Method for assembling a cathode group of an aluminium electrolysis cell, a cathode group of an aluminium electrolysis cell and an aluminium electrolysis cell

Abstract

This application belongs to the field of aluminum electrolysis technology, specifically proposing an assembly method for an aluminum electrolysis cell cathode assembly, an aluminum electrolysis cell cathode assembly, and an aluminum electrolysis cell. The method includes: embedding at least one set of steel rods into the dovetail groove of a cathode carbon block, wherein each set of steel rods includes two cathode steel rods; reserving a connection area of ​​a predetermined width between the two cathode steel rods in each set of steel rods; installing a predetermined number of conductive connecting pieces in the connection area to connect the two cathode steel rods in each set of steel rods; filling the gaps between the cathode steel rods and the cathode carbon block, as well as the gaps between the conductive connecting pieces and the cathode carbon block, to obtain an aluminum electrolysis cell cathode assembly. The target cathode assembly is used to ensure a uniform distribution of the cathode current in the aluminum electrolysis cell. The technical solution provided by this application can improve the uniformity of the cathode current distribution in an aluminum electrolysis cell.

Description

Technical Field

[0001] This application belongs to the field of aluminum electrolysis technology, and particularly relates to an assembly method of the cathode group of an aluminum electrolysis cell, the cathode group of the aluminum electrolysis cell, and the aluminum electrolysis cell. Background Technology

[0002] As the aluminum electrolytic industry continues to upgrade towards larger scale and higher efficiency, 500kA and 600kA large prebaked aluminum electrolytic cells are gradually becoming the industry mainstream. The span and width of the electrolytic cells are constantly increasing. As the core conductive component of the aluminum electrolytic cell, the optimization of the cathode assembly plays a crucial role in the current efficiency, energy consumption control, and operational stability of the electrolytic cell. However, the increase in cell size also presents many challenges to the design of the cathode assembly structure. Traditional long steel rod cathode assemblies suffer from long current paths, high resistance losses, and the risk of carbon block breakage due to thermal expansion. The short steel rods combined with paste connection structure used in existing large prebaked cells are prone to local current concentration and uneven cathode current distribution. Furthermore, the replacement of new anodes further exacerbates the cathode conductivity imbalance, adversely affecting the stable operation, service life, and energy-saving effect of the aluminum electrolytic cell. Therefore, how to improve the uniformity of cathode current distribution in aluminum electrolytic cells has become an urgent technical problem to be solved. Summary of the Invention

[0003] The embodiments of this application provide an assembly method for an aluminum electrolytic cell cathode assembly, an aluminum electrolytic cell cathode assembly, and an aluminum electrolytic cell, which can improve the uniformity of the cathode current distribution in the aluminum electrolytic cell.

[0004] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0005] According to a first aspect of the present application, a method for assembling a cathode assembly for an aluminum electrolytic cell is provided, characterized in that the method includes: embedding at least one set of steel rods into a dovetail groove of a cathode carbon block, wherein each set of steel rods includes two cathode steel rods; reserving a connection area of ​​a predetermined width between the two cathode steel rods in each set of steel rods; installing a predetermined number of conductive connecting pieces in the connection area to connect the two cathode steel rods in each set of steel rods; and filling the gaps between the cathode steel rods and the cathode carbon block, as well as the gaps between the conductive connecting pieces and the cathode carbon block, to obtain an aluminum electrolytic cell cathode assembly, wherein the aluminum electrolytic cell cathode assembly is used to uniformly distribute the cathode current of the aluminum electrolytic cell.

[0006] In some embodiments of this application, based on the foregoing scheme, the step of installing a preset number of conductive connecting pieces in the connection area to connect the two cathode steel bars of each group of steel bars includes: welding and fixing the preset number of conductive connecting pieces to the two cathode steel bars of each group of steel bars in the connection area in a direction parallel to the bottom surface of the aluminum electrolysis cell; or welding and fixing the preset number of conductive connecting pieces to the two cathode steel bars of each group of steel bars in the connection area in a direction perpendicular to the bottom surface of the aluminum electrolysis cell.

[0007] In some embodiments of this application, based on the foregoing scheme, the preset number of conductive connecting pieces is determined by the following formula:

[0008] in, Indicates the preset number of conductive connectors; Indicates the height of the steel bar. Indicates the thickness of the conductive connector. This indicates the gap width between conductive connecting pieces.

[0009] In some embodiments of this application, based on the aforementioned scheme, the thickness of the conductive connecting piece is 2mm to 10mm, and the gap width between the conductive connecting pieces is 1mm to 5mm.

