Carbon anode current density homogenization method, anode carbon block and electrolytic bath

Abstract

The invention discloses a carbon anode current density homogenization method, an anode carbon block and an electrolytic bath, and the method comprises the following steps: determining a cutting mode of the upper part of a matrix of the anode carbon block according to the type of the electrolytic bath, the current intensity, the number of carbon bowls and the positions of the carbon bowls; and according to the cutting mode, cutting the upper part of the matrix of the anode carbon block, and cutting the upper part of the matrix of the anode carbon block into a plurality of conductive areas, so that the current density distribution of the bottom palm of the anode carbon block is uniform. Therefore, cutting or shape change in any form is not carried out on the anode bottom palm participating in the electrolytic reaction, a set of matched upper cutting mode is formulated in advance based on the specific groove type parameters, the total current intensity, the number of the carbon bowls and the spatial position of the electrolytic bath, and physical segmentation is carried out on the upper area of the anode carbon block base body according to the upper cutting mode.

Description

Technical Field

[0001] This invention relates to the field of aluminum electrolysis technology, and in particular to a method for homogenizing the current density of carbon anodes, an anode carbon block, and an electrolytic cell. Background Technology

[0002] In modern aluminum electrolysis production, the prebaked anode, as a key conductive and reactive component, directly affects current efficiency, energy consumption, and greenhouse gas emissions. In actual operation, due to factors such as uneven voltage drop across the anode claws, differences in busbar configuration, and electrolyte flow disturbances, significant uneven current density distribution often occurs at the anode base. Localized high current density areas are prone to anodic effects due to insufficient alumina concentration, generating an insulating fluorocarbon film layer. This not only increases cell voltage and DC power consumption but also triggers large-scale emissions of perfluorocarbons, with a greenhouse effect potential thousands of times greater than that of carbon dioxide. To improve bubble escape, existing technologies often employ longitudinal / transverse grooves on or inside the anode base. However, such grooves often alter the geometry of the base, potentially weakening structural strength, and their primary objective is to reduce gas film pressure drop, without optimizing for current distribution uniformity. Summary of the Invention

[0003] In view of the above problems, the present invention provides a method for uniformizing the current density of carbon anode, an anode carbon block and an electrolytic cell, wherein the current density at the bottom is uniformly achieved by structurally slotting the upper part of the anode carbon block.

[0004] According to a first aspect of the present invention, a method for homogenizing carbon anode current density is provided, comprising: The cutting pattern for the upper part of the anode carbon block substrate is determined based on the electrolytic cell type, current intensity, and the number and position of the carbon bowls. According to the cutting pattern, the upper part of the substrate of the anode carbon block is cut into multiple conductive areas to make the current density distribution of the bottom of the anode carbon block more uniform.

[0005] Optionally, the cutting process is performed using a physical cutting method on the upper part of the substrate of the anode carbon block.

[0006] Optionally, the cutting process performed on the upper part of the substrate of the anode carbon block according to the cutting mode includes: If the cutting mode is the first mode, then the number and position of the slots on the upper part of the substrate of the anode carbon block are determined according to the number and position of the carbon bowls. According to the groove location, a groove with a preset depth and preset width is opened towards the lower part of the substrate of the anode carbon block. The groove divides the upper part of the substrate of the anode carbon block into multiple independent conductive areas.

[0007] Optionally, the slot is located between two adjacent charcoal bowls.

[0008] Optionally, the preset depth can be 10%-60% of the anode height. Optionally, the preset width ranges from 20 mm to 150 mm.

[0009] Optionally, the cutting process performed on the substrate of the anode carbon block according to the cutting mode includes: If the cutting mode is the second mode, then the cutting area on the upper part of the substrate of the anode carbon block is determined according to the number and position of the carbon bowls. Based on the cutting area, a cut is made to a predetermined depth towards the lower part of the substrate of the anode carbon block.

[0010] Optionally, the thickness of the lower part of the substrate of the anode carbon block is not less than 150 mm.

[0011] According to a second aspect of the present invention, an anode carbon block is provided, which is cut using the aforementioned method.

[0012] According to a third aspect of the present invention, an aluminum electrolytic cell is provided, comprising the aforementioned anode carbon block.

