Pretreatment system and process for co-production of needle coke and special pitch coke

Abstract

The invention discloses a pre-treatment system and process for co-production of needle coke and special pitch coke, and the process comprises the following steps: (1) mixing raw material pitch with a mixed solvent, and then separating in a settling tank to obtain a light phase solution and heavy phase mixed oil; (2) heating and distilling the light-phase solution, and extracting a recycled solvent and refined pitch for preparing the needle coke; (3) heating the heavy-phase mixed oil, distilling, recycling part of the solvent, mixing the residual mixed oil with absorber oil or anthracene oil, and carrying out de-ashing treatment; (4) centrifugally separating the de-ashed mixed oil to obtain light-phase and heavy-phase mixed oil with different Qi contents; the invention relates to the technical field of coal-series chemical industry and carbon material processing, and aims to realize co-production of needle coke and special pitch coke and improve the comprehensive utilization rate of resources; 2, process parameters are optimized; the technological process is simple, operation is convenient, and industrial production is easy to achieve. And 4, the prepared needle coke and special pitch coke are stable in performance.

Description

Technical Field

[0001] The invention relates to the technical field of coal-based chemical industry and carbon material processing, and in particular to a system and process for co-producing and pre-treating needle coke and special pitch coke. Background Art

[0002] In the global industrial competition, the production technology of carbon products required for electronic-grade third-generation semiconductors has long been mastered by Japan and South Korea. They have implemented a strict technical blockade against us and do not sell their products to the Chinese market. This has seriously hindered the development of my country's isostatic graphite industry, causing the domestic isostatic graphite industry to face a double shortage of technology and supply. As the main raw material for high-end isostatic graphite, special pitch coke has high standard requirements for its performance indicators, and the selection and pre-reform of its raw materials have a very large impact on the performance of special pitch coke; During the research process, we found that its pretreatment process can be combined with the traditional needle coke pretreatment process, while improving the yield of needle coke pretreatment refined asphalt and improving economic benefits. Therefore, the development of a joint production pretreatment process that can produce needle coke and special asphalt coke at the same time has important industry significance and economic benefits. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a pretreatment system and process for the co-production of needle coke and special pitch coke. By optimizing the steps of mixed sedimentation, distillation, deashing, centrifugation and heating of raw asphalt and mixed solvent, the co-production of needle coke and special pitch coke is achieved, and the product quality is significantly improved and the production cost is reduced.

[0004] To achieve the above objectives, the present invention is implemented by the following technical scheme: a pretreatment process for the co-production of needle coke and special pitch coke, comprising the following steps: (1) The raw asphalt and the mixed solvent are mixed and separated in a settling tank to obtain a light phase solution and a heavy phase mixed oil; (2) The light phase solution is heated and distilled to extract the recycled solvent and refined asphalt for making needle coke; (3) The heavy phase mixed oil is heated and then distilled, part of the solvent is recycled, and the remaining mixed oil is mixed with wash oil or anthracene oil and then deashed; (4) The deashed mixed oil is centrifuged to obtain light phase and heavy phase mixed oils with different Qi contents; (5) The heavy phase mixed oil is heated and distilled to extract wash oil or anthracene oil, which is then processed into special asphalt coke for use in electronic-grade semiconductors.

[0005] Preferably, the step (1) comprises: The raw asphalt and the mixed solvent are mixed in a ratio of 1:1-5 to obtain a mixture; The mixture enters a sedimentation tank for sedimentation treatment to obtain a light phase solution with a Qi content of less than 0.01% and a heavy phase mixed oil enriched with all Qi in the raw material.

[0006] Preferably, the step (2) comprises: The light phase solution flows out from the overflow port at the top of the settling tank and enters the light phase buffer tank. After being pumped to the light phase heating furnace for heating, it enters the light phase distillation tower. The mixed solvent distilled from the upper part of the light phase distillation tower is recycled; The refined asphalt distilled from the lower part of the light phase distillation tower is processed by delayed coking and calcination to prepare needle coke.

[0007] Preferably, the step (3) comprises: The heavy phase mixed oil is pumped to the heavy phase heating furnace through the discharge port at the bottom of the settling tank for heating, and then enters the heavy phase distillation tower; Part of the solvent evaporated from the upper part of the heavy phase distillation tower is recycled, and the mixed oil at the bottom is pumped out; After being mixed with washing oil or anthracene oil through a static mixing distributor, it enters the deashing tank for deashing treatment.