[0010] In some embodiments of this application, based on the foregoing scheme, the filling process for the gap between the cathode steel rod and the cathode carbon block, and the gap between the conductive connecting piece and the cathode carbon block, includes: if the installation direction of the conductive connecting piece is perpendicular to the bottom surface of the aluminum electrolysis cell, then fill the gap between the cathode steel rod and the cathode carbon block with pig iron; fill the gap between the conductive connecting piece and the cathode carbon block with pig iron.

[0011] In some embodiments of this application, based on the foregoing scheme, the filling process for the gap between the cathode steel rod and the cathode carbon block, and the gap between the conductive connecting piece and the cathode carbon block, includes: if the installation direction of the conductive connecting piece is parallel to the bottom surface of the aluminum electrolysis cell, then fill the gap between the cathode steel rod and the cathode carbon block with pig iron phosphorus; and install insulating baffles on both sides of the conductive connecting piece except for the two ends that are welded and fixed to the cathode steel rod, and fill the gap between the insulating baffles and the cathode carbon block with paste.

[0012] In some embodiments of this application, based on the foregoing scheme, the preset width is 100mm to 250mm.

[0013] In some embodiments of this application, based on the foregoing scheme, the resistivity of the conductive connecting piece is 0.10 μΩ·m to 0.20 μΩ·m.

[0014] According to a second aspect of the embodiments of this application, an aluminum electrolytic cell cathode assembly is provided, characterized in that the aluminum electrolytic cell cathode assembly is assembled by the method described in any one of the first aspects above.

[0015] According to a third aspect of the embodiments of this application, an aluminum electrolytic cell is provided, characterized in that the aluminum electrolytic cell includes an aluminum electrolytic cell cathode group as described in the second aspect above.

[0016] Based on the technical solution proposed in this application, the cathode steel rods are stably positioned by embedding them into the dovetail grooves of the cathode carbon blocks. A dedicated connection area is reserved between the two cathode steel rods, and a low-resistivity conductive connecting piece is installed to form a continuous conductive path. Finally, all assembly gaps are tightly filled. This allows short cathode steel rods to replace traditional long steel rods for current transmission, thus avoiding the problem of excessive resistance loss caused by the excessively long current path of long steel rods. At the same time, the traditional connection method of short steel rods with paste can be abandoned, eliminating the phenomenon of local current concentration caused by the poor conductivity of paste. This makes the cathode current distribution of the aluminum electrolysis cell more uniform, and also alleviates the problem of weakened cathode conductivity after the replacement of new anodes. This ensures the stable operation of the electrolysis cell after electrode replacement, reduces the damage of the cathode carbon blocks due to thermal expansion deformation, and extends the overall service life of the aluminum electrolysis cell.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 A flowchart illustrating an assembly method for an aluminum electrolytic cell cathode assembly according to one embodiment of this application is shown. Figure 2 A top view of an aluminum electrolytic cell cathode assembly, in one embodiment of this application, is shown, in which conductive connecting pieces are welded and fixed in a direction parallel to the bottom surface of the aluminum electrolytic cell. Figure 3 This is a cross-sectional front view showing a conductive connecting piece welded and fixed in a direction parallel to the bottom surface of the aluminum electrolytic cell according to one embodiment of this application; Figure 4A top view of an aluminum electrolytic cell cathode assembly, in one embodiment of this application, is shown, in which conductive connecting pieces are welded and fixed in a direction perpendicular to the bottom surface of the aluminum electrolytic cell. Figure 5 The illustration shows a cross-sectional front view of a conductive connecting piece welded and fixed in a direction perpendicular to the bottom surface of the aluminum electrolytic cell according to one embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0021] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0022] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0023] It should also be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0024] As the aluminum electrolytic industry continues to upgrade towards larger scale and higher efficiency, 500kA and 600kA large prebaked aluminum electrolytic cells are gradually becoming the industry mainstream. The span and width of the electrolytic cells are constantly increasing. As the core conductive component of the aluminum electrolytic cell, the structural optimization of the cathode assembly plays a crucial role in the current efficiency, energy consumption control, and operational stability of the electrolytic cell. However, the increase in cell size also presents many challenges to the design of the cathode assembly structure. Traditional long steel rod cathode assemblies suffer from long current paths, high resistance losses, and the risk of thermal expansion causing damage to the cathode carbon blocks. The existing short steel rods combined with paste connection structure used in large prebaked cells are prone to local current concentration and uneven cathode current distribution. Furthermore, the replacement of new anodes will further exacerbate the cathode conductivity imbalance, adversely affecting the stable operation, service life, and energy-saving effect of the aluminum electrolytic cell. Based on this, this application proposes an assembly method for the cathode assembly of an aluminum electrolytic cell to improve the uniformity of the cathode current distribution.

[0025] Next, we will combine Figure 1 The assembly method of the cathode group of the aluminum electrolytic cell proposed in this application is described in detail.

