Continuous anode assembly, preparation method and aluminum electrolysis cell

Abstract

The invention belongs to the technical field of aluminum electrolysis, and discloses a continuous anode assembly, a preparation method and an aluminum electrolysis cell. The continuous anode assembly comprises a metal frame body, a prebaked anode, anode paste and a conductor, wherein the metal frame body is provided with a channel with two open ends; the prebaked anode is sleeved in the channel of the metal frame body and extends out of the metal frame body, and the prebaked anode positioned in the channel is provided with at least one slot; the metal frame body is filled with anode paste, the anode paste makes contact with at least one surface of the prebaked anode, and the space where the anode paste is located is communicated with at least one open groove; the conductor is arranged in the open groove or / and the anode paste, the conductor is connected with the metal frame body, and the size of the open groove is larger than that of the conductor. The continuous anode assembly has the advantages of being stable in structure, high in series current rising speed and uniform in current distribution during use.

Description

Technical Field

[0001] This application belongs to the technical field of aluminum electrolysis, and specifically relates to a continuous anode assembly, a preparation method, and an aluminum electrolysis cell. Background Art

[0002] With the continuous growth of the global demand for aluminum and its alloy materials, the aluminum electrolysis industry is facing unprecedented pressure, that is, how to effectively reduce energy consumption and environmental pollution while improving production efficiency. As the core link in aluminum production, the efficiency and cost of the aluminum electrolysis process directly determine the competitiveness and sustainable development potential of the entire aluminum industry. In an aluminum electrolysis cell, the anode, as a key component for conducting current and participating in electrochemical reactions, its performance has a crucial impact on the operating efficiency and production cost of the electrolysis cell. In order to meet the strict requirements of the aluminum electrolysis cell for the anode, especially the ability to conduct current and participate in electrochemical reactions, the anode used in the continuous anode aluminum electrolysis cell must have the characteristics of low resistivity (not higher than 80 μΩ·m) and high compressive strength (not less than 27 MPa).

[0003] Currently, the preparation of continuous anodes usually uses non-conductive, bulk anode paste as raw materials. This anode paste is mixed by a binder and carbon materials through a specific process and cannot be directly used as an anode. Instead, it needs to be transformed through a series of complex equipment and technological processes. Specifically, in the first step, the anode paste is transformed into a prototype of the continuous anode through high-temperature heating, melting, and forming; in the second step, the prototype of the continuous anode is calcined and carbonized, and the anode paste is completely transformed into a carbonized body before it can be transformed into an anode with good conductivity, high strength, and meeting the electrolysis requirements. In the process of transforming the anode paste into a prototype of the continuous anode, the prior art mainly adopts two process methods: in-tank casting and roasting method and out-of-tank casting and roasting method.

[0004] The in-tank casting and roasting method is a process of directly casting and roasting the anode paste in the electrolysis cell. This method uses an electro-chemical paste furnace to heat the anode paste to a certain temperature (such as about 100 °C), melt it, and flow it into the lower part of the anode frame to cast the required shape. However, this method has many problems. First, the speed of heating, melting, and casting the anode paste is relatively fast, resulting in a large amount of VOC (volatile organic compounds) flue gas escaping, seriously polluting the environment. Second, the impact voltage is relatively high when series current is used to roast the anode paste, and the rising speed of the series current is slow. It usually takes about 72 hours to raise the full series current, which has a serious impact on other normal operating electrolysis cells. In addition, the speed of transforming the anode paste into an anode cone is slow, and the VOC flue gas is continuously emitted, the environment is harsh, and there is a serious pollution risk. At the same time, the current distribution is uneven during the roasting process, and problems such as red rods and broken rods are likely to occur, easily causing accidents of anode scrapping and stopping the roasting and shutdown of the electrolysis cell, and there is a serious safety risk.

[0005] The method of baking the mold outside the cell is a process of baking the anode paste mold and pre-baking outside the electrolytic cell. In this method, a simple open-top baking furnace is built outside the electrolytic cell, the lower part of the anode frame is placed inside the baking furnace, and the anode paste is loaded into the anode frame. The heat generated by the hearth of the baking furnace is used to heat, melt, mold, and pre-bake the anode paste at the lower part of the anode frame. However, this method also has many problems. First, although the impact voltage has decreased, the rising speed of the series current has increased, and the current distribution has improved, it has not completely solved the technical problems such as high impact voltage, slow rising speed of the series current, and uneven current distribution when baking the anode paste with the series current, and there are serious safety risks. Second, the speed of converting the anode paste into the anode cone is still slow, resulting in about 50% of the binder volatilizing and a large amount of VOC flue gas being discharged, seriously polluting the environment and being difficult to control, and there are serious pollution risks. In addition, this method also has problems such as paste flow, oxidation of the anode cone, and cracks, which affect the quality and service life of the anode. At the same time, the yield of converting the anode paste into the anode cone is relatively low, usually less than 90%, increasing the production cost and resource waste.

[0006] In summary, there are still many deficiencies and problems in the existing continuous anode preparation technology, and it is urgent to develop new, efficient, and environmentally friendly continuous anodes and preparation processes. Summary of the Invention

[0007] In order to further reduce the high impact voltage during the baking of the aluminum electrolytic cell, achieve the purpose of quickly raising the full series current and uniform anode current distribution, and at the same time solve the problems of paste flow, large VOC flue gas, environmental pollution, oxidation of the anode cone, and cracks during the melting, molding, baking, and conversion of the anode paste into the anode cone, the present application aims to provide a continuous anode assembly, a preparation method, and an aluminum electrolytic cell.

[0008] In one aspect of the present application, a continuous anode assembly is provided, including:

[0009] A metal frame body having a channel with openings at both ends;

[0010] A pre-baked anode sleeved in the channel of the metal frame body and extending out of the metal frame body, and at least one slot is provided in the pre-baked anode located in the channel;

[0011] An anode paste filled in the metal frame body and in contact with at least one surface of the pre-baked anode, and the space where the anode paste is located communicates with at least one of the slots;

[0012] A conductor assembled in at least one of the slots and / or the anode paste; the conductor is connected to the metal frame body.

[0013] In one embodiment, the slotted openings include a first slotted opening and a second slotted opening. The first slotted opening is in communication with the space where the anode paste is located; the second slotted opening is for assembling the conductor.

[0014] In one embodiment, the bottom end of the pre-baked anode extends out of the metal housing, the anode paste is filled in the metal housing at the top end of the pre-baked anode, and the conductor is assembled in the second slotted opening and the anode paste.

[0015] In one embodiment, the continuous anode assembly includes at least two pre-baked anodes. Each pre-baked anode is respectively in contact with the inner side wall of the channel, and an anode chamber is formed between the pre-baked anodes. The anode paste is filled in the anode chamber, and the conductor is assembled in the second slotted opening.

[0016] In one embodiment, the pre-baked anode is composed of at least one pre-baked block, and at least one of the pre-baked blocks is provided with the slotted opening.

[0017] In one embodiment, when there are more than two pre-baked blocks, the pre-baked blocks are connected by a bonding paste to form the pre-baked anode.

[0018] In one embodiment, the pre-baked anode is replaced by a cathode carbon block.

[0019] In one embodiment, the bulk density of the pre-baked anode is 1.56 - 1.81 g / cm 3 , the resistivity is 36 - 56 μΩ·m, and the compressive strength is 32 - 56 MPa.

[0020] In one embodiment, the bonding paste includes a carbon material and a binder.

[0021] In one embodiment, the anode paste includes a carbon material and a binder.

[0022] In one embodiment, in the anode paste, the mass content of the carbon material is 71 - 79 wt%, and the mass content of the binder is 21 - 29 wt%.

[0023] In one embodiment, the carbon material is selected from one or more of petroleum coke, pitch coke, calcined petroleum coke, graphite, and biomass.

[0024] In one embodiment, the binder is selected from one or more of asphalt, resin, tar, white sugar, syrup, paraffin wax, aluminum dihydrogen phosphate, rosin, ammonium persulfate, starch, lignin, and machine oil.

[0025] In one embodiment, the metal housing is made of aluminum or an aluminum alloy material.

[0026] In one embodiment, one end of the conductor is provided with a warped head, and the warped head is connected to the metal housing.

[0027] In one embodiment, the material of the conductor is selected from one or more of metal, metal alloy, and cryolite.

[0028] In one embodiment, the material of the warped head is selected from one or more of metal, metal alloy, and cryolite.

[0029] In one embodiment, a baffle is connected to one end of the conductor, and the baffle is connected to the metal housing.

[0030] In one embodiment, the material of the baffle is selected from one or more of graphite, ceramics, and graphene.

[0031] On the other hand of the present application, a method for preparing a continuous anode assembly is provided, including:

[0032] Preparing a pre-baked anode with at least one slotted opening, and disposing a conductor in at least one of the slotted openings;

[0033] Sheathing the slotted opening area of the pre-baked anode in a metal housing, connecting the conductor to the metal housing, and allowing a part of the pre-baked anode to protrude from the metal housing;

[0034] Filling anodic paste at at least one surface of the pre-baked anode within the metal housing, or laying a conductor within the metal housing and filling anodic paste at at least one surface of the pre-baked anode; the space where the anodic paste is located communicates with at least one of the slotted openings.

[0035] In one embodiment, the pre-baked anode is formed by connecting at least one pre-baked block, and at least one of the pre-baked blocks is provided with the slotted opening.

[0036] In one embodiment, a plurality of the pre-baked blocks are connected by a bonding paste.

[0037] In one embodiment, the pre-baked anode is replaced by a cathode carbon block.

[0038] In one embodiment, one end of the conductor is provided with a warped head, and the warped head is connected to the metal housing.

[0039] In one embodiment, the material of the conductor is selected from one or more of metal, metal alloy, and cryolite.

[0040] In one embodiment, the material of the warped head is selected from one or more of metal, metal alloy, and cryolite.

[0041] In one embodiment, a baffle is connected to one end of the conductor, and the baffle is connected to the metal frame.

[0042] In one embodiment, the material of the baffle is selected from one or more of graphite, ceramics, and graphene.