[0013] The above-described one or more technical solutions in the embodiments of this specification have at least the following technical effects: This specification provides a method for homogenizing the current density of a carbon anode, an anode carbon block, and an electrolytic cell. The method involves determining a cutting pattern for the upper part of the anode carbon block substrate based on the electrolytic cell type, current intensity, and the number and position of the carbon bowls. According to this cutting pattern, the upper part of the anode carbon block substrate is cut into multiple conductive regions to homogenize the current density distribution at the bottom of the anode carbon block. Thus, without any cutting or morphological alteration of the anode bottom participating in the electrolytic reaction, but rather by pre-determining a suitable upper cutting pattern based on the specific cell type parameters, total current intensity, and the number and spatial position of the carbon bowls, the upper region of the anode carbon block substrate is physically segmented accordingly.

[0014] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference figures denote the same parts throughout the drawings. In the drawings: Figure 1 A flowchart of a method for homogenizing carbon anode current density according to an embodiment of the present invention is shown.

[0016] Figure 2 A schematic diagram of an anode carbon block structure according to an embodiment of the present invention is shown.

[0017] Figure 3 A schematic diagram of another anode carbon block structure in an embodiment of the present invention is shown. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] In modern aluminum electrolysis production, the prebaked anode, as a key conductive and reactive component, directly affects current efficiency, energy consumption, and greenhouse gas emissions. In actual operation, due to factors such as uneven voltage drop across the anode claws, differences in busbar configuration, and electrolyte flow disturbances, significant uneven current density distribution often occurs at the bottom of the anode. Localized high current density areas are prone to anodic effects due to insufficient alumina concentration, generating insulating fluorocarbons (CF₂). x The film layer not only increases the cell voltage and DC power consumption, but also triggers the emission of large amounts of perfluorocarbons (PFCs, such as CF4 and C2F6), whose greenhouse effect potential can be thousands of times that of CO2. To improve bubble escape, existing technologies often employ longitudinal / transverse trenches on or inside the anode base. However, such trenching often alters the geometry of the base, potentially weakening the structural strength, and its primary objective is to reduce the gas film pressure drop, without optimizing for current distribution uniformity. Furthermore, some studies attempt to determine trenching parameters through numerical simulation, but only provide design tools, without offering specific engineering-feasible structural solutions or their compatibility with CF4. x The associated mechanism of inhibition.

[0023] Based on the above, embodiments of the present invention provide a method for homogenizing carbon anode current density, combined with Figure 1 The flowchart shown illustrates that the method includes steps 101 to 102: Step 101: Determine the cutting pattern for the upper part of the anode carbon block substrate based on the electrolytic cell type, current intensity, and the number and position of the carbon bowls. Step 102: According to the cutting pattern, the upper part of the substrate of the anode carbon block is cut into multiple conductive areas to make the current density distribution of the bottom of the anode carbon block uniform.

[0024] In this embodiment, no cutting or morphological alteration is performed on the anode base plate participating in the electrolysis reaction. Instead, based on the specific cell type parameters, total current intensity, and the number and spatial position of the carbon bowls, a suitable upper substrate cutting pattern is pre-defined, and the upper region of the anode carbon block substrate is physically segmented accordingly. The cutting process is performed physically on the upper part of the anode carbon block substrate. This cutting divides the originally continuously conductive upper carbon body into multiple relatively independent conductive regions, each corresponding to a sub-region of the base plate, and each region remains electrically connected to the busbar through its respective anode steel claw. Since the current injected from the steel claw must flow through the isolated upper path before converging to the base plate, this structure artificially introduces a path resistance difference, forcing the current in the high-current region to be diverted to the low-current region, thereby achieving a redistribution and homogenization of the overall current density of the base plate. This embodiment preserves the original flat surface of the bottom, avoiding localized hot spots or mechanical strength degradation caused by grooving. Furthermore, it requires no modification to existing anode vibration molding molds or carbon bowl prefabrication processes, and can be implemented simply as a post-processing step after firing, exhibiting extremely high engineering compatibility. It significantly improves the uniformity of current distribution in the bottom (the ratio of maximum to minimum current density can be reduced from over 2000:1 to below 100:1), effectively suppressing localized CF. x Membrane formation reduces cell voltage by 0.3–0.5 V, reduces DC power consumption per ton of aluminum by 80–150 kWh, and significantly reduces greenhouse gas emissions intensity of PFCs by more than 50%.

