Anode and aluminum electrolysis cell with adjustable current and heat distribution

Abstract

The application discloses anode and aluminum electrolysis cell capable of adjusting current and heat distribution, and relates to the technical field of aluminum electrolysis cell.The present application realizes the free adjustment of anode current distribution and heat distribution by adjusting the apparent density, the electric conductivity area and the iron-carbon pressure drop of the prebaked carbon block, and provides a flexible solution for optimizing the current distribution and adjusting the regional energy balance in the production process.When the prebaked carbon block of the aluminum electrolysis cell is composed of two or more small carbon blocks with different apparent densities or electric conductivity areas or iron-carbon pressure drops, the problem of mismatch between the anode current distribution and the cathode current distribution can be solved, and the horizontal current can be reduced.When the prebaked carbon blocks with larger apparent densities or electric conductivity areas or smaller iron-carbon pressure drops are used at the two ends of the anode than at the middle of the anode, the temperature balance of the aluminum electrolysis cell can be improved, and the problem of regional energy imbalance of the aluminum electrolysis cell can be solved.Finally, the stability of the electrolysis cell can be improved, the economic and technical indexes can be improved, and the service life of the cell can be prolonged.

Description

Technical Field

[0001] This invention relates to the field of aluminum electrolysis cell technology, specifically to an anode and an aluminum electrolysis cell with adjustable current and heat distribution. Background Technology

[0002] Most existing aluminum electrolytic cells adopt the side-outlet power mode. The main current flow path is as follows: the current flows into the upper anode busbar through the column busbar, the anode busbar distributes the current to each group of anodes, and the current flows downward through the anode into the electrolyte layer, aluminum liquid layer, cathode carbon block, and cathode steel rod, and is then horizontally led out to both sides of the electrolytic cell through the cathode steel rod, and then flows into the column busbar of the next electrolytic cell through the cathode busbar.

[0003] Regarding the anode current and heat generation distribution, under normal circumstances, the current entering the molten aluminum through the anode and electrolyte layer is uniform. Since the heat generation in each region of the electrolyte layer is proportional to the magnitude of the current passing through it, the heat generation in each region of the electrolytic cell is also balanced. However, there are significant differences in the heat dissipation in each region of the electrolytic cell. This leads to a mismatch between the existing anode current and heat generation distribution characteristics and the heat dissipation characteristics in each region of the electrolytic cell, resulting in regional energy imbalance problems. For example, the heat dissipation is greater at both ends of the electrolytic cell, especially at the corners. The heat dissipation in these areas is greater than the heat generation, causing the corners to be relatively cold, resulting in enlarged extension legs. In severe cases, this can lead to cracking of the guide rods in the corner extension legs. Conversely, the heat dissipation in the middle region of the electrolytic cell is less than the heat generation, resulting in thinner furnace walls or even no furnace walls in the middle region. Existing technologies generally adjust the thermal balance of the electrolytic cell area by adjusting voltage, aluminum level, molecular ratio, insulation material, and corner heat exchange electrodes. For example, CN106676581A discloses a method for optimizing and controlling the thickness of the furnace side of an aluminum electrolytic cell, CN216192768U discloses a heat preservation device for alleviating corner enlargement of an aluminum electrolytic cell, and CN107245751A discloses a method for eliminating corner leg enlargement of an aluminum electrolytic cell. Existing technologies can only alleviate the regional energy imbalance of the electrolytic cell and do not fundamentally solve the problem of regional energy imbalance. They also have problems such as cumbersome operation and high labor intensity for workers.

[0004] Regarding the cathode current distribution, the presence of a large horizontal current in the molten aluminum layer leads to uneven current distribution. The current density is higher in the side regions of the cathode and lower in the central region. The main reasons for this horizontal current are: first, the current is horizontally drawn from both sides of the electrolytic cell through the cathode steel rod, resulting in a large horizontal current in the molten aluminum layer; second, the flow rate and temperature of the molten aluminum are lower at both ends of the electrolytic cell, especially in the corners, where alumina tends to deposit, reducing the cathode conductivity and increasing the horizontal current; and third, the presence of significant sediment in the central feed area of ​​the electrolytic cell further exacerbates the current concentration in the side regions of the cathode. As is well known, horizontal current has adverse effects on electrolytic production. The electromagnetic force generated by the combined action of the horizontal current and the vertical magnetic field drives the molten aluminum to flow and fluctuate within the electrolytic cell. Rapid flow of the molten aluminum accelerates the physical wear process of the cathode, while fluctuations reduce the stability of the electrolytic cell, leading to decreased current efficiency and increased electrolytic energy consumption.

[0005] Existing technologies offer numerous solutions for suppressing horizontal current in molten aluminum. Regarding the optimization of cathode steel rods, measures such as variable cross-section steel rods, thickened steel rods, high-conductivity steel rods, copper-embedded steel rods, and all-copper steel rods have been adopted. For example, CN116397276A discloses an assembled copper conductive rod cathode assembly for aluminum electrolysis cells and its assembly method. In cathode assembly, adjusting the contact voltage drop between the cathode carbon block and the steel rod reduces the horizontal current. For instance, CN201864785U discloses a structure that significantly reduces the horizontal current in molten aluminum in aluminum electrolysis cells. Regarding cathode structure, CN102400177A provides a cathode carbon block structure that can reduce the horizontal current in molten aluminum in aluminum electrolysis cells, which also has the function of reducing the horizontal current. Existing technologies for reducing the horizontal current in molten aluminum focus on modifying the cathode. While this has achieved some success, as the electrolytic cell ages, the cathode surface is continuously eroded, and deposits gradually accumulate on the cathode surface, causing the horizontal current to gradually increase. Existing technologies lack effective means to address the gradually increasing horizontal current during production.

[0006] Given that the current and heat distribution of aluminum electrolytic cells have a significant impact on the cell's thermal balance, operational stability, current efficiency, and energy consumption, and that the existing current and heat distribution characteristics lead to numerous problems such as low temperatures at both ends of the cell, high temperatures in the middle, and large horizontal currents, these issues negatively affect the economic and technical indicators, safe and stable operation, and cell lifespan of aluminum electrolytic cells. Therefore, developing a technology that can quickly and flexibly adjust the current and heat distribution of aluminum electrolytic cells to completely solve these problems is of great significance for the safe production and energy conservation of aluminum electrolytic plants. Summary of the Invention

[0007] The purpose of this invention is to provide an anode and an aluminum electrolytic cell with adjustable current and heat distribution to solve the problems mentioned in the background art. The main technical problems to be solved include: First, the heat generated at both ends of the electrolytic cell, especially at the corners, is less than the heat dissipation, resulting in enlarged legs, more sediment, and higher horizontal current in the two ends of the cell. Second, the heat generated in the middle area of ​​the electrolytic cell is greater than the heat dissipation, resulting in thin or even no furnace walls in the middle area. Third, the side-mounted power output mode of the electrolytic cell leads to a large horizontal current in the aluminum liquid layer; Fourth, the combined effect of horizontal current and vertical magnetic field drives the aluminum liquid to flow rapidly in the electrolytic cell, which accelerates the physical wear rate of the cathode and leads to a shortened cell life. Fifth, existing technical solutions for suppressing horizontal current in molten aluminum mainly involve modifying the cathode, which can only be implemented during major overhauls of the electrolytic cell. There is a lack of effective solutions to address the problem of the gradually increasing horizontal current during the production process of the electrolytic cell.

[0008] Research and analysis revealed that the main reasons for the above problems in aluminum electrolysis cells are: first, the heat generation and heat dissipation in the electrolysis cell area are mismatched; second, the anode current distribution and cathode current distribution are mismatched. During the design and construction phase of the electrolysis cell, the adverse effects caused by the above problems can be reduced by strengthening the local insulation of the electrolysis cell and optimizing the cathode current distribution. However, after the electrolysis cell is put into operation, the heat dissipation characteristics and cathode current distribution characteristics of the electrolysis cell area cannot be changed. Therefore, this invention mainly solves the above problems by changing the anode current distribution and heat generation distribution.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] First, an anode with adjustable current and heat distribution is provided. The anode includes an aluminum guide rod, a steel claw, and a prebaked carbon block. The prebaked carbon block is composed of two or more small carbon blocks with different apparent densities; or, the prebaked carbon block is composed of two or more small carbon blocks with different conductive areas per unit length; or, the prebaked carbon block is composed of two or more small carbon blocks with different iron-carbon pressure drops, wherein the iron-carbon pressure drop is the pressure drop value measured from the bottom of the aluminum guide rod to the bottom of the small carbon block under room temperature conditions.

[0011] Preferably, when the prebaked carbon block is composed of small carbon blocks with different apparent densities, the small carbon blocks of the prebaked carbon block have a separate structure, and the gap between the small carbon blocks is no more than 50mm.

[0012] Preferably, when the prebaked carbon block is composed of small carbon blocks with different iron-carbon pressure drops, the small carbon blocks of the prebaked carbon block have a separate structure, and the combination gap between the small carbon blocks is no more than 50mm. The diameter of the carbon bowl of the small carbon block with a large iron-carbon pressure drop is smaller than the diameter of the carbon bowl of the small carbon block with a small iron-carbon pressure drop. By increasing the diameter of the carbon bowl, the contact area between iron and carbon can be increased, which can reduce the iron-carbon pressure drop.

[0013] Preferably, when the prebaked carbon block is composed of small carbon blocks with different conductive areas per unit length, the small carbon blocks of the prebaked carbon block have an integral structure, and the small carbon blocks are conductive areas with different conductive areas per unit length in the length direction of the prebaked carbon block.

[0014] Preferably, when the prebaked carbon block is composed of small carbon blocks with different conductive areas per unit length, the conductive area can be adjusted by the width of the small carbon blocks, with the width of the small carbon blocks with smaller conductive areas being smaller than that of the small carbon blocks with larger conductive areas; or, the conductive area can be adjusted by slotting the bottom of the small carbon blocks, with the total width of the slots on the bottom of the small carbon blocks with smaller conductive areas being greater than that on the bottom of the small carbon blocks with larger conductive areas; or, the conductive area can be adjusted by spraying an anti-oxidation coating, with the surface of the small carbon blocks with smaller conductive areas not coated with an anti-oxidation coating, while the surface of the small carbon blocks with larger conductive areas is coated with an anti-oxidation coating. The anti-oxidation coating can prevent the prebaked carbon block from being oxidized by air, thereby increasing the effective conductive area of ​​the prebaked carbon block.

[0015] When prebaked carbon blocks are composed of small carbon blocks with different apparent densities or different conductive areas per unit length, this combination method can adjust the current and heat distribution. The main technical principle is as follows: According to the main chemical equation for aluminum electrolysis: 2Al2O3 (dissolved) + 3C (solid) → 4Al (liquid) + 3CO2. Anode reaction equation: 6O 2- (Complex) + 3C (solid) - 12e → 3CO2. Cathode reaction equation: 4Al 3+ (Complex) + 12e → 4Al (liquid). At the anode, carbon atoms lose electrons and are oxidized into carbon dioxide, while at the cathode, aluminum ions gain electrons and are deposited as aluminum. The anode carbon block not only acts as an electrode to conduct electricity but also participates in the electrochemical reaction. Therefore, the anode carbon block is continuously consumed during electrolysis. When the electrode distance is low, the current increases, and the consumption rate of the anode carbon block accelerates. When the electrode distance is high, the current decreases, and the consumption rate of the anode carbon block slows down. The anode adaptively adjusts the consumption rate to ensure that the daily consumption height of each group of anode carbon blocks is basically consistent, and ultimately maintains the electrode distance uniformly within the range of 4cm to 5cm.

