Preparation method of prebaked anode carbon block

Abstract

The invention provides a preparation method of a prebaked anode carbon block, which comprises the following steps of: screening petroleum coke according to the degree of dryness and wetness, drying a wet material, mixing with a dry material to obtain a petroleum coke dry material, calcining to obtain calcined coke, crushing, performing vibratory screening, mixing a powder coke material, a medium-sized particle material and a coarse particle material to obtain a mixed particle material, adding boric acid, performing dry mixing, and drying to obtain the prebaked anode carbon block. A dry mixed material is obtained; melting asphalt, performing wet mixing on the molten asphalt and the dry mixture to obtain a paste material, performing vibration molding and water bath cooling to obtain an anode green body, and roasting the anode green body to obtain the prebaked anode carbon block. The additive boric acid is selected, so that the oxidation resistance of the prebaked anode carbon block is improved, the CO2 reaction performance and other invalid carbon consumption are reduced, various physical properties of the carbon block are effectively improved, and the requirement of an aluminum electrolysis cell for a high-performance anode material is met under the condition of low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of anode materials, and particularly relates to a method for preparing a prebaked anode carbon block. Background Art

[0002] Prebaked anode carbon blocks are a key component of aluminum electrolysis cells, directly participating in the electrolysis reaction. With the national push for energy conservation and emission reduction and industry development, performance requirements for these blocks are steadily increasing, particularly in terms of reducing ineffective carbon consumption and lowering production costs. However, traditional additive-based technologies, while not only potentially releasing harmful gases during high-temperature calcination, pose a significant environmental management challenge due to waste disposal, but also face significant economic pressures from high costs, hindering industrialization. With the aluminum electrolysis industry's growing demand for high efficiency and low costs, reducing production costs has become a pressing challenge. Therefore, how to reduce costs while minimizing negative environmental impacts is another key issue that must be addressed in the industry. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and provide a method for preparing prebaked anode carbon blocks. This method, by selecting the additive boric acid, improves the anti-oxidation performance of the prebaked anode carbon blocks and reduces ineffective carbon consumption such as CO2 reaction performance, while effectively improving the various physical properties of the carbon blocks. This can not only effectively enhance the conductivity, compressive strength and corrosion resistance of the anode carbon blocks, but also reduce production costs, thus meeting the demand for high-performance anode materials in aluminum electrolysis cells. At the same time, environmental protection measures in the new process have also been optimized, which helps to reduce the negative impact on the environment during the production process, and provides an economical, environmentally friendly and efficient anode carbon block preparation solution for the aluminum electrolysis industry.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing a prebaked anode carbon block, the method comprising: S1. Screening petroleum coke according to the degree of dryness and wetness to obtain wet material and dry material, drying the wet material and then mixing it with the dry material to obtain petroleum coke dry material; Since petroleum coke is an important raw material for anode carbon blocks, it will absorb moisture during transportation and storage. Excessive moisture will affect the structure of the coke, making it difficult to volatilize during the calcination process, affecting the density and mechanical strength of the carbon blocks, resulting in a decrease in their overall performance. Screening the wet material can prevent the adverse effects of moisture on subsequent calcination. S2, calcining and cooling the petroleum coke dry material obtained in S1 to obtain calcined coke; S3, crushing the calcined coke obtained in S2 to obtain crushed calcined coke; S4, the crushed calcined coke obtained in S3 is vibrated and sieved according to particle size range to obtain fine coke, medium particles, and coarse particles; The particle size of the coke powder is d1≤0.15mm, the particle size of the medium granular material is 0.15mm<d2≤3mm, and the particle size of the coarse granular material is 3mm<d3≤5mm; The coke powder, medium granular material and coarse granular material are mixed to obtain mixed granular material; S5. Add boric acid to the mixed pellets obtained in S4 to obtain a mixture of the mixed pellets and boric acid, and dry-mix the mixture at a temperature of 95° C. to 110° C. for 60 minutes to obtain a dry blend; Particle size significantly influences the density, strength, and conductivity of carbon blocks. Finer coke particles can fill the gaps between larger coke particles, thereby improving the density and strength of the carbon blocks. Furthermore, a suitable ratio of medium to coarse coke particles ensures the stability and longevity of the carbon blocks in the electrolytic cell, maintaining the performance of the anode blocks while preventing large-scale carbon block shedding due to reactions during service. Prolonging the mixing time (dry mixing for 60 minutes) and maintaining an appropriate mixing temperature (95°C to 110°C) ensures uniform distribution of the boric acid additive and calcined coke, enhancing the performance of the anode blocks.

