US20130186749A1

US20130186749A1 - Cell Bottom Structure of Reduction Cell

Info

Publication number: US20130186749A1
Application number: US13/520,894
Authority: US
Inventors: Chongai Bao; Pu Zheng; Canming Xi; Bin Cao; Yi Yang; Jun Huang; Tao Yang; Zhaohong Yang
Original assignee: China Aluminum International Engr Corp Ltd
Current assignee: CHINA ALUMINUM INTERNATIONAL ENGINEERING Corp Ltd; China Aluminum International Engr Corp Ltd
Priority date: 2010-01-07
Filing date: 2011-01-06
Publication date: 2013-07-25
Also published as: CA2785868A1; CN102121118A; AU2011204683A1; WO2011082657A1; MY159932A; CA2785868C; AU2011204683B2

Abstract

The present invention discloses a cell bottom structure of a reduction cell which comprises a reduction cell and a cathode bus, wherein the bottom of the reduction cell is provided with column-shaped cathode carbon blocks perpendicular to the bottom of the reduction cell, and a lower end of the column-shaped cathode carbon block is connected to the cathode bus. By means of inserting the column-shaped cathode carbon blocks perpendicular to the bottom of the reduction cell and connecting the lower end of the column-shaped cathode carbon block with the cathode bus, such that electrical current that guided from anode carbon blocks is guided through the molten aluminum to the column-shaped cathode carbon blocks and is downwardly guided out, the present invention reduces horizontal electrical current in the molten aluminum, such that the cathode extending into the molten aluminum can effectively reduce fluctuations of the molten aluminum to obtain a stable surface of the molten aluminum, thereby reducing a polar distance between a cathode and an anode and lowering cell voltage so as to achieve the object of lowering electricity consumption.

Description

FIELD OF THE INVENTION

The present invention relates to a cell bottom structure of a reduction cell, pertaining to the technical field of aluminum reduction cell.

BACKGROUND OF THE INVENTION

In the production of a prebaked reduction cell, most of the aluminum reduction cells select a planar cell bottom with cathode carbon blocks placed horizontally, into which an electric current enters from an upper anode and is guided out of a lateral portion of the cell to form a turn of 90°, thereby forming a relatively large horizontal electric current at a layer of molten aluminum. The horizontal electric current tends to cause the molten aluminum to form an eddy flow under the action of magnetic field to generate a relatively large wave crest, such that on one hand, it influences the stable operation of the reduction cell, and on the other hand, in order to prevent a short circuit due to a wave crest of the molten aluminum scours to a anode, a polar distance of the cathode and the anode must be increased, resulting a rise in cell voltage and an increase in electricity consumption. At the same time, the cathode carbon blocks are placed horizontally, this results in a complicated structure of a cell housing of the reduction cell since thermal expansion and sodium absorption expansion render complicated force conditions for the cell housing and its periphery. In addition, failure of introducing electricity and aggregation of lateral output electric current towards cell edges impact the safety of cell ledges of the reduction cell, resulting a large amount of steel used for the cell ledges.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a cell bottom structure of a reduction cell, which can reduce horizontal electrical current in a layer of molten aluminum, eliminate stresses on a cell housing generated due to cathode expansion, simply the structure of the cell housing, reducing polar distance of the reduction cell and cell voltage, alleviate a construction cost of the cell housing and overcome shortages in the prior art.
The technical solution of the present invention is in that it comprises a reduction cell and a cathode bus, wherein the bottom of the reduction cell is provided with column-shaped cathode carbon blocks perpendicular to the bottom of the reduction cell, and that a lower end of the column-shaped cathode carbon block is connected to the cathode bus.
The column-shaped cathode carbon blocks are located below anode carbon blocks.
There is/are 1˜4 column-shaped cathode carbon blocks provided below each anode carbon block.
The column-shaped cathode carbon blocks extend a length of 5˜200 mm into molten aluminum of the reduction cell.
The column-shaped cathode carbon blocks are connected with the cathode bus through bolts.
The column-shaped cathode carbon blocks have a shape of quadrangular prism or quadrangular prism with steps.
By comparison with the prior art, by means of inserting the column-shaped cathode carbon blocks perpendicular to the bottom of the reduction cell and connecting the lower end of the column-shaped cathode carbon block with the cathode bus, such that electrical current that guided from anode carbon blocks is guided through the molten aluminum to the column-shaped cathode carbon blocks and is downwardly guided out, the present invention reduces horizontal electrical current in the molten aluminum, such that the cathode extending into the molten aluminum can effectively reduce fluctuations of the molten aluminum to obtain a stable surface of the molten aluminum, thereby reducing a polar distance of a cathode and an anode and lowering cell voltage so as to achieve the object of lowering electricity consumption. According to a number of tests by the applicant, a cathode/anode polar distance can reduce 100˜250 mm, a voltage drop of the cathode can reduce 100˜200 mv, a cell voltage can reduce 400˜850 mv, and an effect of saving 1200˜2500 kwh/t-Al is achieved. The column-shaped cathode carbon blocks have a shape of quadrangular prism or quadrangular prism with steps, and segment-splicing arrangement and cell bottom placement thereof eliminate stresses exerted on the cell housing by the thermal expansion and sodium absorption expansion, enabling a simplification of the cell housing design and the material used. According to the statistics of the test examination, the steel amount used for the cell bottom can be saved 70%, the lifespan of the cell can increase 500 days, allowing the impact of electrolyte deposition on the cell bottom electric conduction to be minimized. The column-shaped cathode carbon blocks are located below the anode carbon blocks, so as to facilitate the electric current to be vertically guided from the anode carbon blocks. There is/are 1˜4 column-shaped cathode carbon blocks provided below each of the anode carbon blocks, and the column-shaped cathode carbon blocks extend a length of 5˜200 mm into the molten aluminum of the reduction cell, wherein the specific number and positions thereof are determined in accordance with the reduction cell capacity and the anode dimension. The column-shaped cathode carbon blocks are interconnected with the cathode bus through bolts, wherein the cross-sectional dimension of the bus and the number of the bolts are determined in accordance with the magnitude of current. The present invention can also effectively inhibit eddy flow of molten aluminum, simplify the cell housing structure, decrease initial construction investment, improve current distribution, extend lifespan of the reduction cell, and has a very good popularizing value.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the configuration of the present invention;