[0026] See Figure 1 The flowchart illustrates a method for assembling the cathode assembly of an aluminum electrolytic cell according to one embodiment of this application, as shown below. Figure 1 As shown, the method may include at least the following steps 110 to 140: Step 110: At least one set of steel rods is embedded in the dovetail groove of the cathode carbon block, wherein each set of steel rods includes two cathode steel rods.

[0027] Step 120: Reserve a connection area of ​​a preset width between the two cathode steel bars in each group of steel bars.

[0028] Step 130: Install a preset number of conductive connecting pieces in the connection area to connect the two cathode steel rods of each group of steel rods.

[0029] Step 140: Fill the gaps between the cathode steel rod and the cathode carbon block, and between the conductive connecting piece and the cathode carbon block, to obtain an aluminum electrolytic cell cathode group. The aluminum electrolytic cell cathode group is used to make the cathode current of the aluminum electrolytic cell uniformly distributed.

[0030] In this application, the preset width can be from 100mm to 250mm, specifically 150mm or 200mm, and this application does not make a specific limitation in this regard.

[0031] In this application, the resistivity of the conductive connecting piece can be from 0.10 μΩ·m to 0.20 μΩ·m, specifically 0.13 μΩ·m, 0.15 μΩ·m, or 0.18 μΩ·m. This application does not make any specific limitation in this regard.

[0032] In this application, the steel rod assembly is a basic conductive unit composed of two cathode steel rods. The cathode steel rod is the component in the cathode assembly of the aluminum electrolysis cell that carries current transmission. The cathode carbon block is a key component of the aluminum electrolysis cell lining. It can be used to support the cathode steel rod and also participate in conduction. The dovetail groove opened inside the cathode carbon block is a groove that runs through the length direction. The shape of the groove matches the cathode steel rod and can be used to fix the cathode steel rod to prevent displacement and loosening during operation.

[0033] In this application, the connection area is the space reserved between the two cathode steel bars in each group of steel bars, mainly used for installing conductive connecting pieces, and at the same time, it reserves deformation buffer space for thermal expansion during the operation of the electrolytic cell; the conductive connecting piece is a low resistivity steel sheet component, with a resistivity much lower than that of the steel bar paste used for connecting traditional short steel bars, and is a component that replaces the paste and connects the two sections of cathode steel bars; the filling treatment is a process of sealing the assembly gaps tightly with paste or pig iron phosphate, which can not only strengthen the cathode group structure, but also ensure good contact of conductive parts and no current leakage.

[0034] In this application, at least one set of steel rods is embedded in the dovetail groove of the cathode carbon block. In actual production, one set of steel rods or two sets of steel rods can be embedded, depending on the specifications of the aluminum electrolysis cell. Each set of steel rods contains two cathode steel rods, and the two sets of steel rods are respectively embedded in the two dovetail grooves of the cathode carbon block. The dovetail grooves are continuous along the length of the cathode carbon block, which allows the cathode steel rods to fit tightly against the cell body to achieve initial positioning.

[0035] In this application, a connection area of ​​a predetermined width is left between the two cathode steel bars in each group of steel bars. The width of the connection area can be set according to the specifications of the aluminum electrolysis cell and the size of the cathode steel bars to provide sufficient operating space for the subsequent installation and welding of conductive connecting pieces. Then, a predetermined number of conductive connecting pieces can be installed in the reserved connection area to connect the two cathode steel bars of each group of steel bars into one unit. The conductive connecting pieces and the cathode steel bars can be fixed by welding, specifically by hot melt welding, argon arc welding, or electric arc welding, to ensure the firmness of the connection and the stability of conductivity. The number of conductive connecting pieces can be calculated and determined according to the size of the cathode steel bars, their own thickness, and the gap between the pieces to ensure that the conductivity meets the usage requirements. Finally, the gaps between the cathode steel bars and the cathode carbon blocks, as well as the gaps between the conductive connecting pieces and the cathode carbon blocks, are filled. The filling material can be selected according to the arrangement of the conductive connecting pieces, such as paste or pig iron. After the gaps are filled, the cathode group of the aluminum electrolysis cell is obtained. This cathode group can keep the cathode current in a uniform distribution state during the operation of the aluminum electrolysis cell.