[0005] S6. Heating the asphalt at a temperature of 180° C. to 192° C. until it is melted, and then wet-mixing the asphalt with the dry mix obtained in S5 at a temperature of 162° C. to 168° C. to obtain a paste; S7. Pour the paste obtained in S6 into a mold at a temperature of 145° C. to 160° C., vibrate the mold for 100 seconds, and then cool it in a water bath. After drying the surface moisture, a green anode is obtained. The present invention ensures that the anode carbon block has uniformity, density and high strength during the molding process by precisely controlling the heating, wet mixing, mold insertion, molding and cooling processes of the asphalt; appropriate wet mixing temperature, mold insertion temperature, vibration molding time and cooling control enable the carbon block to be fully bonded and formed during molding, and effectively release stress during the cooling process to avoid cracks or deformation, thereby improving the quality of the final anode carbon block; increasing the wet mixing temperature allows the additive boric acid to decompose and produce boron oxide, while making its distribution more uniform in the carbon block; preventing the moisture generated by the decomposition of boric acid in the subsequent roasting process from negatively affecting the density of the carbon block, thereby affecting the performance of the carbon block, while also making the distribution of the product boron oxide more uniform; S8, baking the anode green body obtained in S7 in a natural gas baking furnace, and naturally cooling it to room temperature to obtain a prebaked anode carbon block; Roasting is divided into four stages, and the roasting method is: Low temperature stage: heat up to 320℃ at a rate of 2℃ / min to 3℃ / min and keep warm for 1 hour. Heat up slowly in this stage to avoid rapid decomposition of residual boric acid, which may lead to excessive release of volatile gas and cause defects such as cracks and holes on the surface of the anode carbon block. This ensures the quality of the carbon block. After heating to 320℃, keep warm for 1 hour to ensure that the boric acid is completely dehydrated and begins to interact with the carbon block matrix. Medium temperature stage: heating to 650℃ at a heating rate of 4℃ / min-5℃ / min. The heating rate is appropriately increased in this stage to accelerate the interaction between the generated product boron oxide and the carbon material. However, it is still necessary to avoid heating too quickly in this stage to prevent excessive pores from being generated inside the carbon block due to gas volatilization. High temperature stage: the temperature is raised to 1050℃ at a heating rate of 6℃ / min to 8℃ / min. At this stage, the carbonization process begins, and the boric acid is completely converted into boron oxide and embedded in the carbon block structure; Final stage: heating to 1250°C at a heating rate of 3°C / min to 4°C / min, and keeping the temperature constant for 22 hours to ensure that the structure of the carbon block is fully stabilized and the additives are well combined in the carbon block, so that the boride can be stably embedded in the carbon block and can fully play its role, thereby improving the comprehensive performance of the prebaked anode carbon block. After naturally cooling to room temperature, the prebaked anode carbon block is obtained; When designing a heating and roasting curve for a carbon block containing boric acid additives, the present invention requires precise control of the heating rate based on the decomposition characteristics of boric acid, the reaction process with the carbon-based material, and the carbonization requirements. In particular, excessive heating should be avoided in the early stages to prevent damage to the carbon block structure caused by excessive gas volatilization. Reasonable heating and insulation designs ensure that the additives in the carbon block are well combined, fully utilizing the additives and improving the overall performance of the carbon block, especially its high-temperature oxidation resistance. Preferably, the water content of the petroleum coke dry material in S1 is ≤8.75%.