[0043] In another aspect of the present application, an aluminum electrolytic cell includes: an electrolytic cell body; a cathode disposed at the bottom of the electrolytic cell body; and a continuous anode assembly mounted on the electrolytic cell body, wherein the continuous anode assembly and the cathode form an electrically conductive connection path through an electrolyte and / or liquid aluminum.

[0044] In one embodiment, the continuous anode assembly includes a metal frame, a pre-baked anode, anode paste, and a conductor. The metal frame has a channel with openings at both ends; the pre-baked anode is sleeved in the channel of the metal frame and extends out of the metal frame. At least one slot is provided in the pre-baked anode located in the channel; the anode paste is filled in the metal frame and contacts at least one surface of the pre-baked anode. The space where the anode paste is located communicates with at least one of the slots; the conductor is assembled in at least one of the slots and / or the anode paste; the conductor is connected to the metal frame.

[0045] The beneficial effects of the present application are as follows:

[0046] 1. By using a pre-baked anode with high conductivity and high strength to replace the non-conductive and bulk part of the anode paste in the continuous anode, the casting and baking steps inside or outside the continuous anode cell are eliminated, significantly shortening the process flow.

[0047] 2. Using a pre-baked anode with high conductivity reduces the impact voltage, makes the anode current distribution more uniform, and improves the stability of the electrolytic cell. At the same time, the emission of volatile organic compounds (VOCs) is reduced or effectively avoided, meeting the requirements of environmentally friendly production. It can quickly increase the full series current, avoid adverse effects on other aluminum electrolytic cells in the series, and ensure the continuity and stability of production. The continuous anode assembly adopts the coke particle baking method and the high-temperature inert gas baking method during the baking process, with low impact voltage, can quickly increase the full current, and has uniform current distribution. It does not require the rapid conversion of the anode paste into an anode cone, avoiding the safety and pollution problems that are prone to occur when the anode paste is converted into an anode cone.

[0048] 3. Utilize the heat energy of the pre-baked anode itself to heat, melt, cast, and pre-bake the anode paste, effectively saving energy. When the anode paste is heated to melting and generates a large amount of VOC flue gas, the metal frame around the continuous anode remains intact, effectively preventing the leakage of flowing paste and VOC flue gas. The VOC value escaping from the upper opening of the metal frame is lower than the requirements of relevant national standards, further reflecting the environmental protection advantages of the present invention.

[0049] 4. The pre-baked anode is located below the anode paste, raising the positions for heating, melting, casting, and pre-baking the anode paste, and reducing the speeds of these processes. This prompts the anode paste to better penetrate into the pre-baked anode, enhancing the connection strength between the anode paste and the pre-baked anode and improving the stability of the overall structure.

[0050] 5. By utilizing the resistance heat generated when a series current passes through the pre-baked anode or the thermal energy carried by high-temperature inert gas for heating and raising the temperature of the pre-baked anode, the anode paste is gradually heated, melted, cast, and pre-baked. When the series current enters the anode paste through the metal frame and the conductor, the anode paste is further baked until it transforms into a carbonized body with good electrical conductivity and high strength. This improves the quality of the carbonized body of the anode paste and enhances its durability and stability during use.

[0051] 6. Under the multiple protections of the pre-baked anode, the metal frame, and the anode paste, the carbonized body does not have problems of oxidation and cracking. This ensures the integrity and performance stability of the anode, enables the continuous operation of the anode, improves the working environment, and has a high degree of automation. Description of the Drawings

[0052] Figure 1 is a schematic structural diagram of the continuous anode assembly in Embodiment 1 of the present application;

[0053] Figure 2 is of the present application Figure 1 side view;

[0054] Figure 3 is of the present application Figure 1 top view;

[0055] Figure 4 is a schematic structural diagram of the continuous anode assembly in Embodiment 2 of the present application;

[0056] In the figures:

[0057] 1 - metal frame, 11 - power input surface, 12 - power output surface; 2 - pre-baked anode, 21 - first slot, 22 - second slot, 23 - pre-baked block; 3 - anode paste; 4 - conductor, 41 - upturned end, 42 - baffle; 5 - anode rod; 6 - bonding paste. Detailed Embodiments

[0058] The following further details the present application in conjunction with the embodiments described in the drawings, where the same numbers in all the drawings represent the same features. Although the specific embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0059] A self-baked anode is an anode that can be used continuously without replacement (but needs to be replenished regularly). It relies on the heat generated during the electrolysis process to complete the baking of the anode paste and form a dense and integral solid anode. Its advantages include a short production process for the anode paste, low cost, investment savings, and the production scale can be large or small. However, it also has some disadvantages, such as a greater impact on the environment when used in electrolytic cells, significant pollution risks, poor working conditions, an increase in the anode voltage drop resulting in high power consumption, and it is not conducive to the mechanization and automation of electrolytic production. It requires manual periodic insertion and extraction of conductive bars, manual lifting of the anode frame and transfer busbars. There are huge safety risks in using coke granule baking for self-baked anodes, and high-temperature inert gas baking for self-baked anodes cannot be used. With the development of aluminum electrolysis technology, pre-baked anodes have gradually replaced self-baked anodes as the mainstream. A pre-baked anode is an anode carbon block pre-baked in a factory, with advantages such as high mechanical strength, low resistivity, and good electrical conductivity. The use of pre-baked anodes improves the current efficiency of electrolytic cells, reduces energy consumption, and is conducive to the mechanization and automation of electrolytic production. However, the process flow of pre-baked anodes is long, and the production cost is relatively high. Before being used in electrolytic cells, the pre-baked anodes must be connected to the anode guide bars through the casting of high-temperature liquid phosphor iron, and they need to be replaced manually regularly. The working environment during replacement is harsh and the labor intensity is high, which affects the stable and efficient operation of electrolytic cells, cannot be automated, and increases the downtime and production cost of electrolytic cells.

[0060] Therefore, the applicant proposes a technical solution that combines self-baked anodes and pre-baked anodes. In the electrolytic cell, the current heats up the pre-baked anode to raise its temperature, and the high temperature of the pre-baked anode is used to pre-bake the anode paste. As the electrolytic cell transfers from the baking and start-up stages to the normal operation stage, the pre-baked anode is gradually consumed, and the anode paste transfers from pre-baking to formal baking, gradually turning into a carbonized body with a resistivity less than 70 μΩ·m, a mechanical strength greater than 30 MPa, and integrated with the top surface of the pre-baked anode. During this process, the impact voltage is low, the anode current distribution is uniform, avoiding the impact on other normal electrolytic cells that are operating, and the degree of automation is high. At the same time, the emitted VOC value is small, which is environmentally friendly.

[0061] In an embodiment of the present application, referring to Figures 1 to 4, a continuous anode assembly is provided, including: a metal housing 1, a pre-baked anode 2, anode paste 3, and a conductor 4. The metal housing 1 has a channel with openings at both ends; the pre-baked anode 2 is sleeved in the channel of the metal housing 1 and extends out of the metal housing 1. At least one slot is provided in the pre-baked anode 2 located in the channel; the anode paste 3 is filled in the metal housing 1 and contacts at least one surface of the pre-baked anode 2. The space where the anode paste 3 is located communicates with at least one of the slots; the conductor 4 is assembled in at least one of the slots, or the conductor 4 is assembled in at least one of the slots and the anode paste 3; the conductor 4 is connected to the metal housing 1.

[0062] Compared with the existing solution of directly self-baking the anode paste 3, the continuous anode assembly has a low impact voltage when series current is used to bake the anode paste 3, a fast rising speed of the series current, and a uniform current distribution. The main reason is that the conductivity of the anode paste 3 is poor. The anode paste 3 does not conduct electricity at room temperature. When the anode paste 3 is heated from room temperature to 120 °C and above, it begins to soften, deform, melt, and flow; when the anode paste 3 is heated to about 320 °C, the binder decomposes, a large amount of VOC is emitted, and it begins to gradually transform into an anode cone and starts to conduct electricity, but the resistivity is greater than 2500 μΩ·m. In this application, the pre-baked anode 2 has good conductivity (the resistivity at room temperature is less than 56 μΩ·m and decreases with increasing temperature). When the series current is conducted into the continuous anode until the pre-baked anode 2, the resistance heat generated by the pre-baked anode 2 is used to pre-bake the anode paste 3. When the electrolytic cell transfers from the baking and start-up stages to the normal operation stage, the pre-baked anode 2 is gradually consumed, and the anode paste 3 on it transfers from pre-baking to formal baking. At this time, the anode paste 3 gradually transforms into a carbonized body with a resistivity less than 70 μΩ·m and a mechanical strength greater than 30 MPa, which is integrated with the top surface of the pre-baked anode 2. Therefore, the current distribution in the anode and the cell voltage can be well controlled.

[0063] Meanwhile, the applicant found that in the existing direct baking technology of anode paste 3, since the interface between the anode paste 3 during the formation of the anode cone and the added anode paste 3 is always in a flowing state, which is a continuous state, there is no connection problem. However, in the technical solution of this application, due to the smooth and dense surface of the pre-baked anode 2 and the shrinkage characteristics of the anode cone formed by the carbonization of the anode paste 3, the adhesion between the anode cone and the pre-baked anode 2 is not firm. Therefore, in this application, slots are opened on the pre-baked anode 2. On the one hand, under the condition that the open pores on the slots become larger due to heat, the excess binder penetrates into the pores and the surface in the slots. During the carbonization process of the binder, the carbonized body is firmly adhered to the pre-baked anode 2, and at the same time, the problem of the binder in the anode paste 3 flowing out when the binder content is high is avoided. On the other hand, when the anode paste 3 is heated to melt and generate VOC, the slot part can accommodate the generated VOC gas. The VOC penetrates into the pre-baked anode 2 and undergoes secondary pyrolysis on the inner wall of the pores of the pre-baked anode 2, further improving the conductivity and mechanical strength of the pre-baked anode 2.

