A regenerated carbon anode, its preparation method, and its application in electrolytic aluminum.

Abstract

This invention provides a recycled carbon anode, its preparation method, and its application in electrolytic aluminum, relating to the field of aluminum electrolysis technology. The recycled carbon anode has an oxygen-containing functional group on its surface carbon framework. X-ray photoelectron spectroscopy shows that the surface O / C atomic ratio of the recycled carbon anode is between 0.05 and 0.25, and the static wetting angle of the recycled carbon anode in molten cryolite electrolyte at 960°C is less than 60°. The preparation method includes: using molten carbonate electrolysis to deposit CO2 on the cathode to obtain carbon material, followed by separation to obtain electrolytic carbon material; mixing a binder and the electrolytic carbon material, and then sequentially molding and calcining to obtain the recycled carbon anode. The recycled carbon anode obtained by this invention has a lower anodic reaction overpotential and preferably enables the recycling of carbon elements in the aluminum electrolysis process, showing broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of aluminum electrolysis technology, and in particular to a regenerated carbon anode, its preparation method, and its application in aluminum electrolysis. Background Technology

[0002] In the traditional aluminum electrolysis industry, prebaked carbon anodes are the main consumable material. During production, the carbon anode reacts with oxygen ions in the molten electrolyte to generate CO2. Approximately 0.4-0.45 tons of carbon anode are consumed per ton of aluminum, resulting in the emission of about 1.5 tons of CO2. This not only consumes a large amount of high-quality petroleum coke and bitumen resources but also makes the aluminum electrolysis industry one of the sources of high carbon emissions.

[0003] Currently, commercial carbon anodes (prebaked anodes) are mainly made from petroleum coke aggregate and coal tar pitch binder through crushing, mixing, molding, and high-temperature calcination. Their performance is significantly affected by raw material quality, formulation, and process. During electrolysis, traditional anodes suffer from poor wettability (large contact angle with cryolite molten salt), high overpotential, susceptibility to anode effects, and uneven consumption rates. Furthermore, their production relies on carbon materials derived from fossil fuels, meaning the source remains solid carbon, making it difficult to achieve carbon reduction at its root.

[0004] To reduce carbon emissions, the industry has explored inert anode technology, but its long-term corrosion problem remains unresolved. Another technological approach is to capture, utilize, and store emitted CO2 (CCUS).

[0005] Therefore, developing a high-performance regenerated carbon anode that uses CO2 emitted from aluminum electrolysis as raw material and is manufactured in a "closed-loop" green electrochemical process is of great significance for promoting the circular economy and deep decarbonization of the aluminum industry. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a regenerated carbon anode, its preparation method, and its application in electrolytic aluminum. By depositing carbon materials through molten carbonate electrolysis, mixing them with a binder, and then molding and calcining, a regenerated carbon anode with oxygen-containing functional groups on its surface can be obtained. Furthermore, the CO2 feed gas of the molten carbonate electrolysis method originates from the CO2 generated by electrolytic aluminum, realizing the internal circulation of carbon elements and showing broad application prospects.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a recycled carbon anode for electrolytic aluminum, wherein the surface carbon framework of the recycled carbon anode has oxygen-containing functional groups. The surface O / C atomic ratio of the recycled carbon anode, as measured by X-ray photoelectron spectroscopy, is between 0.05 and 0.25, and the static wetting angle of the recycled carbon anode in molten cryolite electrolyte at 960°C is less than 60°.

[0009] The regenerated carbon anode for aluminum electrolysis provided by this invention has an O / C atomic ratio between 0.05 and 0.25 on its surface. The abundant oxygen-containing functional groups on the surface facilitate the smooth discharge of anode reaction gases, reducing anode polarization caused by bubble coverage, thereby lowering the anode overpotential during aluminum electrolysis. Furthermore, the oxygen-containing functional groups (especially C=O and C-OH, etc.) alter the electronic state density of the carbon surface, making the carbon-oxygen reaction (C + 2O₂) more efficient. 2- →CO2 + 4e - The activation energy of the alumina decreases, and the reaction kinetics in the electrolytic aluminum process accelerate.

[0010] Preferably, the oxygen-containing functional group includes a carbonyl group and / or a hydroxyl group.

[0011] Preferably, the static wetting angle of the regenerated carbon anode in molten cryolite electrolyte at 960°C is less than 40°.

[0012] Preferably, the molten cryolite electrolyte is a saturated Na3AlF6-Al2O3 electrolyte.

[0013] Preferably, the regenerated carbon anode has a porous structure, and the specific surface area of ​​the regenerated carbon anode is 200~400 m². 2 / g.

[0014] Preferably, the ash content in the regenerated carbon anode is ≤1 wt%. In this invention, ash refers to substances other than carbon.

[0015] Preferably, the anode potential of the regenerated carbon anode under aluminum electrolysis test conditions is 1.35~1.55V.

[0016] The aluminum electrolysis test conditions include using cryolite-alumina molten salt, a test temperature of 960℃, and a current density of 0.8 A / cm³. 2 .

[0017] Preferably, the bulk density of the regenerated carbon anode is 1.50~1.65 g / cm³. 3 .

[0018] Preferably, the resistivity of the regenerated carbon anode is less than 60 μΩ·m.

[0019] Preferably, the carbon source of the regenerated carbon anode includes CO2 generated from aluminum electrolysis.

[0020] In a second aspect, the present invention provides a method for preparing the recycled carbon anode for electrolytic aluminum as described in the first aspect, the method comprising:

[0021] A molten carbonate electrolysis method is used to deposit CO2 on the cathode to obtain carbon materials, which are then separated to obtain electrolytic carbon materials.

[0022] The binder and the electrolytic carbon material are mixed and then successively molded and calcined to obtain the regenerated carbon anode.

[0023] The method for preparing recycled carbon anodes for electrolytic aluminum provided by this invention uses molten carbonate electrolysis to obtain electrolytic carbon materials with oxygen-containing functional groups on the surface. This significantly improves the wettability of the material with highly corrosive cryolite melt, which is beneficial for the escape of anode bubbles, reduces anode overpotential, and decreases the frequency of anode effect occurrence, thereby improving current efficiency and reducing power consumption. Furthermore, after subsequent mixing with a binder, molding, and calcination, a high-performance recycled carbon anode can be obtained.