[0008] Preferably, the step (4) comprises: The mixed oil after deashing treatment, with an ash content of less than 0.1%, is sent to a centrifuge for centrifugal separation; The light phase mixed oil and the mixed solvent after centrifugation are mixed again and enter the sedimentation tank for sedimentation treatment; The Qi content of the heavy phase mixed oil produced after centrifugation is regulated by controlling the speed of the centrifuge to meet the usage requirements of different grades of products.

[0009] Preferably, the step (5) comprises: The heavy phase mixed oil enters the asphalt heating furnace for heating and is then sent to the distillation tower for separation; The wash oil or anthracene oil separated from the upper part of the asphalt distillation tower is recycled, and the high-qi and low-ash reformed asphalt extracted from the bottom is processed by delayed coking and calcination; Prepare the special pitch coke required for third-generation electronic-grade semiconductors.

[0010] Preferably, it includes: a settling tank, a mixed solvent tank, a static mixing distributor, a light phase buffer tank, a light phase heating furnace, a heavy phase heating furnace, a heating furnace, a heavy phase distillation tower, a light phase distillation tower, a static mixing distributor, a deashing tank, a centrifuge, and a distillation tower; The mixed solvent tank is connected to the settling tank, the static mixing distributor is connected to the settling tank for adding raw asphalt, the upper and lower discharge ports of the settling tank are respectively connected to the light phase buffer tank and the heavy phase heating furnace, the light phase buffer tank is connected to the light phase heating furnace, the heavy phase heating furnace is connected to the heavy phase distillation tower, the light phase heating furnace is connected to the light phase distillation tower, the heavy phase distillation tower is connected to the static mixing distributor, the static mixing distributor is connected to the deashing tank, the deashing tank is connected to the centrifuge, the centrifuge is respectively connected to the asphalt heating furnace and the settling tank, and the asphalt heating tank is connected to the asphalt distillation tower.

[0011] Preferably, the solvent is evaporated from the top of the heavy phase distillation tower and the light phase distillation tower for recovery, and anthracene oil or wash oil is separated from the top of the asphalt distillation tower. Beneficial Effects

[0012] The present invention provides a system and process for the joint production pretreatment of needle coke and special pitch coke. The system and process for the joint production pretreatment of needle coke and special pitch coke have the following beneficial effects: 1. The co-production of needle coke and special pitch coke has been realized, which improves the comprehensive utilization rate of resources.

[0013] 2. By optimizing process parameters, product quality is improved and production costs are reduced.

[0014] 3. The process is simple, the operation is convenient, and it is easy to realize industrial production.

[0015] 4. The prepared needle coke and special pitch coke have stable performance and meet the needs of high-end application fields.

[0016] 5. Break through the technical blockade and provide a pretreatment process method for preparing the third-generation semiconductor raw material - special asphalt coke. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a system schematic diagram of the present invention.

[0018] In the figure: 1. Sedimentation tank; 2. Mixed solvent tank; 3. Static mixing distributor 1; 4. Light phase buffer tank; 5. Light phase heating furnace; 6. Heavy phase heating furnace; 7. Asphalt heating furnace; 8. Heavy phase distillation tower; 9. Light phase distillation tower; 10. Static mixing distributor 2; 11. Deashing tank; 12. Centrifuge; 13. Asphalt distillation tower. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] All electrical components in this case are connected to their corresponding power supplies through wires by personnel in this field, and a suitable controller should be selected according to actual conditions to meet control requirements. The specific connection and control sequence should refer to the working sequence between the electrical components in the following working principle to complete the electrical connection. The detailed connection means are well-known technologies in this field. The following mainly introduces the working principle and process, and no longer explains the electrical control.

[0021] See also Figure 1 , the present invention provides a technical solution: Example 1: Standard process flow example Mixing and sedimentation of raw asphalt and mixed solvent: In this embodiment, the raw asphalt and the mixed solvent are mixed in a ratio of 1:3 and then pumped to a sedimentation tank for sedimentation separation. An internal stirring device is provided in the sedimentation tank to maintain a uniform mixing state, and the sedimentation time is 8 hours. After the sedimentation is completed, the light phase solution is collected at the top overflow port, and the heavy phase mixed oil is collected at the bottom.