[0064] In this application, the metal frame 1 serves as the peripheral component of the continuous anode, providing a reliable accommodation space for the pre-baked anode 2 and the anode paste 3. The metal frame 1 has one or more channels with both ends open, which are used to accommodate and connect other components, such as the pre-baked anode 2. The shape, size, structure, and configuration of the channels of the metal frame 1 can be designed according to specific application requirements to ensure compatibility with the pre-baked anode 2 and other components. The metal frame 1 is made of metal materials, which should have good electrical conductivity, mechanical strength, and corrosion resistance to ensure stable current transmission during the electrolysis process, resist the corrosion of the electrolyte, increase the coking value of the binder, avoid the emission of VOC to the surrounding environment, and be able to melt and flow towards the cathode after contacting the electrolyte. It can be understood that the metal frame 1 encompasses all metal components with the above structural, material, and functional characteristics, regardless of their specific shape, size, or manufacturing process.

[0065] In some embodiments, the two side surfaces of the channel of the metal frame 1 are respectively set as the power input surface 11 and the power output surface 12. The pre-baked anode 2 cooperates with the metal frame 1, where one side of the pre-baked anode 2 forms electrical contact with the power input surface 11 of the metal frame 1, and the other side forms electrical contact with the power output surface 12. The power input surface 11 serves as the input end of the current, receiving the current from an external power source. The power output surface 12 serves as the other input end of the current, transmitting the current to the conductor 4 and the pre-baked anode 2 to complete the power transmission process. The shape and size of the pre-baked anode 2 are adapted to the channel of the metal frame 1 so that it can be closely inserted into the channel.

[0066] In some embodiments, at least one anode guide rod 5 is provided on the outer surface of the metal casing 1. The anode guide rod 5 is electrically connected to the anode bus of the electrolytic cell and is used to transmit the electric energy provided by an external power source into the electrolytic cell to realize the electrolysis reaction. The number of anode guide rods 5 is determined by the size of the continuous anode and can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. Preferably, the number of anode guide rods 5 is 6, and the 6 anode guide rods 5 are respectively movably connected to the power input surface 11 and the power output surface 12 of the metal casing 1. The current enters the pre-baked anode 2 from the power input surface 11 and the power output surface 12 through the anode guide rod 5. After being conducted inside the pre-baked anode 2, it then flows out from the cathode and enters the power input end of the next aluminum electrolytic cell, thereby realizing the conduction of the series current.

[0067] In some embodiments, the anode guide rod 5 can be made of materials with high electrical conductivity and high strength, such as copper, aluminum, aluminum alloy, etc., to ensure low-impedance transmission of the current, clamp and lift the continuous anode assembly above the cathode. The shape of the anode guide rod 5 can be columnar, rod-shaped or other shapes suitable for connecting to the anode bus and the metal casing 1. Its inner side and / or both sides are movably connected (such as being pressed) to the metal casing 1. At the same time, the anode guide rod 5 is connected to the anode bus of the electrolytic cell, and the connection method can be welding, clamping, flexible strip connection, bolt connection, etc., to ensure the stability and reliability of the electrical connection. The anode guide rod 5 is connected to the anode lifter to control the lifting and lowering of the continuous anode assembly and the magnitude of the cell voltage, and to lift the anode guide rod 5 alone to avoid being corroded by the liquid electrolyte.

[0068] In some embodiments, the connection position of the anode guide rod 5 to the metal casing 1 is specifically selected at or near the position corresponding to the pre-baked anode 2 to ensure that the current can be directly and effectively introduced into the pre-baked anode 2.

[0069] In some embodiments, the metal casing 1 is made of aluminum or aluminum alloy materials. Aluminum and aluminum alloys have a relatively small density, which is beneficial to reducing the overall weight of the anode assembly. They have good electrical conductivity and mechanical strength, can meet the high-performance requirements of the anode assembly during the electrolysis process, and do not contaminate the product quality of the electrolytic cell.

[0070] In the present application, the pre-baked anode 2 is a key electrode material used in the aluminum electrolysis process. It is made from carbonaceous aggregates such as petroleum coke, pitch coke, and biochar and binders such as coal tar pitch through processes such as high-temperature calcination, crushing, screening, batching, kneading, forming, and baking. It has a stable geometric shape, good electrical conductivity and mechanical properties, and can work stably in the high-temperature, high-voltage and highly corrosive aluminum electrolysis environment. The pre-baked anode 2 usually has a regular geometric shape, such as rectangular, circular, etc., to adapt to the structural requirements of the continuous anode assembly. The size (such as length, width, height, etc.) of the pre-baked anode 2 should be determined according to the design requirements of the electrolytic cell and the electrolysis process conditions.

[0071] In some embodiments, the raw materials of the prebaked anode 2 include carbon materials and binders, where the carbon materials account for 83.5 - 85 wt% by mass and the binders account for 15 - 16.5 wt% by mass. For example, the carbon materials account for 83.5 wt%, 84.0 wt%, 84.5 wt% or 85.0 wt% by mass, and the binders account for 15.0 wt%, 15.2 wt%, 15.4 wt%, 15.6 wt%, 15.8 wt%, 16.0 wt%, 16.2 wt%, 16.4 wt% or 16.5 wt% by mass.

[0072] In some embodiments, the bulk density of the prebaked anode 2 is 1.56 - 1.81 g / cm 3 , the resistivity is 36 - 56 μΩ·m, and the compressive strength is 32 - 56 MPa. For example, the bulk density is 1.56 g / cm 3 , 1.61 g / cm 3 , 1.66 g / cm 3 , 1.71 g / cm 3 , 1.76 g / cm 3 or 1.81 g / cm 3 , the resistivity is 36 μΩ·m, 38 μΩ·m, 40 μΩ·m, 42 μΩ·m, 44 μΩ·m, 46 μΩ·m, 48 μΩ·m, 50 μΩ·m, 52 μΩ·m, 54 μΩ·m or 56 μΩ·m, and the compressive strength is 32 MPa, 34 MPa, 36 MPa, 38 MPa, 40 MPa, 42 MPa, 44 MPa, 46 MPa, 48 MPa, 50 MPa, 52 MPa, 54 MPa or 56 MPa.

[0073] In some embodiments, the prebaked anode 2 is replaced by a cathode carbon block.

[0074] In this application, the cathode carbon block is a key electrode material used in the aluminum electrolysis process. It is made from carbonaceous aggregates such as petroleum coke, pitch coke, electrically calcined anthracite, biochar, graphite, etc. and binders such as coal tar pitch through processes such as high-temperature calcination, crushing, screening, batching, kneading, molding, and baking. It has a stable geometric shape, good electrical conductivity and mechanical properties, and can work stably in the high-temperature, high-current and highly corrosive aluminum electrolysis environment. The cathode carbon block usually has a regular geometric shape, such as rectangular, circular, etc., to meet the structural requirements of the continuous anode assembly. The size (such as length, width, height, etc.) of the cathode carbon block should be determined according to the design requirements of the electrolytic cell and the electrolysis process conditions.

[0075] In some embodiments, the raw materials of the cathode carbon block include carbon materials and binders, where the carbon materials account for 77-81% by mass and the binders account for 19-23% by mass. For example, the carbon materials account for 77%, 78%, 79%, 80% or 81% by mass, and the binders account for 19%, 20%, 21%, 22% or 23% by mass.

[0076] In this application, sleeving means that the pre-baked anode 2 is completely placed or embedded into the internal space of the channel of the metal housing 1, and at least one surface of the pre-baked anode 2 forms a certain contact with the inner wall of the channel.

[0077] In some embodiments, the shape and size of the channel of the metal housing 1 match the pre-baked anode 2 for tightly accommodating the pre-baked anode 2.

[0078] In some embodiments, the number of conductors 4 in the anode paste 3 in a single continuous anode assembly can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, etc., which is specifically determined according to the volume of the continuous anode assembly, the maximum current density of the conductor 4 and the design requirements of the continuous anode assembly.

[0079] In some embodiments, the conductors 4 in the anode paste 3 are parallel to the conductors 4 in the pre-baked anode 2.

[0080] In some embodiments, the grooving can be made along the longitudinal, transverse or other directions of the pre-baked anode 2 to meet specific current transmission or connection requirements. The extension path of the grooving is not particularly limited and can extend either in a straight line direction or in a curved line direction.

[0081] In some embodiments, the grooving includes a first grooving 21 and a second grooving 22. The first grooving 21 communicates with the space where the anode paste 3 is located; the second grooving 22 is used for assembling the conductor 4.

[0082] Since the first slot 21 communicates with the space where the anode paste 3 is located, on the one hand, when the opening pores on the first slot 21 become larger due to heat, the excess binder penetrates into the pores and the surface in the first slot 21. During the carbonization process of the binder, the carbonized body is firmly adhered to the pre-baked anode 2, while avoiding the problem that the anode paste 3 flows out of the anode assembly when the binder content in the anode paste 3 is high. On the other hand, when the anode paste 3 is heated to melt and produce VOCs, the first slot 21 can accommodate the generated VOC gas. The VOC penetrates into the pre-baked anode 2 and undergoes secondary thermal cracking on the inner wall of the pores of the pre-baked anode 2, further improving the conductivity and mechanical strength of the pre-baked anode 2. It also effectively avoids the problem that the anode paste 3 flows out or VOCs escape around the continuous anode assembly.

[0083] In some embodiments, the number of the first slots 21 on a single pre-baked anode 2 is at least 1, for example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, etc. The shape, size, and number of the first slots 21 are set according to actual needs to meet the requirement that the anode paste 3 and the pre-baked anode 2 are integrated.

[0084] Preferably, there is 1 first slot 21 on a single pre-baked anode 2, and the anode paste 3 is filled in the first slot.

[0085] In some embodiments, the first slot 21 includes the case where the original surface of the pre-baked anode 2 in contact with the anode paste is milled off to increase the channels and the number of the binder penetrating into the pre-baked anode 2.

[0086] In some embodiments, the number of the second slots 22 on a single pre-baked anode 2 is at least 1, for example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. The shape, size, and number of the second slots 22 can be set according to actual needs to match the conductor 4 required on a single pre-baked anode 2.

[0087] Preferably, there are 2 second slots 22 on a single pre-baked anode 2. One end of each second slot 22 is close to or in contact with the power input surface 11 of the metal frame 1, and the other end is close to or in contact with the power output surface 12 of the metal frame 1.

[0088] Preferably, the 2 second slots 22 do not communicate with each other.