[0036] In this application, the cathode steel rods are stably positioned by embedding them into the dovetail grooves of the cathode carbon blocks. A dedicated connection area is reserved between the two cathode steel rods, and a low-resistivity conductive connecting piece is installed to form a continuous conductive path. Finally, all assembly gaps are tightly filled. This allows short cathode steel rods to replace traditional long steel rods for current transmission, thus avoiding the problem of excessive resistance loss caused by the excessively long current path of long steel rods. At the same time, the traditional connection method of short steel rods with paste can be abandoned, eliminating the phenomenon of local current concentration caused by the poor conductivity of paste. This makes the cathode current distribution of the aluminum electrolysis cell more uniform, and also alleviates the problem of weakened cathode conductivity after the replacement of new anodes. This ensures the stable operation of the electrolysis cell after electrode replacement, reduces the damage of the cathode carbon blocks due to thermal expansion deformation, and extends the overall service life of the aluminum electrolysis cell.

[0037] In step 130 above, the installation of a predetermined number of conductive connecting pieces in the connection area to connect the two cathode steel rods of each group of steel rods can be specifically performed according to step 131 or step 132 as follows: Step 131: Within the connection area, a predetermined number of conductive connecting pieces are welded and fixed to the two cathode steel rods of each group of steel rods in a direction parallel to the bottom surface of the aluminum electrolysis cell.

[0038] Step 132: Within the connection area, a predetermined number of conductive connecting pieces are welded and fixed to the two cathode steel rods of each group of steel rods in a direction perpendicular to the bottom surface of the aluminum electrolysis cell.

[0039] In this application, please refer to Figure 2 , Figure 2This illustration shows a top view of an aluminum electrolytic cell cathode assembly, in one embodiment of the present application, where conductive connecting pieces are welded and fixed in a direction parallel to the bottom surface of the aluminum electrolytic cell. Figure 2 As shown, the cathode group of the aluminum electrolytic cell includes two groups of steel rods: a first group consisting of cathode steel rods 220a and 220b, and a second group consisting of cathode steel rods 220c and 220d. A connecting space 230 is provided between cathode steel rods 220a and 220b, and a connecting space 260 is provided between cathode steel rods 220c and 220d. Multiple conductive connecting pieces parallel to the bottom surface of the aluminum electrolytic cell are installed in both the connecting spaces 230 and 260. Phosphorus pig iron is filled between cathode steel rods 220a, 220b, 220c, and 220d and the cathode carbon block 210. The conductive connecting pieces in the connecting spaces 230 and 260 are connected to the cathode carbon block.

[0040] In this application, please refer to Figure 3 , Figure 3 This illustration shows a cross-sectional front view of a conductive connecting piece welded and fixed in a direction parallel to the bottom surface of the aluminum electrolytic cell, according to one embodiment of this application. Figure 3 As shown, the cross-sectional view is along Figure 2 The aluminum electrolysis cell is cut by a straight line L. A connecting space is provided between the cathode steel rod 220a and the cathode steel rod 220b, and multiple conductive connecting pieces 270 are installed in the space. The installation direction is parallel to the bottom surface of the aluminum electrolysis cell.

[0041] In this application, please refer to Figure 4 , Figure 4 This illustration shows a top view of an aluminum electrolytic cell cathode assembly, in one embodiment of the present application, where conductive connecting pieces are welded and fixed in a direction perpendicular to the bottom surface of the aluminum electrolytic cell. Figure 4 As shown, the cathode group of the aluminum electrolytic cell includes two groups of steel rods: a first group consisting of cathode steel rods 420a and 420b, and a second group consisting of cathode steel rods 420c and 420d. A connecting space 430 is provided between cathode steel rods 420a and 420b, and a connecting space 450 is provided between cathode steel rods 420c and 420d. Multiple conductive connecting pieces perpendicular to the bottom surface of the aluminum electrolytic cell are installed in both the connecting spaces 430 and 450. Phosphorus pig iron is filled between cathode steel rods 420a, 420b, 420c, and 420d and the cathode carbon block 410.

[0042] In this application, please refer to Figure 5 , Figure 5This illustration shows a cross-sectional front view of a conductive connecting piece welded and fixed in a direction perpendicular to the bottom surface of the aluminum electrolytic cell, according to one embodiment of this application. Figure 5 As shown, the cross-sectional view is along Figure 4 The aluminum electrolysis cell is cut by a straight line N. A connecting space is provided between the cathode steel rod 420a and the cathode steel rod 420b, and multiple conductive connecting pieces 460 are installed in the space. The installation direction is perpendicular to the bottom surface of the aluminum electrolysis cell.

[0043] In this application, the connection area refers to the pre-reserved installation space between two cathode steel rods in each group of steel rods, and the specific width can be 100mm to 250mm; it can provide an assembly position for the conductive connecting piece and also reserve deformation space for the thermal expansion of the components during the operation of the electrolytic cell; the conductive connecting piece is a sheet-shaped conductive component made of low resistivity steel, with a resistivity much lower than that of traditional cathode steel rod paste, and is a component that replaces the paste to connect two sections of cathode steel rods. The thickness of the conductive connecting piece can be 2mm to 10mm, and the gap between two adjacent conductive connecting pieces is 1mm to 5mm. The specific number is calculated and determined according to the size of the cathode steel rod, the thickness of the connecting piece, and the gap width.