[0024] Preferably, the CO2 feed gas in the molten carbonate electrolysis method includes the anode gas generated from aluminum electrolysis.

[0025] Preferably, the anode gas generated from the electrolysis of aluminum is purified to obtain CO2 raw material gas.

[0026] Preferably, the molten carbonate electrolysis method includes: passing CO2 feed gas into a molten carbonate electrolyte, using an inert material as the anode and a porous metal material as the cathode, and performing electrolysis to reduce CO2 and deposit it as carbon material on the cathode.

[0027] Preferably, the porous metal material is an alloy of any one or at least a combination of nickel, copper, or iron.

[0028] Preferably, the porous metal material is a foam material and / or a porous sintered body.

[0029] Preferably, the molten carbonate electrolyte comprises a eutectic mixture formed from any one or at least two of Li2CO3, Na2CO3, or K2CO3.

[0030] Preferably, the molten carbonate electrolyte includes Li2CO3, Na2CO3, and K2CO3.

[0031] Preferably, the molar ratio of Li2CO3, Na2CO3 and K2CO3 in the molten carbonate electrolyte is (35~40):(30~40):(25~30).

[0032] Preferably, the electrolysis temperature is 450~750℃.

[0033] Preferably, the flow rate of CO2 feed gas during electrolysis is 150~250 mL / min.

[0034] Preferably, the voltage of the electrolysis is 1.0~3.5V.

[0035] Preferably, the cathode current density during electrolysis is 0.1~1.0 A / cm². 2 .

[0036] Preferably, the current efficiency of the carbon material obtained by electrolytic conversion is not less than 90%.

[0037] Preferably, the separation process includes: removing the cathode with deposited carbon material, separating and collecting the deposited carbon material, and then sequentially acid washing, water washing and drying the carbon material to obtain electrolytic carbon material.

[0038] Preferably, the particle size of the electrolytic carbon material is 40~280nm.

[0039] Preferably, the electrolytic carbon material comprises amorphous carbon and / or nanocrystalline graphite structures.

[0040] Preferably, the tap density of the electrolytic carbon material is 0.3~0.8 g / cm³. 3 .

[0041] Preferably, the specific surface area of ​​the electrolytic carbon material is greater than 300 m². 2 / g.

[0042] Preferably, before mixing the binder and the electrolytic carbon material, the preparation method further includes: crushing and sieving the electrolytic carbon material.

[0043] Preferably, the mass ratio of the binder to the electrolytic carbon material is (80~95):(5~20).

[0044] Preferably, the binder comprises any one or a combination of at least two of coal tar pitch, petroleum pitch, or resin.

[0045] Preferably, the mixing includes heated kneading.

[0046] Preferably, the temperature of the heating and kneading process is 150~200℃.

[0047] Preferably, the heating and kneading process yields a plastic paste.

[0048] Preferably, the molding process includes: placing the plastic paste obtained by heating and kneading into a mold and pressing it to obtain an anode green body.

[0049] Preferably, the pressure for the pressure molding is 5~200MPa.

[0050] Preferably, the roasting atmosphere includes a protective atmosphere.

[0051] Preferably, the protective atmosphere includes nitrogen and / or argon.

[0052] Preferably, the roasting includes heating to a first temperature at a first heating rate and then holding at that temperature for the first time.

[0053] Preferably, the first heating rate is 0.5~5℃ / min.

[0054] Preferably, the first temperature is 1000~1200℃.

[0055] Preferably, the first heat preservation time is 2 to 15 hours.

[0056] The present invention does not impose any special restrictions on the drying process described above. Any device and method known to those skilled in the art for drying can be used. Adjustments can also be made according to the actual process. For example, it can be air drying, vacuum drying, oven drying, or freeze drying, or a combination of different methods.

[0057] The present invention does not impose any special restrictions on the crushing process described above. Any crushing device and method known to those skilled in the art can be used, and adjustments can be made according to the actual process. For example, it can be grinding, extrusion crushing, splitting crushing or impact crushing, or a combination of different methods.

[0058] Thirdly, the present invention provides an application of a recycled carbon anode in electrolytic aluminum, wherein the recycled carbon anode is the recycled carbon anode for electrolytic aluminum described in the first aspect, and / or, the recycled carbon anode is a recycled carbon anode obtained by the preparation method of the recycled carbon anode for electrolytic aluminum described in the second aspect.

[0059] Preferably, the electrolytic aluminum is produced using the Hall-Eruth process.

[0060] Compared with the prior art, the present invention has at least the following beneficial effects:

[0061] (1) The method for preparing recycled carbon anodes for electrolytic aluminum provided by the present invention preferably turns CO2 generated by electrolytic aluminum into a valuable resource as CO2 raw material gas for producing recycled carbon anodes, thereby realizing a closed-loop cycle of carbon elements, fundamentally eliminating direct CO2 emissions caused by anode consumption, and giving electrolytic aluminum the possibility of "zero carbon anodes".

[0062] (2) In the preparation method of the recycled carbon anode for electrolytic aluminum provided by the present invention, the surface of the electrolytic carbon material is rich in oxygen-containing functional groups, which significantly improves its wettability with the highly corrosive cryolite melt, which is conducive to the escape of anode bubbles, can reduce anode overpotential, reduce the frequency of anode effect, thereby improving current efficiency and reducing power consumption.

[0063] (3) The recycled carbon anode for electrolytic aluminum provided by the present invention can meet or approach the standard of commercial prebaked anodes in terms of key indicators such as shape, specifications, conductivity and mechanical strength. It can be used directly in existing aluminum electrolytic cells without modifying the structure of the electrolytic cells, and the resistance to industrialization is small.

