Cathode carbon block for aluminum electrolysis

Abstract

The application relates to the technical field of aluminum electrolysis, in particular to a cathode carbon block for aluminum electrolysis, which comprises a first part and a second part, wherein the first part comprises a dovetail groove structure, the average graphite content of the first part is a first content, the average graphite content of the second part is a second content, and the first content is greater than the second content. The technical scheme provided by the application can keep a low furnace bottom pressure drop, control horizontal current reduction, reduce inter-electrode energy consumption, and provide support for comprehensive energy saving of aluminum electrolysis.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum electrolysis, in particular to a cathode carbon block for aluminum electrolysis. BACKGROUND

[0002] The cathode of an aluminum electrolysis cell is composed of a cathode carbon block and a cathode steel rod, and the cathode structure of the aluminum electrolysis cell has a significant impact on the service life and operating state of the aluminum electrolysis cell. The poor quality of the cathode in the early stage of aluminum electrolysis leads to a short service life of the electrolysis cell and increases the operating cost of electrolysis. The traditional cathode is currently a semi-graphitic material (i.e., a 50% graphitic cathode, the mass fraction of graphitic material in the dry base material during production of the cathode carbon block is 50%), and the resistivity of this material is relatively high. During normal operation of the electrolysis cell, the average cell bottom voltage drop of the aluminum electrolysis cell can reach 260 mV. In order to reduce the cell bottom voltage drop of the electrolysis cell, some enterprises use graphitic or graphitized cathodes. After using the above cathodes, due to the improved electrical conductivity of the cathode material, the average cell bottom voltage drop of the electrolysis cell can be reduced by 40-80 mV. However, due to the improved electrical conductivity of the material, the horizontal current of the aluminum liquid increases, and the cell voltage cannot be reduced and the current efficiency cannot be improved at the same time, and the energy-saving effect is limited. The proportion of the pressure drop in the dovetail groove part in the cell bottom voltage drop is relatively large, and the proportion of the remaining part is relatively small.

[0003] Therefore, there is an urgent need in the art for a cathode carbon block for aluminum electrolysis that can maintain a low cell bottom voltage drop, control the horizontal current to reduce the inter-electrode energy consumption, and provide support for comprehensive energy saving for aluminum electrolysis. SUMMARY

[0004] Embodiments of the present application provide a cathode carbon block for aluminum electrolysis, which can maintain a low cell bottom voltage drop, control the horizontal current to reduce the inter-electrode energy consumption, and provide support for comprehensive energy saving for aluminum electrolysis.

[0005] Other characteristics and advantages of the present application will become apparent from the detailed description that follows, or can be learned by practice of the present application.

[0006] According to one aspect of the embodiments of the present application, a cathode carbon block for aluminum electrolysis is provided, the cathode carbon block comprising a first portion and a second portion, wherein the first portion comprises a dovetail groove structure, the average graphitic content of the first portion is a first content, the average graphitic content of the second portion is a second content, and the first content is greater than the second content.

[0007] The graphitic content of the first portion is uniform or gradually decreases in the vertical direction, and the graphitic content of the first portion is uniform or gradually decreases in the direction from the center to both ends.

[0008] The graphitic content of the second portion is uniform or gradually decreases in the vertical direction, and the graphitic content of the second portion is uniform or gradually decreases in the direction from the center to both ends.

[0009] The height of the first part is 160mm to 240mm, and the height of the second part is 240mm to 300mm.

[0010] In some embodiments of the present application, the first content is greater than or equal to 30% and less than or equal to 100%.

[0011] In some embodiments of the present application, the second content is greater than or equal to 30% and less than or equal to 100%.

[0012] In some embodiments of the present application, the second part comprises a special-shaped structure, and the special-shaped structure is a boss, and the height of the boss is 50mm to 150mm.

[0013] In some embodiments of the present application, the average room temperature resistivity of the second part is not higher than 34μΩm.

[0014] In some embodiments of the present application, the width and length of the cathode carbon block are determined according to the electrolytic cell specification and the cathode carbon block production equipment specification.

[0015] In some embodiments of the present application, the dovetail groove structure comprises 1 to 3 dovetail grooves.

[0016] Based on the above scheme, the present application has at least the following advantages or progress:

[0017] In the technical scheme provided in some embodiments of the present application, the cathode carbon block comprises a first part and a second part, wherein the first part comprises a dovetail groove structure, the average graphite content of the first part is a first content, the average graphite content of the second part is a second content, and the first content is greater than the second content. Through the actual structure and the setting of the graphite content, the low furnace bottom pressure drop is maintained, the horizontal current reduction is inhibited, and the inter-electrode energy consumption is reduced, thereby providing support for comprehensive energy saving of aluminum electrolysis.