[0016] Regarding the principle of adjusting the anode current distribution, according to the formula for calculating the mass consumed by the carbon block: m = ρ × S × h, where ρ is the apparent density of the small carbon block, S is the conductive area of ​​the small carbon block, and h is the consumption height of the small carbon block. Since the daily consumption height h of the small carbon block is consistent, when the apparent density ρ of the small carbon block is large or the conductive area per unit length S is large, the daily consumption mass m of the small carbon block is also large. According to the aluminum electrolysis anode reaction equation, the mass consumed by the anode carbon block is directly proportional to the current. Therefore, when the mass consumed by the small carbon block is large, the current passing through the small carbon block must also be large, and vice versa. Therefore, by using small carbon blocks with different apparent densities or conductive areas per unit length in the prebaked carbon block, the purpose of adjusting the anode current distribution can be achieved.

[0017] Regarding the principle of adjusting the heat generation distribution, the heat generation calculation formula is: H = U × I × t, where H is the heat generation in joules (J), U is the electrolyte pressure drop in volts (V), I is the current in amperes (A), and t is the time in seconds (s). Since the electrode spacing of the electrolytic cell is uniform, under normal circumstances, the electrolyte pressure drop U in each group of anode regions is basically equal. Therefore, the amount of heat generated in the electrolyte layer mainly depends on the magnitude of the current. When the current can be adjusted by changing the apparent density or the conductive area per unit length of the small carbon blocks, the amount of heat generated in the electrolyte layer in the small carbon block region can naturally be adjusted synchronously.

[0018] When prebaked carbon blocks are composed of small carbon blocks with different iron-carbon pressure drops, this combination method can adjust the anode heat distribution by regulating the electrolyte pressure drop. The main technical principle is as follows: According to the formula for calculating heat generation: H = U × I × t, since the current I of each anode group is uniformly distributed under normal circumstances, the amount of heat generated by the electrolyte layer mainly depends on the electrolyte pressure drop U, which is calculated as U = Uad - Uab - Ubc - U 过 . Uad is the pressure drop from the anode busbar to the aluminum liquid layer. Due to the flow equalization effect of the anode busbar and the aluminum liquid layer, the measuring points of the anode busbar are at the same potential, and the measuring points of the aluminum liquid layer are at the same potential. Therefore, Uad is basically equal in all regions of the electrolytic cell. Uab is the voltage drop from the anode busbar to the bottom of the aluminum conductor. When the current I of each anode is evenly distributed, Uab is also basically equal. U 过 This is the anode overvoltage, typically 400mV to 600mV. Under normal circumstances, the overvoltage U of each anode group... 过 They are basically equal. Ubc represents the iron-carbon pressure drop, which is the pressure drop from the bottom of the aluminum guide rod to the bottom of the small carbon block. When the iron-carbon pressure drop Ubc of the small carbon block is large, the electrolyte pressure drop U in the small carbon block area will be smaller. According to the calorific value calculation formula, the calorific value of the electrolyte layer in this small carbon block area will be smaller, and vice versa. Therefore, using a combination of small carbon blocks with different iron-carbon pressure drops in the prebaked carbon block can achieve the purpose of adjusting the anode heat distribution.

[0019] The present invention also provides an aluminum electrolytic cell with optimized current and heat distribution, wherein the aluminum electrolytic cell includes any of the above-mentioned anodes with adjustable current and heat distribution.

[0020] When the aluminum electrolytic cell is used to reduce the horizontal current of the aluminum liquid layer, the prebaked carbon block of the anode of the aluminum electrolytic cell is composed of more than two small carbon blocks. In the direction from the seam in the aluminum electrolytic cell to the furnace wall, the apparent density of the small carbon blocks of the prebaked carbon block gradually increases; or, the conductive area per unit length of the small carbon blocks of the prebaked carbon block gradually increases.

[0021] The main technical principle for reducing horizontal current in the aluminum electrolysis cell is as follows: The existing aluminum electrolytic cells adopt a side-output mode, which results in uneven distribution of cathode current. Approximately 65% ​​of the current flows into the cathode steel rod from the side region of the cathode, and approximately 35% of the current flows into the cathode steel rod from the central region of the cathode. However, the current flowing through the anode and electrolyte layer into the aluminum liquid layer is uniform, which leads to a large horizontal current in the aluminum liquid layer. After the electrolytic cell is put into operation, the cathode current distribution characteristics cannot be changed. This invention aims to reduce the horizontal current by adjusting the anode current distribution to adapt the anode current distribution characteristics to the cathode current distribution characteristics. The specific technical solution is as follows: An anode with adjustable current and heat distribution is configured within the aluminum electrolytic cell. On the seam side of the aluminum electrolytic cell, the prebaked carbon blocks of the anode are small carbon blocks with low apparent density or small conductive area per unit length, reducing the current in the central region of the anode. On the furnace side side of the aluminum electrolytic cell, small prebaked carbon blocks with high apparent density or large conductive area per unit length are used, increasing the current in the side region of the anode. Ultimately, this achieves adaptation between the anode and cathode current distribution characteristics, thereby reducing the horizontal current in the molten aluminum layer.

[0022] When the aluminum electrolytic cell is used to solve the problem of thin furnace walls in some areas, the prebaked carbon block of the anode of the aluminum electrolytic cell is composed of two or more small carbon blocks. In the direction from the seam in the aluminum electrolytic cell to the furnace wall, the apparent density of the small carbon blocks of the prebaked carbon block gradually decreases; or, the conductive area per unit length of the small carbon blocks of the prebaked carbon block gradually decreases; or, the iron-carbon pressure drop of the small carbon blocks of the prebaked carbon block gradually increases.

[0023] The main technical principle behind the aluminum electrolysis cell for solving the problem of thin furnace walls in certain areas is as follows: Since the thinness of the furnace wall in some areas is mainly related to excessive heat generation in the region, according to the principle of adjusting the heat generation distribution of small carbon blocks mentioned above, using small carbon blocks with lower apparent density, smaller conductive area, or greater iron-carbon pressure drop in areas with thin furnace walls can help reduce the heat generation in these areas and promote the formation of furnace walls.

[0024] When the aluminum electrolytic cell is used to solve the problems of localized thick furnace sides and large leg extensions, the prebaked carbon block of the anode of the aluminum electrolytic cell is composed of two or more small carbon blocks. In the direction from the seam in the aluminum electrolytic cell to the furnace side, the apparent density of the small carbon blocks of the prebaked carbon block gradually increases; or, the conductive area per unit length of the small carbon blocks of the prebaked carbon block gradually increases; or, the iron-carbon pressure drop of the small carbon blocks of the prebaked carbon block gradually decreases.

[0025] The main technical principle behind the aluminum electrolysis cell for solving the problems of localized thick furnace walls and excessively large extension legs is as follows: Since areas with thick furnace walls and large legs are generally related to localized cooling of the electrolytic cell, based on the aforementioned technical principle of using small carbon blocks to regulate the calorific value distribution, using small carbon blocks with higher apparent density, larger conductive area, or smaller iron-carbon voltage drop in areas with thick furnace walls and large legs helps to increase the calorific value of the localized cooling areas, thereby gradually restoring the furnace wall thickness and leg size to a normal state and playing a role in regulating the electrolytic cell furnace.

[0026] Finally, the present invention provides an aluminum electrolytic cell with adjustable regional current and heat distribution. The aluminum electrolytic cell includes two anodes at both ends and a middle anode. The apparent density of the prebaked carbon blocks at the two anodes at both ends is greater than the apparent density of the prebaked carbon blocks at the middle anode. Alternatively, the conductive area of ​​the prebaked carbon blocks at the two anodes at both ends is greater than the conductive area of ​​the prebaked carbon blocks at the middle anode. Alternatively, the average iron-carbon pressure drop at the two anodes at both ends is less than the average iron-carbon pressure drop at the middle anode. The iron-carbon pressure drop is the pressure drop value measured from the bottom of the aluminum guide rod to the bottom of the prebaked carbon block under normal temperature conditions.

[0027] Preferably, the length of the prebaked carbon block at both ends of the anode is greater than the length of the prebaked carbon block at the middle anode.

[0028] Preferably, the surface of the prebaked carbon block of the middle anode is not coated with an anti-oxidation coating, while the surface of the prebaked carbon blocks of the two end anodes is coated with an anti-oxidation coating to protect the prebaked carbon blocks of the two end anodes from oxidation and to increase the effective conductive area of ​​the prebaked carbon blocks of the two end anodes.

[0029] Preferably, a current equalization device is welded between the aluminum guide rods at both anodes and the steel claw beam to reduce the iron-carbon pressure drop at both anodes and increase the electrolyte layer pressure drop and heat generation. The current equalization device is an aluminum plate, a steel-aluminum composite plate, or a combination of an aluminum plate and an explosive weld block. When the current equalization device is an aluminum plate, the aluminum plate and the steel claw beam are welded using steel-aluminum direct welding technology; when the current equalization device is a steel-aluminum composite plate, the steel surface of the steel-aluminum composite plate is welded to the steel claw beam; when the current equalization device is a combination of an aluminum plate and an explosive weld block, one end of the aluminum plate is welded to the aluminum guide rod, the other end is welded to the aluminum surface of the explosive weld block, and the steel surface of the explosive weld block is welded to the steel claw beam.

[0030] Preferably, the diameter of the carbon bowl of the prebaked carbon block at both ends of the anode is larger than the diameter of the carbon bowl of the prebaked carbon block in the middle anode. By increasing the diameter of the carbon bowl, the contact area between iron and carbon can be increased, which can reduce the iron-carbon pressure drop and increase the electrolyte layer pressure drop and heat generation.

[0031] When the apparent density or conductive area of ​​the prebaked carbon blocks at both ends of the anode is greater than that of the middle anode, this configuration can achieve the purpose of adjusting the regional current and heat distribution, and solve the problem of regional energy imbalance. The main technical principle is as follows: Regarding the principle of regulating the regional current distribution, according to the formula for calculating the mass consumed by the prebaked carbon block: m = ρ × S × h, where ρ is the apparent density of the prebaked carbon block, S is the conductive area of ​​the prebaked carbon block, and h is the consumption height of the prebaked carbon block. Since the daily consumption height h of the prebaked carbon block is consistent, when the apparent density ρ or conductive area of ​​the prebaked carbon block at both anodes is greater than that at the middle anode, the daily mass consumed m of the prebaked carbon block at both anodes is also greater than that at the middle anode. According to the anode reaction equation, the mass consumed by the prebaked carbon block is proportional to the current. Therefore, the current passing through the anodes at both anodes must also be greater than that at the middle anode. Regarding the principle of regulating the distribution of regional heat generation, according to the heat generation calculation formula: H=U×I×t, when the electrolyte pressure drop U in the electrolytic cell is basically the same, the amount of heat generation of the electrolyte layer mainly depends on the magnitude of the current. When the current passing through the anodes at both ends is greater than that through the middle anode, according to the heat generation calculation formula, the heat generation of the electrolyte layer in the anode areas at both ends will also be greater than that through the middle anode.