[0006] Preferably, the calcination method in S2 is: using pot calcination, the temperature of the heat transfer oil during the calcination process is 205°C±4°C, the temperature of the calcination circulating water is controlled at no more than 60°C, and the calcination temperature is 1290°C to 1390°C.

[0007] Preferably, the mixed granular material in S4 is composed of the following raw materials in mass fractions: 30% of fine coke material, 55% of medium granular material, and the remainder of coarse granular material.

[0008] Preferably, the mass fraction of boric acid in the mixture of the mixed pellets and boric acid in S5 is 0.05% to 0.15%.

[0009] The mass fraction of boric acid in the mixture of mixed pellets and boric acid is 0.05% to 0.15%, which ensures that the ash content is within a controllable range while ensuring that the carbon-carbon interface bonding matrix in the original anode carbon block is not destroyed due to the presence of too much additive, thereby causing a negative impact on certain physical properties of the anode carbon block, and that the improvement effect is not obvious due to too low an addition content.

[0010] Preferably, the mass fraction of the dry mix in the paste in S6 is 84%.

[0011] Preferably, the water bath cooling in S7 is performed at a temperature of 30° C. to 40° C. for a time of 1 to 2 hours.

[0012] Compared with the prior art, the present invention has the following advantages: 1. The present invention adopts boric acid as an additive. By improving the pre-calcination process and optimizing the calcination process, while ensuring the various physical properties of the anode carbon block, it greatly enhances the antioxidant performance of the anode carbon block, effectively reduces the CO2 reaction performance, and significantly improves the comprehensive performance of the anode carbon block.

[0013] 2. The method of the present invention can significantly improve the oxidation resistance of anode carbon blocks, inhibit oxidation of the carbon anode, and slow the reactivity of the anode with CO2 and air, thereby extending the service life of the anode. By adding a specific proportion of boric acid as an additive, and simultaneously controlling the pre-baking process of the anode carbon blocks after addition, and optimizing the baking process, the resistivity of the carbon blocks is reduced, their high-temperature oxidation resistance is enhanced, and their mechanical strength is improved. This comprehensively improves the performance of pre-baked anode carbon blocks and reduces the ineffective carbon consumption of pre-baked anode carbon blocks during service, thus having significant economic benefits and industrial application prospects.

[0014] 3. The boride additive of the present invention can be fully combined with the carbon block and evenly distributed in the carbon block matrix. The boride distributed in the carbon block matrix will play an improvement role throughout the service life of the carbon block. Due to the thermal stability of the boride, it will not have a negative impact on the carbon block during the high-temperature reaction process and generate harmful substances. Under high-temperature conditions, liquid boron oxide adheres to the surface of the carbon block, preventing oxygen / CO2 from corroding the surface of the carbon block. Its covering, inhibiting and isolating effect significantly improves the antioxidant capacity of the prebaked anode carbon block and reduces ineffective carbon consumption such as CO2 reaction. At the same time, the boride network structure distributed inside the carbon block also reduces the slagging rate of the anode carbon block. The low addition content reduces costs while ensuring that the ash content is within a controllable range, promotes a denser structure of the carbon block, improves the various physical properties of the prebaked anode carbon block, and improves the service life and electrolysis efficiency of the anode carbon block.

[0015] 4. The present invention uses boric acid as a low-cost additive, controls the additive within a suitable range, and forms a process that matches the additive through process optimization, thereby reducing the production cost of anode carbon blocks and reducing dependence on high-cost raw materials, thus having a strong economic advantage. At the same time, the environmental protection measures in the new process have been effectively optimized, reducing harmful gas emissions and waste disposal problems, and meeting modern industrial environmental protection requirements. In addition, the process of the present invention has strong controllability, and can adjust performance according to demand to ensure product stability and consistency. The present invention not only has obvious advantages in performance, cost and environmental protection, but also can meet the demand of aluminum electrolytic cells for high-efficiency, low-cost anode carbon blocks, and has broad market application prospects.