[0018] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings herein are incorporated into the specification and form part of the specification, show embodiments consistent with the present application, and together with the specification serve to explain the principles of the present application.

[0020] Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] In the drawings:

[0022] Figure 1 A structural diagram of a cathode carbon block for aluminum electrolysis according to an embodiment of the present application is shown.

[0023] Figure 2 A structural diagram of a cathode carbon block for aluminum electrolysis according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0024] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the inventive aspects of example implementations to those skilled in the art. Like reference numerals may refer to like elements throughout the description.

[0025] Moreover, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the

[0026] It should be noted that, in the present text, "a plurality of" means two or more. The association relationship of "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the three cases of A existing alone, A and B existing together, and B existing alone. The character " / " generally represents that the associated objects before and after it are in an "or" relationship.

[0027] Reference will now be made to Figure 1 .

[0028] Figure 1 A structural diagram of a cathode carbon block for aluminum electrolysis according to an embodiment of the present application is shown, as Figure 1 shown, the cathode carbon block can include a first portion 101 and a second portion 102, wherein the first portion 101 can further include a dovetail groove structure 103.

[0029] In the present application, the average graphite content of the first portion is a first content, and the average graphite content of the second portion is a second content, and the first content can be greater than the second content.

[0030] In the present application, the first content can be greater than or equal to 30% and less than or equal to 100%.

[0031] In the present application, the second content can be greater than or equal to 30% and less than or equal to 100%.

[0032] In the present application, the cathode carbon block with a graphite content higher than 30% (including 30%) has better mechanical properties, which can meet the basic requirements of the existing large-scale aluminum electrolytic cell for the cathode carbon block.

[0033] In the present application, the graphite content of the first part can be uniform or gradually reduced in the vertical direction, and the graphite content of the first part can be uniform or gradually reduced from the center to the two ends.

[0034] In the present application, the graphite content of the second part can be uniform or gradually reduced in the vertical direction, and the graphite content of the second part can be uniform or gradually reduced from the center to the two ends.

[0035] In the present application, the height of the first part can be 160mm to 240mm, and the height of the second part can be 240mm to 300mm. When the height of the first part is 160mm to 240mm, the cathode steel rod and the cathode carbon block can have appropriate bonding capacity. When the height of the second part is 240mm to 300mm, the service life of the electrolytic cell can be ensured, and the electrolytic cell can have a lower furnace bottom pressure drop.

[0036] In the present application, the second part can include a special-shaped structure, which can be a boss, and the height of the boss can be 50mm to 150mm. For example, reference can be made to Figure 2 , Figure 2 A structural diagram of a cathode carbon block for aluminum electrolysis according to an embodiment of the present application is shown, as shown in Figure 2 The cathode carbon block can include a first part 201 and a second part 202, the first part 201 can further include a dovetail groove structure 203, and the second part 202 can further include a boss special-shaped structure 204.

[0037] In the present application, the average room temperature resistivity of the second part can be not higher than 34μΩm.

[0038] In the present application, the width and length of the cathode carbon block can be determined according to the specifications of the electrolytic cell and the specifications of the cathode carbon block production equipment.

[0039] In the present application, the dovetail groove structure can include 1 to 3 dovetail grooves. More than 3 dovetail grooves are troublesome to use and are not conducive to industrial application.

[0040] Next, the performance of the cathode carbon block provided by the present application will be described in conjunction with specific embodiments.

[0041] Comparative Example 1

[0042] A certain graphite-containing cathode graphite content 30%, the first part of the height 240 mm, the second part of the height 240 mm. The first part and the second part of the room temperature resistivity 34 μΩm. The above cathode carbon block and Q235 steel rod paste combination, used in electrolytic cell tank age 1 year, furnace bottom pressure drop 0.27 V, inter electrode voltage drop 1.3 V, tank voltage 3.91 V, efficiency 91.5%, direct current consumption 12734 kWh / t-Al. Inter electrode energy consumption 4234 kWh / t-Al.

[0043] Example 1

[0044] A cathode carbon block for aluminum electrolysis with a gradient composition, which contains a first part of a dovetail groove portion with an average graphite content of 50% graphite; the second part has an average graphite content of 30%. The graphite content of the first part and the second part is uniform from bottom to top and uniform from center to both ends. The first part has a height of 240 mm, and the second part has a height of 240 mm. The first part has a room temperature resistivity of 20 μΩm, and the second part has a room temperature resistivity of 34 μΩm. The above cathode carbon block and Q235 steel rod paste combination, used in electrolytic cell tank age 1 year, furnace bottom pressure drop 0.26 V, inter electrode voltage drop 1.3 V, tank voltage 3.86 V, efficiency 91.5%, direct current consumption 12571 kWh / t-Al. Inter electrode energy consumption 4234 kWh / t-Al, no change; aluminum electrolysis direct current consumption decreased by 163 kWh / t-Al.