[0089] In some embodiments, the second slot 22 is arranged perpendicular to the power input surface 11 or the power output surface 12 of the metal frame 1.

[0090] In some embodiments, one end of the second slot 22 close to the metal frame 1 is of an open structure to facilitate the electrical connection between the conductor 4 in the second slot 22 and the metal frame 1.

[0091] In some embodiments, the distance that the pre-baked anode 2 extends beyond the bottom end of the metal housing 1 to the lower opening of the channel of the metal housing 1 is not less than 20 cm. Specifically, it can be 20 cm, 21 cm, 22 cm, 23 cm, 24 cm, 25 cm, 26 cm, 27 cm, 28 cm, 29 cm, 30 cm, 31 cm, 32 cm, 33 cm, 34 cm, 35 cm, 36 cm, 37 cm, 38 cm, 39 cm, 40 cm. This allows the anode paste 3 to melt, flow, form, and carbonize within the space formed by the pre-baked anode 2 and the metal housing 1, avoiding the unorganized emission of VOCs generated by the anode paste 3 and forming an electrical connection with the electrolytic cell system.

[0092] In this application, the anode paste 3 is a paste containing carbonaceous materials used in a continuous anode assembly, mainly made by mixing calcined petroleum coke or pitch coke with binders such as coal tar pitch. The anode paste 3 serves as the initial material of the anode during electrolysis and is baked through the Joule heat generated by the conductor 4 and the heat supplied by the electrolyte to form a dense carbon body, participating in the conduction and electrochemical reactions at the bottom of the continuous anode assembly. The processes of the anode paste 3 are diverse, including different aspects such as composition, particle size, kneading temperature, and kneading time. Different processes may affect the performance of the anode paste 3, but as long as it can meet the requirements of being the initial material of the anode in the final product, it can be regarded as the anode paste 3 in this patent.

[0093] In some embodiments, the bonding paste 6 includes carbon materials and binders. Among them, the carbon materials are selected from one or more of petroleum coke, pitch coke, calcined petroleum coke, graphite, and biomass. The binders are selected from one or more of asphalt, resin, tar, white sugar, syrup, paraffin, aluminum dihydrogen phosphate, rosin, ammonium persulfate, starch, lignin, and machine oil.

[0094] In some embodiments, in the anode paste 3, the mass content of the carbon material is 71-79 wt%, and the mass content of the binder is 21-29 wt%. Compared with the anode paste 3 used in the prior art, the content of the binder in the anode paste 3 in contact with the pre-baked anode in this application increases by 1-5 wt%, improving the fluidity of the anode paste 3. Under the condition that the open pores on the pre-baked anode 2 expand due to heat, the excess binder penetrates into the pores and the surface in the grooves. During the carbonization process of the binder, the carbonized body of the anode paste 3 is firmly adhered to the pre-baked anode 2 and integrated into one body. At the same time, the damage to the pre-baked anode 2 caused by grooving is repaired, the open pores on the pre-baked anode 2 are filled, the bulk density is increased, the electrical conductivity and mechanical strength are improved, and the negative problems that occur when the binder content in the anode paste 3 is high are avoided. An anode paste with a normal asphalt content is added above the anode paste with a high binder content. Specifically, the mass content of the carbon material can be 71 wt%, 73 wt%, 75 wt%, 77 wt%, 79 wt%. The mass content of the binder can be 21 wt%, 23 wt%, 25 wt%, 27 wt%, 29 wt%.

[0095] In some embodiments, the anode paste 3 is filled in the metal frame 1 and covers the top surface or the side surface of the pre-baked anode 2. So as to be able to make the most of the heat generated by the pre-baked anode 2, improve the pre-baking effect on the anode paste 3, avoid the unorganized emission of VOC, and improve the yield rate of the anode paste 3.

[0096] In this application, the conductor 4 is a substance or material with a low resistivity and capable of efficiently conducting current. There are a large number of free charge carriers (such as free electrons, ions, etc.) inside such substances or materials. Under the action of an external electric field, these carriers can move directionally to form an electric current. In this application, it is not limited to a specific material, form or application environment. As long as the substance or material can exhibit significant electrical conductivity under specific conditions, it is regarded as the conductor 4 in this application.

[0097] In some embodiments, the material of the conductor 4 is selected from one or more of metals, metal alloys, and cryolite.

[0098] In some embodiments, the shape of the conductor 4 is not strictly limited and can be designed into any suitable shape according to actual needs. It can be linear, rod-shaped, plate-shaped, sheet-shaped or any other suitable shape. Preferably, when the conductor 4 is placed in a specific groove, its shape matches the shape of the groove, or the conductor 4 is poured in a liquid form into the groove and then solidifies to ensure good electrical contact and mechanical stability.

[0099] In some embodiments, the conductor 4 is assembled within the second slotted groove 22. One end of the second slotted groove 22 near the metal housing 1 is of an open structure, and the conductor 4 is in contact connection with the metal housing 1. This ensures that current can be stably, uniformly, and efficiently transmitted to the pre-baked anode 2, thus meeting the normal operating requirements of the electrolytic cell system. The number of conductors 4 matches the number of the second slotted grooves 22.

[0100] In some embodiments, a baffle 42 is connected to one end of the conductor 4, and the baffle 42 is in contact connection with the metal housing 1. The baffle 42 is used to conduct current from the metal housing 1 into the conductor 4, or to add a path for current to be conducted from the metal housing 1 into the conductor 4, preventing the conductor 4 from flowing out of the continuous anode prematurely and maintaining the continuous conduction of current from the conductor 4 into the continuous anode. The shape and size of the baffle 42 match the contact surfaces of the metal housing 1 and the conductor 4 to ensure tight contact and good electrical connection among the three. The baffle 42 can be designed as a plane, a curved surface, or a contact surface with a specific shape to adapt to the different structures of the metal housing 1 and the conductor 4.

[0101] In some embodiments, the conductor 4 is assembled within the second slotted groove 22. One end of the second slotted groove 22 near the metal housing 1 is of an open structure. The baffle 42 is located at the opening of the second slotted groove and is in contact connection with the metal housing 1, and the conductor 4 is in contact connection with the baffle 42. The size of the baffle 42 is the same as the opening size of the second slotted groove 22 so that it can closely fit at the opening of the second slotted groove 22 and form a stable electrical contact with the metal housing 1. The shape of the baffle 42 can be designed according to the shape of the contact surface of the metal housing 1, such as a plane, a curved surface, etc., to meet different contact requirements.

[0102] In some embodiments, the material of the baffle 42 is selected from one or more of graphite, ceramics, and graphene.

[0103] In some embodiments, a warped head 41 is provided at one end of the conductor 4, and the warped head 41 is in contact connection with the metal housing 1. The main function of the warped head 41 is to serve as a bridge for current transmission, efficiently conducting current from the metal housing 1 into the conductor 4. The shape and size of the warped head 41 are not limited. The shape of the warped head 41 matches the contact surface of the metal housing 1 to ensure tight connection between the two, with a large connection area and good electrical contact. At the same time, the warped head 41 can be welded to the metal housing 1 to reduce the contact resistance and improve the efficiency and stability of current transmission.

[0104] In some embodiments, the warped head 41 extends out of the second slotted groove 22 along the extension direction of the channel of the metal housing 1.

[0105] In some embodiments, the material of the upturned head 41 is selected from one or more of metal, metal alloy, and cryolite.

[0106] Preferably, the material of the upturned head 41 is the same as that of the conductor 4.

[0107] In some embodiments, one end of the conductor 4 close to the metal housing 1 is connected with an upturned head 41 and a baffle 42. Both the upturned head 41 and the baffle 42 are in contact connection with the metal housing 1. The baffle 42 is arranged between the conductor 4 and the metal housing 1, and the upturned head 41 is arranged on one side of the conductor 4.

[0108] In some embodiments, when there are multiple conductors 4, the conductors 4 can be freely matched with the upturned heads 41 and / or the baffles 42. Taking 3 conductors 4 as an example, upturned heads 41 or baffles 42 can be respectively arranged at one end of 2 of the conductors 4, and an upturned head 41 and a baffle 42 can be simultaneously arranged at one end of 1 of the conductors 4.

[0109] In another embodiment of the present application, referring to Figures 1 to 3 , the bottom end of the pre-baked anode 2 extends out of the metal housing 1, and the pre-baked anode 2 is provided with the first slot 21 and / or the second slot 22; the anode paste 3 is filled in the metal housing 1 on the top surface of the pre-baked anode 2 and covers the top surface of the pre-baked anode 2 and the first slot 21; the conductor 4 is arranged in the second slot 22 and in the anode paste 3.

[0110] Specifically, the upper part of the pre-baked anode 2 sleeve is sleeved in the channel of the metal housing 1, the bottom of the pre-baked anode 2 sleeve extends out of the lower opening of the channel of the metal housing 1. The first slot 21 and / or the second slot 22 are opened on the top surface of the pre-baked anode 2. The conductor 4 is arranged in the second slot 22, and one end of the conductor 4 is connected with the inner surface of the metal housing 1. The anode paste 3 is filled in the metal housing 1 and is located on the top surface of the pre-baked anode 2 and in the first slot 21, and the conductor 4 is passed through the stacked anode paste 3, and the conductor 4 is connected with the metal housing 1.

[0111] During use, the continuous anode assembly is installed on an aluminum electrolytic cell. After passing an electric current, the current flows through the metal frame 1 and the conductor 4 into the pre-baked anode 2, heating up the temperature of the pre-baked anode 2. The high-temperature pre-baked anode 2 heats, melts, shapes, and pre-roasts the anode paste 3. The melted anode paste 3 automatically flows downward to the anode carbon block, and the binder penetrates into the anode carbon block. When the electrolytic cell transfers from the roasting and start-up stages to the normal operation stage, the pre-baked anode 2 is gradually consumed, and the anode paste 3 thereon transfers from pre-roasting to formal roasting, gradually turning into a carbonized body with a resistivity less than 70 μΩ·m, a mechanical strength greater than 30 MPa, and integrated with the top surface and the first slot 21 of the pre-baked anode 2. Meanwhile, a new metal frame 1 and conductor 4 are continuously connected within the upper opening of the channel of the metal frame 1, and new anode paste 3 is added into the space of the metal frame 1 and the conductor 4. The new anode paste 3 gradually transforms into a carbonized body through heating, melting, shaping, and roasting, becoming a part of the continuous anode assembly. As the continuous anode is consumed, the above process is repeated.

