WO2013016930A1

WO2013016930A1 - Method for reducing horizontal current in liquid aluminum in aluminum reduction cell

Info

Publication number: WO2013016930A1
Application number: PCT/CN2011/084507
Authority: WO
Inventors: 李旺兴; 杨建红; 邱仕麟; 张艳芳; 王跃勇; 侯光辉
Original assignee: 中国铝业股份有限公司
Priority date: 2011-08-04
Filing date: 2011-12-23
Publication date: 2013-02-07
Also published as: CN102234820B; CN102234820A

Abstract

Disclosed is a method for reducing the horizontal current in liquid aluminum in an aluminum reduction cell, comprising: placing a part of current conducting material at a cathode carbon block, or a steel bar, or a connecting material cathode paste thereof, or phosphorus pig iron, and making the current in the liquid aluminum enter the cathode carbon block evenly, pass through the steel bar, and exit from a side portion of the reduction cell. The method provided by the present invention changes the resistance distribution at the cathode, adjusts the current distribution at the cathode, reduces the horizontal current in the liquid aluminum, improves the stability of the magnetic fluid in the reduction cell, improves the efficiency of the current, and extends the service life of the cell.

Description

Method for reducing horizontal current of aluminum liquid in aluminum electrolytic cell

Technical field

The invention relates to the technical field of electrolytic cells, in particular to a method for reducing the horizontal current of aluminum liquid in an aluminum electrolytic cell. Background technique

In a conventional aluminum electrolysis cell, current flows down the anode into the cell, through the molten electrolyte and aluminum liquid, to the cathode carbon block, and then through the carbon block and the confluence horizontally embedded in the cathode carbon block by the cathode paste or phosphorus pig iron. The steel rods come out from both sides of the cell and pass through the cathode bus to the next cell. Under this structure, since the current always flows through the path of the smallest resistance, a third of the current close to the power-off side of the steel bar is loaded with most of the current, resulting in a large amount of horizontal current in the aluminum liquid layer, the aluminum liquid layer The current distribution of the cathode carbon block is uneven, and the closer to the output end, the higher the current density. The larger horizontal current in the aluminum liquid will generate electromagnetic force under the action of the magnetic field, increase the instability of the electrolytic cell, reduce the current efficiency, and increase the power consumption; the uneven current distribution in the cathode carbon block will cause the carbon block to be easily Corrosion, reducing groove life. At present, with the increase of the size of the electrolytic cell, the increase of the width of the electrolytic cell leads to more horizontal current of the aluminum liquid and uneven distribution of the cathode current. Although the magnetic field of large tanks is constantly being optimized, the large increase in horizontal current still limits the development of large tanks and the advancement of aluminum industry technology. Summary of the invention

The technical problem to be solved by the present invention is to provide a aluminum electrolytic cell aluminum which can make the current distribution in the aluminum liquid more uniform, reduce the horizontal current in the aluminum liquid, and is beneficial to the stable, high-efficiency and long-life operation of the large aluminum electrolytic cell. Liquid level current method.

In order to solve the above technical problems, the present invention provides a method for reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell, and laying a partial current conduction in a cathode carbon block, or a steel rod, or a connecting material thereof, or a phosphorus pig iron. The material causes the current in the aluminum liquid to be relatively uniformly hooked into the cathode carbon block, and exits from the side of the electrolytic cell through the steel rod.

The invention provides a method for reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell, which can effectively change the yin The pole resistance distribution adjusts the cathode current distribution to reduce the horizontal current in the aluminum liquid, increase the magnetic fluid stability of the electrolytic cell, and improve current efficiency and tank life. DRAWINGS

1 is a schematic view showing the structure of a first embodiment of the present invention.

2 is a schematic diagram of the structure of Embodiment 2 of the present invention.

FIG. 3 is another schematic diagram of the structure of Embodiment 3 of the present invention.

Figure 4 is a cross-sectional view of Figures 2 and 3 of the present invention.

Figure 5 is a top plan view of Figures 1, 2, 3 of the present invention.

FIG. 6 is a schematic diagram of a structure of a third embodiment of the present invention.

FIG. 7 is another schematic diagram of the structure of Embodiment 3 of the present invention.

Figure 8 is a cross-sectional view of Figures 6 and 7 of the present invention.

Figure 9 is a top plan view of Figures 6 and 7 of the present invention.

FIG. 10 is a schematic diagram showing the structure of Embodiment 4 of the present invention.

FIG. 11 is another schematic diagram of the structure of Embodiment 4 of the present invention.

Figure 12 is a cross-sectional view of Figures 10 and 11 of the present invention.