[0032] When the average iron-carbon pressure drop at both ends of the anode is lower than that at the middle anode, this anode configuration can adjust the amount of heat generated in the region and solve the problem of regional energy imbalance. The main technical principle is as follows: The relationship between electrolyte pressure drop and iron-carbon pressure drop has been explained in detail above and will not be repeated here. According to the calorific value calculation formula: H = U × I × t, since the current I of each anode group is normally uniformly distributed, when the average iron-carbon pressure drop at both anodes is lower than that at the middle anode, the electrolyte pressure drop U = Uad - Uab - Ubc - U 过According to the formula, the electrolyte pressure drop at both ends of the anode must be greater than that at the middle anode. Therefore, according to the formula for calculating the heat generation, the heat generation of the electrolyte layer in the anode regions at both ends must also be greater than that in the middle anode.

[0033] Positive and beneficial effects: First, the present invention provides an anode with adjustable current and heat distribution. The prebaked carbon block of the anode is composed of two or more small carbon blocks. By adjusting the apparent density, conductive area per unit length, or iron-carbon voltage drop of the small carbon blocks, the anode current distribution and heat distribution can be freely adjusted, providing a flexible, convenient and quick solution for optimizing current distribution and adjusting regional energy balance in the aluminum electrolysis cell production process. Secondly, this invention provides an aluminum electrolytic cell with optimized current and heat distribution. The cell is equipped with an anode whose current and heat distribution are adjustable. By reducing the current in the central region of the anode and increasing the current in the side region, this invention adapts the anode current distribution characteristics to the cathode current distribution characteristics, thereby reducing the horizontal current. Simultaneously, by adjusting the heat generation in the side region of the anode, this invention can solve problems such as locally thin furnace walls or locally thick furnace walls with excessively large legs in the aluminum electrolytic cell, thus helping to regulate the furnace chamber. Finally, this invention provides an aluminum electrolytic cell with adjustable regional current and heat distribution. The aluminum electrolytic cell includes two anodes at both ends and a middle anode. The two anodes at both ends use prebaked carbon blocks with a larger apparent density, larger conductive area, or smaller iron-carbon voltage drop than the middle anode. This further increases the heat generation in the two end regions, especially the corner regions, and reduces the heat generation in the middle region. This solves the regional energy imbalance problem in aluminum electrolytic cells, such as the heat dissipation in the two end regions being greater than the heat generation, and the heat generation in the middle region being greater than the heat dissipation. At the same time, by increasing the electrolyte temperature in the two end regions, the sedimentation at the bottom of the furnace in the two end regions, especially the corner regions, can be eliminated, the cathode conductivity in the two end regions of the electrolytic cell can be enhanced, the cathode current distribution can be improved, and the operational stability of the electrolytic cell can be improved. In summary, the present invention provides an anode and aluminum electrolytic cell with adjustable current and heat distribution, which allows for online modification of the aluminum electrolytic cell without waiting for major overhaul. The present invention can solve the problems of mismatch between heat generation and heat dissipation in the aluminum electrolytic cell area and mismatch between anode current distribution and cathode current distribution. It can significantly improve the energy balance of the aluminum electrolytic cell, significantly reduce the horizontal current of the aluminum electrolytic cell, and play a positive role in improving the operational stability of the electrolytic cell, improving economic and technical indicators, slowing down the physical wear rate of the cathode, and extending the life of the aluminum electrolytic cell. Attached Figure Description

[0034] Figure 1 This is a schematic diagram showing the distribution of hot and cold zones in an aluminum electrolysis cell.

[0035] Figure 2This is a schematic diagram of the cathode and anode current distribution in an existing aluminum electrolysis cell.

[0036] Figure 3 These are schematic diagrams showing the cathode and anode current distributions in the aluminum electrolysis cells of Examples 1 and 2.

[0037] Figure 4 A schematic diagram of an anode structure consisting of two small carbon blocks with different apparent densities;

[0038] Figure 5 A schematic diagram of an anode structure consisting of two small carbon blocks with different conductive areas;

[0039] Figure 6 A schematic diagram of an anode structure consisting of two small carbon blocks with different iron-carbon pressure drops;

[0040] Figure 7 This is a three-dimensional schematic diagram of the anode configuration of the aluminum electrolytic cell for adjusting the apparent density to reduce the horizontal current in Example 1.

[0041] Figure 8 This is a three-dimensional schematic diagram of the anode configuration of the aluminum electrolytic cell for reducing horizontal current by adjusting the conductive area, as shown in Example 2.

[0042] Figure 9 This is a schematic diagram of the anode configuration of an aluminum electrolytic cell for adjusting apparent density to address thin furnace sides, as shown in Example 3.

[0043] Figure 10 This is a schematic diagram of the anode configuration of an aluminum electrolytic cell with thin furnace sides, as shown in Example 4, where the conductive area is adjusted to address the issue.

[0044] Figure 11 This is a three-dimensional schematic diagram of the anode configuration of the aluminum electrolytic cell used in Example 5 to address the issue of leg hypertrophy by adjusting apparent density.

[0045] Figure 12 This is a schematic diagram of the anode configuration of the aluminum electrolytic cell in Example 6, showing how adjusting the conductive area solves the problem of excessive leg extension.

[0046] Figure 13 This is a three-dimensional schematic diagram of the anode configuration of the aluminum electrolytic cell used in Example 7 to address the issue of leg hypertrophy by adjusting the iron-carbon pressure drop.

[0047] Figure 14 This is a schematic diagram of an extended anode structure at both ends;

[0048] Figure 15 A schematic diagram of a two-ended anode structure with a smaller iron-carbon pressure drop;

[0049] Figure 16 This is a schematic diagram of a stepped intermediate anode structure.

[0050] Figure 17This is a plan view of the anode configuration of the aluminum electrolytic cell in Example 8, where the apparent density is used to adjust the regional current and heat distribution.

[0051] Figure 18 This is a plan view of the anode configuration of the aluminum electrolytic cell in Example 9, where the current and heat distribution in the conductive area are adjusted.

[0052] Figure 19 This is a three-dimensional schematic diagram of the anode configuration of the aluminum electrolytic cell in Example 10, which adjusts the regional heat distribution by adjusting the iron-carbon pressure drop.

[0053] In the diagram: 10. Anode with adjustable current and heat distribution; 101. Aluminum guide rod; 102. Steel claw; 103. Prebaked carbon block; 104. Flow equalization device; 1031. Small carbon block; 1032. Carbon bowl; 20. Anodes at both ends; 201. Aluminum guide rod of anodes at both ends; 202. Steel claw of anodes at both ends; 203. Prebaked carbon block of anodes at both ends; 204. Flow equalization device of anodes at both ends; 30. Middle anode; 301. Aluminum guide rod of middle anode; 302. Steel claw of middle anode; 303. Prebaked carbon block of middle anode. Detailed Implementation

[0054] The technical solution and effects of the present invention will be further described below with reference to the accompanying drawings and embodiments:

[0055] Example 1

[0056] This embodiment uses an aluminum electrolytic cell with optimized current and heat distribution provided by the present invention.

[0057] like Figure 4 , Figure 7 As shown, the aluminum electrolytic cell is equipped with an anode 10 with adjustable current and heat distribution. The anode 10 includes an aluminum guide rod 101, a steel claw 102, and a prebaked carbon block 103.

[0058] The aluminum electrolytic cell provided in this embodiment adjusts the apparent density of the small carbon block 1031, thereby changing the anode current distribution and adapting the anode and cathode current distribution characteristics to reduce the horizontal current of the aluminum liquid layer.

[0059] like Figure 4 , Figure 7 As shown, the prebaked carbon block 103 is composed of two small carbon blocks 1031 with different apparent densities.

[0060] like Figure 4 , Figure 7 As shown, on the seam side of the aluminum electrolysis cell, the prebaked carbon block 103 of the anode 10 adopts a small carbon block 1031 with low apparent density, which is marked as L in the figure. On the furnace side of the aluminum electrolysis cell, the prebaked carbon block 103 of the anode 10 adopts a small carbon block 1031 with high apparent density, which is marked as H in the figure.

[0061] like Figure 4 , Figure 7 As shown, the prebaked carbon block 103 has a split structure between its small carbon blocks 1031, and the gap between the small carbon blocks 1031 is no more than 20mm.

[0062] like Figure 4 , Figure 7 As shown, the apparent density of the small carbon blocks 1031 on the seam side of the aluminum electrolytic cell is 1.50–1.54 g / cm³. 3 The apparent density of the small carbon blocks 1031 on the side of the aluminum electrolysis cell furnace is 1.56–1.60 g / cm³. 3 .

[0063] Specific implementation plan and results: A company's 500KA aluminum electrolytic cell has 48 sets of single anodes per cell. The prebaked carbon block of each anode set is 1750mm long, 740mm wide, and 680mm high, with an apparent density of 1.55g / cm³. 3 The anode current density is: 500 / 48 / 175 / 74*1000=0.804A / cm² 2 . like Figure 2 As shown, the uneven distribution of cathode current occurs due to the side-outlet power supply mode of the aluminum electrolysis cell. Approximately 35% of the current flows into the cathode steel rod from the cathode center seam side, and approximately 65% ​​of the current flows into the cathode steel rod from the cathode furnace side region. The average cathode current density on the center seam side is approximately: 0.804 * 2 * 0.35 = 0.563 A / cm². 2 The average current density of the cathode on the furnace side is approximately: 0.804 * 2 * 0.65 = 1.045 A / cm² 2 . In this embodiment, when the density difference of the small carbon blocks is 0.02 g / cm³ 3 At that time, the anode current density on the center slit side was 0.804 A / cm². 2 *1.54 / (1.54+1.56)*2=0.799A / cm 2 The anode current density on the furnace side is 0.804 A / cm². 2 *1.56 / (1.54+1.56)*2=0.809A / cm 2 Using the same algorithm, when the density difference of the small carbon blocks is 0.06 g / cm³... 3 At that time, the anode current density on the center slit side was 0.788 A / cm². 2 The anode current density on the furnace side is 0.820 A / cm². 2 When the density difference of the small charcoal blocks is 0.10 g / cm³ 3 At that time, the anode current density on the center slit side was 0.778 A / cm².2 The anode current density on the furnace side is 0.830 A / cm². 2 . The relationship between the apparent density difference of small carbon blocks on the center seam side and the furnace side side and the effect of reducing horizontal current is shown in Table 1: Table 1: Correspondence between density difference of small carbon blocks and effect on reduction of horizontal current

[0064] This embodiment calculates the effect of reducing horizontal current based on a 500KA electrolytic cell. Other cell types can refer to the algorithm in this embodiment for calculation. By reducing the horizontal current, this embodiment can further reduce the flow rate of aluminum liquid, improve the operational stability of the electrolytic cell, slow down the cathode wear rate, and achieve the purpose of extending the cell life.

[0065] In this embodiment, by adjusting the apparent density difference between the small carbon blocks on the center seam side and the furnace side, the anode current distribution is adjusted, thereby achieving a match between the anode and cathode current distribution characteristics. The adjusted anode and cathode current distribution characteristics are as follows: Figure 3 As shown.