[0025] Optionally, the cutting process performed on the substrate of the anode carbon block according to the cutting mode includes: If the cutting mode is the first mode, then the number and position of the slots on the upper part of the substrate of the anode carbon block are determined according to the number and position of the carbon bowls. According to the groove location, a groove with a preset depth and preset width is opened towards the lower part of the substrate of the anode carbon block. The groove divides the upper part of the substrate of the anode carbon block into multiple independent conductive areas.

[0026] In this embodiment, combined with Figure 2As shown, when using the first cutting mode, the geometric center line or optimal current isolation line between adjacent carbon bowls is calculated based on the actual number of carbon bowls on the anode carbon block (commonly 2 or 4) and their precise coordinate layout on the top surface. This scientifically determines the number and specific spatial location of the required grooves. Subsequently, through-grooves of preset depth and width are cut vertically downwards from the top of the anode along these preset trajectories. "Through-through" means that these grooves completely penetrate the upper part of the substrate, not the entire carbon body. This physically divides the substrate into several block-shaped or strip-shaped independent conductive units. Each unit is electrically driven primarily by the current from the corresponding steel claw above it, while the lower part covers a relatively independent area of ​​the bottom. This design ensures that the current path is effectively zoned and managed, preventing the current injected by different steel claws from freely mixing in the upper part before flowing to the bottom, thus breaking the original uneven distribution pattern. This embodiment achieves precise matching of the electrical input points of the steel claws, enabling each conductive area to form an independent current channel, maximizing the current redistribution efficiency, and ensuring that the current density distribution of the bottom palm is highly coordinated with the arrangement of the steel claws. Simulation results show that the maximum current density can be reduced by more than 25%, the minimum current density can be increased by an order of magnitude, and the overall uniformity index (standard deviation / mean) is improved, which is significantly better than the traditional integral anode.

[0027] To optimize the structural layout and ensure connection reliability, the slots are preferably positioned along the centerline between two adjacent carbon bowls. For example, in a four-claw rectangular anode layout, a longitudinal slot can be provided between each pair of carbon bowls in the X direction, or a transverse slot can be provided in the Y direction, forming an "I" or "well" shaped division. This positioning strategy makes full use of the unused carbon body space between the carbon bowls, avoiding the grooves being too close to the edge of the carbon bowls and weakening the anchoring cross-sectional area of ​​the phosphorus cast iron rings, thereby preventing the steel claws from loosening or falling out during use due to thermal stress or mechanical vibration. At the same time, the centerline position is easy to automatically calculate using the center coordinates of the carbon bowls, facilitating precise positioning by CNC equipment and reducing human error. In addition, symmetrical slotting also helps maintain the overall center of gravity stability of the anode, preventing tilting during hoisting or installation. This ensures effective electrical isolation between conductive areas while maximizing the mechanical strength and sealing of the carbon bowl-steel claw connection interface. Actual tests show that no cases of claw detachment or cracking occurred in the modified anode within a 30-day service period. At the same time, the current distribution uniformity was improved stably, and the standard deviation of voltage fluctuation in the entire cell was reduced by 30%, significantly enhancing the stability of the electrolysis process.

[0028] The trench depth is a key parameter affecting current regulation and structural safety. This invention strictly limits it to 10%–60% of the total anode height (preferably 30%–50%). If the depth is too shallow (e.g., less than 10%), the resistance increment to the upper current path is insufficient, failing to effectively guide current redistribution; if it is too deep (e.g., greater than 60%), it excessively weakens the overall structural strength of the anode, especially at high temperatures, easily leading to longitudinal cracks due to thermal stress concentration, and even causing bottom perforation during the residual anode stage. This range was obtained through extensive multiphysics simulations (including electro-thermal-mechanical coupling) and laboratory small-cell verification, showing good adaptability in mainstream 400–600 kA trench types. For example, for an anode with a height of 600 mm, a trench depth of 180–300 mm is recommended, which provides a sufficient resistance gradient while retaining 300–420 mm of intact carbon body at the bottom to withstand electrolyte scouring and thermal load. In this way, while ensuring the structural integrity of the anode throughout its entire life cycle, the optimal current path control capability is achieved, reducing the standard deviation of the bottom current density by more than 40%, while avoiding unplanned shutdowns or safety accidents caused by excessively deep slotting. The residual electrode rate is stabilized at 18%–22%, which meets the requirements of industrial production.