[0112] In some embodiments, the pre-baked anode 2 is composed of at least one pre-baked block 23, and slots are provided on the co-directional surfaces of the at least one pre-baked block 23. A plurality of pre-baked blocks 23 with the same specifications are bonded together to form an integral pre-baked anode 2. Specifically, the number of pre-baked blocks 23 constituting the pre-baked anode 2 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. Preferably, the number of pre-baked blocks 23 constituting the pre-baked anode 2 is 2 or 3.

[0113] In some embodiments, the connection method of the pre-baked blocks 23 is not limited, and the pre-baked blocks 23 are connected by at least one of the following methods:

[0114] Side connection method: The pre-baked blocks 23 have mutually matching side structures, enabling adjacent pre-baked blocks 23 to be closely and fixedly connected along their sides. The design of side connection allows the pre-baked blocks 23 to expand in the horizontal direction, thereby forming a pre-baked anode 2 with the required width and length.

[0115] Up-and-down stacking method: The pre-baked blocks 23 have flat or mortise-and-tenon structured top and bottom surfaces, enabling one pre-baked block 23 to be stably stacked on another pre-baked block 23. The design of up-and-down stacking allows the pre-baked blocks 23 to be stacked in the vertical direction, thereby forming a pre-baked anode 2 with the required height.

[0116] By means of side connection and / or up-and-down stacking, the size and shape of the pre-baked anode 2 can be flexibly adjusted to meet the requirements of different electrolytic cells.

[0117] In some embodiments, the side connection method is preferably selected.

[0118] When there are two pre-baked blocks 23 that make up the pre-baked anode 2, a first slot 21 is provided on the top surface of each pre-baked block 23 to communicate with the space where the anode paste 3 is located, and at least one of the pre-baked blocks 23 is provided with a second slot 22 inside for placing the conductor 4. The first slots 21 on the two pre-baked blocks 23 can be in the same straight line, can also be arranged in parallel, or can be staggeredly arranged. Preferably, the slots on the two pre-baked blocks 23 are arranged in parallel to provide current to heat the pre-baked anode 2 to the greatest extent.

[0119] When there are three pre-baked blocks 23 that make up the pre-baked anode 2, the three pre-baked blocks 23 are bonded together through the sides to form the pre-baked anode 2. First slots 21 are provided in parallel on the top surfaces of the three pre-baked blocks 23, and second slots 22 are provided inside all three pre-baked blocks 23.

[0120] In some embodiments, there can be multiple first slots 21 and second slots 22 provided on each pre-baked block 23. The first slots 21 are evenly distributed on the top surface of the pre-baked block 23 to enhance the connection strength between the carbonized body of the anode paste 3 and the pre-baked block 23; for uniform heating, when multiple pre-baked blocks 23 make up the pre-baked anode 2, the number of second slots 22 on each pre-baked block 23 is the average value of the total number of second slots 22 of the pre-baked anode 2 and is evenly distributed in each pre-baked block 23.

[0121] In some embodiments, the multiple pre-baked blocks 23 are connected by a bonding paste 6. The bonding paste 6 includes a carbon material and a binder.

[0122] In some embodiments, the carbon material is selected from one or more of petroleum coke, pitch coke, calcined petroleum coke, graphite, and biomass.

[0123] In some embodiments, the binder is selected from one or more of asphalt, resin, tar, white sugar, syrup, paraffin wax, aluminum dihydrogen phosphate, rosin, ammonium persulfate, starch, and machine oil.

[0124] In another embodiment of the present application, referring to Figure 4 , the continuous anode assembly includes at least two pre-baked anodes 2. Each pre-baked anode 2 is in contact with the inner side wall of the channel respectively, and an anode cavity is formed between the pre-baked anodes 2. The anode paste 3 is filled in the anode cavity, and the conductor 4 is arranged in the slot.

[0125] Specifically, one end of each of the multiple pre-baked anodes 2 is in contact with the power input surface 11 and the power output surface 12 of the metal housing 1 respectively. Between the other ends of the multiple pre-baked anodes 2, an anode cavity is formed. The anode cavity is coaxially arranged with the channel of the metal housing 1. The anode paste 3 is filled in the anode cavity. At the top of each pre-baked anode 2, a first slot 21 and a second slot 22 are provided. The first slot 21 is located on the side of the pre-baked anode 2 away from the metal housing 1 and communicates with the space where the anode paste 3 is located.

[0126] During use, the continuous anode assembly is installed on the aluminum electrolytic cell. After current is applied, the current on the anode rod 5 flows through the metal housing 1 and the conductor 4 into the pre-baked anode 2, heating up the temperature of the pre-baked anode 2. The pre-baked anodes 2 are firmly bonded together. At the same time, the high-temperature pre-baked anodes 2 heat, melt, form, and bake the anode paste 3. The anode paste 3 is firmly connected to the pre-baked anodes 2 and gradually bakes into a carbonized body with a resistivity less than 70 μΩ·m and a mechanical strength greater than 30 MPa, becoming part of the continuous anode. When the electrolytic cell transfers from the baking and startup stages to the normal operation stage, the pre-baked anodes 2 and the carbonized body are gradually consumed. At the same time, a new metal housing 1 is continuously connected inside the upper opening of the metal housing 1. A bonding paste 6 is coated on the top surface of the pre-baked anode 2. A new pre-baked anode 2 is placed on the bonding paste 6. The conductor 4 connected to the metal housing 1 is placed in the slot of the pre-baked anode 2. New anode paste 3 is added to the anode cavity formed by the new pre-baked anodes 2. The new anode paste 3 gradually turns into a carbonized body firmly bonded to the pre-baked anodes 2 through heating, melting, forming, and baking. The pre-baked anodes 2 are firmly bonded together. As the carbonized body and the pre-baked anodes 2 are consumed, the above process is repeated. When a certain clamping force is applied by the anode rod 5 to the power input surface 11 and the power output surface 12 of the metal housing 1 to lift the continuous anode, the pre-baked anodes 2 on both sides and the anode paste 3 or the carbonized body in the middle together bear the clamping force, without shrinking or deforming, nor causing technical accidents such as the anode falling off from the fixture. At the same time, the pre-baked anodes 2 and the carbonized body are bonded together, and there will be no displacement or crack between the two.

[0127] In some embodiments, the multiple pre-baked anodes 2 can be 1, 2, 3, 4, 5, 6, etc. Preferably, the pre-baked anodes 2 can be 2.

[0128] When there are 2 pre-baked anodes 2, one pre-baked anode 2 is in contact with the power input surface 11 of the metal housing 1, and the other pre-baked anode 2 is in contact with the power output surface 12 of the metal housing 1. An anode cavity extending along the channel of the metal housing 1 is formed between the two pre-baked anodes 2. Filling the anode cavity with the anode paste 3 forms the continuous anode assembly.

[0129] In some embodiments, the number of the first slits 21 and the second slits 22 on each of the pre-baked anodes 2 may be multiple, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

[0130] In some embodiments, the extending paths of the first slits 21 and the second slits 22 are not subject to specific limitations, and may extend in a straight line direction or in a curved line direction.

[0131] In some embodiments, the second slits 22 on multiple pre-baked anodes 2 may be arranged in parallel with each other, or grouped and in the same straight line, or may be arranged in a staggered manner. Preferably, the second slits 22 on multiple pre-baked anodes 2 are parallel to each other, and the second slits 22 of the pre-baked anodes 2 that are grouped together are in the same straight line.

[0132] In some embodiments, the pre-baked anode 2 is composed of at least one pre-baked block 23, and multiple pre-baked blocks 23 are combined together by a specific connection method to form an anode integral with the required shape and size. Multiple pre-baked blocks 23 of the same specification are bonded together to form a whole pre-baked anode 2. Specifically, the number of pre-baked blocks 23 constituting the pre-baked anode 2 may be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. Preferably, the number of pre-baked blocks 23 constituting the pre-baked anode 2 is 2 or 3.

[0133] In some embodiments, the connection method of the pre-baked blocks 23 is not limited, and the pre-baked blocks 23 are connected by at least one of the following methods:

[0134] Side connection method: The pre-baked blocks 23 have mutually matching side structures, so that adjacent pre-baked blocks 23 can be closely and fixedly connected along their sides. The design of side connection allows the pre-baked blocks 23 to expand in the horizontal direction, so as to form a pre-baked anode 2 with the required width and length.

[0135] Up-and-down stacking method: The pre-baked blocks 23 have flat top surfaces and bottom surfaces, so that one pre-baked block 23 can be stably stacked on another pre-baked block 23. The design of up-and-down stacking allows the pre-baked blocks 23 to be stacked in the vertical direction, so as to form a pre-baked anode 2 with the required height.

[0136] By the side connection and / or the up-and-down stacking method, the size and shape of the pre-baked anode 2 can be flexibly adjusted to meet the requirements of different electrolytic cells.

[0137] In some embodiments, the up-and-down stacking method is preferably selected.

[0138] When the number of pre-baked blocks 23 constituting the pre-baked anode 2 is three, a second slot 22 for placing the conductor 4 is provided on the top surface of each pre-baked block 23. The second slots 22 on the three pre-baked blocks 23 can be in the same straight line or plane, can also be arranged in parallel, or can be staggeredly opened. Preferably, the second slots 22 on the three pre-baked blocks 23 are arranged in parallel to provide current to heat the pre-baked anode 2 to the greatest extent. A first slot 21 is provided on the side surface of each pre-baked block 23. The first slots 21 on the three pre-baked blocks 23 can be in the same straight line or plane, can also be arranged in parallel, or can be staggeredly opened.

[0139] In some embodiments, the number of the first slots 21 and the second slots 22 provided on each pre-baked block 23 can be multiple. The multiple first slots 21 are evenly distributed on the side surface of the pre-baked block 23 to enhance the connection strength between the carbonized body of the anode paste 3 and the pre-baked block 23; the multiple second slots 22 are evenly distributed at the top end of the pre-baked block 23.