[0064] (4) The recycled carbon anode for electrolytic aluminum provided by the present invention reduces the dependence on traditional fossil-based carbon raw materials such as petroleum coke and asphalt, and enhances the resilience and sustainability of the aluminum industry supply chain; moreover, the parameters of the molten salt electrochemical process are easy to control precisely, and the composition and structure of the produced electrolytic carbon material are highly consistent, which is conducive to the final preparation of a recycled carbon anode with uniform and stable performance. Attached Figure Description

[0065] Figure 1 This is a schematic flowchart of a method for preparing a recycled carbon anode for electrolytic aluminum, provided in a specific embodiment of the present invention.

[0066] Figure 2 The image shows a scanning electron microscope (SEM) image of the electrolytic carbon material prepared in Example 1.

[0067] Figure 3 This is a size distribution diagram of the electrolytic carbon material prepared in Example 1. Detailed Implementation

[0068] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0069] It should be understood that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0070] Currently, commercial carbon anodes (prebaked anodes) are mainly made from petroleum coke aggregate and coal tar pitch binder through crushing, mixing, molding, and high-temperature calcination. Their performance is greatly affected by the quality of raw materials, formulation, and process. During electrolysis, traditional anodes suffer from problems such as poor wettability (large contact angle with cryolite molten salt), high overpotential, susceptibility to anode effects, and uneven consumption rate.

[0071] In response, this invention develops a high-performance regenerated carbon anode that uses CO2 emitted from aluminum electrolysis as raw material and is manufactured through a green electrochemical process in a "closed loop," which is of great significance for promoting the circular economy development and deep decarbonization of the aluminum industry.

[0072] Molten carbonate electrolysis can efficiently convert CO2 into solid carbon materials, but existing research has mainly focused on the preparation of functional materials such as carbon nanotubes and carbon fibers. There are no reports on the targeted design and development of these products into high-performance, industrially producible carbon anodes that can be directly used in aluminum electrolysis.

[0073] The following is a detailed description of the specific implementation method.

[0074] As a specific embodiment of the present invention, a recycled carbon anode for electrolytic aluminum is provided, wherein the surface carbon framework of the recycled carbon anode has oxygen-containing functional groups. The surface O / C atomic ratio of the recycled carbon anode, as measured by X-ray photoelectron spectroscopy, is between 0.05 and 0.25, and the static wetting angle of the recycled carbon anode in molten cryolite electrolyte at 960°C is less than 60°.

[0075] The regenerated carbon anode for aluminum electrolysis provided by this invention has an O / C atomic ratio between 0.05 and 0.25 on its surface. The abundant oxygen-containing functional groups on the surface facilitate the smooth discharge of anode reaction gases, reducing anode polarization caused by bubble coverage, thereby lowering the anode overpotential during aluminum electrolysis. Furthermore, the oxygen-containing functional groups (especially C=O and C-OH, etc.) alter the electronic state density of the carbon surface, making the carbon-oxygen reaction (C + 2O₂) more efficient. 2- →CO2 + 4e - The activation energy of the alumina decreases, and the reaction kinetics in the electrolytic aluminum process accelerate.

[0076] Specifically, the surface O / C atomic ratio of the regenerated carbon anode, as measured by X-ray photoelectron spectroscopy, can be, for example, 0.05, 0.08, 0.1, 0.12, 0.14, 0.17, 0.19, 0.21, 0.23, or 0.25, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0077] In some embodiments, the oxygen-containing functional group includes a carbonyl group and / or a hydroxyl group.

[0078] In some embodiments, the static wetting angle of the regenerated carbon anode in molten cryolite electrolyte at 960° is less than 60°, for example, it can be 10°, 16°, 22°, 27°, 33°, 38°, 44°, 49°, 55° or 59°, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably less than 40°.

[0079] In some embodiments, the molten cryolite electrolyte is a saturated Na3AlF6-Al2O3 electrolyte.

[0080] In some embodiments, the regenerated carbon anode has a porous structure, and the specific surface area of ​​the regenerated carbon anode is 200~400 m². 2 / g, for example, could be 200m 2 / g、223m 2 / g、245m 2 / g、267m 2 / g、289m 2 / g、312m 2 / g、334m 2 / g、356m 2 / g、378m 2 / g or 400m 2 / g, etc., but not limited to the listed values, other unlisted values ​​within this range also apply.

[0081] In some embodiments, the ash content in the regenerated carbon anode is ≤1 wt%, for example, it can be 0.01 wt%, 0.12 wt%, 0.23 wt%, 0.34 wt%, 0.45 wt%, 0.56 wt%, 0.67 wt%, 0.78 wt%, 0.89 wt%, or 1 wt%, but is not limited to the listed values; other unlisted values ​​within this range also apply. Ash in this invention refers to substances other than carbon.

[0082] In some embodiments, the anode potential of the regenerated carbon anode under aluminum electrolysis test conditions is 1.35~1.55V, for example, it can be 1.35V, 1.38V, 1.4V, 1.42V, 1.44V, 1.47V, 1.49V, 1.51V, 1.53V or 1.55V, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0083] The aluminum electrolysis test conditions include using cryolite-alumina molten salt, a test temperature of 960℃, and a current density of 0.8 A / cm³. 2 .

[0084] In some embodiments, the bulk density of the regenerated carbon anode is 1.50~1.65 g / cm³. 3 For example, it could be 1.50 g / cm³ 3 1.52g / cm 3 1.54g / cm 3 1.55g / cm 3 1.57g / cm 3 1.59g / cm 3 1.6g / cm 3 1.62g / cm 3 1.64 g / cm 3 Or 1.65g / cm 3 This includes, but is not limited to, the listed values; other unlisted values ​​within this range also apply.

[0085] In some embodiments, the resistivity of the regenerated carbon anode is less than 60 μΩ·m, for example, it can be 30 μΩ·m, 34 μΩ·m, 37 μΩ·m, 40 μΩ·m, 44 μΩ·m, 47 μΩ·m, 50 μΩ·m, 54 μΩ·m, 57 μΩ·m or 59 μΩ·m, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0086] In some embodiments, the carbon source of the regenerated carbon anode includes CO2 generated from aluminum electrolysis.