[0029] The groove width also needs to be scientifically designed; in this embodiment, its range is set to 20 mm–150 mm. This width directly affects the groove wall resistance, carbon consumption, and processing efficiency. Narrower grooves (20–50 mm) are suitable for low-to-medium current density grooves (e.g., below 300 kA), reducing ineffective carbon volume loss and improving anode utilization; while wider grooves (100–150 mm) are used for ultra-high current grooves (e.g., above 600 kA) to provide a larger path resistance increment and enhance current shunting effect. The width also determines the choice of processing method: narrow grooves are suitable for precision sawing, while wide grooves can be machined using high-efficiency milling. In addition, the groove width must also consider the ease of carbon debris cleaning; too narrow a groove is prone to clogging, while too wide a groove increases dust. Experiments have verified that 80 mm is the optimal balance point for most groove types. By flexibly adjusting the cell width, the current requirements of electrolytic cells of different sizes can be precisely matched. While ensuring the uniformity of the bottom current (maximum / minimum ratio ≤80:1), the material utilization rate (carbon consumption increase <1%) and processing cost (single cell processing energy consumption <0.5 kWh) are optimized, achieving the best technical and economic efficiency.

[0030] Optionally, the cutting process performed on the substrate of the anode carbon block according to the cutting mode includes: If the cutting mode is the second mode, then the cutting area on the upper part of the substrate of the anode carbon block is determined according to the number and position of the carbon bowls. Based on the cutting area, a cut is made to a predetermined depth towards the lower part of the substrate of the anode carbon block.

[0031] Specifically, combining Figure 3 As shown, in addition to the first mode (creating a through groove), this embodiment also provides a second cutting mode: that is, determining several non-through local cutting areas according to the carbon bowl layout, and only performing surface cutting to a certain depth in these areas (such as milling out rectangular pits, arc-shaped steps, or grid-like shallow grooves), rather than completely dividing the carbon body. This mode is suitable for scenarios with extremely high requirements for structural integrity (such as weak anode support in old tank types) or small differences in current distribution (such as newly commissioned tanks). The cutting depth is usually controlled at 10%–30% of the anode height, forming a local resistance "bulge," slightly disturbing the current flow without completely isolating the area. This method preserves the continuous mechanical skeleton of the upper carbon body, with a bending strength loss of <5%, which is far superior to a through groove. In this way, a gradual, low-risk current control method is provided, which, while slightly improving uniformity (reducing the current density standard deviation by 15%–25%), maintains the overall structural integrity of the anode to the greatest extent. It is particularly suitable for production lines sensitive to modification risks and can serve as a supplement or transitional solution to the first mode, expanding the applicable boundaries of the present invention.

[0032] It should be noted that, regardless of the cutting mode used, this embodiment requires that the thickness of the lower part of the anode carbon block substrate (i.e., the area from the bottom to the cutting termination surface) be no less than 150 mm. This thickness is the minimum safety threshold verified through long-term industrial practice and thermo-mechanical simulation: below this value, the anode is prone to thermal stress cracking, local perforation, or accelerated oxidation consumption due to the excessively thin bottom carbon body in high-temperature (e.g., 960 degrees Celsius) and highly corrosive electrolyte environments, leading to premature failure. A thickness of 150 mm ensures that the anode maintains sufficient mechanical strength during a 25–30 day service life, resisting electrolyte convection erosion and aluminum molten metal fluctuations, while providing the necessary margin for residual anode recovery. This limitation also indirectly restricts the maximum slot depth, preventing over-processing. This fundamentally guarantees the service safety and lifespan reliability of the modified anode. Field application data shows that the breakage rate of anodes meeting this condition is less than 0.5%, comparable to traditional anodes, completely eliminating safety hazards caused by structural weakening and laying the foundation for large-scale application.

