A cathode replaceable aluminium electrolytic cell

Abstract

A kind of cathode replaceable aluminum electrolytic cell, insulating baffle is vertically fixed in the middle of aluminum electrolytic cell, aluminum liquid passage hole is opened in the bottom of insulating baffle, the region of both sides of insulating baffle is anode carbon block region and cathode carbon block region respectively, the bottom of two regions is communicated by aluminum liquid passage hole;Insulating baffle is one or more;When insulating baffle is one, anode carbon block region and cathode carbon block region are one, and two regions are symmetrically distributed in the both sides of insulating baffle;When insulating baffle is more, anode carbon block region and cathode carbon block region are alternately arranged;Cathode carbon block is installed in cathode region using suspension type structure;Cathode carbon block is suspended above the bottom lining by cathode steel claw, cathode steel claw is connected with cathode bus, and cathode carbon block is immersed in aluminum liquid.In the production process of aluminum electrolytic cell, damaged cathode can be replaced, without stopping tank overhaul bottom lining, ensure continuous production operation, reduce solid waste output, improve the service life of aluminum electrolytic cell, cathode carbon block utilization rate and economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of aluminum electrolysis cell technology, and in particular relates to an aluminum electrolysis cell with a replaceable cathode. Background Technology

[0002] The Hall-Eruth process is a modern industrial method for producing primary aluminum, and its main equipment is the aluminum electrolytic cell. During operation, the cathode carbon blocks in the bottom lining of a traditional aluminum electrolytic cell are continuously permeated by alkali metal sodium and electrolyte, leading to volume expansion, increased internal stress, and consequently, sludge accumulation, increased cell temperature, and current wastage. Severe permeation can cause damage to the bottom lining, resulting in aluminum leakage and necessitating cell shutdown, production interruption, and major overhaul of the electrolytic cell.

[0003] Traditional electrolytic cell overhauls typically last over 20 days, consuming significant manpower and resources and severely impacting continuous production. During overhauls, in addition to damaged bottom linings, a large amount of waste is generated from the electrolytic cell itself; all of this waste is collectively referred to as overhaul slag. Overhaul slag is a solid waste containing soluble fluorides and cyanides. Soluble fluorides are highly corrosive and classified as hazardous substances. Cyanides are extremely toxic, requiring further resource consumption for harmless treatment. In summary, overhaul slag is a complex waste containing numerous hazardous substances, making it difficult to manage and extremely harmful to the environment. It is difficult to utilize as a resource and requires substantial resources for harmless treatment.

[0004] Related studies have shown that the current present in the bottom cathode carbon block of traditional electrolytic cells greatly exacerbates the penetration of sodium and electrolytes, accelerates the damage to the bottom lining, and ultimately reduces the lifespan of the electrolytic cell. In traditional electrolytic cells, the current must pass through the bottom cathode carbon block for normal production to proceed, which is precisely the contradiction in the structural design of traditional electrolytic cells.

[0005] In summary, while traditional electrolytic cells can operate normally in the short term, after prolonged operation, the cathode carbon blocks will suffer severe penetration and corrosion from sodium and electrolytes due to the presence of current. This leads to damage to the bottom lining after a few years of operation, necessitating a major overhaul. Major overhauls of electrolytic cells consume significant manpower and resources and generate substantial solid waste. Production is interrupted during the overhaul, resulting in economic losses, and the generated overhaul residue also pollutes the environment. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides an aluminum electrolysis cell with a replaceable cathode, which enables the replacement of damaged cathodes during normal production without requiring a major overhaul of the bottom lining, ensuring continuous production, reducing solid waste output, increasing the service life of the aluminum electrolysis cell, improving the utilization rate of cathode carbon blocks, and increasing economic benefits.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: an aluminum electrolytic cell with a replaceable cathode, wherein an insulating baffle is vertically fixed in the middle of the aluminum electrolytic cell, and an aluminum liquid channel hole is opened at the bottom of the insulating baffle. The areas on both sides of the insulating baffle are the anode carbon block area and the cathode carbon block area, respectively, and the bottom of the anode carbon block area and the cathode carbon block area are connected through the aluminum liquid channel hole.