[0087] As another specific embodiment of the present invention, the present invention provides a method for preparing the recycled carbon anode for electrolytic aluminum as described in any of the above specific embodiments, the preparation method comprising:

[0088] A molten carbonate electrolysis method is used to deposit CO2 on the cathode to obtain carbon materials, which are then separated to obtain electrolytic carbon materials.

[0089] The binder and the electrolytic carbon material are mixed and then successively molded and calcined to obtain the regenerated carbon anode.

[0090] The method for preparing recycled carbon anodes for electrolytic aluminum provided by this invention uses molten carbonate electrolysis to obtain electrolytic carbon materials with oxygen-containing functional groups on the surface. This significantly improves the wettability of the material with highly corrosive cryolite melt, which is beneficial for the escape of anode bubbles, reduces anode overpotential, and decreases the frequency of anode effect occurrence, thereby improving current efficiency and reducing power consumption. Furthermore, after subsequent mixing with a binder, molding, and calcination, a high-performance recycled carbon anode can be obtained.

[0091] In some embodiments, the CO2 feed gas in the molten carbonate electrolysis method includes the anode gas generated from aluminum electrolysis.

[0092] In some embodiments, the anode gas generated from the electrolysis of aluminum is purified to obtain CO2 feed gas.

[0093] In some embodiments, the molten carbonate electrolysis method includes: passing CO2 feed gas into a molten carbonate electrolyte, using an inert material as the anode and a porous metal material as the cathode, and performing electrolysis to reduce CO2 and deposit it as carbon material on the cathode.

[0094] In some embodiments, the porous metal material is an alloy of any one or at least a combination of nickel, copper, or iron.

[0095] In some embodiments, the porous metal material is a foam material and / or a porous sintered body.

[0096] In some embodiments, the molten carbonate electrolyte comprises a eutectic mixture of any one or at least two of Li2CO3, Na2CO3, or K2CO3, wherein typical but non-limiting combinations are combinations of Li2CO3 and Na2CO3, combinations of K2CO3 and Na2CO3, combinations of Li2CO3 and K2CO3, and combinations of K2CO3, Li2CO3, and Na2CO3.

[0097] In some embodiments, the molar ratio of Li₂CO₃, Na₂CO₃, and K₂CO₃ in the molten carbonate electrolyte is (35~40):(30~40):(25~30). The molar percentages of Li₂CO₃ can be, for example, 35, 36, 37, 38, 39, or 40; the molar percentages of Na₂CO₃ can be, for example, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, or 40; and the molar percentages of K₂CO₃ can be, for example, 25, 26, 27, 28, 29, or 30.

[0098] In some embodiments, the electrolysis temperature is 450~750°C, for example, it can be 450°C, 484°C, 517°C, 550°C, 584°C, 617°C, 650°C, 684°C, 717°C or 750°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0099] In some embodiments, the flow rate of the CO2 feed gas during electrolysis is 150~250 mL / min, for example, it can be 150 mL / min, 162 mL / min, 173 mL / min, 184 mL / min, 195 mL / min, 206 mL / min, 217 mL / min, 228 mL / min, 239 mL / min or 250 mL / min, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0100] In some embodiments, the electrolysis voltage is 1.0 to 3.5V, for example, it can be 1.0V, 1.3V, 1.6V, 1.9V, 2.2V, 2.4V, 2.7V, 3V, 3.3V or 3.5V, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0101] In some embodiments, the cathode current density during electrolysis is 0.1~1.0 A / cm². 2 For example, it could be 0.1 A / cm 2 0.2A / cm 2 0.3A / cm 2 0.4A / cm 2 0.5A / cm 2 0.6A / cm 2 0.7A / cm 2 0.8A / cm 2 0.9A / cm 2 Or 1.0A / cm 2 This includes, but is not limited to, the listed values; other unlisted values ​​within this range also apply.

[0102] In some embodiments, the electrolysis time is 8 to 15 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours or 15 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0103] In some embodiments, the current efficiency of the carbon material obtained by electrolytic conversion is not less than 90%, for example, it can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97% or 98%, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0104] In some embodiments, the separation process includes: removing the cathode with deposited carbon material, separating and collecting the deposited carbon material, and then sequentially acid washing, water washing and drying the carbon material to obtain electrolytic carbon material.

[0105] The present invention does not have special requirements for the pickling, as long as it can remove the residual salt in the carbon material. For example, hydrochloric acid solution can be used for pickling, and the concentration of the hydrochloric acid solution is 0.01~2 mol / L, such as 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L or 2 mol / L, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0106] In some embodiments, the particle size of the electrolytic carbon material is 40~280nm, for example, it can be 40nm, 67nm, 94nm, 120nm, 147nm, 174nm, 200nm, 227nm, 254nm or 280nm, but is not limited to the listed values, and other unlisted values ​​in this range are also applicable.

[0107] In some embodiments, the electrolytic carbon material comprises amorphous carbon and / or nanocrystalline graphite structures.

[0108] In some embodiments, the tap density of the electrolytic carbon material is 0.3~0.8 g / cm³. 3 For example, it could be 0.3 g / cm³. 3 0.36g / cm 3 0.42g / cm 3 0.47g / cm 3 0.53g / cm 3 0.58g / cm 3 0.64 g / cm 3 0.69g / cm 3 0.75g / cm 3 or 0.8g / cm 3 This includes, but is not limited to, the listed values; other unlisted values ​​within this range also apply.

[0109] In some embodiments, the specific surface area of ​​the electrolytic carbon material is greater than 300 m². 2 / g, for example, could be 301m 2 / g、310m 2 / g、323m 2 / g、334m 2 / g、345m 2 / g、356m 2 / g、367m 2 / g、378m 2 / g、389m 2 / g or 400m 2 / g, etc., but not limited to the listed values, other unlisted values ​​within this range also apply.

[0110] In some embodiments, the preparation method further includes crushing and sieving the electrolytic carbon material before mixing the binder and the electrolytic carbon material.