FIG. 13 is a schematic diagram of Embodiment 5 of the present invention. detailed description

The invention provides a method for reducing the horizontal current of the aluminum liquid in the aluminum electrolytic cell, and laying a part of the current guiding material 3 at the cathode carbon block 1 or the steel rod 2 or its connecting material cathode paste or phosphorus pig iron 4, so that the cathode resistance is from the inner side Gradually increasing outside, the current in the aluminum liquid is relatively uniform and enters the cathode carbon block, thereby achieving the purpose of reducing the horizontal current of the aluminum liquid. The method for reducing the horizontal current of the aluminum liquid in the aluminum electrolytic cell will be described in detail below in conjunction with the specific embodiments of the present invention and the accompanying drawings.

Embodiment 1

As shown in Fig. 1 and Fig. 5, a flow guiding material is laid between the cathode carbon block and the steel rod, and the current guiding material 3 can be laid in various ways as needed. A thin layer of current-conducting material 3 is laid between the blocks of carbon block 1 and steel rod 2 without changing the carbon block and steel rod structure, or first combined with steel rod 2. The current guiding material 3 may be one or more materials having a resistivity greater than that of the carbon block, or The non-continuously laid insulation material is placed on the outer 1/3 or 2/3 of the carbon block 1 as needed to increase the cathode resistance of the section and reduce the current throughput, thereby reducing the horizontal current in the aluminum liquid. .

Embodiment 2

As shown in Fig. 2, a flow guiding material 3 is laid between the cathode carbon block and the steel rod, and the current guiding material 3 can be laid in various ways as needed. A thin layer of current-conducting material 3 is laid between the blocks of carbon block 1 and steel rod 2 without changing the carbon block and steel rod structure. The current guiding material 3 may be a material or an insulating material having a resistivity greater than that of the carbon block, and is laid between the carbon block 1 and the steel rod 2, and the length of the flow guiding material may be changed from the head of the steel rod as needed. The position or position in the middle begins to lay out to the steel rod and the electricity is aligned with the edge of the carbon block. The upper surface of the steel bar completely covers the width of the steel bar. As shown in Fig. 5, the side portion is gradually widened from the inside to the outside, or is stepped wide; the widest portion can be the same width as the steel bar, or smaller than the width of the steel bar. The inward width gradually increases as shown in Fig. 2 and Fig. 3; the cathode resistance of the corresponding section of the flow guiding material is gradually increased, and the current throughput is adjusted, thereby reducing the horizontal current in the aluminum liquid.

Embodiment 3

As shown in Figures 6, 7, 8, and 9, the current-conducting material 3 is embedded in the carbon block to replace a portion of the steel rod. As shown in the figure, a material having a lower electrical resistance than the steel rod is used to replace the upper end of the inner end of the steel rod. Part of the steel bar, the length of which can be less than or equal to the length of the steel bar in the carbon block, the width is the same as that of the steel bar, and its height gradually decreases from the inside to the outside (as shown in Figure 7) or stepwise (as shown in Figure 6). The height of the corresponding steel bar material 2 under the flow guiding material 3 gradually increases from the inside to the outside until the height of the steel bar at the flow guiding material 3 is no longer changed. The closer the cathode is to the internal resistance, the more the conductivity inside the cathode is increased, so that the current in the aluminum liquid is more evenly distributed, and the horizontal current in the aluminum liquid is reduced.

Embodiment 4

As shown in Figures 10, 11, and 12, the current-conducting material 3 is embedded in the bottom of the carbon block to replace a portion of the carbon block material to form a combined cathode carbon block. The current guiding material 3 can be made of a conductivity material different from the original carbon block, and is equal in width and length to the original carbon block, and is combined with the carbon block at the bottom of the carbon block by a slope or a stepped interface as shown in Figs. 10 and 11 It is indicated that if an anthracite or graphite carbon block with a large electrical resistivity is used as the original cathode carbon block, a flow guiding material 3 having a resistivity lower than that of the carbon block, such as a graphitized material, a thin inner guiding material 3 and inner can be used. The thin outer carbon block material will be combined; if the original cathode carbon block is made of a graphitized carbon block having a smaller resistivity, a graphite material having a resistivity higher than that of the graphite material may be used. The flow guiding material 3, the inner and outer thick thickness of the flow guiding material 3 and the inner thick outer thin carbon block material will be combined; the cathode carbon block resistance is gradually increased from the inside to the outside. Reduce the external current throughput, thereby reducing the horizontal current in the aluminum liquid.

Embodiment 5

As shown in Fig. 13, a cathode carbon block can be formed by combining two or more carbon block materials having different resistivities, and the resistivity is gradually increased from the inside to the outside, so that the current flows into the steel bar material through the cathode carbon block. The present invention has been described in detail with reference to the accompanying drawings, and the embodiments of the invention It is intended to be included within the scope of the appended claims.