[0008] The number of insulating baffles is one or more.

[0009] When there is one insulating baffle, there is one anode carbon block region and one cathode carbon block region, which are symmetrically distributed on both sides of the insulating baffle.

[0010] When there are multiple insulating baffles, the anode carbon block area and the cathode carbon block area are arranged alternately.

[0011] The cathode carbon block is installed in a suspended structure within the cathode carbon block area.

[0012] The cathode carbon block is suspended above the bottom liner by cathode steel claws, which are connected to the cathode busbar. The cathode carbon block is immersed in the aluminum liquid.

[0013] The thickness of the molten aluminum in the cathode carbon block area is 5cm to 100cm, and the thickness of the electrolyte in the cathode carbon block area is 1cm to 30cm.

[0014] The width of the aluminum liquid channel hole is 1cm to 80cm, and the aluminum liquid channel hole is 1cm to 10cm lower than the aluminum liquid level in the anode carbon block area.

[0015] Beneficial effects of the invention:

[0016] The aluminum electrolytic cell with replaceable cathode of the present invention abandons the traditional design of placing the cathode carbon block in the bottom lining of the electrolytic cell, and improves it by suspending the cathode carbon block inside the aluminum electrolytic cell. Under this structural design, there is space around the cathode carbon block, which will not be damaged due to volume expansion, so that the cathode carbon block has a longer service life. Even if the cathode carbon block is damaged, the damaged cathode carbon block can be lifted out and quickly replaced with a brand new cathode carbon block. The continuous production of the aluminum electrolytic cell will not be interrupted, which is conducive to the continuous operation of the aluminum electrolytic cell.

[0017] The aluminum electrolytic cell with replaceable cathode of the present invention has a current conduction path as follows: carbon blocks on both sides of the anode → electrolyte in the area of ​​carbon blocks on both sides of the anode → molten aluminum in the area of ​​carbon blocks on both sides of the anode → molten aluminum in the area of ​​carbon blocks on the cathode → carbon block on the cathode. The resistance of the bottom lining is hundreds of times that of the molten aluminum. Therefore, almost no current passes through the bottom lining of the aluminum electrolytic cell, which can effectively reduce the penetration of sodium and electrolyte into the bottom lining, and can also effectively avoid corrosion of the bottom lining caused by electrochemical reaction, improve the service life of the bottom lining, avoid frequent cell shutdowns and major repairs caused by bottom lining damage, and also reduce solid waste production.

[0018] The aluminum electrolytic cell with replaceable cathode of the present invention allows the cathode carbon block to be directly lifted out and reused as the anode carbon block. This not only enables the resource utilization of waste cathode carbon blocks and reduces production costs, but also reduces solid waste output and is more environmentally friendly. Attached Figure Description

[0019] Figure 1 This is a schematic diagram (side view) of the structure of an aluminum electrolysis cell with a replaceable cathode (Example 1) according to the present invention;

[0020] Figure 2 This is a schematic diagram (front view) of a cathode-replaceable aluminum electrolytic cell (Example 1) according to the present invention;

[0021] Figure 3 This is a schematic diagram (side view) of the structure of an aluminum electrolysis cell with a replaceable cathode (Example 2) according to the present invention;

[0022] Figure 4 This is a top view of a structural schematic diagram of an aluminum electrolysis cell with a replaceable cathode (Example 2) according to the present invention;

[0023] Figure 5 This is a schematic diagram (side view) of the structure of an aluminum electrolysis cell with a replaceable cathode (Example 3) according to the present invention;

[0024] Figure 6 This is a top view of a structural schematic diagram of an aluminum electrolysis cell with a replaceable cathode (Example 3) according to the present invention;