[0140] In some embodiments, the multiple pre-baked blocks 23 are connected by a bonding paste 6. The bonding paste 6 includes a carbon material and a binder.

[0141] In some embodiments, the carbon material is selected from one or more of petroleum coke, pitch coke, calcined petroleum coke, graphite, and biomass.

[0142] In some embodiments, the binder is selected from one or more of asphalt, resin, tar, white sugar, syrup, paraffin wax, aluminum dihydrogen phosphate, rosin, ammonium persulfate, starch, and machine oil.

[0143] In another embodiment of the present application, a method for preparing a continuous anode assembly is provided, including: prefabricating a pre-baked anode 2 having at least one slot, and arranging a conductor 4 in at least one of the slots; sleeving the area of the pre-baked anode 2 having the slot in a metal frame 1, connecting the conductor 4 to the metal frame 1, and a part of the pre-baked anode 2 extends out of the metal frame 1; filling anode paste 3 at at least one surface of the pre-baked anode 2 within the metal frame 1, or laying a conductor 4 within the metal frame 1 and filling anode paste 3 at at least one surface of the pre-baked anode 2; the space where the anode paste 3 is located communicates with at least one of the slots.

[0144] In this application, the pre-baked anode 2 is prefabricated by conventional methods. For example, carbon materials and binders are put into a kneading pot according to a predetermined formula for kneading to form a non-fluid loose paste. Then, the paste is loaded into a mold of a special molding machine (such as a vibrating molding machine), and relying on the acting force of the molding machine, a green anode is formed. Subsequently, the green blank is placed into a special ring-type roasting furnace, and in an air-insulated environment, the binder in the green blank is carbonized by the heat released after fuel combustion. The coke formed after carbonization binds the carbon materials together to form a pre-baked anode 2 with high conductivity and high strength.

[0145] In some embodiments, the roasting temperature of the ring-type roasting furnace is higher than 1150 °C, the coking rate of the binder is as high as 70%, and the carbonization rate reaches more than 99%.

[0146] In some embodiments, the bulk density of the pre-baked anode 2 is 1.56 - 1.81 g / cm 3 , the resistivity is 36 - 56 μΩ·m, and the compressive strength is 32 - 56 MPa. For example, the bulk density is 1.56 g / cm 3 , 1.61 g / cm 3 , 1.66 g / cm 3 , 1.71 g / cm 3 , 1.76 g / cm 3 or 1.81 g / cm 3 , the resistivity is 36 μΩ·m, 38 μΩ·m, 40 μΩ·m, 42 μΩ·m, 44 μΩ·m, 46 μΩ·m, 48 μΩ·m, 50 μΩ·m, 52 μΩ·m, 54 μΩ·m or 56 μΩ·m, and the compressive strength is 32 MPa, 34 MPa, 36 MPa, 38 MPa, 40 MPa, 42 MPa, 44 MPa, 46 MPa, 48 MPa, 50 MPa, 52 MPa, 54 MPa or 56 MPa.

[0147] In some embodiments, the slotted openings can be formed along the axial direction, radial direction or other directions of the pre-baked anode 2 to meet specific current transmission or connection requirements. The extension path of the slotted openings is not subject to specific limitations and can extend either in a straight line direction or in a curved line direction.

[0148] In some embodiments, there is at least 1 slotted opening. For example, it can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. The number of slotted openings can be set according to actual needs.

[0149] In some embodiments, the bonding paste 6 includes a carbon material and a binder. Among them, the carbon material is selected from one or more of petroleum coke, pitch coke, calcined petroleum coke, graphite, and biomass. The binder is selected from one or more of asphalt, resin, tar, white sugar, syrup, paraffin wax, aluminum dihydrogen phosphate, rosin, ammonium persulfate, starch, and machine oil.

[0150] In some embodiments, in the anode paste 3, the mass content of the carbon material is 71-79 wt%, and the mass content of the binder is 21-29 wt%. Specifically, the mass content of the carbon material can be 71 wt%, 73 wt%, 75 wt%, 77 wt%, 79 wt%. The mass content of the binder can be 21 wt%, 23 wt%, 25 wt%, 27 wt%, 29 wt%.

[0151] In some embodiments, at least two pre-baked blocks 23 are connected to form the pre-baked anode 2. Specifically, the pre-baked anode 2 is formed by connecting at least two pre-baked blocks 23 in a bonding manner. The selected bonding material is evenly coated on the bonding surface of the pre-baked block 23. Subsequently, the pre-baked blocks 23 coated with the bonding material are put together to ensure that the bonding surfaces are closely fitted. Fixtures or other fixing devices are used to fix the pre-baked blocks 23 to prevent displacement or misalignment during the bonding process. According to the properties of the bonding material, appropriate curing conditions (such as temperature, time, etc.) are selected for curing treatment to make the bonding material completely cured and form a strong bonding layer.

[0152] In some embodiments, the bonding material is connected by using the bonding paste, and the bonding paste 6 includes a carbon material and a binder.

[0153] In some embodiments, the carbon material is selected from one or more of petroleum coke, pitch coke, calcined petroleum coke, graphite, and biomass.

[0154] In some embodiments, the binder is selected from one or more of asphalt, resin, tar, and lignin.

[0155] In some embodiments, a warping head 41 and / or a baffle 42 are provided at one end of the conductor 4. The connection manner between the warping head 41 and / or the baffle 42 and the conductor 4 can be various, specifically including but not limited to:

[0156] Integral molding: The warping head 41 and / or the baffle 42 and the main body part of the conductor 4 are integrally formed by processes such as casting, forging, and extrusion to form an integral structure.

[0157] Welding: The warping head 41 and / or the baffle 42 are fixed on the conductor 4 by welding. Welding can be carried out in various ways such as arc welding, laser welding, and brazing, and the specific selection is determined according to the material properties and connection requirements.

[0158] Mechanical connection: The warping head 41 and / or the baffle 42 are fixed on the conductor 4 through mechanical fasteners such as bolts, screws, and buckles.

[0159] Adhesion: The baffle 42 is adhered to the conductor 4 using an adhesive.

[0160] In some embodiments, the material of the conductor 4 is selected from one or more of metals, metal alloys, cryolite, or alumina.

[0161] In some embodiments, the material of the warping head 41 is selected from one or more of metals, metal alloys, cryolite, or alumina.

[0162] In some embodiments, the material of the baffle 42 is selected from one or more of graphite, ceramics, or graphene.

[0163] In another embodiment of the present application, an aluminum electrolysis cell is provided, including: an electrolysis cell body; a cathode disposed at the bottom of the electrolysis cell body; and a continuous anode assembly installed on the electrolysis cell body, wherein the continuous anode assembly and the cathode form an electrically conductive connection path through an electrolyte and liquid aluminum.

[0164] In some embodiments, the continuous anode assembly includes a metal frame 1, a pre-baked anode 2, anode paste 3, and a conductor 4. The metal frame 1 has a channel with openings at both ends; the pre-baked anode 2 is sleeved in the channel of the metal frame 1 and extends out of the metal frame 1, and at least one slot is provided in the pre-baked anode 2 located in the channel; the anode paste 3 is filled in the metal frame 1 and contacts at least one surface of the pre-baked anode 2, and the space where the anode paste 3 is located communicates with at least one of the slots; the conductor 4 is assembled in at least one of the slots and / or the anode paste 3; the conductor 4 is connected to the metal frame 1.

[0165] The technical solution of the present application will be further described in detail below with specific exemplary embodiments.

[0166] Coking rate

[0167] The coking value of the binder in the anode paste 3 is related to the roasting speed, the highest roasting temperature, and the roasting environment, and the three act together. The slower the roasting speed, the higher the coking value of the binder under the same conditions; the higher the roasting temperature, the higher the coking value of the binder under the same conditions; under the condition of isolating air, the higher the coking value of the binder under the same conditions. The coking value of the binder is expressed by the coking rate. If the coking value is high, the coking rate is high, and vice versa.

[0168] The green body of the pre-baked anode 2 is calcined at a high temperature above 1150°C under air isolation conditions. Its coking rate is mainly related to the calcination speed and the device of the ring-type calcining furnace. The slower the calcination speed, the higher the coking rate of the binder under the same conditions; the better the sealing effect of the ring-type calcining furnace device, the higher the coking rate of the binder under the same conditions, and vice versa.

[0169] The coking rate is generally measured by precise laboratory instruments and devices. The measurement method for the anode paste 3 is as follows: First, weigh the anode paste 3 with a mass of W1, simulate the actual working environment of the anode paste 3 to carbonize the anode paste 3, and then weigh the mass W2 of the carbonized anode paste 3. The binder content in the anode paste 3 is A wt%,

[0170] Then

[0171] The measurement method for the coking rate of the pre-baked anode 2 is as follows: First, take a green body sample with a mass of W for the green body from the green body, simulate the actual calcination process of the pre-baked anode 2, or place it in the ring-type calcining furnace to calcine with a batch of green bodies, and then weigh the mass W2 of the calcined sample. The binder content in the green body is A wt%,

[0172] Then

[0173] [[ID=!7]]Carbonization rate

[0174] The carbonization rate of the anode paste 3 reflects the degree of the coking reaction of the binder in the anode paste 3. The higher the degree of the coking reaction, the lower its resistivity, and vice versa. The resistivity of the anode paste 3 without a coking reaction is the highest. The degree of the coking reaction is expressed by the carbonization rate. Under the same conditions, it is mainly related to the calcination temperature, that is, the higher the calcination temperature, the higher the carbonization rate of the anode paste 3, and vice versa. Because the temperatures at different parts of the continuous anode are inconsistent, the temperature is high near the lower part and the central area of the anode, and the carbonization rate of the anode paste 3 here is high; the temperature is low near the upper part and the surrounding area of the anode, and the carbonization rate of the anode paste 3 here is low, or the carbonization reaction has not started yet, and the carbonization rate is zero.