[0044] In this application, after completing the cathode steel rod embedding and connection area reservation, it is necessary to install and fix the conductive connecting pieces in the connection area. Specifically, there are two layout methods. One method is to arrange a preset number of conductive connecting pieces in a direction parallel to the bottom surface of the aluminum electrolysis cell, and then weld the two ends of each conductive connecting piece to the two cathode steel rods of the same steel rod group to form a whole. The other method is to arrange a preset number of conductive connecting pieces in a direction perpendicular to the bottom surface of the aluminum electrolysis cell, and similarly weld the two ends of the conductive connecting pieces to the two cathode steel rods to fix them. At the same time, the overall size of the laid conductive connecting pieces does not exceed the cross-sectional size of the cathode steel rod to avoid assembly interference with the cathode carbon block.

[0045] In this application, by welding and fixing the conductive connecting piece to the cathode steel rod in a direction parallel to or perpendicular to the bottom surface of the aluminum electrolytic cell within the connection area, an appropriate installation method can be flexibly selected according to the different specifications of the cathode steel rod and the cathode carbon block structure. This allows the conductive connecting piece and the cathode steel rod to form a strong and stable conductive connection structure, thereby enabling the two short cathode steel rods to form a continuous and complete conductive path. This avoids the problem of local current concentration caused by the traditional short steel rod with paste connection, while retaining the advantages of short current path and low resistance loss of the short steel rod, effectively improving the uniformity of cathode current distribution.

[0046] Based on the technical solution proposed in this application, the preset number of conductive connecting pieces can be determined by the following formula (1): (1) in, Indicates the preset number of conductive connectors; Indicates the height of the steel bar. Indicates the thickness of the conductive connector. This indicates the gap width between conductive connecting pieces.

[0047] In this application, the thickness of the conductive connecting piece can be from 2 mm to 10 mm, and the gap between two adjacent conductive connecting pieces can be from 1 mm to 5 mm. This application does not make any specific limitation on this.

[0048] In this application, the preset number of conductive connecting pieces is determined by formula (1), which fully combines the conductivity requirements, structural dimensions and thermal expansion characteristics of the cathode group of the large prebaked aluminum electrolytic cell. No additional parameter adjustment is required during calculation. Only the actual selected component size needs to be substituted to obtain accurate results. The calculated number can ensure that the conductive connecting pieces completely cover the conductive cross section of the cathode steel rod. There will be no waste of materials due to excessive quantity, nor will there be a lack of conductivity due to insufficient quantity.

[0049] In this application, by using a proprietary formula to calculate the preset number of conductive connecting pieces, the number of conductive connecting pieces can be matched with the size of the cathode steel rod, the thickness of the connecting pieces, and the gap width. This ensures that the conductive connecting pieces can provide sufficient conductive cross-sectional area to meet the stable transmission requirements of the cathode current, while reserving a reasonable thermal expansion gap for the operation of the electrolytic cell. This effectively solves the problem of local current concentration caused by traditional short steel rod paste connection, making the cathode current distribution of the aluminum electrolytic cell more uniform, reducing resistance loss during current transmission, and preventing the conductive connecting pieces from being damaged by thermal expansion and compression of the cathode carbon block. This ensures the stable operation of the aluminum electrolytic cell after the replacement of the new anode and extends the overall service life of the electrolytic cell.

[0050] In step 140 above, the filling process for the gaps between the cathode steel rod and the cathode carbon block, and between the conductive connecting piece and the cathode carbon block, can be specifically performed according to steps 141 to 142 below: Step 141: If the installation direction of the conductive connecting piece is perpendicular to the bottom surface of the aluminum electrolysis cell, then fill the gap between the cathode steel rod and the cathode carbon block with pig iron.

[0051] Step 142: Fill the gap between the conductive connecting piece and the cathode carbon block with pig iron phosphorus.

[0052] In this application, the filling process refers to the operation of sealing the assembly gaps between the cathode steel rod and the cathode carbon block, and between the conductive connecting piece and the cathode carbon block, using a specialized conductive and high-strength material. The purpose is to ensure the components are securely fixed and that current transmission is smooth. The gap between the cathode steel rod and the cathode carbon block is the natural assembly gap formed between the outer wall of the steel rod and the inner wall of the dovetail groove after the cathode steel rod is inserted into the dovetail groove of the cathode carbon block. Failure to fill this gap will cause the cathode steel rod to loosen and shift during operation. The gap between the conductive connecting piece and the cathode carbon block is the gap formed between the side and end face of the conductive connecting piece and the inner wall of the cathode carbon block after the conductive connecting piece is installed in the connection area between the two cathode steel rods. This gap directly affects the stability of the conductive connecting piece.