[0016] The present invention is further described in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0017] Example 1 The preparation method of the prebaked anode carbon block of this embodiment is as follows: S1. Screening petroleum coke according to the degree of dryness and wetness to obtain a wet material (water content > 8.75%) and a dry material (water content ≤ 8.75%), drying the wet material and then mixing it with the dry material to obtain a petroleum coke dry material; the water content of the petroleum coke dry material is ≤ 8.75%; Since petroleum coke is an important raw material for anode carbon blocks, it will absorb moisture during transportation and storage. Excessive moisture will affect the structure of the coke, making it difficult to volatilize during the calcination process, affecting the density and mechanical strength of the carbon blocks, resulting in a decrease in their overall performance. Screening the wet material can prevent the adverse effects of moisture on subsequent calcination. S2, calcining the petroleum coke obtained in S1 and naturally cooling it to room temperature to obtain calcined coke; The parameters of calcined coke are: ash content ≤ 0.38%, true density 2.065g / cm 3 , powder resistivity 430μΩ·m, particle stability ≥75%; The calcination method in this step is as follows: pot calcination is adopted, the temperature of the heat transfer oil during the calcination process is 205℃±4℃ (the heat transfer property of the heat transfer oil is used to achieve the purpose of precise temperature control); the temperature of the calcination circulating water is controlled at no more than 60℃ (the circulating water participates in regulating the temperature fluctuation in the furnace and maintains the temperature stability of the entire system); the calcination temperature is 1290℃, and the heat is kept for 20 hours; The calcination temperature at this stage is crucial for increasing the density and strength of the carbon blocks and reducing volatile matter. Controlling the temperature uniformly around 1300°C (1290°C in this example) helps maintain temperature consistency during the calcination process and prevents unstable carbon block quality due to local overheating or low temperatures. S3, crushing the calcined coke obtained in S2 to obtain crushed calcined coke; S4, subjecting the crushed calcined coke obtained in S3 to vibratory screening, and screening according to particle size ranges to obtain fine coke, medium particles, and coarse particles; The particle size of the coke powder is d1≤0.15mm, the particle size of the medium granular material is 0.15mm<d2≤3mm, and the particle size of the coarse granular material is 3mm<d3≤5mm; The coke powder, medium granular material and coarse granular material are mixed to obtain mixed granular material; The mixed granular material is composed of the following raw materials in mass fractions: 30% of fine coke material, 55% of medium granular material, and the balance of coarse granular material; S5. Add boric acid to the mixed pellets obtained in S4 to obtain a mixture of the mixed pellets and boric acid, and dry-mix the mixture at a temperature of 95° C. for 60 minutes to obtain a dry blend; the mass fraction of boric acid in the mixture of the mixed pellets and boric acid is 0.05%; Since particle size has an important influence on the density, strength and conductivity of carbon blocks. Finer coke particles can fill the gaps between larger coke particles, thereby improving the density and strength of the carbon blocks. At the same time, the appropriate ratio of medium and coarse coke particles can ensure the stability and long life of the carbon blocks in the electrolytic cell, ensure the performance of the anode carbon blocks, and ensure that large-scale carbon blocks do not fall off due to reactions during service. The proportion of boric acid is controlled at 0.05%, ensuring that the ash content is within a controllable range while ensuring that the carbon-carbon interface bonding matrix in the original anode carbon blocks is not destroyed due to the presence of too many additives, thereby negatively affecting