[0022] Heating and distillation of light phase solution: The light phase solution is pumped into the light phase buffer tank, then heated to 150°C in the light phase heating furnace, and then enters the light phase distillation tower. The top of the light phase distillation tower is equipped with a condensation reflux system for recovering the solvent, and the bottom of the tower collects the refined asphalt. After the refined asphalt is treated with delayed coking and calcination, high-purity needle coke is obtained.

[0023] Treatment of heavy phase mixed oil: The heavy phase mixed oil is heated to 250°C in a heavy phase heating furnace and then sent to a heavy phase distillation tower. The heavy phase distillation tower is equipped with multiple trays to enhance separation efficiency. The mixed solvent is recovered at the top of the tower, and the high boiling point mixed oil at the bottom of the tower is mixed with anthracene oil at a ratio of 1:0.5 and then enters the deashing tank. In the deashing tank, after the mixed oil fully reacts with the deashing agent, it is centrifuged to obtain low-ash special asphalt coke.

[0024] Example 2: Example focusing on deashing Mixing and settling of raw asphalt and solvent: In this example, the raw asphalt and the mixed solvent are mixed in a ratio of 1:4 and then pumped into a settling tank. In this example, a longer settling time (12 hours) and a higher temperature (70°C) are used to ensure complete separation of the light and heavy phases. The light phase solution is collected in a light phase buffer tank, while the heavy phase mixed oil is discharged from the bottom.

[0025] Refining of light phase solution: The light phase solution is sent from the buffer tank to the light phase heating furnace, where the temperature is raised to 180°C, and then enters the distillation tower. The distillation tower adopts a five-stage distillation tray design to further purify the light phase components. The solvent at the top of the tower is recycled, and the refined asphalt at the bottom of the tower is used for delayed coking and calcination to prepare needle coke.

[0026] Deashing and refining of heavy phase mixed oil: The heavy phase mixed oil is first heated to 300°C by a heating furnace, and then enters a distillation tower to recover high-boiling point components. The heavy phase oil after distillation is mixed with the wash oil in a ratio of 1:1 and enters a deashing tank for treatment. During the deashing process, the amount of deashing agent (10%) and the reaction time (6 hours) are controlled to reduce the ash content to 0.05%. The deashed mixed oil is separated by centrifugation to obtain high-quality special asphalt coke.

[0027] Example 3: Example of Optimizing Light Phase Processing Mixing and settling: In this embodiment, the raw asphalt and the mixed solvent are mixed in a ratio of 1:2.5. The mixture is pumped into a settling tank, and the settling time is set to 10 hours at a temperature of 65°C. The light phase solution is discharged from the top of the settling tank and collected in a light phase buffer tank. The heavy phase mixed oil is discharged from the bottom for subsequent treatment.

[0028] Heating and deep distillation of light phase solution: The light phase solution is pumped from the buffer tank to the heating furnace and heated to 200°C. The heated light phase solution enters the distillation tower, which adopts a six-stage tray design to achieve higher distillation efficiency. The top condensation reflux system ensures efficient recovery of the solvent, while the refined asphalt at the bottom of the tower is used for the production of needle coke.

[0029] Treatment and deashing of heavy phase mixed oil: After the heavy phase mixed oil is heated to 270°C, it enters the distillation tower for further solvent recovery and component separation. The heavy phase mixed oil discharged from the bottom of the tower is mixed with the wash oil at a ratio of 1:0.8 and enters the deashing tank. In this process, the deashing conditions are specially optimized, 15% of the deashing agent is used, and the reaction time is extended to 8 hours to ensure the lowest ash content. The heavy phase oil after deashing is centrifuged to finally obtain high-quality special asphalt coke.

[0030] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pretreatment process for the co-production of needle coke and special pitch coke, characterized in that: The following steps are involved: (1) The raw asphalt and the mixed solvent are mixed and separated in a settling tank (1) to obtain a light phase solution and a heavy phase mixed oil; (2) The light phase solution is heated and distilled to extract the recycled solvent and refined asphalt for making needle coke; (3) The heavy phase mixed oil is heated and then distilled, part of the solvent is recycled, and the remaining mixed oil is mixed with wash oil or anthracene oil and then deashed; (4) The deashed mixed oil is centrifuged to obtain light phase and heavy phase mixed oils with different Qi contents; (5) The heavy phase mixed oil is heated and distilled to extract wash oil or anthracene oil, which is then processed into special asphalt coke for use in electronic-grade semiconductors.