[0066] Installation and implementation steps: When replacing electrodes in the aluminum electrolysis cell, gradually replace the original ordinary anodes with anodes 10, which are composed of small carbon blocks with a lower apparent density on the center seam side than on the furnace side side. After all replacements are completed, proceed as follows: Figure 7 As shown.

[0067] Example 2

[0068] The difference from Example 1 is that:

[0069] This embodiment uses an aluminum electrolytic cell with optimized current and heat distribution provided by the present invention. By adjusting the conductive area of ​​the small carbon block 1031, the anode current distribution is changed, so as to adapt the anode and cathode current distribution characteristics and reduce the horizontal current of the aluminum liquid layer.

[0070] like Figure 5 , Figure 8 As shown, the prebaked carbon block 103 is composed of two small carbon blocks 1031 with different conductive areas. On the seam side of the aluminum electrolysis cell, the prebaked carbon block 103 of the anode 10 uses a small carbon block 1031 with a small conductive area, while on the furnace side side of the aluminum electrolysis cell, the prebaked carbon block 103 of the anode 10 uses a small carbon block 1031 with a large conductive area.

[0071] like Figure 5 , Figure 8 As shown, the prebaked carbon block 103 has an integral structure with the small carbon blocks 1031, and the small carbon blocks 1031 are conductive areas of the prebaked carbon block 103 with different widths in the length direction.

[0072] like Figure 5 , Figure 8 As shown, in this embodiment, the conductive area is adjusted by adjusting the width of the small carbon block 1031. The width of the small carbon block 1031 on the center seam side is 715-735mm, and the width of the small carbon block 1031 on the furnace side side is 745mm.

[0073] Specific implementation plan and results: A certain company's 500KA aluminum electrolysis cell has 48 sets of single anodes per cell. The data such as the size of the prebaked carbon block, the anode current density, and the cathode current distribution are the same as in Example 1. In this embodiment, when the width difference of the small carbon blocks is 10 mm, the anode current density on the center slit side is 0.804 A / cm². 2 *735 / (735+745)*2=0.799A / cm 2 The anode current density on the furnace side is 0.804 A / cm². 2 *745 / (735+745) *2=0.809A / cm 2 Using the same algorithm, when the width difference of the small carbon blocks is 20mm, the anode current density on the center slit side is 0.793A / cm². 2 The anode current density on the furnace side is 0.815 A / cm². 2 When the width difference of the small carbon blocks is 30 mm, the anode current density on the center slit side is 0.787 A / cm². 2 The anode current density on the furnace side is 0.821 A / cm². 2 . The relationship between the width difference of the small carbon blocks on the center seam side and the furnace side side and the effect of reducing the horizontal current is shown in Table 2: Table 2: Correspondence between the width difference of small carbon blocks and the effect of reducing horizontal current

[0074] This embodiment calculates the effect of reducing horizontal current based on a 500KA electrolytic cell. Other cell types can refer to the algorithm in this embodiment for calculation. This embodiment adjusts the conductive area by adjusting the width of the small carbon blocks. Adjusting the conductive area by adjusting the width of the bottom slot is similar to this embodiment. For specific implementations of this method, please refer to this embodiment and will not be described separately.

[0075] Comparative example, the current distribution characteristics of the anode and cathode are as follows: Figure 2 As shown in the figure, in this embodiment, by adjusting the width difference between the small carbon blocks on the center seam side and the furnace side side, the anode current distribution is adjusted, thereby achieving a match between the anode and cathode current distribution characteristics. The adjusted anode and cathode current distribution characteristics are as follows: Figure 3 As shown.

[0076] Installation and implementation steps: When changing electrodes in the aluminum electrolysis cell, gradually replace the original ordinary anodes with anode 10, which is composed of small carbon blocks with a width smaller than that on the furnace side. After all replacements are completed, proceed as follows: Figure 8 As shown.

[0077] Example 3

[0078] The difference from Example 1 is that:

[0079] This embodiment uses an aluminum electrolytic cell with optimized current and heat distribution provided by the present invention. By adjusting the apparent density of small carbon blocks 1031, the anode current and heat generation distribution are changed, thus solving the problem of thin furnace walls in some areas of the aluminum electrolytic cell.

[0080] like Figure 4 , Figure 9 As shown, at the thinner section of the aluminum electrolytic cell furnace wall, the apparent density of the small carbon blocks 1031 on the side of the central seam of the prebaked carbon block 103 is 1.56–1.60 g / cm³. 3 The apparent density of the small charcoal lumps 1031 on the side of the furnace is 1.53 g / cm³. 3 .

[0081] Specific implementation plan and results: A certain company's 500KA aluminum electrolysis cell has 48 sets of single anodes per cell. The data such as the size of the prebaked carbon block, the anode current density, and the cathode current distribution are the same as in Example 1. like Figure 9 As shown, this embodiment uses small carbon blocks with low apparent density in the thinner parts of the furnace side to reduce the heat generation of the electrolyte layer on the furnace side and lower the electrolyte temperature on the furnace side, thereby achieving the purpose of thickening the furnace side. The specific effects are as follows: In this embodiment, the dimensions of the small charcoal blocks on the furnace side are: width 740mm, length 1750mm / 2 = 875mm, and the conductive area on the furnace side is 74 * 87.5 = 6475cm². 2 The apparent density of the small carbon block 1031 on the mid-suture side is 1.60 g / cm³. 3 The apparent density of the small charcoal lumps 1031 on the side of the furnace is 1.53 g / cm³. 3 The apparent density difference of the small charcoal blocks is 0.7 g / cm3. In the comparative example, the conductive area on the furnace side is the same as that in this embodiment, 6475 cm². 2 Calculate the heat generation of the electrolyte layer on the furnace side. Electrolyte in the area of ​​small carbon blocks on the side of the furnace (height 18cm, electrode distance 4.5cm, density 2100Kg / m³) 3 The mass is 2100 kg / m³. 3 ×6475cm 2 ×4.5cm×10 -6= 61.2Kg; The specific heat capacity of the liquid electrolyte is based on the specific heat capacity of liquid cryolite (molecular ratio of 3), which is 1.887×10. 3 Given J / (kg·℃), the amount of heat required to raise the temperature of 61.2 kg of electrolyte by 1℃ is: 1.887 × 10⁻⁶. 3 J / (kg.℃)×61.2kg×1℃=0.115×10 6 J. Liquid aluminum in the small carbon block area on the side of the furnace (aluminum liquid height 28cm, density 2300Kg / m³) 3 The mass is 2300 kg / m³. 3 ×6475cm 2 ×28cm×10 -6 = 417 kg. The specific heat capacity of liquid aluminum is 1.176 × 10⁻⁶ kg. 3 Given J / (kg·℃), the amount of heat required to raise the temperature of 417 kg of liquid aluminum by 1℃ is: 1.176 × 10⁻⁶ J / (kg·℃). 3 J / (kg.℃)×417kg×1℃=0.49×10 6 J. The total heat required to raise the temperature of 61.2 kg of electrolyte and 417 kg of liquid aluminum by 1 °C is: 0.115 × 10⁻⁶. 6 J+0.49×10 6 J = 0.605 × 10 6 J. In this embodiment and the comparative example, the electrolyte voltage drop was calculated based on a 1.4V electrolyte layer heat generation. In comparison, the calorific value of the electrolyte layer in the area of ​​a single small carbon block on the furnace side over 1 hour is: 1.4V × 0.804A / cm². 2 ×6475cm 2 ×1h×10 -3 ×3.6×10 6 J / kWh=26.2×10 6 J. In this embodiment, according to the above calorific value calculation, the calorific value of a single small charcoal block area on the furnace side in 1 hour is: 25.65 × 10⁻⁶. 6 J. In the comparative example, the electrolyte temperature on the furnace side was set at 950℃. In this embodiment, the calorific value of the electrolyte on the furnace side is reduced by 26.2 × 10⁻⁶ compared to the control group. 6 J-25.65×10 6 J = 0.55 × 10 6 J, Electrolyte temperature decrease on the furnace side: 0.55 × 10 6 J÷0.605×10 6J×1℃=0.91℃, that is, the electrolyte temperature on the furnace side is 950℃-0.91℃=949.09℃. The empirical formula for calculating furnace side thickness is: δ=α(T1-Ts) / (Tb-T1)-H, where: δ—furnace side thickness, mm; Tb—electrolyte temperature, ℃; T1—electrolyte primary crystallization temperature, taken as 940℃; Ts—temperature of the furnace side shell, taken as 260℃; H—thickness of the side lining material and shell steel plate, taken as 106mm; α—thermal resistance coefficient of the furnace side, a typical value of 3.075mm for a 500kA electrolytic cell. According to the comparative example, the thickness of the furnace side is calculated using the empirical formula as: 3.075*(940-260) / (950-940)-106=103mm. In this embodiment, the thickness of the furnace side is: 3.075*(940-260) / (949.09-940)-106=124mm. This embodiment also calculated the apparent density difference to be 0.03 g / cm³. 3 and 0.05g / cm 3 The results of the study are shown in Table 3. Table 3 shows the effect of the apparent density difference of small charcoal blocks on adjusting the calorific value, temperature, and thickness of the furnace side: Table 3: Correspondence between density difference of small char blocks and calorific value, temperature and furnace wall thickness over 1 hour

[0082] This embodiment calculates the temperature and thickness changes of the furnace side based on the assumption that a 500KA electrolytic cell reaches thermal equilibrium in 1 hour. Other cell types can refer to the algorithm in this embodiment and combine it with actual measurement data for calculation. However, in general, by using small carbon blocks with a lower apparent density on the furnace side than on the center seam side, the anode current density and heat generation on the furnace side can be reduced, and the electrolyte temperature and superheat on the furnace side can be lowered, thereby achieving the purpose of thickening the furnace side.

[0083] Installation and implementation steps: When replacing electrodes at weak points in the furnace side of the aluminum electrolysis cell, replace the original ordinary anodes with anode 10, which is composed of small carbon blocks with a lower apparent density on the furnace side than on the center seam side. After all replacements are completed, as follows: Figure 9 As shown.

[0084] Example 4

[0085] The difference from Example 3 is that:

[0086] This embodiment uses an aluminum electrolytic cell with optimized current and heat distribution provided by the present invention. By adjusting the conductive area of ​​the small carbon block 1031, the anode current and heat generation distribution are changed, thus solving the problem of thin furnace walls in some areas of the aluminum electrolytic cell.

[0087] like Figure 5 , Figure 10 As shown, the prebaked carbon block 103 has an integral structure with the small carbon blocks 1031, and the small carbon blocks 1031 are conductive areas of the prebaked carbon block 103 with different widths in the length direction.

[0088] like Figure 5 , Figure 10 As shown, in this embodiment, the conductive area is adjusted by adjusting the width of the small carbon block 1031. The width of the small carbon block 1031 on the seam side of the aluminum electrolysis cell is 745 mm, and the width of the small carbon block 1031 on the furnace side side of the aluminum electrolysis cell is 715-735 mm.

