbon block, wherein the stacking thickness is higher than the upper surface of the surrounding cathode carbon block and is usually 9-11cm higher than the upper surface of the cathode carbon block. The magnesium brick is directly purchased from the market, and the size of the crushed magnesium brick after the crushing treatment is preferably 3-5 cm.

S3, manually taking the smashed crusting blocks 8 and stacking the smashed crusting blocks on the magnesium bricks at the cathode breakage points. The crusting blocks are sediment materials cleaned from the electrolytic bath; in order to precipitate alumina in normal production on the furnace bottom, heavy solids are formed under the condition of long-term high temperature (more than 920 ℃), and the main component is alpha-alumina. The size of the fragments after the crust block is crushed is preferably 3-5 cm.

S4, manually stacking the powdery aluminum oxide 9 on the crusting blocks to completely cover the repair materials, namely the crushed magnesium bricks and the crushed crusting blocks;

s5, electrifying the electrolytic cell, and observing the temperature change condition of the conductive square steel 4 at the position corresponding to the damaged point at the bottom of the electrolytic cell through an electrolytic cell control system. Judging the temperature of the conductive square steel at the damaged point according to the temperature rising gradient of the conductive square steel, and cutting off the welding part of the square steel head of the conductive square steel and the soft connecting belt 5 after repairing when the temperature of the conductive square steel is more than 350 ℃ so as to prevent current from passing through the conductive square steel of the damaged cathode; when the temperature of the conductive square steel is less than 350 ℃, temperature tracking is carried out after repairing, if the temperature continuously rises, the welding part of the square steel head and the flexible connecting belt is cut off, current does not pass through the conductive square steel of the damaged cathode, and if the temperature drops, tracking measurement is continuously carried out.

And S6, when the repair material formed by mixing the magnesia bricks, the crusting blocks and the alumina is completely melted on the surface of the cathode, uniformly filling the damage points, and forming into a whole, completing the damage repair of the cathode.