[0025] In the figure, 1—insulating baffle, 2—aluminum liquid channel hole, 3—cathode carbon block, 4—cathode steel claw, 5—cathode busbar, 6—aluminum liquid, 7—electrolyte, 8—covering material, 9—steel shell, 10—refractory and heat insulation material, 11—bottom lining, 12—tamping paste, 13—side lining, 14—feeder, 15—anode carbon block, 16—anode steel claw, 17—anode busbar, 18—tank cover. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0027] like Figures 1-6 As shown, an aluminum electrolytic cell with a replaceable cathode has an insulating baffle 1 vertically fixed in the middle of the aluminum electrolytic cell. An aluminum liquid channel hole 2 is opened at the bottom of the insulating baffle 1. The areas on both sides of the insulating baffle 1 are the anode carbon block area and the cathode carbon block area, respectively. The bottom of the anode carbon block area and the cathode carbon block area are connected through the aluminum liquid channel hole 2.

[0028] The main structure of the aluminum electrolytic cell follows a traditional design. The outermost layer of the aluminum electrolytic cell is a steel shell 9, and the bottom layer is a refractory and insulation material 10. Above the refractory and insulation material 10 is the bottom lining 11. The material of the bottom lining 11 can be graphitized carbon blocks, semi-graphitized carbon blocks, silicon carbide combined with silicon nitride, or other refractory materials. The bottom lining 11 no longer serves as the cathode of the aluminum electrolytic cell, therefore, there are no conductive steel rods inside the bottom lining 11. The two sides of the bottom lining 11 are tamping paste 12, and the space between the tamping paste 12 and the steel shell 9 is the side lining 13. A feeder 14 is also included. The anode carbon block 15 is located in the anode carbon block area and is suspended above the bottom liner 11 by the anode steel claw 16. The anode steel claw 16 is connected to the anode busbar 17. The anode carbon block 15 is immersed in the electrolyte. A movable tank cover 18 is provided from the top to the side of the aluminum electrolysis cell. The tank cover 18 is equipped with a transmission device and an insulated transmission wheel is installed at the bottom of the tank cover 18. Two to four cover plates are connected into a whole tank cover 18 by fixing buckles. The anode busbar 17 is connected to a stainless steel support frame. The support frame extends upward through the tank cover 18, and the perforation is sealed.

[0029] The insulating baffle 1 runs horizontally through the entire aluminum electrolysis cell. The part of the top of the insulating baffle 1 that contacts the cell cover 18 is fixed with screws. The bottom of the insulating baffle 1 can be appropriately thickened or its shape changed to ensure that the aluminum liquid 6 passes smoothly through the aluminum liquid channel hole 2, while further shielding the horizontal current in the aluminum electrolysis cell and preventing the sediment in the aluminum electrolysis cell from blocking the aluminum liquid channel hole 2, so as to make the operation of the aluminum electrolysis cell more stable.

[0030] The anode carbon block area specifically refers to the space containing the covering material 8, electrolyte 7, and molten aluminum 6 on the anode side of the insulating baffle 1, and there can be one or more of them. The cathode carbon block area specifically refers to the space containing the covering material 8, electrolyte 7, and molten aluminum 6 on the cathode side of the insulating baffle 1, and there can be one or more of them. The anode carbon block area and the cathode carbon block area are separated by the insulating baffle 1.

[0031] Within the anode carbon block area, from the bottom to the top of the anode carbon block 15, it is sequentially filled with molten aluminum 6, electrolyte 7, and covering material 8. The thickness of molten aluminum 6 is 5cm to 40cm, and the thickness of electrolyte 7 is 10cm to 40cm. Within the cathode carbon block area, from the bottom to the top of the cathode carbon block 3, it is also sequentially filled with molten aluminum 6, electrolyte 7, and covering material 8. The thickness of molten aluminum 6 is 5cm to 100cm, and the thickness of electrolyte 7 is 1cm to 30cm.

[0032] The width of the aluminum liquid channel hole 2 at the bottom of the insulating baffle 1 is 1cm to 80cm, and the aluminum liquid channel hole 2 is 1cm to 10cm lower than the aluminum liquid 6 in the anode carbon block area.

[0033] The anode carbon block 15 can be one or more of the following regular shapes: sphere, cuboid, cube, trapezoid, etc., or other irregular shapes. The shapes of the anode carbon blocks 15 can be the same or different. The anode carbon block 15 and the cathode carbon block 3 can be made of the same or different materials, and their shapes can be the same or different.