[0089] Specific implementation plan and results: A certain company's 500KA aluminum electrolysis cell has 48 sets of single anodes per cell. The data such as the size of the prebaked carbon block, the anode current density, and the cathode current distribution are the same as in Example 1. like Figure 10 As shown, this embodiment uses small carbon blocks with a small conductive area in the thinner parts of the furnace side to reduce the heat generation of the electrolyte layer on the furnace side, lower the electrolyte temperature on the furnace side, and achieve the purpose of thickening the furnace side. The specific effects are as follows: Comparatively, the dimensions of the small carbon block on the side of the furnace are: width 740mm, length 1750mm / 2 = 875mm. Therefore, the conductive area on the side of the furnace is... =74 * 87.5 = 6475cm 2 . In this embodiment, the width of the small carbon block on the center seam side is 745mm, and the width of the small carbon block on the furnace side side is 715mm, with a width difference of 30mm. The conductive area on the furnace side side is 6256cm². 2 The anode current density on the furnace side is calculated as follows: 0.804 * 715 / (715 + 745) * 2 = 0.787 A / cm² 2 . In this embodiment and the comparative example, the electrolyte voltage drop is calculated based on 1.4V for the heat generation of the electrolyte layer. Comparatively, the calorific value of the electrolyte layer in the area of ​​a single small carbon block on the furnace side is: 1.4V × 0.804A / cm 2 ×6475cm 2 ×1h×10 -3 ×3.6×10 6 J / kWh=26.2×10 6 J. In this embodiment, according to the above calorific value calculation, the calorific value of a single small charcoal block area on the furnace side in 1 hour is: 25.68 × 10⁻⁶. 6 J. In the comparative example, the electrolyte temperature on the furnace side was set at 950℃. The amount of heat required to raise the temperature of the electrolyte and liquid aluminum by 1°C in the area of ​​a single small carbon block on the furnace side is: 0.605 × 10⁻⁶. 6 J. In this embodiment, the calorific value of the electrolyte on the furnace side is reduced by 26.2 × 10⁻⁶ compared to the control group. 6 J-25.68×10 6 J = 0.52 × 10 6 J, Electrolyte temperature decrease on the furnace side: 0.52 × 10 6 J÷0.605×10 6 J×1℃=0.85℃, that is, the electrolyte temperature on the furnace side is 950℃-0.85℃=949.15℃. According to the comparative example, the thickness of the furnace side is calculated using the empirical formula as: 3.075*(940-260) / (950-940)-106=103mm. In this embodiment, the thickness of the furnace side is: 3.075*(940-260) / (949.15-940)-106=123mm. This embodiment also measured the effect data when the width difference of the small carbon blocks was 20 mm and 10 mm, and the results are shown in Table 4. Table 4 shows the effect of the difference in the width of small charcoal blocks on adjusting the calorific value, temperature, and thickness of the furnace side: Table 4: Correspondence between the width difference of small char blocks and the calorific value, temperature and thickness of the furnace side over 1 hour.

[0090] This embodiment calculates the temperature and thickness changes of the furnace side based on the assumption that a 500KA electrolytic cell reaches thermal equilibrium in 1 hour. Other cell types can refer to the algorithm in this embodiment and combine it with actual measurement data for calculation. However, in general, by reducing the conductive area of ​​the small carbon blocks 1031 on the furnace side, the problem of localized thin furnace sides in aluminum electrolytic cells can be solved.

[0091] Installation and implementation steps: When replacing electrodes at locations with thinner furnace sides in aluminum electrolysis cells, replace the original ordinary anodes with anode 10, which is composed of small carbon blocks with a smaller conductive area on the furnace side than on the center seam side. After all replacements are completed, proceed as follows: Figure 10 As shown.

[0092] Example 5

[0093] The difference from Example 3 is that:

[0094] This embodiment employs an aluminum electrolytic cell with optimized current and heat distribution. By adjusting the apparent density of the small carbon blocks 1031, the anode current and heat generation distribution are changed, thus solving the problem of thick furnace walls and large legs in the aluminum electrolytic cell.

[0095] like Figure 4, Figure 11 As shown, the apparent density of the small carbon blocks 1031 on the seam side of the prebaked carbon block 103 at the location of the localized thick furnace wall in the aluminum electrolysis cell is 1.55 g / cm³. 3 The apparent density of the small charcoal lumps 1031 on the side of the furnace is 1.57–1.61 g / cm³. 3 .

[0096] Specific implementation plan and results: A certain company's 500KA aluminum electrolysis cell has 48 sets of single anodes per cell. The data such as the size of the prebaked carbon block, the anode current density, and the cathode current distribution are the same as in Example 1. like Figure 11 As shown in the figure, the aluminum electrolysis cell at both ends corresponds to a thicker furnace side. Small carbon blocks with high apparent density are used in the thicker furnace side to increase the heat generation on the anode furnace side, thus solving the problem of excessively thick furnace side legs. The specific effects are as follows: In this embodiment, the dimensions of the small carbon block on the furnace side are: 740mm wide and 1750mm / 2 = 875mm long. The conductive area on the furnace side... =74 * 87.5 = 6475cm 2 The apparent density of the small carbon block 1031 on the mid-suture side is 1.55 g / cm³. 3 The apparent density of the small charcoal lumps 1031 on the side of the furnace is 1.61 g / cm³. 3 The apparent density difference of the small charcoal blocks is 0.6 g / cm³. 3 . In the comparative example, the conductive area on the furnace side is the same as that in this embodiment, 6475 cm². 2 Calculate the heat generation of the electrolyte layer on the furnace side. In this embodiment and the comparative example, the electrolyte voltage drop was calculated based on a 1.4V electrolyte layer heat generation. Comparatively, the calorific value of the electrolyte layer in the area of ​​a single small carbon block on the furnace side is: 1.4V × 0.804A / cm 2 ×6475cm 2 ×1h×10 -3 ×3.6×10 6 J / kWh=26.2×10 6 J. In this embodiment, according to the above calorific value calculation, the calorific value of a single small charcoal block area on the furnace side in 1 hour is: 27.25 × 10⁻⁶. 6 J. In comparison, the furnace side temperature is set at 950℃. The amount of heat required to raise the temperature of the electrolyte and liquid aluminum by 1°C in the area of ​​a single small carbon block on the furnace side is: 0.605 × 10⁻⁶. 6 J. In this embodiment, the ratio of electrolyte calorific value on the furnace side is increased by 27.25 × 10⁻⁶. 6 J-26.2×10 6 J = 1.05 × 10 6 J, Electrolyte temperature increase on the furnace side: 1.05 × 10 6 J÷0.605×10 6 J×1℃=1.67℃, that is, the electrolyte temperature on the furnace side is 950℃-0.85℃=951.67℃. The empirical formula for calculating furnace side thickness is: δ=α(T1-Ts) / (Tb-T1)-H, where: δ—furnace side thickness, mm; Tb—electrolyte temperature, ℃; T1—electrolyte primary crystallization temperature, taken as 942℃; Ts—temperature of the furnace side shell, taken as 230℃; H—thickness of the side lining material and shell steel plate, taken as 106mm; α—thermal resistance coefficient of the furnace side, a typical value of 3.075mm for a 500kA electrolytic cell; According to the comparative example, the thickness of the furnace side is calculated using the empirical formula as: 3.075*(942-230) / (950-942)-106=168mm. In this embodiment, the thickness of the furnace side is: 3.075*(942-230) / (951.67-942)-106=120mm. This embodiment also calculated the apparent density difference to be 0.02 g / cm³. 3 and 0.04 g / cm 3 The results of the study are shown in Table 5. Table 5 shows the effect of the apparent density difference of small charcoal blocks on adjusting the calorific value, temperature, and thickness of the furnace side: Table 5: Correspondence between density difference of small char blocks and calorific value, temperature and thickness of furnace side in 1 hour.

[0097] This embodiment calculates the temperature and thickness changes of the furnace side based on the assumption that a 500KA electrolytic cell reaches thermal equilibrium in 1 hour. Other cell types can refer to the algorithm in this embodiment and make corrections based on actual measurement data. However, in general, increasing the apparent density of small carbon blocks on the furnace side can solve the problem of local furnace side thickness in electrolytic cells.

[0098] Installation and implementation steps: When replacing electrodes in areas with thicker furnace sides and larger extension legs in aluminum electrolysis cells, replace the original ordinary anodes with anode 10, which is composed of small carbon blocks with a higher apparent density on the furnace side than on the center seam side. After all replacements are completed, proceed as follows: Figure 11 As shown.

[0099] Example 6

[0100] The difference from Example 5 is that:

[0101] This embodiment employs an aluminum electrolytic cell with optimized current and heat distribution. By adjusting the conductive area of ​​the small carbon block 1031, the anode current and heat generation distribution are changed, thus solving the problem of thick furnace walls and large legs in the aluminum electrolytic cell.

[0102] like Figure 5 , Figure 12 As shown, in this embodiment, the conductive area is adjusted by the width of the small carbon block 1031. The width of the small carbon block 1031 on the seam side of the aluminum electrolysis cell is 735mm, and the width of the small carbon block 1031 on the furnace side is 745mm.

[0103] Specific implementation plan and results: A certain company's 500KA aluminum electrolysis cell has 48 sets of single anodes per cell. The data such as the size of the prebaked carbon block, the anode current density, and the cathode current distribution are the same as in Example 1. In this embodiment, the width of the small carbon block on the center seam side is 735mm, and the width of the small carbon block on the furnace side side is 745mm, with a width difference of 10mm. The anode current density on the furnace side side is 0.804*745 / (735+745)*2 = 0.809A / cm². 2 . In this embodiment and the comparative example, the electrolyte voltage drop is calculated based on a 1.4V electrolyte layer heat generation. In this embodiment and the comparative example, the area of ​​a single small charcoal block on the side of the furnace is 6475 cm². 2 Calculate the heat output. In comparison, the calorific value of the electrolyte layer in the furnace side region over 1 hour is: 1.4V × 0.804A / cm². 2 ×6475cm 2 ×1h×10 -3 ×3.6×10 6 J / kWh=26.2×10 6 J. In this embodiment, according to the above calorific value calculation, the calorific value of a single small charcoal block area on the furnace side in 1 hour is: 26.4 × 10⁻⁶. 6 J. In comparison, the furnace side temperature is set at 950℃. The amount of heat required to raise the temperature of the electrolyte and liquid aluminum by 1°C in the area of ​​a single small carbon block on the furnace side is: 0.605 × 10⁻⁶. 6 J. In this embodiment, the ratio of electrolyte calorific value on the furnace side is increased by 26.4 × 10⁻⁶. 6 J-26.2×10 6 J = 0.2 × 10 6 J, Electrolyte temperature increase on the furnace side: 0.2 × 10 6 J÷0.605×10 6J×1℃=0.27℃, that is, the electrolyte temperature on the furnace side is 950℃+0.27℃=950.27℃. According to the comparative example, the thickness of the furnace side is calculated using the empirical formula as: 3.075*(942-230) / (950-942)-106=168mm; In this embodiment, the furnace side thickness is: 3.075*(942-230) / (950.27-942)-106=159mm. Table 6 shows the effect of the difference in the width of small charcoal blocks on adjusting the calorific value, temperature, and thickness of the furnace side: Table 6: Correspondence between the width difference of small carbon blocks and calorific value, temperature, and furnace wall thickness over 1 hour

[0104] This embodiment calculates the temperature and thickness changes of the furnace side based on the assumption that a 500KA electrolytic cell reaches thermal equilibrium in 1 hour. Other cell types can refer to the algorithm in this embodiment and combine it with actual measurement data for calculation. However, in general, by using a furnace side conductive area that is larger than the conductive area of ​​the small carbon block on the center seam side, the problems of local furnace side thickness and leg enlargement in aluminum electrolytic cells can be solved.