[0033] In summary, the method for homogenizing the current density of a carbon anode provided in this specification determines a cutting pattern for the upper part of the anode carbon block substrate based on the electrolytic cell type, current intensity, and the number and position of the carbon bowls. According to this cutting pattern, the upper part of the anode carbon block substrate is cut into multiple conductive regions, thereby homogenizing the current density distribution at the bottom of the anode carbon block. Thus, without any cutting or morphological alteration of the anode bottom participating in the electrolytic reaction, but rather by pre-determining a suitable upper cutting pattern based on the specific cell type parameters, total current intensity, and the number and spatial position of the carbon bowls, the upper region of the anode carbon block substrate is physically segmented accordingly.

[0034] To facilitate understanding and implementation by those skilled in the art, the following examples are provided: Taking a 400 kA prebaked anode electrolytic cell as an example, it adopts a four-claw anode, and the carbon bowls are symmetrically distributed in a 2×2 rectangle.

[0035] Based on the measured data inside the groove, it was determined that one longitudinal groove should be opened between each pair of carbon cups in the X direction, for a total of two grooves. Anode height 600 mm, groove depth 240 mm (40%), groove width 80 mm, with 360 mm (greater than 150 mm) remaining below the bottom. The top of the baked anode was cut using a CNC diamond saw, taking 8 minutes per piece. The steel claw is inserted normally into the carbon bowl, and phosphorus iron is poured in to complete the anode assembly; After several days of operation, monitoring showed that the ratio of maximum to minimum current density at the bottom decreased from 2115:1 to 73:1; the average voltage of the tank decreased from 4.17 V to 3.69 V; and the CF4 concentration decreased from 0.018% to 0.008%.

[0036] Based on the same inventive concept, this invention also provides an anode carbon block, which is cut using the aforementioned method.

[0037] Specifically, the anode carbon block can be made from raw materials such as petroleum coke and asphalt through vibration molding and calcination. The bottom surface is smooth and intact, without any grooving or cutting marks. The top has one or more grooves cut according to design rules, dividing the upper part into two or more conductive areas. Each area is connected to the anode steel claw through its corresponding carbon bowl, forming a multi-channel parallel conductive structure. This product can directly replace traditional integral anodes without modifying the electrolytic cell structure or control system. Its manufacturing process only adds a CNC cutting step at the end of conventional anode production, making it compatible with the existing supply chain. As a plug-and-play new functional anode, it possesses comprehensive advantages such as highly uniform current distribution and low cell voltage.

[0038] The following steps can be used to cut the anode carbon blocks: The cutting pattern for the upper part of the anode carbon block substrate is determined based on the electrolytic cell type, current intensity, and the number and position of the carbon bowls. According to the cutting pattern, the upper part of the substrate of the anode carbon block is cut into multiple conductive areas to make the current density distribution of the bottom of the anode carbon block more uniform.

[0039] In this embodiment, no cutting or morphological alteration is performed on the anode base plate participating in the electrolysis reaction. Instead, based on the specific cell type parameters, total current intensity, and the number and spatial position of the carbon bowls, a suitable upper substrate cutting pattern is pre-defined, and the upper region of the anode carbon block substrate is physically segmented accordingly. The cutting process is performed physically on the upper part of the anode carbon block substrate. This cutting divides the originally continuously conductive upper carbon body into multiple relatively independent conductive regions, each corresponding to a sub-region of the base plate, and each region remains electrically connected to the busbar through its respective anode steel claw. Since the current injected from the steel claw must flow through the isolated upper path before converging to the base plate, this structure artificially introduces a path resistance difference, forcing the current in the high-current region to be diverted to the low-current region, thereby achieving a redistribution and homogenization of the overall current density of the base plate. This embodiment preserves the original flat surface of the bottom, avoiding localized hot spots or mechanical strength degradation caused by grooving. Furthermore, it requires no modification to existing anode vibration molding molds or carbon bowl prefabrication processes, and can be implemented simply as a post-processing step after firing, exhibiting extremely high engineering compatibility. It significantly improves the uniformity of current distribution in the bottom (the ratio of maximum to minimum current density can be reduced from over 2000:1 to below 100:1), effectively suppressing localized CF. x Membrane formation reduces cell voltage by 0.3–0.5 V, reduces DC power consumption per ton of aluminum by 80–150 kWh, and significantly reduces greenhouse gas emissions intensity of PFCs by more than 50%.