[0175] The carbonization rate of the pre-baked anode 2 reflects the degree of the coking reaction of the binder in the green body, which is expressed by the carbonization rate and is mainly related to the highest calcination temperature and time of the ring-type calcining furnace, that is, the higher the highest calcination temperature of the ring-type calcining furnace and the calcination time exceeds the minimum limit, the higher the carbonization rate. Because the binder content in the green body is low, generally the calcination temperature is higher than 1150°C and the calcination time exceeds 192 hours, so the carbonization rate of the pre-baked anode 2 is basically constant and close to 100%, that is, the binder in the green body is basically all carbonized.

[0176] The carbonization rate of the anode paste 3 is generally measured by precise laboratory instruments and devices. The measurement method of the anode paste 3 is as follows: First, weigh a sample of the anode paste 3 with a binder content of A wt% and a mass of W1. After roasting the sample at the simulated actual working temperature and cooling it to room temperature, measure the resistivity R1 of the roasted sample with a resistivity tester. Then, heat the sample to 1150 °C under the same conditions and keep it for 3 hours, and then cool it to normal temperature. Measure the resistivity R2 of the sample at high temperature with the same resistivity tester.

[0177] Then

[0178] Because the binder content in the green body is low, the roasting temperature is generally higher than 1150 °C, and the roasting time exceeds 192 hours, the carbonization rate of the pre-baked anode 2 is calculated as 100%.

[0179] Example 1

[0180] Refer to Figures 1 to 3 A continuous anode assembly includes a metal frame 1, a pre-baked anode 2, an anode paste 3, and a conductor 4. The two sides of the metal frame 1 are respectively an electricity inlet surface 11 and an electricity outlet surface 12, and the upper and lower ends are open. Three anode guide rods 5 are connected to each of the electricity inlet surface 11 and the electricity outlet surface 12 on both sides of the metal frame 1. The pre-baked anode 2 is composed of three pre-baked blocks 23. The sides of the three pre-baked blocks 23 are pasted together by a bonding paste 6 to form the pre-baked anode 2. The pre-baked anode 2 is sleeved inside the metal frame 1. The bottom end of the pre-baked anode 2 extends out of the lower opening of the metal frame 1, and the extending part is 20 cm away from the lower opening of the metal frame 1. A first slot 21 and two second slots 22 are respectively opened at the top of the three pre-baked blocks 23. A conductor 4 is placed in each second slot 22. First, the anode paste 3 with a binder content 2.5% higher than the normal value is filled in the metal frame 1 at the top of the pre-baked anode 2 and fills the first slot 21. Then, the anode paste 3 with a binder content at the normal value is added on the upper surface of the above-mentioned anode paste 3, and several conductors 4 are arranged in the above-mentioned anode paste 3. At least one end of the conductor 4 is connected with a warping head 41 and / or a baffle 42. The warping head 41 is connected to the upper surface of the conductor 4 and is in contact connection with the electricity inlet surface 11 and / or the electricity outlet surface 12 of the metal frame 1.

[0181] Among them, the bulk density of the pre-baked anode 2 is 1.62 g / cm 3 , the resistivity is 53 μΩ·m, the compressive strength is 42 MPa, and the coking rate is 75%.

[0182] The anode paste 3 is composed of petroleum coke and pitch. The content of petroleum coke is 76 wt%, and the normal content of pitch is 24 wt%.

[0183] Install 3 sets of continuous anode assemblies above the cathode of an 180Ka aluminum electrolysis cell. The distance between the bottom of the continuous anode and the cathode is 15 - 30 cm. The perimeter of the continuous anode and the upper opening of the cathode are sealed with thermal insulation cotton. Introduce high-temperature inert gas into the space between the bottom of the continuous anode and the cathode to bake the cathode and the continuous anode. Gradually raise the temperature of the lower parts of the cathode and the continuous anode from room temperature to 890 - 920 °C, then quickly pour high-temperature liquid electrolyte (composed of cryolite, including a small amount of alumina) into the electrolysis cell, covering the lower part of the continuous anode by 10 - 30 cm. Immediately pass the series current into the aluminum electrolysis cell, raise the current to the full series within 10 minutes, with the impact voltage less than 3.26 V, and the anode current distribution is uniform. No anodic effect occurs in other operating aluminum electrolysis cells in the series due to the speed of raising the current to the full series. The aluminum electrolysis cell starts normal operation 30 days after startup. As the pre-baked anode 2 is consumed, a new aluminum frame, conductor, and anode paste are continuously connected inside the upper opening of the metal frame body 1.

[0184] During the baking of the aluminum electrolysis cell with high-temperature inert gas, first start heating and raising the temperature of the cathode and the pre-baked anode 2. Then, the high-temperature pre-baked anode 2 starts to heat, melt, cast, and pre-bake the anode paste 3 in contact with its top surface. At this time, no additional energy is required for baking the anode paste 3, so energy is saved. When the anode paste 3 is heated to melting and generates VOC, there are no problems of paste flowing and VOC escaping around the continuous anode. Measure the VOC value at the upper opening of the aluminum frame with a portable VOC detector, which is between 8 - 12 mg / NM 3 Between. Since the anode paste 3 is located on the top surface of the pre-baked anode 2, the time for starting to heat, melt, cast, and pre-bake the anode paste is extended by about 48 hours, reducing the speed of heating, melting, casting, and pre-baking the anode paste. The heating rate of the anode paste 3 is controlled at 3 °C / hour, promoting the penetration of the anode paste 3 into the pre-baked anode, reducing the generation of VOC and the carbonization rate of the binder. The coking rate of the binder is above 86%, enhancing the connection between the anode paste 3 and the pre-baked anode 2. After the anode paste 3 is heated, melted, cast, and baked using the heat of the pre-baked anode 2, it is tightly connected to the pre-baked anode 2, forming a firm, non-separable, and high-strength whole.

[0185] The anode paste 3 is located on the top surface of the pre-baked anode 2, extending the time for starting to heat, melt, cast, and pre-bake the anode paste 3 by about 72 hours, reducing the speed of heating, melting, casting, and pre-baking the anode paste 3. The heating rate of the anode paste 3 is controlled at 1 °C / hour, promoting the penetration of the anode paste 3 into the pre-baked anode 2, reducing the generation of VOC and the carbonization rate of the binder. Through laboratory simulation and testing of the coking value of the binder in the anode paste 3 under the same conditions, the coking rate of the binder in the anode paste 3 is measured to be about 86%, enhancing the connection between the anode paste 3 and the pre-baked anode 2. After the anode paste 3 is heated, melted, cast, and baked using the resistance heat of the pre-baked anode 2, it is tightly connected to the pre-baked anode 2, forming a firm, non-separable, and high-strength whole.

[0186] As the pre-baked anode 2 is consumed, the series current gradually enters the anode paste 3 through the aluminum frame and the conductor 4, further baking the anode paste 3. By simulating in the laboratory and testing the coking reaction degree of the anode paste 3 used under the same conditions, it is measured that the carbonization rate of the anode paste 3 reaches more than 98%.

[0187] In order to clamp and lift the continuous anode, the anode conductor bar 5 applies a certain clamping force to the power input surface 11 and the power output surface 12 of the aluminum frame. When the clamping force moves from the end face of the pre-baked anode 2 inside the aluminum frame to the end face of the carbonized body, observing the operation of the continuous anode on site every day, it is found that the carbonized body of the anode paste 3 lifts the pre-baked anode 2 and the pre-baked anode 2 does not fall off from under the carbonized body.

[0188] Example 2

[0189] Refer to Figure 4 A continuous anode assembly includes a metal frame body 1, two groups of pre-baked anodes 2, anode paste 3, and a conductor 4. The two sides of the metal frame body 1 are respectively a power input surface 11 and a power output surface 12, with openings at the upper and lower ends. Three anode conductor bars 5 are connected to each of the power input surface 11 and the power output surface 12 on both sides of the metal frame body 1. Each group of pre-baked anodes 2 is composed of two pre-baked blocks 23 stacked up and down. A first slot 21 is opened on the side surface of each pre-baked block 23, and two second slots 22 are opened on the top. The two groups of pre-baked anodes 2 are respectively sleeved inside the metal frame body 1. The bottom end of each group of pre-baked anodes 2 extends out of the lower opening of the metal frame body 1, and the extending part is 35 cm away from the lower opening of the metal frame body 1. And one of the two groups of pre-baked anodes 2 is in contact with the power input surface 11 of the metal frame body 1, and the other group is in contact with the power output surface 12 of the metal frame body 1. The second slot 22 on the top of the pre-baked block 23 points to the power input surface 11 or the power output surface 12 of the metal frame body 1. The two groups of pre-baked anodes 2 form an anode cavity, and the anode paste 3 is filled in the anode cavity. The first slot 21 communicates with the anode cavity. A conductor 4 is placed in each second slot 22. One end of each conductor 4 is connected with a baffle 42 and / or a warping head 41. The warping head 41 is connected to the upper surface of the conductor 4. The baffle 42 is in contact connection with the power input surface 11 or the power output surface 12 of the metal frame body 1. The warping head 41 is located at one end of the second slot 22 close to the metal frame body 1 and is in contact connection with the power input surface 11 or the power output surface 12 of the metal frame body 1. The baffle 42 blocks the opening of the slot close to the metal frame body 1.

[0190] Among them, the bulk density of the pre-baked anode 2 is 1.62 g / cm 3 , the resistivity is 53 μΩ·m, the compressive strength is 42 MPa, and the coking rate is 75%.

[0191] The anode paste 3 is composed of petroleum coke and pitch. The content of petroleum coke is 76 wt%, and the normal content of pitch is 24 wt%.

[0192] In an 180Ka aluminum reduction cell, a layer of calcined petroleum coke particles (CPCC) with a particle size range of 2 to 4 mm is evenly laid on the cathode surface. Three continuous anode assemblies are then installed on top of this layer. Current is then simultaneously applied to these three continuous anode assemblies. The current first passes through the aluminum frame and conductor 4 before entering the prebaked anode 2. The current flows within the prebaked anode 2, then through the CPCC layer, through the cathode, and finally to the next adjacent aluminum reduction cell. After a 96-hour baking process, the cell temperature gradually rises to approximately 700°C. At this point, the continuous anode assemblies are gradually raised. During this process, the anode paste 3 in contact with the prebaked anode 2 begins to carbonize, forming a strong bond between the paste 3 and the prebaked anode 2. When the cell temperature rises further, reaching 920°C or higher, liquid electrolyte is added to the cell, and the continuous anode assemblies are further raised, officially starting the cell. The aluminum electrolytic cell gradually transitions to normal operation within 30 days of startup. As the prebaked anodes 2 and anode paste are consumed, new aluminum frames, conductors, prebaked anodes, and anode paste 3 are promptly connected to the upper edge of the aluminum frame to ensure the cell's continued stable operation, environmentally friendly operation, and high degree of automation.