[0045] Comparative Example 2

[0046] A certain graphite-containing cathode graphite content 100%, the first part of the height 240 mm, the second height 240 mm. The first part and the second part of the room temperature resistivity 15 μΩm. The above cathode carbon block and high-conductivity steel rod phosphorus cast iron combination, used in electrolytic cell tank age 1 year, furnace bottom pressure drop 0.22 V, inter electrode voltage drop 1.25 V, tank voltage 3.85 V, efficiency 92.5%, direct current consumption 12416 kWh / t-Al. Inter electrode energy consumption 4027 kWh / t-Al.

[0047] Example 2

[0048] A cathode carbon block for aluminum electrolysis, a first part containing dovetail groove part has an average graphite content of 100%; a second part has an average graphite content of 70%. The graphite content of the first part and the second part is uniform from bottom to top and uniform from center to both ends. The first part has a height of 240 mm, and the second part has a height of 240 mm. The first part has a room temperature resistivity of 15 μΩm, and the second part has a room temperature resistivity of 18 μΩm. The above-mentioned cathode carbon block is combined with high-conductivity steel bar cast phosphorus pig iron, and is used in an electrolytic cell with an age of 1 year, a furnace bottom pressure drop of 0.22 V, an inter-electrode pressure drop of 1.25 V, a cell voltage of 3.83 V, an efficiency of 92.6%, and a direct current consumption of 12325 kWh / t-Al. The inter-electrode energy consumption is 4022 kWh / t-Al, reduced by 5 kWh / t-Al; the direct current consumption for aluminum electrolysis is reduced by 91 kWh / t-Al.

[0049] Comparative Example 3

[0050] A cathode carbon block for aluminum electrolysis, a first part containing dovetail groove part has an average graphite content of 100%; a second part has an average graphite content of 70%. The graphite content of the first part and the second part is uniform from bottom to top and uniform from center to both ends. The first part has a height of 240 mm, and the second part has a height of 240 mm. The first part has a room temperature resistivity of 15 μΩm, and the second part has a room temperature resistivity of 18 μΩm. The above-mentioned cathode carbon block is combined with high-conductivity steel bar cast phosphorus pig iron, and is used in an electrolytic cell with an age of 1 year, a furnace bottom pressure drop of 0.22 V, an inter-electrode pressure drop of 1.25 V, a cell voltage of 3.83 V, an efficiency of 92.6%, and a direct current consumption of 12325 kWh / t-Al. The inter-electrode energy consumption is 4022 kWh / t-Al, reduced by 5 kWh / t-Al; the direct current consumption for aluminum electrolysis is reduced by 91 kWh / t-Al.

[0051] Example 3

[0052] A cathode carbon block for aluminum electrolysis, a first part containing dovetail groove part has an average graphite content of 100%; a second part has an average graphite content of 70%. The graphite content of the first part and the second part is uniform from bottom to top and uniform from center to both ends. The first part has a height of 240 mm, and the second part has a height of 240 mm. The first part has a room temperature resistivity of 15 μΩm, and the second part has a room temperature resistivity of 18 μΩm. The above-mentioned cathode carbon block is combined with high-conductivity steel bar cast phosphorus pig iron, and is used in an electrolytic cell with an age of 1 year, a furnace bottom pressure drop of 0.22 V, an inter-electrode pressure drop of 1.25 V, a cell voltage of 3.83 V, an efficiency of 92.6%, and a direct current consumption of 12325 kWh / t-Al. The inter-electrode energy consumption is 4022 kWh / t-Al, reduced by 5 kWh / t-Al; the direct current consumption for aluminum electrolysis is reduced by 91 kWh / t-Al.

[0053] Comparative Example 4

[0054] A cathode carbon block for aluminum electrolysis with a graphite content of 50%, a first portion with a height of 60 mm, a second portion with a height of 300 mm, and a boss height of 50 mm. The first portion and the second portion have a room temperature resistivity of 20 μΩm. The above cathode carbon block is combined with a Q235 steel rod to form a paste for an electrolytic cell with an age of 1 year, a furnace bottom pressure drop of 0.27 V, an inter-electrode pressure drop of 1.27 V, a cell voltage of 3.89 V, an efficiency of 92%, a direct current power consumption of 12600 kWh / t-Al, and an inter-electrode energy consumption of 4114 kWh / t-Al.