[0040] Optionally, the cutting process performed on the substrate of the anode carbon block according to the cutting mode includes: If the cutting mode is the first mode, then the number and position of the slots on the upper part of the substrate of the anode carbon block are determined according to the number and position of the carbon bowls. According to the groove location, a groove with a preset depth and preset width is opened towards the lower part of the substrate of the anode carbon block. The groove divides the upper part of the substrate of the anode carbon block into multiple independent conductive areas.

[0041] In this embodiment, when using the first cutting mode, the geometric center line or optimal current isolation line between adjacent carbon bowls is calculated based on the actual number of carbon bowls on the anode carbon block (commonly 2 or 4) and their precise coordinate layout on the top surface. This scientifically determines the number and specific spatial location of the required grooves. Subsequently, through-grooves of preset depth and width are cut vertically downwards from the top of the anode along these preset trajectories. "Through-through" means that these grooves completely penetrate the upper part of the substrate, not the entire carbon body. This physically divides the substrate into several block-shaped or strip-shaped independent conductive units. Each unit is electrically driven primarily by the current from the corresponding steel claw above it, while the lower part covers a relatively independent area of ​​the bottom. This design ensures that the current path is effectively partitioned and managed, preventing the current injected by different steel claws from freely mixing in the upper part before flowing to the bottom, thus breaking the original uneven distribution pattern. This embodiment achieves precise matching of the electrical input points of the steel claws, enabling each conductive area to form an independent current channel, maximizing the current redistribution efficiency, and ensuring that the current density distribution of the bottom palm is highly coordinated with the arrangement of the steel claws. Simulation results show that the maximum current density can be reduced by more than 25%, the minimum current density can be increased by an order of magnitude, and the overall uniformity index (standard deviation / mean) is improved, which is significantly better than the traditional integral anode.

[0042] To optimize the structural layout and ensure connection reliability, the slots are preferably positioned along the centerline between two adjacent carbon bowls. For example, in a four-claw rectangular anode layout, a longitudinal slot can be provided between each pair of carbon bowls in the X direction, or a transverse slot can be provided in the Y direction, forming an "I" or "well" shaped division. This positioning strategy makes full use of the unused carbon body space between the carbon bowls, avoiding the grooves being too close to the edge of the carbon bowls and weakening the anchoring cross-sectional area of ​​the phosphorus cast iron rings, thereby preventing the steel claws from loosening or falling out during use due to thermal stress or mechanical vibration. At the same time, the centerline position is easy to automatically calculate using the center coordinates of the carbon bowls, facilitating precise positioning by CNC equipment and reducing human error. In addition, symmetrical slotting also helps maintain the overall center of gravity stability of the anode, preventing tilting during hoisting or installation. This ensures effective electrical isolation between conductive areas while maximizing the mechanical strength and sealing of the carbon bowl-steel claw connection interface. Actual tests show that no cases of claw detachment or cracking occurred in the modified anode within a 30-day service period. At the same time, the current distribution uniformity was improved stably, and the standard deviation of voltage fluctuation in the entire cell was reduced by 30%, significantly enhancing the stability of the electrolysis process.

[0043] The trench depth is a key parameter affecting current regulation and structural safety. This invention strictly limits it to 10%–60% of the total anode height (preferably 30%–50%). If the depth is too shallow (e.g., less than 10%), the resistance increment to the upper current path is insufficient, failing to effectively guide current redistribution; if it is too deep (e.g., greater than 60%), it excessively weakens the overall structural strength of the anode, especially at high temperatures, easily leading to longitudinal cracks due to thermal stress concentration, and even causing bottom perforation during the residual anode stage. This range was obtained through extensive multiphysics simulations (including electro-thermal-mechanical coupling) and laboratory small-cell verification, showing good adaptability in mainstream 400–600 kA trench types. For example, for an anode with a height of 600 mm, a trench depth of 180–300 mm is recommended, which provides a sufficient resistance gradient while retaining 300–420 mm of intact carbon body at the bottom to withstand electrolyte scouring and thermal load. In this way, while ensuring the structural integrity of the anode throughout its entire life cycle, the optimal current path control capability is achieved, reducing the standard deviation of the bottom current density by more than 40%, while avoiding unplanned shutdowns or safety accidents caused by excessively deep slotting. The residual electrode rate is stabilized at 18%–22%, which meets the requirements of industrial production.