[0193] During firing, the series current was initially set at 10 kJ / cm2. After 25 minutes of operation, the series current gradually increased to 181 kJ / cm2. During this process, the cell control panel displayed a surge voltage of 2.82 V, and the current distribution on the anodes was uniform. Notably, the other operating aluminum reduction cells in the series did not experience anode effects due to the series current not reaching full current within a short period of time. This is primarily due to the use of a continuous anode assembly, which results in a low resistivity of the prebaked anode 2. This eliminates the need for rapid carbonization of the anode paste 3 and eliminates the need for the anode cone required for current conduction, as is the case with conventional technology. This eliminates safety and pollution risks. During the firing phase of the aluminum reduction cell, the resistive heat generated by the series current passing through the prebaked anode 2 begins to take effect, gradually heating and raising the temperature of the prebaked anode 2. Subsequently, the prebaked anode 2 begins to exert its heating effect, causing the anode paste 3 in contact with it to undergo heating, melting, casting, and prebaking. During this period, no additional energy is required to heat the anode paste 3, thus achieving energy savings.

[0194] The results of the test using a portable VOC detector showed that the VOC value was between 3 and 6 mg / NM. 3Among them. The main reason is that the binder in the anode paste 3 and the VOC generated by the binder will penetrate into the inside of the pre-baked anode 2, and a secondary thermal cracking reaction will occur on the inner wall of the pores of the pre-baked anode 2 to repair the damaged pre-baked anode 2 due to grooving. When the anode paste 3 is heated to a molten state and volatile organic compounds (VOCs) are generated, there are no problems of paste flowing or VOC escaping around the continuous anode. At the same time, this process not only helps to further improve the conductivity of the pre-baked anode 2, but also enhances its mechanical strength.

[0195] When the series current conducts into the continuous anode and then into the pre-baked anode 2, the resistance heat generated by the series current passing through the pre-baked anode 2 starts to further heat and raise the temperature of the pre-baked anode 2. The pre-baked anode 2 then further heats, melts, casts, and pre-bakes the anode paste 3 in contact with its surface. At this time, no additional energy is required for baking the anode paste, so energy is saved, and the carbonization rate of the anode paste 3 reaches more than 98%.

[0196] The current distribution of the continuous anode is uniform. After carbonization, the anode paste 3 is protected by the pre-baked anode 2, the metal frame 1, and the anode paste 3, and there are no problems of oxidation and cracking. When the anode rod 5 applies a certain clamping force to the power input surface 11 and the power output surface 12 of the aluminum frame, the anode paste 3 or the carbonized body and the pre-baked anode 2 together withstand the clamping force without shrinking or deforming, and no technical accident of continuous anode detachment occurs. At the same time, the pre-baked anode 2 and the carbonized body are firmly bonded, and the carbonized body and the anode paste do not detach from the anode cavity formed by the pre-baked anode 2.

[0197] Adhesion experiment between pre-baked block and anode paste

[0198] Experimental example 1 tests the bonding strength between the anode paste and the pre-baked block with grooves on the upper surface

[0199] Select a pre-baked block with a diameter of 50 mm and a height of 60 mm, and a bulk density of 1.62 g / cm 3, the resistivity is 53 μΩ·m, and the compressive strength is 42 MPa. Four grooves with a depth of 5 mm and a width of 5 mm are prefabricated on the upper surface of the pre-baked block, distributed in a "well" shape on the upper surface of the pre-baked block, and both ends of the grooves communicate with the periphery of the pre-baked block; then a iron sheet cylinder with a diameter of 51 mm and a height of 300 mm is placed in an alumina crucible, and the pre-baked block is placed in the iron sheet cylinder with the upper surface facing up. Filler is added around the iron sheet cylinder and tamped; anode paste particles made of calcined petroleum coke and pitch are loaded into the iron sheet cylinder, the particles are less than 15 mm, the anode paste fills the upper surface of the pre-baked block, the height of the anode paste is 180 mm, and a cardboard, filler and iron column are placed in the iron cylinder on the upper surface of the anode paste. The alumina crucible, pre-baked block and anode paste are moved to an electric furnace, and the pre-baked block and anode paste are baked to 950 °C at the actual heating rate of the electrolytic cell and maintained for 3 hours. The sample composed of the above pre-baked block and anode paste is taken out from the electric furnace and alumina crucible and cooled to room temperature, and the tensile strength between the pre-baked block and the carbonized anode paste is tested with a tensile testing machine. The composition of the added anode paste is shown in Table 1.

[0200] Table 1 Influence of different anode paste compositions on bonding strength

[0201] Petroleum coke content Pitch content Tensile strength 79 wt% 21 wt% 2.15 MPa 75.5 wt% 24.5 wt% 3.06 MPa 74.5 wt% 25.5 wt% 4.29 MPa 72.5 wt% 27.5 wt% 3.86 MPa 71 wt% 29 wt% 3.53 MPa

[0202] Experimental Example 2 Test the bonding strength of the anode paste and the pre-baked block with a flat upper surface

[0203] Select a pre-baked block with a diameter of 50 mm and a height of 60 mm. The upper surface of the pre-baked block is flat, dense and without concavities and convexities, and its bulk density is 1.62 g / cm 3 , the resistivity is 53 μΩ·m, and the compressive strength is 42 MPa. A iron sheet cylinder with a diameter of 51 mm and a height of 300 mm is placed in an alumina crucible, and the pre-baked block is placed in the iron sheet cylinder. After adding filler around the iron sheet cylinder and tamping; anode paste particles made of calcined petroleum coke and pitch are loaded into the iron sheet cylinder, the particles are less than 15 mm, the anode paste fills the upper surface of the pre-baked block, the height of the anode paste is 180 mm, and a cardboard, filler and iron column are placed in the iron cylinder on the upper surface of the anode paste. The alumina crucible, pre-baked block and anode paste are moved to an electric furnace, and the pre-baked block and anode paste are baked to 950 °C at the actual heating rate of the electrolytic cell and maintained for 3 hours. The sample composed of the above pre-baked block and anode paste is taken out from the electric furnace and alumina crucible and cooled to room temperature, and the tensile strength between the pre-baked block and the carbonized anode paste is tested with a tensile testing machine. The composition of the added anode paste is shown in Table 2.

[0204] Table 2 Influence of different anode paste compositions on bonding strength

[0205] Petroleum coke content Pitch content Tensile strength 79 wt% 21 wt% 0.15 MPa 75.5 wt% 24.5 wt% 0.21 MPa 74 wt% 25.5 wt% 0.29 MPa 72.5 wt% 27.5 wt% 0.26 MPa 71 wt% 29 wt% 0.24 MPa

[0206] Although the embodiments of the present application have been described above in conjunction with the accompanying drawings, the present application is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Those of ordinary skill in the art can also make many forms under the inspiration of this specification and without departing from the scope protected by the claims of the present application, and these all fall within the scope of protection of the present application.

Claims

1. A continuous anode assembly, comprising: A metal housing having a channel with openings at both ends; A pre-baked anode sleeved in the channel of the metal housing and protruding from the metal housing, and at least one slot is provided in the pre-baked anode located in the channel; Anode paste filled in the metal housing and in contact with at least one surface of the pre-baked anode, and the space where the anode paste is located communicates with at least one of the slots; A conductor assembled in at least one of the slots and / or in the anode paste; the conductor is connected to the metal housing.

2. The continuous anode assembly according to claim 1, wherein the slot includes a first slot and a second slot, the first slot communicates with the space where the anode paste is located; the second slot is for assembling the conductor.

3. The continuous anode assembly according to claim 2, wherein the bottom end of the pre-baked anode protrudes from the metal housing, the anode paste is filled in the metal housing at the top end of the pre-baked anode, and the conductor is assembled in the second slot and the anode paste.

4. The continuous anode assembly according to claim 1, wherein the pre-baked anode is composed of at least one pre-baked block, and at least one of the pre-baked blocks is provided with the slot; or the pre-baked anode is replaced by a cathode carbon block.

5. The continuous anode assembly according to any one of claims 1 to 4, wherein the pre-baked anode has a bulk density of 1.56 to 1.81 g / cm 3 , a resistivity of 36 to 56 μΩ·m, and a compressive strength of 32 to 56 MPa.

6. The continuous anode assembly according to any one of claims 1 to 4, wherein the anode paste comprises a carbon material and a binder; Preferably, the mass content of the carbon material is 71-79 wt%, and the mass content of the binder is 21-29 wt%.

7. The continuous anode assembly according to any one of claims 1 to 4, wherein one end of the conductor is provided with a warped head, and the warped head is connected to the metal housing.

8. The continuous anode assembly according to any one of claims 1 to 4, wherein one end of the conductor is connected with a baffle, and the baffle is connected to the metal housing.

9. A method for preparing the continuous anode assembly according to any one of claims 1 to 8, comprising: Preparing a pre-baked anode with at least one slot, and arranging a conductor in at least one of the slots; Sleeving the area of the pre-baked anode with the slot in a metal housing, connecting the conductor to the metal housing, and part of the pre-baked anode protrudes from the metal housing; Filling anode paste at at least one surface of the pre-baked anode in the metal housing, or laying a conductor in the metal housing and filling anode paste at at least one surface of the pre-baked anode; the space where the anode paste is located communicates with at least one of the slots.

10. An aluminum electrolysis cell, comprising: An electrolysis cell body; A cathode arranged at the bottom of the electrolysis cell body; And The continuous anode assembly according to any one of claims 1 to 8 installed on the electrolysis cell body, wherein the continuous anode assembly and the cathode form an electrical connection path through an electrolyte and / or molten aluminum.

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