certain physical properties of the anode carbon blocks, and the improvement effect will not be insignificant due to too low an addition content. Prolonging the mixing time (dry mixing for 60 minutes) and controlling the appropriate mixing temperature (95°C) can ensure the uniform distribution of the boric acid additive and calcined coke, thereby enhancing the performance of the anode carbon blocks. S6. After heating the asphalt at a temperature of 180° C. until it is melted, wet mixing it with the dry mix obtained in S5 at a temperature of 162° C. to obtain a paste; the mass fraction of the dry mix in the paste is 84%; S7. Pour the paste obtained in S6 into a mold at a temperature of 145° C. and vibrate for 100 seconds. Then, cool in a water bath at a temperature of 30° C. for 1 hour. After drying the surface moisture, obtain an anode green body. This embodiment ensures that the anode carbon blocks have uniformity, density and high strength during the molding process by precisely controlling the heating, wet mixing, mold pouring, forming and cooling processes of the pitch. Appropriate wet mixing temperature, mold pouring temperature, vibration molding time and cooling control enable the carbon blocks to be fully bonded and formed during molding, and effectively release stress during the cooling process to avoid cracks or deformation, thereby improving the quality of the final anode carbon blocks. The wet mixing temperature is increased to decompose the additive boric acid to produce boron oxide, while making its distribution more uniform in the carbon block. The moisture generated by the decomposition of boric acid during the subsequent roasting process is prevented from negatively affecting the density of the carbon block, thereby affecting the performance of the carbon block, while making the distribution of the product boron oxide more uniform. The anode green sheets prepared in step S7 are subjected to quality inspection, unqualified anode green sheets are recycled for secondary use, and qualified anode green sheets are subjected to the next step of operation; S8, baking the anode green body obtained in S7 in a natural gas baking furnace, and naturally cooling it to room temperature to obtain a prebaked anode carbon block; Roasting is divided into four stages, and the roasting method is: Low temperature stage: heat up to 320℃ at a rate of 2℃ / min and keep warm for 1h. Heat up slowly in this stage to avoid rapid decomposition of residual boric acid, which may lead to excessive release of volatile gas and cause defects such as cracks and holes on the surface of the anode carbon block. This ensures the quality of the carbon block. After heating to 320℃, keep warm for 1h to ensure that the boric acid is completely dehydrated and begins to interact with the carbon block matrix. Medium temperature stage: the temperature is raised to 650℃ at a heating rate of 4℃ / min. The heating rate is appropriately increased in this stage to accelerate the interaction between the generated product boron oxide and the carbon material. However, it is still necessary to avoid heating too quickly in this stage to prevent excessive pores from being generated inside the carbon block due to gas volatilization; High temperature stage: the temperature is raised to 1050°C at a heating rate of 6°C / min. At this stage, the carbonization process begins, and the boric acid is completely converted into boron oxide and embedded in the carbon block structure; Final stage: heating to 1250℃ at a heating rate of 3℃ / min and keeping the temperature constant for 22h to ensure that the structure of the carbon block is fully stabilized and the additives are well combined in the carbon block, so that the boride can be stably embedded in the carbon block and can fully play its role, thereby improving the comprehensive performance of the prebaked anode carbon block. After naturally cooling to room temperature, the prebaked anode carbon block is obtained; The roasting waste gas is treated by spraying, the waste water after spraying is purified and reused, and the gas after spraying is discharged after electrostatic dust removal.