2. The process for the co-production of needle coke and special pitch coke according to claim 1, characterized in that , the step (1) comprises: The raw asphalt and the mixed solvent are mixed in a ratio of 1:1-5 to obtain a mixture; The mixture enters a sedimentation tank (1) for sedimentation treatment to obtain a light phase solution with a Qi content of less than 0.01% and a heavy phase mixed oil enriched with all Qi in the raw material.

3. The process for the co-production of needle coke and special pitch coke according to claim 1, characterized in that , the step (2) comprises: The light phase solution flows out from the overflow port at the top of the settling tank (1) and enters the light phase buffer tank (4). After being pumped to the light phase heating furnace (5) for heating, it enters the light phase distillation tower (9). The mixed solvent distilled from the upper part of the light phase distillation tower (9) is recycled; The refined asphalt distilled from the lower part of the light phase distillation tower (9) is processed by delayed coking and calcination to prepare needle coke.

4. The process for the co-production of needle coke and special pitch coke according to claim 1, characterized in that , the step (3) comprises: The heavy phase mixed oil is pumped to the heavy phase heating furnace (6) through the bottom discharge port of the settling tank (1) for heating, and then enters the heavy phase distillation tower (8); Part of the solvent evaporated from the upper part of the heavy phase distillation tower (8) is recycled, and the mixed oil at the bottom is pumped out; After being mixed with washing oil or anthracene oil by the static mixing distributor 2 (10), it enters the deashing tank (11) for deashing treatment.

5. The process for the co-production of needle coke and special pitch coke according to claim 1, characterized in that , the step (4) comprises: The mixed oil after deashing treatment has an ash content of less than 0.1% and is sent to a centrifuge (12) for centrifugal separation; The light phase mixed oil and the mixed solvent are mixed again after centrifugation and enter the sedimentation tank (1) for sedimentation treatment; The Qi content of the heavy phase mixed oil obtained after centrifugation is regulated by controlling the speed of the centrifuge (12) so as to meet the use requirements of products of different grades.

6. The process for the co-production of needle coke and special pitch coke according to claim 1, characterized in that , the step (5) comprises: The heavy phase mixed oil enters the asphalt heating furnace (7) for heating and is then sent to the distillation tower for separation; The wash oil or anthracene oil separated from the upper part of the asphalt distillation tower (13) is recycled, and the high-Qi and low-ash reformed asphalt extracted from the bottom is processed by delayed coking and calcination; Prepare the special pitch coke required for third-generation electronic-grade semiconductors.

7. The system for co-production and pretreatment of needle coke and special pitch coke according to claim 1, characterized in that , including: a settling tank (1), a mixed solvent tank (2), a static mixing distributor 1 (3), a light phase buffer tank (4), a light phase heating furnace (5), a heavy phase heating furnace (6), an asphalt heating furnace (7), a heavy phase distillation tower (8), a light phase distillation tower (9), a static mixing distributor 2 (10), a deashing tank (11), a centrifuge (12), and an asphalt distillation tower (13); The mixed solvent tank (2) is connected to the settling tank (1), the static mixing distributor 1 (3) is connected to the settling tank (1) for adding raw asphalt, the upper and lower discharge ports of the settling tank (1) are respectively connected to the light phase buffer tank (4) and the heavy phase heating furnace (6), the light phase buffer tank (4) is connected to the light phase heating furnace (5), the heavy phase heating furnace (6) is connected to the heavy phase distillation tower (8), the light phase heating furnace (5) is connected to the light phase distillation tower (9), the heavy phase distillation tower (8) is connected to the static mixing distributor 2 (10), the static mixing distributor 2 (10) is connected to the deashing tank (11), the deashing tank (11) is connected to the centrifuge (12), the centrifuge (12) is respectively connected to the asphalt heating furnace (7) and the settling tank (1), and the asphalt heating tank is connected to the asphalt distillation tower (13).

8. The system for co-production and pretreatment of needle coke and special pitch coke according to claim 1, characterized in that The solvent is evaporated from the top of the heavy phase distillation tower (8) and the light phase distillation tower (9) for recovery, and anthracene oil or wash oil is separated from the top of the asphalt distillation tower (13).

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