[0034] The anode carbon block 15 is made using traditional processes. Due to the maturity of the process, its production cost is lower. The cathode carbon block 3 allows for more flexible design to obtain a more stable electromagnetic field and aluminum liquid 6 flow field.

[0035] Within the cathode carbon block area, the cathode carbon block 3 is suspended above the bottom liner 11 by the cathode steel claw 4. The cathode steel claw 4 is connected to the cathode busbar 5. The cathode carbon block 3 is immersed in the aluminum liquid 6. The cathode busbar 5 is also connected to the corresponding support frame. The support frame extends upward through the trough cover 18, and the perforation is sealed.

[0036] The cathode carbon block 3 can be made of carbon material or other conductive materials. The shape of the cathode carbon block 3 can be one or more of the following: regular shape such as sphere, cuboid, cube, trapezoid, or other irregular shape. The shapes of each cathode carbon block 3 can be the same or different.

[0037] When the cathode carbon block 3 has the same material and shape as the anode carbon block 15, it is beneficial for the cathode carbon block 3 to directly participate in the electrochemical reaction as the anode carbon block 15 after long-term use and damage, thus making resource-efficient use of waste cathodes and being more environmentally friendly.

[0038] Both the cathode carbon block 3 and the anode carbon block 15 can be replaced independently during the aluminum electrolysis cell production process. The number of cathode carbon blocks 3 and anode carbon blocks 15 in the aluminum electrolysis cell can be one or more, and the number of cathode carbon blocks 3 and anode carbon blocks 15 can be the same or different.

[0039] The cathode reaction occurs at the interface between the electrolyte 7 and the molten aluminum 6 below the anode carbon block 15. The sodium vapor generated by the reaction cannot reach the vicinity of the cathode carbon block 3 through the insulating baffle 1. Therefore, the cathode carbon block 3 is difficult to be permeated by sodium. Even if the cathode carbon block 3 is permeated by the electrolyte 7 or the molten aluminum 6, because the cathode carbon block 3 adopts a suspended installation scheme with space around it, the main structure of the aluminum electrolysis cell will not be damaged due to the volume expansion of the cathode carbon block 3, thus giving the electrolysis cell a longer service life. Even if the cathode carbon block 3 is damaged, the damaged cathode carbon block 3 can be lifted out and quickly replaced with a brand new cathode carbon block 3, so the continuous production of the aluminum electrolysis cell will not be interrupted, which is beneficial to the continuous operation of the aluminum electrolysis cell. As for the damaged cathode carbon block 3, it can be directly used as the anode carbon block 15 in the aluminum electrolysis cell, or it can be processed and used as raw material for the production of anodes or cathodes.

[0040] The current conduction path of the aluminum electrolytic cell can be simplified as follows: anode carbon block 15 → aluminum liquid 6 → cathode carbon block 3. Since the bottom liner 11 is no longer used as the cathode of the aluminum electrolytic cell, and the resistance of the bottom liner 11 is hundreds of times that of the aluminum liquid 6, there is no current or only a weak current in the bottom liner 11. This greatly reduces the penetration and corrosion of sodium into the bottom liner 11, and also greatly reduces the penetration of electrolyte, avoiding damage to the bottom liner 11, thereby significantly extending the life of the electrolytic cell.

[0041] In summary, the aluminum electrolytic cell with replaceable cathodes adopted in this invention solves the problem of frequent shutdowns and major repairs caused by damage to the bottom lining 11 in traditional aluminum electrolytic cells. This improves the production efficiency of aluminum electrolysis, saves manpower and material costs during shutdowns and major repairs, and reduces the output of repair slag, which is more environmentally friendly. Furthermore, thanks to the suspended installation scheme of the cathode carbon block 3, it can be replaced independently, significantly reducing electrode replacement time and labor intensity, while ensuring continuous production of the aluminum electrolytic cell.

[0042] Example 1

[0043] like Figure 1 , 2 As shown, in this embodiment, there is one insulating baffle 1, and the anode carbon block area and the cathode carbon block area are symmetrically distributed on both sides of the insulating baffle 1.