[0053] In this application, pig iron is a filler material specifically used for assembling the cathode of an aluminum electrolytic cell. It has excellent electrical conductivity, structural strength, and high-temperature stability. After being filled by casting, it can be quickly cured, which can firmly fix the components without hindering the normal transmission of current, thus exhibiting good performance.

[0054] In this application, after the conductive connecting piece and the cathode steel rod are welded and fixed, two key gaps need to be filled sequentially. First, the gap between the cathode steel rod and the cathode carbon block is filled with pig iron phosphate. In actual construction, the pig iron phosphate is poured into this gap. After the pig iron phosphate hardens, it firmly locks the cathode steel rod within the dovetail groove of the cathode carbon block, preventing the cathode steel rod from shaking or shifting during long-term high-temperature operation of the electrolytic cell. This also ensures stable current transmission between the cathode steel rod and the cathode carbon block, preventing additional contact resistance. Subsequently, the gap between the conductive connecting piece and the cathode carbon block is also filled with pig iron phosphate. The gap is completely filled by pouring, allowing the conductive connecting piece and the cathode carbon block to form a tightly bonded whole, preventing voids or loosening at the gap. In this application, by filling the gaps between the cathode steel rod and the cathode carbon block, as well as the gaps between the conductive connecting piece and the cathode carbon block, with phosphorus pig iron when the conductive connecting piece is installed perpendicular to the bottom surface of the aluminum electrolysis cell, the cathode steel rod and the conductive connecting piece can be effectively fixed, thereby ensuring the continuity and stability of the overall conductive path of the cathode group, avoiding the problem of local current concentration caused by loose parts or poor contact, and thus making the cathode current distribution of the aluminum electrolysis cell more uniform.

[0055] In step 140 above, the filling process for the gap between the cathode steel rod and the cathode carbon block, and the gap between the conductive connecting piece and the cathode carbon block, can be further performed according to steps 143 to 144 below: Step 143: If the installation direction of the conductive connecting piece is parallel to the bottom surface of the aluminum electrolysis cell, then fill the gap between the cathode steel rod and the cathode carbon block with pig iron.

[0056] Step 144: Install insulating baffles on both sides of the conductive connecting piece, except for the two ends that are welded and fixed to the cathode steel rod, and fill the gap between the insulating baffles and the cathode carbon block with paste.

[0057] In this application, the filling process involves using specialized materials to completely seal the assembly gaps between the cathode steel rod and the cathode carbon block, and between the conductive connecting piece and the cathode carbon block. This process directly affects the structural stability and conductivity of the cathode assembly. The insulating baffle is an insulating component installed on the non-welded side of the conductive connecting piece. Its main function is to isolate abnormal conductive paths, prevent current shunting or leakage, and ensure that the current is transmitted along the designated path. The paste is a special binding material for cathode assembly. It has high plasticity and can tightly fill narrow gaps, meeting the gap filling requirements between the insulating baffle and the cathode carbon block.

[0058] In this application, after the conductive connecting piece and the cathode steel rod are welded and fixed, the gap between the cathode steel rod and the cathode carbon block is first filled with pig iron phosphate. In actual construction, the pig iron phosphate is poured into the gap. After the pig iron phosphate solidifies, it will fix the cathode steel rod in the dovetail groove, preventing the cathode steel rod from shaking or shifting during long-term high-temperature operation of the electrolytic cell, and ensuring stable current transmission between the cathode steel rod and the cathode carbon block. Subsequently, insulating baffles are installed on the two sides of the conductive connecting piece, excluding the two ends welded to the cathode steel rod, to isolate the gap between the paste and the conductive connecting piece, preventing blockage during paste filling and causing the conductive connecting piece in the connection space to lose its buffering function.

[0059] In this application, by filling the gap between the cathode steel rod and the cathode carbon block with pig iron when the conductive connecting piece is installed parallel to the bottom surface of the aluminum electrolysis cell, the cathode steel rod can be effectively fixed. Insulating baffles are arranged on the two sides of the conductive connecting piece other than the two ends welded to the cathode steel rod, which can isolate the gap between the paste and the conductive connecting piece, and prevent the gap from being blocked when the paste is filled, so as to prevent the conductive connecting piece in the connection space from losing its buffering function. This can ensure the stability of the cathode group of the electrolysis cell, avoid the current diversion or leakage of the conductive connecting piece, and effectively solve the problem of local current concentration caused by traditional short steel rod paste connection, so as to make the cathode current distribution of the aluminum electrolysis cell more uniform.