FIG. 2 is an A-A view of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1: as shown in FIGS. 1 and 2, in a design of a reduction cell, cathodes are made as column-shaped cathode carbon blocks 3 which have a shape of quadrangular prism or quadrangular prism with steps. The column-shaped cathode carbon blocks 3 are placed perpendicular to a cell bottom of the reduction cell 1 when placing the column-shaped cathode carbon blocks 3. Upper ends of the perpendicularly placed column-shaped cathode carbon blocks 3 extend a length of 5˜200 mm into molten aluminum in the reduction cell 1 and lower ends of the column-shaped cathode carbon blocks 3 are connected with a cathode bus 2 through bolts. When placing and mounting the column-shaped cathode carbon blocks 3 perpendicular to the cell bottom of the reduction cell, the column-shaped cathode carbon blocks 3 are mounted below anode carbon blocks 4. There is/are 1˜4 column-shaped cathode carbon blocks 3 provided below each anode carbon block 4, wherein the specific number and positions thereof are determined in accordance with the reduction cell capacity and the anode dimension. Besides, the reduction cell 1 arranged according to the present invention can eliminate the cathode steel rod and steel cell housing in the cathode carbon blocks. The reduction cell employs heat insulation materials and corrosion resistant materials to design a lava pool, thus it is only necessary to consider self expansion of the materials during the manufacture, enabling the structure of the reduction cell to be simplified to a great extent. The design of the reduction cell is based on a low cell voltage, thereby decreasing the amount of heat dissipation. According to a test examination, the reduction cell produced in accordance with the present invention can save 10%˜20% of energy compared to conventional reduction cells.

Claims

1. A cell bottom structure of a reduction cell comprising a reduction cell (1) and a cathode bus (2), characterized in that the bottom of the reduction cell (1) is provided with column-shaped cathode carbon blocks (3) perpendicular to the bottom of the reduction cell (1), and that a lower end of the column-shaped cathode carbon block (3) is connected to the cathode bus (2).

2. The cell bottom structure of a reduction cell according to claim 1, characterized in that: the column-shaped cathode carbon blocks (3) are located below anode carbon blocks (4).

3. The cell bottom structure of a reduction cell according to claim 2, characterized in that: there is/are 1˜4 column-shaped cathode carbon blocks (3) provided below each anode carbon block (4).

4. The cell bottom structure of a reduction cell according to claim 1, characterized in that: the column-shaped cathode carbon blocks (3) extend a length of 5˜200 mm into molten aluminum of the reduction cell (1).

5. The cell bottom structure of a reduction cell according to claim 1, characterized in that: the column-shaped cathode carbon blocks (3) are connected with the cathode bus (2) through bolts.

6. The cell bottom structure of a reduction cell according to claim 1, characterized in that: the column-shaped cathode carbon blocks (3) have a shape of quadrangular prism or quadrangular prism with steps.