[0018] The prebaked anode carbon blocks prepared in this example were subjected to various tests using ordinary prebaked anode carbon blocks as a control: The ordinary pre-baked anode carbon blocks are pre-baked anode carbon blocks from the same batch under the same process conditions, with the dry mixing time in step S5 being 30 minutes, the wet mixing temperature in step S6 being 152° C., and no boric acid additive being added in step S5.

[0019] (1) Chemical properties: The air reaction residual electrode rate of the prebaked anode carbon block prepared in this embodiment is 91.56%, and the air reaction shedding degree is 0.1%; the CO2 reaction residual electrode rate is 92.95%, and the CO2 reaction shedding degree is 0.25%.

[0020] Compared with ordinary pre-heated anode carbon blocks, the air reaction residual rate is 66.70%, and the air reaction shedding degree is 10.65%; the CO2 reaction residual rate is 86.63%, and the CO2 reaction shedding degree is 1.65%, both of which have been greatly improved.

[0021] (2) Physical properties: The ash content of the prebaked anode carbon block prepared in this embodiment is 0.37% and the true density is 2.07 g / cm 3 , volume density 1.58g / cm 3 , compressive strength 38.68MPa, resistivity 56.36μΩ·m, flexural strength 9.9MPa, thermal expansion 3.65×10 -6 k -1 , thermal conductivity 2.81W / mK, permeability 0.86nPm.

[0022] Compared with ordinary pre-cultured anode carbon blocks, the ash content is 0.35% and the true density is 2.07g / cm 3 , volume density 1.584g / cm 3 , compressive strength 38.69MPa, resistivity 56.25μΩ·m, flexural strength 9.8MPa, thermal expansion 3.97×10 -6 k -1 , thermal conductivity 3.50W / mK, permeability 1.04nPm, and physical properties have been improved.

[0023] Example 2 The preparation method of the prebaked anode carbon block of this embodiment is as follows: S1. Screening petroleum coke according to the degree of dryness and wetness to obtain a wet material (water content > 8.75%) and a dry material (water content ≤ 8.75%), drying the wet material and then mixing it with the dry material to obtain a petroleum coke dry material; the water content of the petroleum coke dry material is ≤ 8.75%; S2, calcining and cooling the petroleum coke dry material obtained in S1 to obtain calcined coke; The parameters of calcined coke are: ash content ≤ 0.38%, true density 2.095g / cm 3, powder resistivity 500μΩ·m, particle stability ≥75%; The calcination method in this step is: using a tank calcination, the temperature of the heat transfer oil during the calcination process is 205℃±4℃, the temperature of the calcination circulating water is controlled at no more than 60℃, the calcination temperature is 1390℃, and the heat preservation is 20h; S3, crushing the calcined coke obtained in S2 to obtain crushed calcined coke; S4, the crushed calcined coke obtained in S3 is vibrated and sieved according to particle size range to obtain fine coke, medium particles, and coarse particles; The particle size of the coke powder is d1≤0.15mm, the particle size of the medium granular material is 0.15mm<d2≤3mm, and the particle size of the coarse granular material is 3mm<d3≤5mm; The coke powder, medium granular material and coarse granular material are mixed to obtain mixed granular material; The mixed granular material is composed of the following raw materials in mass fractions: 30% of fine coke, 55% of medium granular material, and the balance of coarse granular material; S5. Add boric acid to the mixed pellets obtained in S4 to obtain a mixture of the mixed pellets and boric acid, and dry-mix the mixture at a temperature of 110° C. for 60 minutes to obtain a dry blend; the mass fraction of boric acid in the mixture of the mixed pellets and boric acid is 0.15%; S6. After heating the asphalt at a temperature of 192° C. until it is melted, wet mixing it with the dry mix obtained in S5 at a temperature of 168° C. to obtain a paste; the mass fraction of the dry mix in the paste is 84%; S7. Pour the paste obtained in S6 into a mold at a temperature of 160° C. and vibrate the mold for 100 seconds. Then, cool the mold in a water bath at a temperature of 40° C. for 2 hours. After drying the surface moisture, a green anode is obtained. S8, baking the anode green body obtained in S7 in a natural gas baking furnace, and naturally cooling it to room temperature to obtain a prebaked anode carbon block; The calcination method is as follows: heating from room temperature to 320°C at a heating rate of 3°C / min, keeping the temperature constant for 1 hour, then heating to 650°C at a heating rate of 5°C / min, then heating to 1050°C at a heating rate of 8°C / min, then heating to 1250°C at a heating rate of 4°C / min, and keeping the temperature constant for 22 hours.

[0024] (1) Chemical properties: The air reaction residual electrode rate of the prebaked anode carbon block prepared in this embodiment is 93.24%, and the air reaction shedding degree is 0.14%; the CO2 reaction residual electrode rate is 94.46%, and the CO2 reaction shedding degree is 0.39%.