[0044] The groove width also needs to be scientifically designed; in this embodiment, its range is set to 20 mm–150 mm. This width directly affects the groove wall resistance, carbon consumption, and processing efficiency. Narrower grooves (20–50 mm) are suitable for low-to-medium current density grooves (e.g., below 300 kA), reducing ineffective carbon volume loss and improving anode utilization; while wider grooves (100–150 mm) are used for ultra-high current grooves (e.g., above 600 kA) to provide a larger path resistance increment and enhance current shunting effect. The width also determines the choice of processing method: narrow grooves are suitable for precision sawing, while wide grooves can be machined using high-efficiency milling. In addition, the groove width must also consider the ease of carbon debris cleaning; too narrow a groove is prone to clogging, while too wide a groove increases dust. Experiments have verified that 80 mm is the optimal balance point for most groove types. By flexibly adjusting the cell width, the current requirements of electrolytic cells of different sizes can be precisely matched. While ensuring the uniformity of the bottom current (maximum / minimum ratio ≤80:1), the material utilization rate (carbon consumption increase <1%) and processing cost (single cell processing energy consumption <0.5 kWh) are optimized, achieving the best technical and economic efficiency.

[0045] Optionally, the cutting process performed on the substrate of the anode carbon block according to the cutting mode includes: If the cutting mode is the second mode, then the cutting area on the upper part of the substrate of the anode carbon block is determined according to the number and position of the carbon bowls. Based on the cutting area, a cut is made to a predetermined depth towards the lower part of the substrate of the anode carbon block.

[0046] Specifically, in addition to the first mode (creating a through groove), this embodiment also provides a second cutting mode: that is, determining several non-through local cutting areas based on the carbon bowl layout, and only performing surface cutting to a certain depth in these areas (such as milling out rectangular pits, arc-shaped steps, or grid-like shallow grooves), rather than completely dividing the carbon body. This mode is suitable for scenarios with extremely high requirements for structural integrity (such as weak anode support in old tank types) or small differences in current distribution (such as newly commissioned tanks). The cutting depth is usually controlled at 10%–30% of the anode height, forming a local resistance "bulge," slightly disturbing the current flow without completely isolating the area. This method preserves the continuous mechanical skeleton of the upper carbon body, with a bending strength loss of <5%, far superior to through grooves. In this way, a gradual, low-risk current control method is provided, which, while slightly improving uniformity (reducing the current density standard deviation by 15%–25%), maintains the overall structural integrity of the anode to the greatest extent. It is particularly suitable for production lines sensitive to modification risks and can serve as a supplement or transitional solution to the first mode, expanding the applicable boundaries of this invention.

[0047] It should be noted that, regardless of the cutting mode used, this embodiment requires that the thickness of the lower part of the anode carbon block substrate (i.e., the area from the bottom to the cutting termination surface) be no less than 150 mm. This thickness is the minimum safety threshold verified through long-term industrial practice and thermo-mechanical simulation: below this value, the anode is prone to thermal stress cracking, local perforation, or accelerated oxidation consumption due to the excessively thin bottom carbon body in high-temperature (e.g., 960 degrees Celsius) and highly corrosive electrolyte environments, leading to premature failure. A thickness of 150 mm ensures that the anode maintains sufficient mechanical strength during a 25–30 day service life, resisting electrolyte convection erosion and aluminum molten metal fluctuations, while providing the necessary margin for residual anode recovery. This limitation also indirectly restricts the maximum slot depth, preventing over-processing. This fundamentally guarantees the service safety and lifespan reliability of the modified anode. Field application data shows that the breakage rate of anodes meeting this condition is less than 0.5%, comparable to traditional anodes, completely eliminating safety hazards caused by structural weakening and laying the foundation for large-scale application.