[0111] In some embodiments, the mass ratio of the binder to the electrolytic carbon material is (80~95):(5~20). Specifically, the mass fraction of the binder in the sum of the binder and the electrolytic carbon material can be, for example, 5%, 7%, 9%, 10%, 12%, 14%, 15%, 17%, 19%, or 20%, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0112] In some embodiments, the binder comprises any one or a combination of at least two of coal tar pitch, petroleum pitch, or synthetic resin, wherein typical but non-limiting combinations are combinations of coal tar pitch and petroleum pitch, combinations of synthetic resin and petroleum pitch, and combinations of coal tar pitch and synthetic resin.

[0113] In some embodiments, the mixing includes heated kneading.

[0114] In some embodiments, the heating and kneading temperature is 150~200℃, for example, it can be 150℃, 156℃, 162℃, 167℃, 173℃, 178℃, 184℃, 189℃, 195℃ or 200℃, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0115] In some embodiments, the heating and kneading yields a plastic paste.

[0116] In some embodiments, the molding process includes: placing a heated and kneaded plastic paste into a mold and pressing it to obtain an anodized green body.

[0117] In some embodiments, the pressure for pressurization is 5 to 200 MPa, for example, it can be 5 MPa, 27 MPa, 49 MPa, 70 MPa, 92 MPa, 114 MPa, 135 MPa, 157 MPa, 179 MPa or 200 MPa, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0118] In some embodiments, the pressure molding time is 1 to 20 minutes, for example, it can be 1 minute, 4 minutes, 6 minutes, 8 minutes, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes or 20 minutes, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0119] In some embodiments, the roasting atmosphere includes a protective atmosphere.

[0120] In some embodiments, the protective atmosphere includes nitrogen and / or argon.

[0121] In some embodiments, the calcination includes heating to a first temperature at a first heating rate and then holding at that temperature for a first time.

[0122] In some embodiments, the first heating rate is 0.5~5℃ / min, for example, it can be 0.5℃ / min, 1℃ / min, 1.5℃ / min, 2℃ / min, 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min or 5℃ / min, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0123] In some embodiments, the first temperature is 1000~1200℃, for example, it can be 1000℃, 1020℃, 1045℃, 1060℃, 1080℃, 1110℃, 1130℃, 1150℃, 1170℃ or 1200℃, but is not limited to the listed values, and other unlisted values ​​in this range are also applicable.

[0124] In some embodiments, the first heat preservation time is 2 to 15 hours, for example, it can be 2 hours, 4 hours, 5 hours, 7 hours, 8 hours, 10 hours, 11 hours, 13 hours, 14 hours or 15 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0125] In some embodiments, the calcination includes heating to a first sub-temperature at a first sub-heating rate, then heating to a first temperature at a second sub-heating rate, and then holding at a first temperature.

[0126] In some embodiments, the first sub-heating rate is 2~5℃ / min, for example, it can be 2℃ / min, 2.4℃ / min, 2.7℃ / min, 3℃ / min, 3.4℃ / min, 3.7℃ / min, 4℃ / min, 4.4℃ / min, 4.7℃ / min or 5℃ / min, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0127] In some embodiments, the second heating rate is 1 to 2.5 °C / min, for example, it can be 1 °C / min, 1.2 °C / min, 1.4 °C / min, 1.5 °C / min, 1.7 °C / min, 1.9 °C / min, 2 °C / min, 2.2 °C / min, 2.4 °C / min or 2.5 °C / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0128] In some implementations, the first sub-temperature is 500~700°C, for example, it can be 500°C, 520°C, 545°C, 560°C, 580°C, 610°C, 630°C, 650°C, 670°C or 700°C, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0129] In some implementations, such as Figure 1 As shown, the preparation method includes the following steps:

[0130] S1. Collect the anode gas generated by aluminum electrolysis. After purification, the anode gas is used to obtain CO2 raw material gas.

[0131] S2. CO2 feed gas is passed into a molten carbonate electrolyte. Electrolysis is performed using an inert material as the anode and a porous metal material as the cathode. The electrolysis temperature is 450~750℃, the voltage is 1.0~3.5V, and the cathode current density is 0.1~1.0A / cm². 2 The process involves reducing CO2 and depositing it as carbon material on the cathode; the current efficiency of the carbon material obtained by the electrolytic conversion is not less than 90%.

[0132] The porous metal material is an alloy of any one or at least a combination of nickel, copper, or iron, and the molten carbonate electrolyte is a eutectic mixture formed of any one or at least two of Li2CO3, Na2CO3, or K2CO3.

[0133] S3. Remove the cathode with deposited carbon material, separate and collect the deposited carbon material, and then sequentially perform acid washing, water washing and drying to obtain electrolytic carbon material; the particle size of the electrolytic carbon material is 40~280nm, the electrolytic carbon material includes amorphous carbon and / or nanocrystalline graphite structure, and the tap density of the electrolytic carbon material is 0.3~0.8g / cm³. 3 Specific surface area greater than 300m² 2 / g.

[0134] S4. The electrolytic carbon material described in step S3 is crushed and sieved to obtain the sieved electrolytic carbon material.

[0135] The electrolytic carbon material and binder are heated and kneaded at 150~200℃ to obtain a plastic paste; the heated and kneaded plastic paste is placed in a mold and pressed at 5~200MPa to obtain an anode green body;

[0136] S5. The anode green blank described in step S4 is placed in a calcining furnace and calcined in a nitrogen and / or argon atmosphere at a rate of 0.5~5℃ / min to 1000~1200℃ and held for 2~15h. Then it is cooled to obtain the regenerated carbon anode.

[0137] The method of this invention has a short process path and can efficiently and directionally convert CO2 into carbon materials with excellent aluminum electrolysis performance.

[0138] In some implementations, the CO2 feed gas contains CO and / or N2.

[0139] As another specific embodiment of the present invention, the present invention provides an application of a recycled carbon anode in electrolytic aluminum, wherein the recycled carbon anode is the recycled carbon anode for electrolytic aluminum described in any of the above specific embodiments, and / or, the recycled carbon anode is a recycled carbon anode obtained by the preparation method of the recycled carbon anode for electrolytic aluminum described in any of the above specific embodiments.