[0044] The insulating baffle 1 has a height of 200cm and a thickness of 7cm. The insulating baffle 1 is made of SiC combined with Si4N3 insulating composite material. The aluminum liquid channel hole 2 at the bottom of the insulating baffle 1 has a square cross-sectional shape. The square aluminum liquid channel hole 2 has a height of 5cm and a width of 20cm. The bottom lining 11 is made of graphitized carbon block.

[0045] Within the anode carbon block area, the thickness of the aluminum liquid 6 is 20cm, the thickness of the electrolyte 7 is 30cm, the thickness of the covering material 8 is 15cm, the number of anode carbon blocks 15 is 10, the 10 anode carbon blocks 15 are distributed at equal intervals in the horizontal direction, the distance between adjacent anode carbon blocks 15 is 18cm, and the distance between the bottom of the anode carbon block 15 and the bottom liner 11 is 23cm.

[0046] Within the cathode carbon block area, the aluminum liquid 6 has a thickness of 40cm, the electrolyte 7 has a thickness of 8cm, the covering material 8 has a thickness of 15cm, and there are 10 cathode carbon blocks 3. The 10 cathode carbon blocks 3 are distributed at equal intervals in the horizontal direction, the distance between adjacent cathode carbon blocks 3 is 18cm, and the distance between the bottom of the cathode carbon block 3 and the bottom liner 11 is 7cm.

[0047] The anode carbon block 15 is made of traditional carbon material. The anode carbon block 15 is rectangular in shape and its dimensions are 170cm × 66cm × 55cm (length × width × height).

[0048] The cathode carbon block 3 is made of graphitized carbon block. The cathode carbon block 3 is rectangular in shape. The cathode carbon block 3 has the same dimensions as the anode carbon block 15, which is 170cm×66cm×55cm (length×width×height).

[0049] During the operation of the aluminum electrolysis cell, the current conduction path is as follows: anode carbon block 15 → electrolyte 7 within the anode carbon block area → molten aluminum 6 within the anode carbon block area → molten aluminum 6 within the cathode carbon block area → cathode carbon block 3. The main chemical reaction in the aluminum electrolysis cell is: Al₂O₃ + C = CO₂ + Al. Specifically, the alumina in electrolyte 7 and anode carbon block 15 are consumed, and carbon dioxide is generated at the contact point between the anode carbon block 15 and electrolyte 7. After the alumina in electrolyte 7 loses oxygen, pure aluminum liquid is formed.

[0050] If the cathode carbon block 3 is damaged during the operation of the aluminum electrolysis cell, the damaged cathode carbon block 3 can be replaced directly, and the aluminum electrolysis cell production can continue during the replacement of the cathode carbon block 3.

[0051] Example 2

[0052] like Figure 3 , 4 As shown, in this embodiment, there are two insulating baffles 1, one cathode carbon block area located between the two insulating baffles 1, and two anode carbon block areas symmetrically distributed on both sides of the cathode carbon block area.

[0053] The insulating baffle 1 has a height of 210cm. A thickened part is provided at the bottom of the insulating baffle 1. The thickened part has an inclination angle of 30° and extends to both sides. The aluminum liquid channel hole 2 is located at the bottom thickened part of the insulating baffle 1. The thickness of the non-thickened part of the insulating baffle 1 is 8cm. The height of the thickened part of the insulating baffle 1 is 10cm. The width of the thickened part of the insulating baffle 1 is 16cm. The insulating baffle 1 is made of SiC combined with Si4N3 insulating composite material. The cross-sectional shape of the aluminum liquid channel hole 2 at the bottom of the insulating baffle 1 is square. The height of the square aluminum liquid channel hole 2 is 6cm. The width of the square aluminum liquid channel hole 2 is 25cm. The material of the bottom lining 11 is graphitized carbon block.