[0060] Based on the technical solution proposed in this application, the cathode steel rods are stably positioned by embedding them into the dovetail grooves of the cathode carbon blocks. A dedicated connection area is reserved between the two cathode steel rods, and a low-resistivity conductive connecting piece is installed to form a continuous conductive path. Finally, all assembly gaps are tightly filled. This allows short cathode steel rods to replace traditional long steel rods for current transmission, thus avoiding the problem of excessive resistance loss caused by the excessively long current path of long steel rods. At the same time, the traditional connection method of short steel rods with paste can be abandoned, eliminating the phenomenon of local current concentration caused by the poor conductivity of paste. This makes the cathode current distribution of the aluminum electrolysis cell more uniform, and also alleviates the problem of weakened cathode conductivity after the replacement of new anodes. This ensures the stable operation of the electrolysis cell after electrode replacement, reduces the damage of the cathode carbon blocks due to thermal expansion deformation, and extends the overall service life of the aluminum electrolysis cell.

[0061] Next, the technical solution proposed in this application will be explained in detail with reference to some specific embodiments.

[0062] Example 1: The cathode carbon block has two dovetail grooves, which run through the length of the cathode carbon block. Two sets of four short steel rods are respectively placed at both ends of the two dovetail grooves. The preset width of the connection area for each set is 150mm, and the cross-sectional dimensions of the steel rods are 180mm × 90mm. In this example, the conductive connecting pieces are arranged parallel to the bottom surface of the aluminum electrolysis cell. The conductive connecting pieces are made of 2mm thick steel sheets, with a width of 90mm and a length of 150mm. The gap between each piece is 2mm. The calculated number of connecting pieces is 45, and the welding is carried out using argon arc welding. After welding, insulating baffles are installed on both sides of the conductive connecting pieces, except for the two ends that are welded and fixed to the cathode steel rods. The gap between the insulating baffles and the cathode carbon block is fixed with cathode steel rod paste, and the gap between the cathode steel rods and the carbon block is fixed with cast iron.

[0063] The cathode group obtained by this method has a cold-state voltage drop of 28mV, an initial hot-state voltage drop of 254mV, and a voltage drop of 268mV after one year. The cathode carbon block bulge is 10mm, and the noise value after the new anode is replaced is 18mV.

[0064] Example 2: The cathode carbon block has two dovetail grooves, which run through the length of the cathode carbon block. Two sets of four short steel rods are respectively placed at both ends of the two dovetail grooves. The preset width of the connection area for each set is 200mm, and the cross-sectional dimensions of the steel rods are 150mm × 70mm. In this example, the conductive connecting pieces are arranged perpendicular to the bottom surface of the aluminum electrolysis cell. The conductive connecting pieces are made of 3mm thick steel sheets, 70mm wide, and 200mm long, with a 4mm gap between each piece. The calculated number of connecting pieces is 10, and the welding is carried out using hot-melt welding. After the conductive connecting pieces are welded, the gaps between them and the cathode carbon block, and the gaps between the cathode steel rods and the carbon block, are fixed by casting with phosphorus pig iron.

[0065] The cathode group cold-state voltage drop obtained using this method was 26mV, the initial hot-state voltage drop was 248mV, and it was 262mV after one year. The cathode carbon block bulge was 10.5mm, and the noise level after replacing the anode was 17.5mV.

[0066] Example 3: The cathode carbon block has two dovetail grooves, which run through the length of the cathode carbon block. Two sets of four short steel rods are respectively placed at both ends of the two dovetail grooves. The preset width of the connection area for each set is 250mm, and the cross-sectional dimensions of the steel rods are 200mm × 100mm. In this example, the conductive connecting pieces are arranged parallel to the bottom surface of the aluminum electrolysis cell. The conductive connecting pieces are made of 1mm thick steel sheets, 100mm wide, and 250mm long, with a 3mm gap between each piece. The calculated number of connecting pieces is 50, and the welding is carried out using hot-melt welding. After welding, insulating baffles are installed on both sides of the conductive connecting pieces, except for the two ends that are welded and fixed to the cathode steel rods. The gap between the insulating baffles and the cathode carbon block is secured with cathode steel rod paste, and the gap between the cathode steel rods and the carbon block is fixed by casting with phosphorus pig iron.

[0067] The cathode group cold-state voltage drop obtained using this method was 27mV, the initial hot-state voltage drop was 249mV, and it was 266mV after one year. The cathode carbon block bulge was 9mm, and the noise level after replacing the anode was 18.5mV.