[0140] In some embodiments, the electrolytic aluminum is produced using the Hall-Erud process to produce metallic aluminum.

[0141] Example 1

[0142] This embodiment provides a recycled carbon anode for electrolytic aluminum, and the preparation method of the recycled carbon anode for electrolytic aluminum includes the following steps:

[0143] S1. Collect the anode gas generated by aluminum electrolysis. After purification, the anode gas is used to obtain CO2 raw material gas (90% CO2 and 10% N2 by volume).

[0144] S2. The CO2 feed gas is introduced at a rate of 150 mL / min into a molten carbonate electrolyte (specifically, a mixture of Li2CO3, Na2CO3, and K2CO3 in a eutectic molar ratio of 43.5:31.5:25). An inert material (specifically, a nickel rod) is used as the anode, and a porous metal material (copper foam with a porosity of 95%, dimensions of 20 mm × 20 mm × 5 mm) is used as the cathode. Electrolysis is performed under a constant DC voltage at a temperature of 650℃, a voltage of 2.6 V, and a cathode current density of 0.6 A / cm². 2 The process involves reducing CO2 and depositing it as carbon material on the cathode, with electrolysis continuing for 10 hours before stopping; the current efficiency of the carbon material obtained by the electrolytic conversion is not less than 90%.

[0145] S3. Take out the cathode (copper foam, with black fluffy solid deposited in its pores) with deposited carbon material, separate and collect the deposited carbon material, then place the carbon material in 0.1 mol / L dilute hydrochloric acid and sonicate it at 1000W for 30 min to dissolve the residual salt, then wash it with water until neutral, and finally dry it in a vacuum oven at 80℃ for 12 h to obtain electrolytic carbon material.

[0146] like Figures 2-3 As shown, the particle size range of the electrolytic carbon material is 40~280nm, and the electrolytic carbon material includes interwoven amorphous carbon aggregates and nanocrystalline graphite sheet structures.

[0147] The tap density of the electrolytic carbon material is 0.5 g / cm³. 3 Specific surface area is 320m² 2 / g.

[0148] S4. Mechanically crush and screen the electrolytic carbon material described in step S3 to obtain electrolytic carbon material with a sieve size of 75~150 μm.

[0149] The electrolytic carbon material and the binder (specifically coal tar pitch, softening point 90℃) are heated and kneaded at 170℃ for 40 minutes to obtain a plastic paste; the heated and kneaded plastic paste is placed in a mold and pressed at 150MPa for 3 minutes to obtain an anode green blank with dimensions of 100mm×50mm×30mm.

[0150] S5. The anode green blank described in step S4 is placed in a calcining furnace and heated to 500°C at 2°C / min in a nitrogen atmosphere, then heated to 1150°C at 1°C / min and held for 8 hours for calcination. After cooling, the regenerated carbon anode is obtained.

[0151] Example 2

[0152] This embodiment provides a recycled carbon anode for electrolytic aluminum, and the preparation method of the recycled carbon anode for electrolytic aluminum includes the following steps:

[0153] S1. Collect the anode gas generated by aluminum electrolysis. After purification, the anode gas is used to obtain CO2 raw material gas (85% CO2 and 15% N2 by volume).

[0154] S2. The CO2 feed gas is introduced at a rate of 200 mL / min into a molten carbonate electrolyte (specifically, a mixture of Li2CO3, Na2CO3, and K2CO3 in a eutectic molar ratio of 40:30:30). An inert material (specifically, a nickel rod) is used as the anode, and a porous metal material (copper foam with a porosity of 95%, dimensions of 20 mm × 20 mm × 5 mm) is used as the cathode. Electrolysis is performed under a constant DC voltage at a temperature of 750℃, a voltage of 3.2 V, and a cathode current density of 1.0 A / cm². 2 The process involves reducing CO2 and depositing it as carbon material on the cathode, with electrolysis continuing for 8 hours before stopping; the current efficiency of the carbon material obtained by the electrolytic conversion is not less than 90%.

[0155] S3. Remove the cathode (copper foam, with black fluffy solid deposited in its pores) from which carbon material has been deposited, and separate and collect the deposited carbon material. Then, place the carbon material in 0.15 mol / L dilute hydrochloric acid and sonicate it at 1000W for 20 minutes to dissolve the residual salt. Then, wash it with water until it is neutral, and finally dry it in a vacuum oven at 70℃ for 15 hours to obtain electrolytic carbon material.

[0156] The electrolytic carbon material has a particle size range of 100~250 nm, and comprises amorphous carbon and nanocrystalline graphite structures. The tap density of the electrolytic carbon material is 0.35 g / cm³. 3 Specific surface area is 360m² 2 / g.

[0157] S4. The electrolytic carbon material described in step S3 is mechanically crushed and sieved to obtain electrolytic carbon material with a sieve size of 75~120μm.

[0158] The electrolytic carbon material and the binder (specifically petroleum asphalt with a softening point of 80°C) are heated and kneaded at 180°C for 30 minutes to obtain a plastic paste; the plastic paste obtained by heating and kneading is placed in a mold and pressed at 200MPa for 1 minute to obtain an anode green blank with a size of 100mm×50mm×30mm.

[0159] S5. The anode green blank described in step S4 is placed in a calcining furnace and heated to 600°C at 5°C / min in a nitrogen atmosphere, then heated to 1200°C at 1.5°C / min and held for 2 hours for calcination. After cooling, the regenerated carbon anode is obtained.

[0160] Example 3

[0161] This embodiment provides a recycled carbon anode for electrolytic aluminum, and the preparation method of the recycled carbon anode for electrolytic aluminum includes the following steps:

[0162] S1. Collect the anode gas generated by aluminum electrolysis. After purification, the anode gas is used to obtain CO2 raw material gas (88% CO2 and 12% N2 by volume).