Claims

Claim

A method for reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell, comprising: laying a part of a current guiding material on a cathode carbon block, or a steel rod, or a connecting material thereof, or a phosphorus pig iron, to make aluminum The liquid current in the liquid is relatively uniform and enters the cathode carbon block, and exits from the side of the electrolytic cell through the steel rod.

2. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 1, wherein:

The current guiding material is a material that replaces part of the carbon block, or a material that replaces part of the steel bar, or partially replaces the connecting material.

3. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 2, wherein:

The current-conducting material is laid at a location where the carbon block, the steel rod, or a connecting material therebetween.

The method for reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 2, wherein:

The current directing material is assembled with a carbon block or steel rod.

5. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 1, wherein:

The current guiding material adopts different resistance materials at different positions according to the need to adjust the resistance distribution of the cathode carbon block, so that the current in the aluminum liquid is relatively uniform and enters the cathode carbon block.

6. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 1, wherein:

The current guiding material adopts different resistance materials at different positions according to requirements, and adjusts the resistance distribution of the cathode steel rod so that the current in the aluminum liquid is relatively uniform and enters the cathode carbon block.

7. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 1, wherein:

The current guiding material adopts different resistance materials at different positions as needed, and adjusts the resistance distribution of the position of the phosphorus pig iron or the steel bar paste between the carbon block and the cathode steel bar, so that the current in the aluminum liquid is relatively uniform and enters the cathode carbon. Piece.

The method for reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to any one of claims 1, 5, 6, or 7, wherein:

The current-conducting material is laid with at least one current-conducting material or a combination of insulating materials different in carbon block and steel bar resistivity, or first combined with a carbon block or a steel bar.

9. The method of reducing horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 8, wherein:

When the current guiding material is laid at the position of the carbon block, a common carbon block, a graphite carbon block, a semi-graphitized carbon block, or a fully graphitized carbon block different in electrical resistivity from the bulk carbon block material is used depending on the laying position. .

10. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 8, wherein:

When the current guiding material is laid at the position of the steel bar, a steel bar different in electrical resistivity from the main steel bar material or other high-temperature conductive metal having better electrical conductivity than the original steel bar is used depending on the laying position, or other resistance is adopted. The high-temperature conductivity is better than the original steel rod, which completely replaces the original steel rod.

11. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 8, wherein:

When the current guiding material is laid between the carbon block and the steel rod, other phosphorus pig iron or steel rod materials having different electrical resistivity from the main phosphorus pig iron steel bar paste are used depending on the laying position.

12. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 8, wherein:

When the current guiding material is laid between the carbon block and the steel rod, various high temperature resistant insulating materials may be partially used depending on the laying position.

13. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to any one of claims 1, 5, 6, or 7, wherein:

The current guiding material adjusts the resistance distribution of the carbon block or the steel bar by changing the shape and thickness thereof at different positions, so that the current in the aluminum liquid is more uniformly hooked into the cathode carbon block.

14. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 12, wherein:

When the high temperature resistant insulating material is located between the carbon block and the steel bar, the shape is changed by The length is laid from the head position or the middle position of the steel bar until the steel rod is discharged and aligned with the edge of the carbon block or slightly longer.

15. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to claim 14, wherein:

The high temperature resistant insulating material completely covers the width of the steel bar on the upper surface of the steel bar, and the side portion gradually changes from the inside to the outside, or changes stepwise; the widest portion is wider than the steel bar, or smaller than the width of the steel bar.

16. A method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to any one of claims 1 to 7, wherein:

The current guiding material replaces part of the steel bar material, and the material with the electric resistance smaller than the steel bar is used, and a part of the steel bar is replaced at the upper end of the steel bar near the center of the steel bar, and the length thereof is less than or equal to the length of the steel bar in the carbon block, and the width is smaller than Equal to the steel bar, its height and width are gradually changed from the inside to the outside or a stepwise change replaces part of the original steel bar material.

17. A method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to any one of claims 1 to 7, wherein:

The current guiding material replaces part of the carbon block material, and adopts a conductivity material having a conductivity different from that of the original carbon block, and is equal in width and equal length to the original carbon block, and is combined with the carbon block at the bottom of the carbon block by a slope or a stepped interface. a conductive material having a resistivity lower than that of the inner and outer thickness of the carbon block is combined with a carbon material having a thin inner and outer thickness; or a conductive material having a resistivity higher than the inner thin outer thickness of the carbon block and a carbon block having a thin outer thickness The materials will be combined.

18. The method of reducing the horizontal current of an aluminum liquid in an aluminum electrolytic cell according to any one of claims 1 to 7, wherein:

The method is applied to any cathode structure, the cathode carbon block is a flat top surface, or a convex top surface, and is a cathode having one or more steel rods of any cross-sectional shape.