[0105] Installation and implementation steps: When replacing electrodes at the enlarged position of the rear extension leg of the aluminum electrolysis cell furnace side, replace the original ordinary anode with an anode 10 composed of small carbon blocks with a larger conductive area on the furnace side side than on the center seam side. After all replacements are completed, as follows: Figure 12 As shown.

[0106] Example 7

[0107] The difference from Example 5 is that:

[0108] This embodiment uses an aluminum electrolytic cell with optimized current and heat distribution provided by the present invention. By adjusting the iron-carbon pressure drop of the small carbon block 1031, the anode heat distribution is changed, thus solving the problem of thick furnace walls and large legs in the aluminum electrolytic cell.

[0109] like Figure 6 , Figure 13 As shown, a flow equalization device 104 is welded between the aluminum guide rod 101 on the furnace side of the anode 10 and the crossbeam of the steel claw 102. The flow equalization device 104 is an aluminum plate. The aluminum plate is directly welded to the aluminum guide rod 101. The aluminum plate is welded to the crossbeam of the steel claw 102 using steel-aluminum direct welding technology. The flow equalization device 104 helps to reduce the iron-carbon pressure drop and increase the electrolyte layer pressure drop and heat generation.

[0110] like Figure 6 , Figure 13As shown, the diameter of the carbon bowl 1032 of the small carbon block 1031 on the seam side of the aluminum electrolysis cell is 180-190mm, and the diameter of the carbon bowl 1032 of the small carbon block 1031 on the furnace side is 220-230mm.

[0111] The average iron-carbon pressure drop of the small carbon blocks 1031 on the center seam side of the aluminum electrolysis cell is 400 mV, and the average iron-carbon pressure drop of the small carbon blocks 1031 on the furnace side is 355 mV to 385 mV. The iron-carbon pressure drop is measured using an iron-carbon pressure drop measuring instrument. Figure 6 As shown, the iron-carbon pressure drop is the pressure drop between points D1 and D2.

[0112] Specific implementation plan and results: A certain company's 500KA aluminum electrolysis cell has 48 sets of single anodes per cell. The data such as the size of the prebaked carbon block, the anode current density, and the cathode current distribution are the same as in Example 1. Electrolyte pressure drop U = Uad - Uab - Ubc - U 过 Uad is the pressure drop from the anode busbar to the molten aluminum layer, taken as 2350 mV; Uab is the pressure drop from the anode busbar to the bottom of the aluminum guide rod, taken as 30 mV; U 过 Ubc is the anode overvoltage, typically 400mV to 600mV, with a value of 500mV; Ubc is the iron-carbon voltage drop. For the comparative example, the electrolyte pressure drop U = 2350mv - 30mv - 400mv - 500mv = 1420mv; In this embodiment, the iron-carbon pressure drop of the small carbon block on the center seam side is 400 mV, and the iron-carbon pressure drop of the small carbon block on the furnace side side is 355 mV, with a pressure drop difference of 45 mV. According to the comparative calculation, the electrolyte pressure drop on the center seam side is 1420 mV, and the electrolyte pressure drop on the furnace side side is 1465 mV. Comparatively, the calorific value of the electrolyte layer in the area of ​​a single small carbon block on the furnace side is: 1.42V × 0.804A / cm 2 ×6475cm 2 ×1h×10 -3 ×3.6×10⁶ J / kWh=26.61×10 6 J. Comparatively, the calorific value of the electrolyte layer in the area of ​​a single small carbon block on the furnace side is: 1.465V × 0.804A / cm 2 ×6475cm 2 ×1h×10 -3 ×3.6×10 6 J / kWh=27.46×10 6 J. In comparison, the furnace side temperature is set at 950℃. The amount of heat required to raise the temperature of the electrolyte and liquid aluminum by 1°C in the area of ​​a single small carbon block on the furnace side is: 0.605 × 10⁻⁶. 6 J. In this embodiment, the ratio of electrolyte calorific value on the furnace side is increased by 27.46 × 10⁻⁶. 6 J-26.2×10 6 J = 1.26 × 10 6 J, Electrolyte temperature increase on the furnace side: 1.26 × 10⁻⁶ 6 J÷0.605×10 6 J×1℃=1.39℃, that is, the electrolyte temperature on the furnace side is 950℃+0.27℃=951.39℃. According to the comparative example, the thickness of the furnace side is calculated using the empirical formula as: 3.075*(942-230) / (950-942)-106=168mm; In this embodiment, the thickness of the furnace side is: 3.075*(942-230) / (951.39-942)-106=127mm. This embodiment also calculated the effect data for iron-carbon voltage drop differences of 15mV and 30mV, and the results are shown in Table 7. Table 7 shows the effect of the iron-carbon pressure drop difference of small carbon blocks on regulating the calorific value, temperature, and thickness of the furnace side. Table 7: Correspondence between the iron-carbon pressure drop difference of small carbon blocks and the calorific value, temperature and furnace wall thickness over 1 hour.

[0113] This embodiment calculates the temperature and thickness changes of the furnace side based on the assumption that a 500KA electrolytic cell reaches thermal equilibrium in 1 hour. Other cell types can refer to the algorithm in this embodiment and combine it with actual measurement data for calculation. However, in general, by reducing the iron-carbon pressure drop of the small carbon blocks 1031 on the furnace side, the problems of local furnace side thickness and leg enlargement in aluminum electrolytic cells can be solved.

[0114] Installation and implementation steps: When replacing electrodes at the enlarged rear extension leg of the aluminum electrolysis cell furnace side, replace the original ordinary anode with an anode 10 composed of small carbon blocks from the furnace side side, which has a smaller iron-carbon pressure drop than the center seam side. After all replacements are completed, proceed as follows: Figure 13 As shown.

[0115] Example 8

[0116] This embodiment employs an aluminum electrolytic cell with adjustable regional current and heat distribution to solve the regional energy imbalance problem existing in aluminum electrolytic cells, such as the heat generation at both ends being less than the heat dissipation, and the heat generation in the middle region being greater than the heat dissipation.

[0117] Research and analysis revealed that the electrolyte temperature distribution in different areas of the aluminum electrolysis cell is uneven. There is a temperature difference of approximately 6°C between the central region and the corner regions. The distribution characteristics of the hot and cold regions in the electrolysis cell are as follows: Figure 1 As shown, the main purpose of this embodiment is to reduce the temperature difference between different areas of the electrolytic cell and improve the temperature uniformity of the electrolytic cell.

[0118] like Figure 17 As shown, the aluminum electrolytic cell includes two anodes 20 at both ends and a middle anode 30. The two anodes 20 at both ends include aluminum guide rods 201, steel claws 202, and prebaked carbon blocks 203. The middle anode 30 includes aluminum guide rods 301, steel claws 302, and prebaked carbon blocks 303. The apparent density of the prebaked carbon blocks 203 in the two anodes 20 at both ends is greater than the apparent density of the prebaked carbon blocks 303 in the middle anode 30.

[0119] The apparent density of the prebaked carbon blocks 203 at both ends of the aluminum electrolysis cell anode 20 is 1.57–1.61 g / cm³. 3 The apparent density of the prebaked carbon block 303 in the intermediate anode 30 of the aluminum electrolytic cell is 1.53 g / cm³. 3 .

[0120] Specific implementation plan and results: A company has a 500KA aluminum electrolytic cell with 48 sets of single anodes per cell. Each set of anodes uses a prebaked carbon block (103) with a length of 1750mm, a width of 740mm, and a height of 680mm. The average anode current density is: 500 / 48 / 175 / 74*1000=0.804A / cm² 2 . like Figure 17 As shown, the aluminum electrolysis cell has 16 sets of anodes 20 at both ends, and the remaining 32 sets are intermediate anodes 30. Comparative example: the apparent density of prebaked charcoal blocks is 1.55 g / cm³. 3 In this embodiment, the apparent density of the prebaked carbon block with anodes 20 at both ends is 1.61 g / cm³. 3 The apparent density of the prebaked carbon block of intermediate anode 30 is 1.55 g / cm³. 3 The apparent density difference is 0.06 g / cm³. 3 . Single anode conductive area = 74 * 175 = 12950 cm² 2 . In this embodiment, the conductive area of ​​the anode 20 regions at both ends is 12950 cm². 2 *16=207200cm 2 The conductive area of ​​the intermediate anode region 30 is 12950 cm². 2 *32=414400cm 2 . Electrolyte in a single anode area (height 18cm, electrode spacing 4.5cm, density 2100Kg / m³) 3 The mass is 2100 kg / m³. 3 ×12950m 2 ×4.5cm×10 -6 = 122.38Kg; The specific heat capacity of the liquid electrolyte is based on the specific heat capacity of liquid cryolite (molecular ratio of 3), which is 1.887 × 10⁻⁶. 3 If the heat required to raise the electrolyte temperature by 1°C is calculated using J / (kg·°C), then the heat required is 1.887 × 10⁻⁶. 3 J / (kg.℃)×122.38kg×1℃=0.231×10 6 J. Liquid aluminum in a single anode area (aluminum liquid height 28cm, density 2300Kg / m³) 3 The mass is 2300 kg / m³. 3 ×12950cm 2 ×28cm×10 -6 = 834 kg. The specific heat capacity of liquid aluminum is 1.176 × 10⁻⁶ kg. 3 Given J / (kg·℃), the amount of heat required to raise the temperature of 834 kg of liquid aluminum by 1℃ is: 1.176 × 10⁻⁶. 3 J / (kg.℃)×834kg×1℃=0.981×10 6 J. The total heat required to raise the temperature of 122.38 kg of electrolyte and 834 kg of liquid aluminum by 1 °C is: 0.231 × 10⁻⁶ 6 J+0.981×10 6 J = 1.212 × 10 6 J. Comparative example, anodic current density 0.804 A / cm 2 . To maintain the stability of the electrode spacing in the aluminum electrolysis cell, the daily consumption height of the anode carbon block is consistent. Under normal circumstances, the average daily consumption height of the carbon anode during aluminum electrolysis is approximately 2 cm. Therefore, the daily carbon anode consumption for the 16 sets of end anodes is: 16 * 12950 cm. 2 *2cm*1.61g / cm 3 =667184g, the daily carbon anode consumption of 32 intermediate anodes is: 32 * 12950cm³ 2 *2cm*1.55g / cm 3 =1284640g. Since the magnitude of the anode current is directly proportional to the mass of prebaked carbon blocks consumed, the average daily current of the 16 groups of anodes at both ends is: 500KA*667184g / (667184g+1284640g)=170.913KA, and the average daily current of the 32 groups of anodes in the middle is: 500KA*1284640g / (667184g+1284640g)=329.087KA. In this embodiment, the anode current density at both ends is: 170.913KA*1000 / 16 / 12950cm² 2 =0.825A / cm 2 The intermediate anode current density is: 329.087KA*1000 / 32 / 12950cm³ 2 =0.794A / cm 2 Compared to the comparative example, the current in the regions at both ends of the electrolytic cell was enhanced by 0.825 A / cm. 2 / 0.804A / cm 2 -1 = 2.6%, the current in the intermediate region decreased by 1 -0.794 A / cm 2 / 0.804A / cm 2 =1.24%. In this embodiment and the comparative example, the electrolyte voltage drop was calculated based on a 1.4V electrolyte layer heat generation. In comparison, the heat generated by the electrolyte layer in the single anode region at both ends of the electrolytic cell over 1 hour is: 1.4V × 0.804A / cm². 2 ×207200cm 2 ×1h×10 -3 ×3.6×10⁶ J / kWh ÷ 16 = 52.5×10 6 J; The calorific value of the electrolyte layer in the middle single-group anode region of the electrolytic cell over 1 hour is: 1.4V × 0.804A / cm². 2 ×414400cm 2 ×1h×10 -3 ×3.6×10⁶ J / kWh ÷ 32 = 52.5×10 6 J. In this embodiment, according to the above-described calorific value calculation, the calorific value of the electrolyte layer in the single anode region at both ends over 1 hour is: 53.84 × 10⁻⁶. 6 J, the heat generation of the electrolyte layer in the middle single-group anode region over 1 hour is: 51.83 × 10⁻⁶. 6 J; In the comparative example, the intermediate electrolyte temperature was set at 952℃, and the electrolyte temperatures at both ends were set at 948℃. In this embodiment, the calorific value of the electrolyte in the anode regions at both ends is increased by 53.84 × 10⁻⁶. 6 J-52.5×10 6 J = 1.34 × 106 J, Electrolyte temperature rise: 1.34 × 10 6 J÷1.212×10 6 J×1℃=1.1℃, electrolyte temperature is 948℃+1.1℃=949.1℃; the calorific value of the electrolyte in the intermediate anode region is reduced by 52.5×10 compared to the control group. 6 J-51.83×10 6 J = 0.67 × 10 6 J, Electrolyte temperature decrease: 0.67 × 10 6 J÷1.212×10 6 J×1℃=0.55℃, electrolyte temperature is 952℃-0.55℃ =951.45℃. The empirical formula for calculating furnace side thickness is: δ=α(T1-Ts) / (Tb-T1)-H, where: δ—furnace side thickness, mm; Tb—electrolyte temperature, °C; T1—electrolyte primary crystallization temperature, taken as 940 °C; Ts—temperature of the furnace side shell, taken as 260 °C in the middle area and 230 °C at both ends; H—thickness of the side lining material and shell steel plate, taken as 106 mm; α—thermal resistance coefficient of the furnace side, a typical value of 3.075 mm for a 500 kA electrolytic cell; The thickness of the furnace lining is calculated using the empirical formula as follows: In comparison, the thickness of the furnace sidewalls at both ends is: 3.075*(940-230) / (948-940)-106=167mm; the thickness of the furnace sidewalls in the middle area is: 3.075*(940-260) / (952-940)-106=68mm. In this embodiment, the thickness of the furnace sidewall at both ends is: 3.075*(940-230) / (949.1-940)-106=134mm; the thickness of the furnace sidewall in the middle area is: 3.075*(940-260) / (951.45-940)-106=77mm. This embodiment also calculated the apparent density difference to be 0.02 g / cm³. 3 and 0.04 g / cm 3 The results of the study are shown in Table 8. Table 8 shows the effect of the apparent density difference of prebaked char blocks on the calorific value, temperature, and furnace wall thickness of the adjustment zone. Table 8: Relationship between prebaked carbon block density difference and regional electrolyte temperature and furnace wall thickness