[0055] Example 4

[0056] A cathode carbon block for aluminum electrolysis with a dovetail groove portion, a first portion with an average graphite content of 70%, and a second portion with an average graphite content of 50%. The graphite content of the first portion and the second portion is uniform from bottom to top. The graphite content of the first portion gradually decreases from the center to both ends, from 100% to 40%. The graphite content of the second portion gradually decreases from the center to both ends, from an average of 70% to an average of 30%. The first portion has a height of 60 mm, the second portion has a height of 300 mm, and the boss height is 50 mm. The first portion has a room temperature resistivity of 18 μΩm, and the second portion has a room temperature resistivity of 20 μΩm. The above cathode carbon block is combined with a high-conductivity steel rod phosphorus cast iron pouring to form a paste for an electrolytic cell with an age of 1 year, a furnace bottom pressure drop of 0.23 V, an inter-electrode pressure drop of 1.25 V, a cell voltage of 3.81 V, an efficiency of 92.6%, a direct current power consumption of 12261 kWh / t-Al, and an inter-electrode energy consumption of 4023 kWh / t-Al, which is reduced by 91 kWh / t-Al; the direct current power consumption for aluminum electrolysis is reduced by 339 kWh / t-Al.

[0057] Example 5

[0058] The cathode carbon block for aluminum electrolysis has a first part with a dovetail groove and an average graphite content of 50%, and a second part with an average graphite content of 40%. The graphite content of the first part decreases uniformly from 60% to 40% in the direction from bottom to top, and decreases uniformly from 55% to 45% in the direction from center to both ends. The graphite content of the second part decreases uniformly from 50% to 30% in the direction from bottom to top, and decreases uniformly from 40% to 35% in the direction from center to both ends. The height of the first part is 60 mm, the height of the second part is 300 mm, and the height of the boss is 100 mm. The first part has a room temperature resistivity of 20 μΩm, and the second part has a room temperature resistivity of 22 μΩm. The above cathode carbon block is combined with high-conductivity steel rod cast phosphorus pig iron to be used in an electrolysis cell with a cell age of 1 year, a cell bottom pressure drop of 0.27 V, an inter-electrode pressure drop of 1.26 V, a cell voltage of 3.88 V, an efficiency of 92.4%, a direct current power consumption of 12513 kWh / t-Al, an inter-electrode energy consumption of 4064 kWh / t-Al, a reduction of 50 kWh / t-Al, and a reduction of aluminum electrolysis direct current power consumption of 87 kWh / t-Al.

[0059] In summary, the cathode carbon block includes a first part and a second part, wherein the first part includes a dovetail groove structure, the first part has an average graphite content of a first content, the second part has an average graphite content of a second content, the first content is greater than the second content, and through the actual structure and the graphite content, a lower cell bottom pressure drop is maintained, the horizontal current is reduced, the inter-electrode energy consumption is reduced, and comprehensive energy saving is provided for aluminum electrolysis.

[0060] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the aspects disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

[0061] It is to be understood that the application is not limited to the precise construction here described and as shown in the attached drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application is to be interpreted only by the appended claims.

Claims

1. A cathode carbon block for aluminum electrolysis, characterized in that, The cathode carbon block includes a first part and a second part, wherein the first part includes a dovetail groove structure, the average graphite content of the first part is a first content, the average graphite content of the second part is a second content, and the first content is greater than the second content. The graphite content of the first part is uniform or gradually decreases in the vertical direction, and the graphite content of the first part is uniform or gradually decreases from the center to both ends. The graphite content of the second part is uniform or gradually decreases in the vertical direction, and the graphite content of the second part is uniform or gradually decreases from the center to both ends. The height of the first part is 160mm to 240mm, and the height of the second part is 240mm to 300mm.

2. The cathode carbon block according to claim 1, characterized in that, The first content is greater than or equal to 30% and less than or equal to 100%.

3. The cathode carbon block according to claim 1, characterized in that, The second content is greater than or equal to 30% and less than or equal to 100%.

4. The cathode carbon block according to claim 1, characterized in that, The second part includes an irregular structure, which is a boss, and the height of the boss is 50mm to 150mm.

5. The cathode carbon block according to claim 1, characterized in that, The average room temperature resistivity of the second part is no higher than 34 μΩm.

6. The cathode carbon block according to claim 1, characterized in that, The width and length of the cathode carbon block are determined according to the specifications of the electrolytic cell and the cathode carbon block production equipment.

7. The cathode carbon block according to claim 1, characterized in that, The dovetail groove structure includes 1 to 3 dovetail grooves.

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