[0068] Comparative Example 1: Using the same cathode carbon block and cathode steel rod as in Example 1, the cathode steel rod was secured with cathode paste within the reserved connection space. The cathode group obtained by this method had a cold-state voltage drop of 31mV, an initial hot-state voltage drop of 274mV, and 286mV after one year. The cathode carbon block bulge was 10mm, and the noise level after replacing the anode was 21mV.

[0069] Comparative Example 2: Using the same cathode carbon block as in Example 1, the cathode steel rods were changed from two short steel rods to long steel rods, while the cross-sectional dimensions remained unchanged. The cathode group obtained using this method had a cold-state voltage drop of 28mV, an initial hot-state voltage drop of 253mV, and 271mV after one year. The cathode carbon block bulge was 14mm, and the noise level after replacing the anode was 18mV.

[0070] The above embodiments demonstrate that the cathode assembly of the aluminum electrolytic cell assembled using the technical solution proposed in this application has higher conductivity and saves more electricity in the long term; the current distribution is uniform and stable, and the electrolytic cell can operate quickly and smoothly after electrode replacement; the cathode carbon block is less prone to bulging and damage, greatly reducing the risk of damage to the inner lining structure and extending the overall service life of the electrolytic cell.

[0071] As another embodiment of this application, an aluminum electrolytic cell cathode assembly is also provided, which is assembled by the method described in the above embodiments.

[0072] As another embodiment of this application, an aluminum electrolytic cell is also provided, characterized in that the aluminum electrolytic cell includes an aluminum electrolytic cell cathode group as described in the above embodiments.

[0073] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for assembling a cathode assembly in an aluminum electrolytic cell, characterized in that, The method includes: At least one set of steel rods is embedded in the dovetail groove of the cathode carbon block, wherein each set of steel rods includes two cathode steel rods. A connection area of ​​a predetermined width is reserved between the two cathode steel bars in each group of steel bars. A predetermined number of conductive connecting pieces are installed in the connection area to connect the two cathode steel rods of each group of steel rods; The gaps between the cathode steel rod and the cathode carbon block, as well as the gaps between the conductive connecting piece and the cathode carbon block, are filled to obtain an aluminum electrolytic cell cathode assembly. The aluminum electrolytic cell cathode assembly is used to ensure a uniform distribution of the cathode current in the aluminum electrolytic cell.

2. The method according to claim 1, characterized in that, The installation of a predetermined number of conductive connecting pieces within the connection area to connect the two cathode steel rods of each group of steel rods includes: Within the connection area, a predetermined number of conductive connecting pieces are welded and fixed to the two cathode steel rods of each group of steel rods in a direction parallel to the bottom surface of the aluminum electrolysis cell; or, Within the connection area, a predetermined number of conductive connecting pieces are welded and fixed to the two cathode steel rods of each group of steel rods in a direction perpendicular to the bottom surface of the aluminum electrolysis cell.

3. The method according to claim 1, characterized in that, The preset number of conductive connecting pieces is determined by the following formula: in, Indicates the preset number of conductive connectors; Indicates the height of the steel bar. Indicates the thickness of the conductive connector. This indicates the gap width between conductive connecting pieces.

4. The method according to claim 3, characterized in that, The thickness of the conductive connecting piece is 2mm to 10mm, and the gap width between the conductive connecting pieces is 1mm to 5mm.

5. The method according to claim 2, characterized in that, The filling process for the gaps between the cathode steel rod and the cathode carbon block, and between the conductive connecting piece and the cathode carbon block, includes: If the installation direction of the conductive connecting piece is perpendicular to the bottom surface of the aluminum electrolysis cell, then the gap between the cathode steel rod and the cathode carbon block is filled with pig iron. The gap between the conductive connecting piece and the cathode carbon block is filled with pig iron phosphorus.

6. The method according to claim 2, characterized in that, The filling process for the gaps between the cathode steel rod and the cathode carbon block, and between the conductive connecting piece and the cathode carbon block, includes: If the installation direction of the conductive connecting piece is parallel to the bottom surface of the aluminum electrolysis cell, then the gap between the cathode steel rod and the cathode carbon block is filled with pig iron. Insulating baffles are installed on both sides of the conductive connecting piece, except for the two ends that are welded and fixed to the cathode steel rod. Paste is filled in the gap between the insulating baffles and the cathode carbon block.

7. The method according to claim 1, characterized in that, The preset width is 100mm to 250mm.

8. The method according to claim 1, characterized in that, The resistivity of the conductive connector is from 0.10 μΩ·m to 0.20 μΩ·m.

9. A cathode assembly for an aluminum electrolytic cell, characterized in that, The cathode assembly of the aluminum electrolysis cell is assembled by the method described in any one of claims 1 to 8.

10. An aluminum electrolytic cell, characterized in that, The aluminum electrolytic cell includes the aluminum electrolytic cell cathode group as described in claim 9.

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