[0025] (2) Physical properties: The ash content of the prebaked anode carbon block prepared in this embodiment is 0.38%, and the true density is 2.07 g / cm 3 , volume density 1.59g / cm 3 , compressive strength 42.8MPa, resistivity 55.04μΩ·m, flexural strength 10.1MPa, thermal expansion 3.28×10 -6 k -1 , thermal conductivity 2.99W / mK, permeability 0.84nPm.

[0026] The prebaked anode carbon block prepared in this embodiment is used as an anode material for an aluminum electrolytic cell.

[0027] The above is only a preferred embodiment of the present invention and is not intended to be a complete description of the present invention. Any simple modification, change and equivalent variation made to the above embodiments based on the essence of the invention technology shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a prebaked anode carbon block, characterized in that: The method is: S1. Screening petroleum coke according to the degree of dryness and wetness to obtain wet material and dry material, drying the wet material and then mixing it with the dry material to obtain petroleum coke dry material; S2, calcining and cooling the petroleum coke dry material obtained in S1 to obtain calcined coke; S3, crushing the calcined coke obtained in S2 to obtain crushed calcined coke; S4, the crushed calcined coke obtained in S3 is vibrated and sieved according to particle size range to obtain fine coke, medium particles, and coarse particles; The particle size of the coke powder is d1≤0.15mm, the particle size of the medium granular material is 0.15mm<d2≤3mm, and the particle size of the coarse granular material is 3mm<d3≤5mm; The coke powder, medium granular material and coarse granular material are mixed to obtain mixed granular material; S5. Add boric acid to the mixed pellets obtained in S4 to obtain a mixture of the mixed pellets and boric acid, and dry-mix the mixture at a temperature of 95° C. to 110° C. for 60 minutes to obtain a dry blend; S6. Heating the asphalt at a temperature of 180° C. to 192° C. until it is melted, and then wet-mixing the asphalt with the dry mix obtained in S5 at a temperature of 162° C. to 168° C. to obtain a paste; S7. Pour the paste obtained in S6 into a mold at a temperature of 145° C. to 160° C., vibrate the mold for 100 seconds, and then cool it in a water bath. After drying the surface moisture, a green anode is obtained. S8, baking the anode green body obtained in S7 in a natural gas baking furnace, and naturally cooling it to room temperature to obtain a prebaked anode carbon block; The calcination method is as follows: heating from room temperature to 320°C at a heating rate of 2°C / min to 3°C / min, keeping the temperature constant for 1 hour, then heating to 650°C at a heating rate of 4°C / min to 5°C / min, then heating to 1050°C at a heating rate of 6°C / min to 8°C / min, then heating to 1250°C at a heating rate of 3°C / min to 4°C / min, and keeping the temperature constant for 22 hours.

2. The method for preparing a prebaked anode carbon block according to claim 1, wherein: The moisture content of the petroleum coke dry material described in S1 is ≤8.75%.

3. The method for preparing a prebaked anode carbon block according to claim 1, wherein: The calcination method described in S2 is: using pot calcination, the temperature of the heat transfer oil during the calcination process is 205℃±4℃, the temperature of the calcination circulating water is controlled at no more than 60℃, and the calcination temperature is 1290℃~1390℃.

4. The method for preparing a prebaked anode carbon block according to claim 1, wherein: The mixed granular material in S4 is composed of the following raw materials in mass fractions: 30% of fine coke material, 55% of medium granular material, and the remainder of coarse granular material.

5. The method for preparing a prebaked anode carbon block according to claim 1, wherein: The mass fraction of boric acid in the mixture of the mixed pellets and boric acid in S5 is 0.05% to 0.15%.

6. The method for preparing a prebaked anode carbon block according to claim 1, wherein: The mass fraction of the dry mix in the paste in S6 is 84%.

7. The method for preparing a prebaked anode carbon block according to claim 1, characterized in that: The water bath cooling in S7 is performed at a temperature of 30° C. to 40° C. for 1 to 2 hours.