[0163] S2. The CO2 feed gas is introduced at a rate of 250 mL / min into a molten carbonate electrolyte (specifically, a mixture of Li2CO3, Na2CO3, and K2CO3 in a eutectic molar ratio of 35:40:25). An inert material (specifically, a nickel rod) is used as the anode, and a porous metal material (copper foam with a porosity of 90%, dimensions of 20 mm × 20 mm × 5 mm) is used as the cathode. Electrolysis is performed under a constant DC voltage at a temperature of 500℃, a voltage of 1.0 V, and a cathode current density of 0.1 A / cm². 2 The process involves reducing CO2 and depositing it as carbon material on the cathode, with electrolysis continuing for 15 hours before stopping; the current efficiency of the carbon material obtained by the electrolytic conversion is not less than 90%.

[0164] S3. Take out the cathode (copper foam, with black fluffy solid deposited in its pores) with deposited carbon material, separate and collect the deposited carbon material, then place the carbon material in 0.08 mol / L dilute hydrochloric acid and sonicate it at 1000W for 40 min to dissolve the residual salt, then wash it with water until neutral, and finally dry it in a vacuum oven at 100℃ for 5 h to obtain electrolytic carbon material.

[0165] The electrolytic carbon material has a particle size range of 100~260 nm, and comprises amorphous carbon and nanocrystalline graphite structures. The tap density of the electrolytic carbon material is 0.7 g / cm³. 3 Specific surface area is 310 m² 2 / g.

[0166] S4. The electrolytic carbon material described in step S3 is mechanically crushed and sieved to obtain electrolytic carbon material with a sieve size of 85~150μm.

[0167] The electrolytic carbon material is then heated and kneaded with a binder (specifically coal tar pitch, softening point 90℃) at 200℃ for 15 minutes to obtain a plastic paste; the heated and kneaded plastic paste is placed in a mold and pressed at 5MPa for 20 minutes to obtain an anode green blank with dimensions of 100mm×50mm×30mm.

[0168] S5. The anode green blank described in step S4 is placed in a calcining furnace and heated to 700°C at 4.5°C / min in an argon atmosphere, then heated to 1000°C at 2.5°C / min and held at that temperature for 15 hours for calcination. After cooling, the regenerated carbon anode is obtained.

[0169] Example 4

[0170] This embodiment provides a recycled carbon anode for electrolytic aluminum, wherein the preparation method of the recycled carbon anode for electrolytic aluminum has a cathode current density of 1.2 A / cm². 2 Except for the above, everything else is the same as in Example 1, and will not be repeated here.

[0171] Example 5

[0172] This embodiment provides a recycled carbon anode for electrolytic aluminum, wherein the preparation method of the recycled carbon anode for electrolytic aluminum is except that the cathode current density is 0.05 A / cm. 2 Except for the above, everything else is the same as in Example 1, and will not be repeated here.

[0173] Example 6

[0174] This embodiment provides a carbon anode for electrolytic aluminum. The preparation method of the carbon anode for electrolytic aluminum is the same as that in Example 1, except that the electrolysis temperature is 450°C, and will not be repeated here.

[0175] Example 7

[0176] This embodiment provides a carbon anode for electrolytic aluminum. The preparation method of the carbon anode for electrolytic aluminum is the same as that in Example 1, except that the electrolysis temperature is 550°C, and will not be repeated here.

[0177] Comparative Example 1

[0178] This comparative example provides a carbon anode for electrolytic aluminum. The preparation method of the carbon anode for electrolytic aluminum is the same as that in Example 1, except that steps S1 to S4 are omitted and the electrolytic carbon material is directly replaced with biomass carbon material. Therefore, it will not be described again here.

[0179] Comparative Example 2

[0180] This comparative example provides a carbon anode for electrolytic aluminum, wherein the recycled carbon anode for electrolytic aluminum is a commercially available prebaked anode.

[0181] Test methods: The O / C atomic ratio of the carbon anode surface was determined by X-ray photoelectron spectroscopy; the static wetting angle of the carbon anode in molten cryolite (Na3AlF6-Al2O3 saturated) electrolyte at 960℃ was measured by a contact angle meter; the resistivity of the material was determined by YS / T 63.6 "Method for Determination of Resistivity of Carbon Materials"; the specific surface area of ​​the material was determined by GB / T 19587 "Determination of Specific Surface Area of ​​Solid Substances by Gas Adsorption BET Method"; and the bulk density of the material was determined by ISO 12985-2:2018 "Determination of Apparent Density and Open Porosity by Static Method".

[0182] Aluminum electrolysis test: using cryolite-alumina molten salt, 960℃, current density 0.8 A / cm³.2 Using the carbon anode from the examples and comparative examples as the anode and the molten aluminum as the cathode, the anode working potential under aluminum electrolysis test conditions was tested.

[0183] The test results of the above embodiments and comparative examples are shown in Table 1.

[0184] Table 1

[0185]

[0186] The following points can be observed from Table 1:

[0187] (1) As can be seen from Examples 1-3 and Examples 6-7, the regenerated carbon anode for electrolytic aluminum provided by the present invention can not only make full use of the CO2 generated by electrolytic aluminum, but also has an O / C atomic ratio between 0.05 and 0.25, a static wetting angle of less than 60°, and a resistivity of only less than 55 μΩ·m, and a bulk density of 1.50~1.65 g / cm³. 3 Between these values, the anode working potential is below 1.55V, indicating broad application prospects.

[0188] (2) As can be seen from the combined examples 1 and 4-5, the present invention preferably controls the cathode current density within a reasonable range, which can obtain a regenerated carbon anode with a lower anode working potential.

[0189] (3) In Comparative Example 1, steps S1 to S4 are not performed, and the electrolytic carbon material is directly replaced with biomass carbon material. In Comparative Example 2, a commercial prebaked anode is used. Comparative Examples 1 and 2 not only fail to achieve the recycling of CO2 generated by electrolytic aluminum, but also the static wetting angle of the carbon anode is not within the range of this application, resulting in a higher anode potential.

[0190] Taking Examples 1 and 6-7 as examples, the specific C and O atom ratio data obtained from XPS testing are shown in Table 2.