[0121] This embodiment calculates the calorific value, temperature, and furnace wall thickness changes based on a 500KA electrolytic cell reaching thermal equilibrium in 1 hour. Other cell types can refer to the algorithm in this embodiment and combine it with actual measurement data for calculation. However, in general, by using prebaked carbon blocks with a higher apparent density at both ends than in the middle, the anode current density, calorific value, and temperature in the middle of the electrolytic cell can be reduced, while the anode current density, temperature, and calorific value at both ends can be increased, thus achieving the purpose of regulating the furnace chamber. At the same time, the increase in electrolyte temperature at both ends helps to eliminate the sedimentation at the bottom of the furnace, especially in the corner areas, thereby enhancing the cathode conductivity at both ends, reducing the horizontal current at both ends, and improving the operational stability of the electrolytic cell.

[0122] Installation and implementation steps: When replacing electrodes at both ends of the aluminum electrolysis cell, gradually replace the original ordinary anodes with prebaked carbon blocks 203 anodes 20 that have a higher apparent density. After all replacements are completed, proceed as follows: Figure 17 As shown.

[0123] Example 9

[0124] The difference from Example 8 is that:

[0125] like Figure 18 As shown, this embodiment employs an aluminum electrolytic cell with adjustable regional current and heat distribution provided by the present invention. It is mainly used to solve the regional energy imbalance problem existing in aluminum electrolytic cells. The aluminum electrolytic cell includes two anodes 20 at both ends and a middle anode 30. The two anodes 20 at both ends include aluminum guide rods 201, steel claws 202, and prebaked carbon blocks 203. The middle anode 30 includes aluminum guide rods 301, steel claws 302, and prebaked carbon blocks 303. The conductive area of ​​the prebaked carbon blocks 203 at both ends of the anodes 20 is greater than the conductive area of ​​the prebaked carbon blocks 303 at the middle anode 30.

[0126] like Figure 14 , Figure 16 , Figure 18 As shown, the prebaked carbon blocks 203 of the anodes 20 at both ends of the aluminum electrolysis cell have a length of 1765-1795 mm and a width of 740 mm. The prebaked carbon blocks 303 of the middle anode 30 have a length of 1750 mm. The prebaked carbon blocks 203 of the middle anode 30 are stepped and have an average width of 730 mm. The width of the middle seam side is 720 mm and the width of the furnace side side is 740 mm. In this embodiment, by increasing the length of the anodes at both ends and reducing the width of the middle anode, the conductive area and heat generation of the anodes 20 at both ends are greater than those of the middle anode 30.

[0127] Specific implementation plan and results: A company has a 500KA aluminum electrolytic cell with 48 sets of single anodes per cell. The prebaked carbon block of each anode set is 1750mm long, 740mm wide, and 680mm high. The average anode current density is: 500 / 48 / 175 / 74*1000=0.804A / cm² 2 . like Figure 18 As shown, the aluminum electrolysis cell has 16 sets of anodes 20 at both ends, and the remaining 32 sets are intermediate anodes 30. The apparent density of the prebaked char blocks in both the comparative example and this embodiment is 1.55 g / cm³. 3 . In this embodiment, the length of the prebaked carbon blocks at both ends of the anode is 1795 mm, and the conductive area is 74 * 179.5 = 13283 cm². 2 The conductive area of ​​the intermediate anode = 73 * 175 = 12775 cm² 2 The conductive area of ​​the anode 20 regions at both ends is 13283 cm². 2 *16=212528cm 2 The conductive area of ​​the intermediate anode region 30 is 12775 cm². 2 *32=418800cm 2 . According to the algorithm in Example 8, the area of ​​a typical anode is 74 * 175 = 12950 m². 2 Calculating the mass of electrolyte and molten aluminum in a single anode region, the total heat required to raise the temperature of 122.38 kg of electrolyte and 834 kg of liquid aluminum by 1℃ is: 0.231 × 10⁻⁶. 6 J+0.981×10 6 J = 1.212 × 10 6 J. Under normal circumstances, the average daily consumption height of carbon anodes during aluminum electrolysis is approximately 2 cm. Therefore, the daily carbon anode consumption for 16 sets of end anodes is: 16 * 13283 cm. 2 *2cm*1.55g / cm 3 =658837g, the daily carbon anode consumption of 32 intermediate anodes is: 32 * 12775cm³ 2 *2cm*1.55g / cm 3 =1267280g. Since the magnitude of the anode current is directly proportional to the mass of prebaked carbon blocks consumed, the average daily current of the 16 groups of anodes at both ends is: 500KA*658837g / (658837g+1267280g)=171KA, and the average daily current of the 32 groups of intermediate anodes is: 500KA*1267280g / (658837g+1267280g)=329KA. Comparative example, single anode current: 500KA / 48=10.42KA. In this embodiment, the single anode current in the anode regions at both ends is 171KA / 16 = 10.69KA, and the single anode current in the middle anode region is 329KA / 32 = 10.28KA. In this embodiment and the comparative example, the electrolyte voltage drop was calculated based on a 1.4V electrolyte layer heat generation. In comparison, the heat generated by the electrolyte layer in the anode region of a single electrolytic cell over 1 hour is: 1.4V × 10.42KA × 1h × 10 -3 ×3.6×10 6 J / kWh=52.5×10 6 J. In this embodiment, according to the above-described calorific value calculation, the calorific value of the electrolyte layer in the anode region at both ends of a single group per hour is: 53.88 × 10⁻⁶. 6 J, The heat generation of the electrolyte layer in the intermediate anode region of a single group over 1 hour is: 51.81 × 10⁻⁶. 6 J; In the comparative example, the intermediate electrolyte temperature was set at 952℃, and the electrolyte temperatures at both ends were set at 948℃. In this embodiment, the calorific value of the electrolyte in the anode regions at both ends is increased by 53.88 × 10⁻⁶. 6 J-52.5×10 6 J = 1.35 × 10 6 J, Electrolyte temperature rise: 1.35 × 10 6 J÷1.212×10 6 J×1℃=1.11℃, electrolyte temperature is 948℃+1.11℃=949.11℃; the calorific value of the electrolyte in the intermediate anode region is reduced by 52.5×10 compared to the control group. 6 J-51.81×10 6 J = 0.69 × 10 6 J, electrolyte temperature decrease: 0.69 × 10 6 J÷1.212×10 6 J×1℃=0.57℃, electrolyte temperature is 952℃-0.57℃ =951.43℃. The thickness of the furnace lining is calculated using the empirical formula as follows: In comparison, the thickness of the furnace side walls in the two end areas is 167mm; the thickness of the furnace side walls in the middle area is 68mm. In this embodiment, the thickness of the furnace lining at both ends is 3.075*(940-230) / (949.11-940)-106=134mm; the thickness of the furnace lining in the middle area is 3.075*(940-260) / (951.43-940)-106=77mm. This embodiment also calculated the length of the prebaked carbon blocks at both ends of the anode to be 1780 mm and the difference in conductive area to be 397 cm². 2 The results of the study are shown in Table 9. Table 9 shows the effect of the difference in the conductive area of ​​prebaked carbon blocks on the calorific value, temperature, and furnace wall thickness of the regulating zone. Table 9: Relationship between the difference in conductive area of ​​prebaked carbon blocks and the regional electrolyte temperature and furnace wall thickness

[0128] This embodiment calculates the calorific value, temperature, and furnace wall thickness changes based on a 500KA electrolytic cell reaching thermal equilibrium in 1 hour. Other cell types can refer to the algorithm in this embodiment and combine it with actual measurement data for calculation. However, in general, by using prebaked carbon blocks with a larger conductive area at both ends than in the middle, the anode current density, calorific value, and temperature in the middle area of ​​the electrolytic cell can be reduced, while the anode current density, temperature, and calorific value at both ends can be increased, thus achieving the purpose of regulating the furnace chamber. At the same time, the increase in electrolyte temperature at both ends helps to eliminate sedimentation at the bottom of the furnace, especially in the corner areas, thereby enhancing the cathode conductivity at both ends, reducing the horizontal current at both ends, and improving the operational stability of the electrolytic cell. In this embodiment, the middle anode uses prebaked carbon blocks with a center seam width smaller than the furnace wall width, which also helps to reduce the horizontal current.