[0048] In summary, the anode carbon block provided in this embodiment of the specification determines the cutting pattern of the upper part of the anode carbon block substrate based on the electrolytic cell type, current intensity, and the number and position of the carbon bowls. According to the cutting pattern, the upper part of the anode carbon block substrate is cut into multiple conductive regions to homogenize the current density distribution at the bottom of the anode carbon block. Thus, without any cutting or morphological alteration of the anode bottom participating in the electrolytic reaction, but rather based on the specific cell type parameters, total current intensity, and the number and spatial position of the carbon bowls, a suitable upper cutting pattern is pre-defined, and the upper region of the anode carbon block substrate is physically segmented accordingly.

[0049] Based on the same inventive concept, embodiments of the present invention also provide an aluminum electrolytic cell, including the aforementioned anode carbon block.

[0050] This electrolytic cell is structurally identical to a conventional cell, but it achieves a qualitative leap in operational performance: Because the current density at the bottom of all anodes is highly uniform, localized high-current zones disappear, and the alumina consumption rate becomes more consistent, greatly reducing the frequency of anode effects caused by localized material shortages; simultaneously, CF... x Film formation is effectively suppressed, the wettability of the anode-electrolyte interface is improved, bubble adhesion is reduced, and the gas film pressure drop is decreased. In addition, the uniform current distribution leads to a more balanced magnetic field distribution, reduced aluminum liquid fluctuations, and improved electrode spacing stability. These effects work together to make the entire tank operate more smoothly and efficiently.

[0051] In summary, the electrolytic cell provided in this specification determines the cutting pattern of the upper part of the anode carbon block substrate based on the cell type, current intensity, and the number and position of the carbon bowls. According to the cutting pattern, the upper part of the anode carbon block substrate is cut into multiple conductive regions to homogenize the current density distribution at the bottom of the anode carbon block. Thus, without any cutting or morphological alteration of the anode bottom participating in the electrolytic reaction, but rather by pre-determining a suitable upper cutting pattern based on the specific cell type parameters, total current intensity, and the number and spatial position of the carbon bowls, the upper region of the anode carbon block substrate is physically segmented accordingly.

[0052] The above are merely various embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for homogenizing the current density of a carbon anode, characterized in that, include: The cutting pattern for the upper part of the anode carbon block substrate is determined based on the electrolytic cell type, current intensity, and the number and position of the carbon bowls. According to the cutting pattern, the upper part of the substrate of the anode carbon block is cut to divide the upper part of the substrate of the anode carbon block into multiple conductive areas.

2. The method for homogenizing carbon anode current density according to claim 1, characterized in that: The cutting process is performed using a physical cutting method on the upper part of the substrate of the anode carbon block.

3. The method for homogenizing carbon anode current density according to claim 1, characterized in that, The cutting process performed on the upper part of the substrate of the anode carbon block according to the cutting mode includes: If the cutting mode is the first mode, then the number and position of the slots on the upper part of the substrate of the anode carbon block are determined according to the number and position of the carbon bowls. According to the groove location, a groove with a preset depth and preset width is opened towards the lower part of the substrate of the anode carbon block. The groove divides the upper part of the substrate of the anode carbon block into multiple independent conductive areas.

4. The method for homogenizing carbon anode current density according to claim 3, characterized in that, The slot is located between two adjacent charcoal bowls.

5. The method for homogenizing carbon anode current density according to claim 3, characterized in that, The preset depth ranges from 10% to 60% of the anode height.

6. The method for homogenizing carbon anode current density according to claim 3, characterized in that, The preset width ranges from 20 mm to 150 mm.

7. The method for homogenizing carbon anode current density according to claim 1, characterized in that, The cutting process performed on the upper part of the substrate of the anode carbon block according to the cutting mode includes: If the cutting mode is the second mode, then the cutting area on the upper part of the substrate of the anode carbon block is determined according to the number and position of the carbon bowls. Based on the cutting area, a cut is made to a predetermined depth towards the lower part of the substrate of the anode carbon block.

8. The method for homogenizing carbon anode current density according to claim 1, characterized in that, The thickness of the lower part of the substrate of the anode carbon block is not less than 150 mm.

9. An anode carbon block, characterized in that, The anode carbon block is cut using the method described in any one of claims 1-8.

10. An aluminum electrolytic cell, characterized in that, Includes the anode carbon block as described in claim 9.

Images