[0054] Within the anode carbon block area, the thickness of the aluminum liquid 6 is 20cm, the thickness of the electrolyte 7 is 30cm, and the thickness of the covering material 8 is 14cm. The number of anode carbon blocks 15 in each anode carbon block area is 14. The 14 anode carbon blocks 15 are evenly distributed in the horizontal direction, the distance between adjacent anode carbon blocks 15 is 17cm, and the distance between the bottom of the anode carbon block 15 and the bottom liner 11 is 24cm.

[0055] Within the cathode carbon block area, the thickness of the aluminum liquid 6 is 38cm, the thickness of the electrolyte 7 is 10cm, the thickness of the covering material 8 is 14cm, and the number of cathode carbon blocks 3 is also 14. The 14 cathode carbon blocks 3 are distributed at equal intervals in the horizontal direction, the distance between adjacent cathode carbon blocks 3 is 18cm, and the distance between the bottom of the cathode carbon block 3 and the bottom liner 11 is 8cm.

[0056] The anode carbon block 15 is made of traditional carbon material. The anode carbon block 15 is rectangular in shape and its dimensions are 170cm × 66cm × 55cm (length × width × height).

[0057] The cathode carbon block 3 is made of graphitized carbon block. The cathode carbon block 3 is rectangular in shape. The cathode carbon block 3 has the same dimensions as the anode carbon block 15, which is 170cm×66cm×55cm (length×width×height).

[0058] During the operation of the aluminum electrolytic cell, the current conduction path is as follows: anode carbon blocks 15 on both sides → electrolyte 7 in the anode carbon block area on both sides → molten aluminum 6 in the anode carbon block area on both sides → molten aluminum 6 in the cathode carbon block area → cathode carbon block 3. The main chemical reaction in the aluminum electrolytic cell is: Al2O3 + C = CO2 + Al. Specifically, the alumina in the electrolyte 7 and the anode carbon blocks 15 are consumed, and carbon dioxide is generated at the contact point between the anode carbon blocks 15 and the electrolyte 7. After the alumina in the electrolyte 7 loses oxygen, pure aluminum liquid is formed.

[0059] If the cathode carbon block 3 is damaged during the operation of the aluminum electrolysis cell, the damaged cathode carbon block 3 can be replaced directly, and the aluminum electrolysis cell production can continue during the replacement of the cathode carbon block 3.

[0060] Since one cathode carbon block 3 corresponds to two anode carbon blocks 15, and the two anode carbon blocks 15 are symmetrically distributed on both sides of one cathode carbon block 3, this layout can better realize the distribution of electric and magnetic fields, which is more conducive to the stable operation of the electrolytic cell and also has higher space utilization efficiency.

[0061] Example 3

[0062] like Figure 5 , 6 As shown, in this embodiment, there are two insulating baffles 1, one cathode carbon block area located between the two insulating baffles 1, and two anode carbon block areas symmetrically distributed on both sides of the cathode carbon block area.

[0063] The insulating baffle 1 has a height of 220cm. A thickened part is provided at the bottom of the insulating baffle 1, which extends to both sides with equal thickness and rounded corners. The aluminum liquid channel hole 2 is located at the bottom thickened part of the insulating baffle 1. The thickness of the non-thickened part of the insulating baffle 1 is 8cm. The height of the thickened part of the insulating baffle 1 is 11cm and the width of the thickened part of the insulating baffle 1 is 20cm. The insulating baffle 1 is made of SiC combined with Si4N3 insulating composite material. The cross-sectional shape of the aluminum liquid channel hole 2 at the bottom of the insulating baffle 1 is square. The height of the square aluminum liquid channel hole 2 is 7cm and the width of the square aluminum liquid channel hole 2 is 32cm. The material of the bottom lining 11 is graphitized carbon block.

[0064] Within the anode carbon block area, the thickness of the aluminum liquid 6 is 20cm, the thickness of the electrolyte 7 is 30cm, and the thickness of the covering material 8 is 14cm. The number of anode carbon blocks 15 in each anode carbon block area is 14. The 14 anode carbon blocks 15 are evenly distributed in the horizontal direction, the distance between adjacent anode carbon blocks 15 is 17cm, and the distance between the bottom of the anode carbon block 15 and the bottom liner 11 is 24cm.