[0191] Table 2

[0192]

[0193] As can be seen from Table 2, the surface O / C ratio of the regenerated carbon anode obtained by the present invention is between 0.05 and 0.25.

[0194] The present invention has been illustrated with the above embodiments to illustrate its detailed features, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the selected technical features, additions of auxiliary technical features, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A recycled carbon anode for electrolytic aluminum, characterized in that, The surface carbon framework of the regenerated carbon anode has oxygen-containing functional groups; The regenerated carbon anode has an O / C atomic ratio between 0.05 and 0.25 as measured by X-ray photoelectron spectroscopy, and the static wetting angle of the regenerated carbon anode in molten cryolite electrolyte at 960° is less than 60°.

2. The regenerated carbon anode according to claim 1, characterized in that, The regenerated carbon anode satisfies at least one of the following conditions: Preferably, the oxygen-containing functional group includes a carbonyl group and / or a hydroxyl group; Preferably, the static wetting angle of the regenerated carbon anode in a molten cryolite electrolyte at 960°C is less than 40°; wherein the molten cryolite electrolyte is a saturated Na3AlF6-Al2O3 electrolyte; Preferably, the regenerated carbon anode has a porous structure, the specific surface area of the regenerated carbon anode being 200 to 400 m 2 / g; Preferably, the ash content in the recycled carbon anode is ≤1 wt%; Preferably, the regenerated carbon anode has an anode potential of 1.35-1.55 V under aluminum electrolysis test conditions; the aluminum electrolysis test conditions include using cryolite-alumina molten salt, a test temperature of 960 ℃, and a current density of 0.8 A / cm 2 ; Preferably, the bulk density of the regenerated carbon anode is 1.50~1.65 g / cm³. 3 ; Preferably, the resistivity of the regenerated carbon anode is less than 60 μΩ·m; Preferably, the carbon source of the regenerated carbon anode includes CO2 generated from aluminum electrolysis.

3. A method for preparing a recycled carbon anode for electrolytic aluminum as described in claim 1 or 2, characterized in that, The preparation method includes: A molten carbonate electrolysis method is used to deposit CO2 on the cathode to obtain carbon materials, which are then separated to obtain electrolytic carbon materials. The binder and the electrolytic carbon material are mixed and then successively molded and calcined to obtain the regenerated carbon anode.

4. The preparation method according to claim 3, characterized in that, The CO2 feed gas in the molten carbonate electrolysis method includes the anode gas generated from aluminum electrolysis; Preferably, the anode gas generated from the electrolysis of aluminum is purified to obtain CO2 feed gas; Preferably, the molten carbonate electrolysis method includes: passing CO2 feed gas into a molten carbonate electrolyte, using an inert material as the anode and a porous metal material as the cathode, and performing electrolysis to reduce CO2 and deposit it as carbon material on the cathode; Preferably, the porous metal material is an alloy of any one or at least a combination of nickel, copper, or iron. Preferably, the porous metal material is a foam material and / or a porous sintered body; Preferably, the molten carbonate electrolyte comprises any one or at least two of Li2CO3, Na2CO3, or K2CO3 forming a eutectic mixture; Preferably, the molten carbonate electrolyte comprises Li2CO3, Na2CO3, and K2CO3; Preferably, the molar ratio of Li2CO3, Na2CO3 and K2CO3 in the molten carbonate electrolyte is (35~40):(30~40):(25~30).

5. The preparation method according to claim 3 or 4, characterized in that, The electrolysis temperature is 450~750℃; Preferably, the flow rate of the CO2 feed gas during electrolysis is 150~250 mL / min; Preferably, the voltage of the electrolysis is 1.0~3.5V; Preferably, the cathode current density during electrolysis is 0.1~1.0 A / cm². 2 ; Preferably, the current efficiency of the carbon material obtained by electrolytic conversion is not less than 90%.

6. The preparation method according to any one of claims 3 to 5, characterized in that, The separation process includes: removing the cathode with deposited carbon material, separating and collecting the deposited carbon material, and then sequentially acid washing, water washing and drying the carbon material to obtain electrolytic carbon material; Preferably, the particle size of the electrolytic carbon material is 40~280 nm; Preferably, the electrolytic carbon material comprises amorphous carbon and / or nanocrystalline graphite structures; Preferably, the tap density of the electrolytic carbon material is 0.3~0.8 g / cm³. 3 ; Preferably, the specific surface area of ​​the electrolytic carbon material is greater than 300 m². 2 / g; Preferably, before mixing the binder and the electrolytic carbon material, the preparation method further includes: crushing and sieving the electrolytic carbon material.

7. The preparation method according to any one of claims 3 to 6, characterized in that, The mass ratio of the binder to the electrolytic carbon material is (80~95):(5~20); Preferably, the binder comprises any one or a combination of at least two of coal tar pitch, petroleum pitch, or resin.

8. The preparation method according to any one of claims 3 to 7, characterized in that, The mixing includes heated kneading; Preferably, the temperature for heating and kneading is 150~200℃; Preferably, the heating and kneading process yields a plastic paste.

9. The preparation method according to any one of claims 3 to 8, characterized in that, The molding process includes: placing a plastic paste obtained by heating and kneading into a mold and pressing it to obtain an anodized green body; Preferably, the pressure applied during the pressure molding process is 5~200MPa; Preferably, the roasting atmosphere includes a protective atmosphere; Preferably, the protective atmosphere includes nitrogen and / or argon; Preferably, the calcination includes heating to a first temperature at a first heating rate and then holding at that temperature for the first time. Preferably, the first heating rate is 0.5~5℃ / min; Preferably, the first temperature is 1000~1200℃; Preferably, the first heat preservation time is 2 to 15 hours.

10. The application of a recycled carbon anode in electrolytic aluminum, characterized in that, The regenerated carbon anode is the regenerated carbon anode for electrolytic aluminum as described in claim 1 or 2, and / or the regenerated carbon anode is the regenerated carbon anode prepared by the method for preparing the regenerated carbon anode for electrolytic aluminum as described in any one of claims 3 to 9. Preferably, the electrolytic aluminum is produced using the Hall-Eruth process.

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