[0129] Installation and implementation steps: When replacing electrodes at both ends of the aluminum electrolysis cell, gradually replace the original ordinary anodes with the prebaked carbon block 203 anodes 20 that have a larger conductive area. When replacing electrodes in the middle area of ​​the aluminum electrolysis cell, gradually replace the original ordinary anodes with the middle anode 30 of the prebaked carbon block 303 whose center seam width is smaller than the furnace side width. After all replacements are completed, as follows: Figure 18 As shown.

[0130] Example 10

[0131] The difference from Example 8 is that:

[0132] like Figure 19 As shown, this embodiment employs an aluminum electrolytic cell with adjustable regional current and heat distribution provided by the present invention to solve the problem of regional energy imbalance in aluminum electrolytic cells. The aluminum electrolytic cell includes two anodes 20 at both ends and a middle anode 30. The two anodes 20 at both ends include aluminum guide rods 201, steel claws 202, prebaked carbon blocks 203, and a flow equalization device 204. The middle anode 30 includes aluminum guide rods 301, steel claws 302, and prebaked carbon blocks 303. The average iron-carbon pressure drop of the prebaked carbon blocks 203 at the two anodes 20 at both ends is less than the average iron-carbon pressure drop of the prebaked carbon blocks 303 at the middle anode 30.

[0133] like Figure 15 , Figure 19As shown, the flow equalization device 204 of the two anodes 20 includes an explosive welding block and an aluminum plate. The steel surface of the explosive welding block is welded to the steel claw 202 crossbeam of the two anodes 20. The aluminum plate is welded to the aluminum guide rod 201 of the two anodes 20 and the aluminum surface of the explosive welding block, respectively.

[0134] like Figure 15 , Figure 19 As shown, the diameter of the carbon bowl of the prebaked carbon block 303 of the intermediate anode 30 is 180-190 mm, and the diameter of the carbon bowl of the prebaked carbon block 203 of the two end anodes 20 is 220-230 mm.

[0135] The average iron-carbon voltage drop at the intermediate anode 30 of the aluminum electrolysis cell is 400 mV, and the average iron-carbon voltage drop at the two anodes 20 at both ends of the aluminum electrolysis cell is 355 mV to 385 mV. The iron-carbon voltage drop is measured using an iron-carbon voltage drop measuring instrument. Figure 15 As shown, the iron-carbon pressure drop is the pressure drop between points D1 and D2.

[0136] Specific implementation plan and results: A company has a 500KA aluminum electrolytic cell with 48 sets of single anodes per cell. Each set of anodes uses a prebaked carbon block (103) with a length of 1750mm, a width of 740mm, and a height of 680mm. The average anode current density is: 500 / 48 / 175 / 74*1000=0.804A / cm² 2 . like Figure 19 As shown, the aluminum electrolysis cell has 24 sets of anodes 20 at both ends, and the remaining 24 sets are intermediate anodes 30. The apparent density of the prebaked char blocks in both the comparative example and this embodiment is 1.55 g / cm³. 3 . The single anode current in both the comparative example and this embodiment is 500KA / 48 = 10.42KA. Electrolyte pressure drop U = Uad - Uab - Ubc - U 过 Uad is the pressure drop from the anode busbar to the molten aluminum layer, taken as 2350 mV; Uab is the pressure drop from the anode busbar to the bottom of the aluminum guide rod, taken as 30 mV; U 过 Ubc is the anode overvoltage, typically 400mV to 600mV, with a value of 500mV; Ubc is the iron-carbon voltage drop. For the comparative example, the electrolyte pressure drop U = 2350mv - 30mv - 400mv - 500mv = 1420mv; In this embodiment, the electrolyte pressure drop is calculated using a comparative method. The iron-carbon pressure drop at the middle anode is 400 mV, and the electrolyte pressure drop is 1420 mV. The average iron-carbon pressure drop at both anodes is 355 mV, and the electrolyte pressure drop is 1465 mV. In comparison, the heat generated by the electrolyte layer in the anode region of a single group over 1 hour is: 1.42V × 10.42KA × 1h × 10 -3 ×3.6×10 6 J / kWh=53.27×10 6 J. In this embodiment, according to the above-described calorific value calculation, the calorific value of the electrolyte layer in the single anode region at both ends over 1 hour is: 54.96 × 10⁻⁶. 6 J, the heat generation of the electrolyte layer in the middle single-group anode region over 1 hour is: 53.27 × 10⁻⁶. 6 J. In the comparative example, the intermediate electrolyte temperature was set at 952℃, and the electrolyte temperatures at both ends were set at 948℃. In this embodiment, the calorific value of the electrolyte in the anode regions at both ends is increased by 54.96 × 10⁻⁶. 6 J-53.27×10 6 J = 1.69 × 10 6 J, electrolyte temperature rise: 1.69 × 10 6 J÷1.212×10 6 J×1℃=1.39℃, the electrolyte temperature is: 948℃+1.39℃=949.39℃; the calorific value of the electrolyte in the intermediate anode region is the same as that in the comparative example, and the electrolyte temperature is the same as that in the comparative example: 952℃. The thickness of the furnace lining is calculated using the empirical formula as follows: In comparison, the thickness of the furnace side walls in the two end areas is 167mm; the thickness of the furnace side walls in the middle area is 68mm. In this embodiment, the thickness of the furnace sidewall at both ends is: 3.075*(940-230) / (949.39-940)-106=127mm; the thickness of the furnace sidewall in the middle area is: 3.075*(940-260) / (952-940)-106=68mm. This embodiment also calculated the effect data for iron-carbon voltage drop differences of 15mV and 35mV, and the results are shown in Table 10. Table 10 shows the effect of the iron-carbon pressure drop difference of prebaked carbon blocks on the calorific value, temperature, and furnace wall thickness in the regulating zone. Table 10: Relationship between iron-carbon pressure drop difference in prebaked carbon blocks and regional electrolyte temperature and furnace wall thickness

[0137] This embodiment calculates the calorific value, temperature, and furnace wall thickness changes based on a 500KA electrolytic cell reaching thermal equilibrium in 1 hour. Other cell types can refer to the algorithm in this embodiment and combine it with actual measurement data for calculation. However, in general, by using prebaked carbon blocks with smaller iron-carbon pressure drop at both ends than in the middle, the temperature and calorific value at both ends are increased, thereby achieving the purpose of regulating the furnace. At the same time, the increase in electrolyte temperature at both ends can eliminate the sedimentation at the bottom of the furnace, especially in the corner areas, thereby enhancing the cathode conductivity at both ends, reducing the horizontal current at both ends, and improving the operational stability of the electrolytic cell.

[0138] Installation and implementation steps: When replacing electrodes at both ends of the aluminum electrolysis cell, gradually replace the original ordinary anodes with the prebaked carbon block 203 anodes (which have a lower iron-carbon voltage drop) at both ends. After all replacements are completed, proceed as follows: Figure 19 As shown.

[0139] The above embodiments are some embodiments of the present invention and are only used to illustrate the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, etc., made by those skilled in the art without creative effort within the spirit and principles of the present invention should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An anode with adjustable current and heat distribution, characterized in that: The anode (10) with adjustable current and heat distribution includes an aluminum guide rod (101), a steel claw (102), and a prebaked carbon block (103). The prebaked carbon block (103) is composed of two or more small carbon blocks (1031) with different apparent densities; or, the prebaked carbon block (103) is composed of two or more small carbon blocks (1031) with different conductive areas per unit length; or, the prebaked carbon block (103) is composed of two or more small carbon blocks (1031) with different iron-carbon pressure drops. The iron-carbon pressure drop is the pressure drop value measured at room temperature from the bottom of the aluminum guide rod (101) to the bottom of the small carbon block (1031).

2. The anode with adjustable current and heat distribution according to claim 1, characterized in that: When the prebaked carbon block (103) is composed of small carbon blocks (1031) with different apparent densities, the small carbon blocks (1031) of the prebaked carbon block (103) have a split structure, and the gap between the small carbon blocks (1031) is no more than 50 mm.

3. The anode with adjustable current and heat distribution according to claim 1, characterized in that: When the prebaked carbon block (103) is composed of small carbon blocks (1031) with different iron-carbon pressure drops, the small carbon blocks (1031) of the prebaked carbon block (103) have a split structure, the assembly gap between the small carbon blocks (1031) is no more than 50mm, and the diameter of the carbon bowl (1032) of the small carbon block (1031) with a large iron-carbon pressure drop is smaller than the diameter of the carbon bowl (1032) of the small carbon block (1031) with a small iron-carbon pressure drop.

4. The anode with adjustable current and heat distribution according to claim 1, characterized in that: When the prebaked carbon block (103) is composed of small carbon blocks (1031) with different conductive areas per unit length, the small carbon blocks (1031) of the prebaked carbon block (103) are integrated into one structure, and the small carbon blocks (1031) are conductive areas with different conductive areas per unit length in the length direction of the prebaked carbon block (103).

5. The anode with adjustable current and heat distribution according to claim 1, characterized in that: When the prebaked carbon block (103) is composed of small carbon blocks (1031) with different conductive areas per unit length, the conductive area can be adjusted by the width of the small carbon block (1031), with the width of the small carbon block (1031) with a smaller conductive area being smaller than the width of the small carbon block (1031) with a larger conductive area; or, the conductive area can be adjusted by slotting the bottom of the small carbon block (1031), with the total width of the slot at the bottom of the small carbon block (1031) with a smaller conductive area being greater than the total width of the slot at the bottom of the small carbon block (1031) with a larger conductive area.

6. An aluminum electrolytic cell with optimized current and heat distribution, characterized in that: The aluminum electrolytic cell includes an anode (10) with adjustable current and heat distribution as described in any one of claims 1 to 5.

7. An aluminum electrolytic cell with adjustable regional current and heat distribution, characterized in that: The aluminum electrolytic cell includes two anodes (20) at both ends and a middle anode (30). The apparent density of the prebaked carbon block (203) of the two anodes (20) is greater than that of the prebaked carbon block (303) of the middle anode (30); or, the conductive area of ​​the prebaked carbon block (203) of the two anodes (20) is greater than that of the prebaked carbon block (303) of the middle anode (30); or, the average iron-carbon pressure drop of the two anodes (20) is less than that of the middle anode (30). The iron-carbon pressure drop is the pressure drop value measured from the bottom of the aluminum guide rod to the bottom of the prebaked carbon block under normal temperature conditions.

8. An aluminum electrolytic cell with adjustable current and heat distribution according to claim 7, characterized in that: The length of the prebaked carbon block (203) of the two end anodes (20) is greater than the length of the prebaked carbon block (303) of the middle anode (30).

9. An aluminum electrolytic cell with adjustable current and heat distribution according to claim 7, characterized in that: A flow equalization device (204) is welded between the aluminum guide rod (201) of the two anodes (20) and the steel claw (202) of the two anodes (20).

10. An aluminum electrolytic cell with adjustable current and heat distribution according to claim 7, characterized in that: The diameter of the carbon bowl of the prebaked carbon block (203) of the two end anodes (20) is larger than the diameter of the carbon bowl of the prebaked carbon block (303) of the middle anode (30).

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