[0065] Within the cathode carbon block area, the thickness of the aluminum liquid 6 is 38cm, the thickness of the electrolyte 7 is 10cm, the thickness of the covering material 8 is 14cm, and the number of cathode carbon blocks 3 is also 7. The 7 cathode carbon blocks 3 are distributed at equal intervals in the horizontal direction, the distance between adjacent cathode carbon blocks 3 is 18cm, and the distance between the bottom of the cathode carbon block and the bottom liner 11 is 8cm.

[0066] The anode carbon block 15 is made of traditional carbon material. The anode carbon block 15 is rectangular in shape and its dimensions are 170cm × 69cm × 53cm (length × width × height).

[0067] The cathode carbon block 3 is made of semi-graphitized carbon block. The cathode carbon block 3 is rectangular in shape. The cathode carbon block 3 and the anode carbon block 15 have the same size, which is 170cm×69cm×54cm (length×width×height). The cathode carbon block 3 and the anode carbon block 15 are distributed perpendicularly. One of the long and wide surfaces of the cathode carbon block 3 is directly opposite the wide and high surfaces of the two anode carbon blocks 15.

[0068] During the operation of the aluminum electrolytic cell, the current conduction path is as follows: anode carbon blocks 15 on both sides → electrolyte 7 in the anode carbon block area on both sides → molten aluminum 6 in the anode carbon block area on both sides → molten aluminum 6 in the cathode carbon block area → cathode carbon block 3. The main chemical reaction in the aluminum electrolytic cell is: Al2O3 + C = CO2 + Al. Specifically, the alumina in the electrolyte 7 and the anode carbon blocks 15 are consumed, and carbon dioxide is generated at the contact point between the anode carbon blocks 15 and the electrolyte 7. After the alumina in the electrolyte 7 loses oxygen, pure aluminum liquid is formed.

[0069] If the cathode carbon block 3 is damaged during the operation of the aluminum electrolysis cell, the damaged cathode carbon block 3 can be replaced directly, and the aluminum electrolysis cell production can continue during the replacement of the cathode carbon block 3.

[0070] Since one cathode carbon block 3 corresponds to four anode carbon blocks 15, and two anode carbon blocks 15 are distributed on each side of the cathode carbon block 3, this layout can better realize the distribution of electric and magnetic fields, which is more conducive to the stable operation of the electrolytic cell and also has higher space utilization efficiency.

[0071] The solutions described in the embodiments are not intended to limit the scope of patent protection of this invention. All equivalent implementations or modifications that do not depart from the scope of this invention are included in the patent scope of this case.

Claims

1. An aluminum electrolytic cell with a replaceable cathode, characterized in that: An insulating baffle is vertically fixed in the middle of the aluminum electrolysis cell. An aluminum liquid channel hole is opened at the bottom of the insulating baffle. The areas on both sides of the insulating baffle are the anode carbon block area and the cathode carbon block area, respectively, and the bottoms of the anode carbon block area and the cathode carbon block area are connected through the aluminum liquid channel hole. There can be one or more insulating baffles. When there is only one insulating baffle, there is also only one anode carbon block area and one cathode carbon block area, symmetrically distributed on both sides of the insulating baffle. When there are multiple insulating baffles, the anode carbon block area and the cathode carbon block area are arranged alternately. The cathode carbon block area is equipped with a suspended structure. The cathode carbon block is suspended above the bottom liner by cathode steel claws, which are connected to the cathode busbar, and the cathode carbon block is immersed in the aluminum liquid.

2. The aluminum electrolytic cell with replaceable cathode according to claim 1, characterized in that: The thickness of the molten aluminum in the cathode carbon block area is 5cm to 100cm, and the thickness of the electrolyte in the cathode carbon block area is 1cm to 30cm.

3. The aluminum electrolytic cell with replaceable cathode according to claim 1, characterized in that: The width of the aluminum liquid channel hole is 1cm to 80cm, and the aluminum liquid channel hole is 1cm to 10cm lower than the aluminum liquid level in the anode carbon block area.

Images