A high-strength graphite material for rectifying column and a method for manufacturing the same

Abstract

The application discloses a kind of high-strength graphite materials for rectifying tower and a preparation method thereof, and relates to the technical field of graphite materials for rectifying tower, comprising the following raw materials by weight: calcined coke 40-60 parts, modified pitch coke 30-45 parts, coal pitch 25-35 parts, synergist 0.5-1 part.The high-strength graphite material for rectifying tower of the application is obtained by mixing modified pitch coke, liquid coal pitch and synergist after calcined coke is classified by particle size and combined, and then mixing, kneading, molding, baking and graphitizing.The modified pitch coke and synergist are used together, which enhances the infiltration and combination of powder and pitch binder, promotes the filling of pores, generates reinforcing phase, and controls the synergistic effect of graphitization degree, so that the graphite material has strong mechanical strength under high temperature working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of graphite materials for rectifying columns, in particular to a high-strength graphite material for rectifying columns and a preparation method thereof. BACKGROUND

[0002] Graphite can be made into various types of towers due to its excellent corrosion resistance, temperature resistance, and easy processing performance. As a widely used mass and heat transfer device in chemical production, a rectifying column separates components with different volatility, i.e., different vapor pressures at the same temperature, to achieve the purpose of separation. Graphite rectifying columns are particularly suitable for the separation of corrosive materials, such as the concentration of hydrochloric acid and the refining of epoxy chloropropane.

[0003] The graphite material for rectifying columns is prepared by crushing and grading calcined coke (calcined petroleum coke), dissolving coal tar pitch to form liquid pitch, mixing calcined coke with different particle size ranges and liquid pitch for high-pressure impregnation and kneading, and then forming graphite blanks. The graphite blanks are obtained by calcining and graphitizing sintering. However, the performance of the raw materials used in the preparation process results in insufficient mechanical strength of the graphite material, which limits its use in rectifying columns.

[0004] Pitch coke is a solid combustible product obtained by coking of coal tar pitch, which is a low-sulfur, low-ash high-quality coke and an easy graphitizable carbon. The volatile matter of pitch coke is low, the structure is dense, and the particle mechanical strength and wear resistance are high. To improve the mechanical strength of the graphite material while not reducing other excellent properties of the graphite material, pitch coke can be added together with petroleum coke. However, the particle size and surface properties of pitch coke have a great influence on the infiltration and combination of pitch coke and coal tar pitch. If they are not fully mixed, the pitch coke particles and coal tar pitch binder cannot be evenly distributed, which is not conducive to the effective improvement of the mechanical strength of the graphite material. In addition, the particle size and addition amount of pitch coke also have a great influence on the density and mechanical strength of the graphite material.

[0005] Therefore, it is worth further exploring how to adjust the addition method, addition amount, and particle size of pitch coke to prepare a high-strength graphite material for rectifying columns with excellent mechanical strength and other properties by using it together with calcined petroleum coke. SUMMARY

[0006] To solve the above technical problems, the present application provides a high-strength graphite material for rectifying columns and a preparation method thereof.

[0007] The object of the present application can be achieved by the following technical solutions:

[0008] A high-strength graphite material for rectifying tower, comprising the following raw materials by weight: calcined coke 40-60 parts, modified pitch coke 30-45 parts, coal pitch 25-35 parts, and synergist 0.5-1 part.

[0009] A preparation method of a high-strength graphite material for rectifying tower, comprising the following steps:

[0010] Step S1, crushing the calcined coke through a crusher, and then screening the calcined coke through a vibrating screen to obtain the calcined coke with graded particle sizes;

[0011] Step S2, heating the coal pitch in a water bath to obtain liquid coal pitch; combining the calcined coke with graded particle sizes, and mixing the calcined coke with the liquid coal pitch; first heating and kneading the mixture in a kneading pot, then adding the modified pitch coke and the synergist, and continuing to heat and knead to obtain a paste;

[0012] Step S3, pressing and forming the paste to form a green body, placing the green body in a roasting furnace to be roasted in a protective gas atmosphere, and then transferring the green body to a graphitization furnace to be sintered, thereby obtaining the high-strength graphite material for rectifying tower;

[0013] The preparation method of the high-strength graphite material for rectifying tower comprises the following specific steps:

[0014] Step S1, crushing the calcined coke through a crusher, and then screening the calcined coke through a vibrating screen to obtain the calcined coke with graded particle sizes;

[0015] Further, the particle sizes of the calcined coke with graded particle sizes are respectively 2-4 mm, 0.5-2 mm, and 0.074-0.5 mm; and the mass ratio of the particles with the particle sizes of 2-4 mm, 0.5-2 mm, and 0.074-0.5 mm is 40-50:25-35:15-35;

[0016] Step S2, heating the coal pitch in a water bath at 95-100℃ for 1-2h to obtain liquid coal pitch; combining the calcined coke with graded particle sizes, and mixing the calcined coke with the liquid coal pitch; first heating the mixture to 115-130℃ in a kneading pot for 10-15min, then adding the modified pitch coke and the synergist, and heating the mixture to 140-160℃ for 20-25min to obtain a paste;

[0017] Step S3, pressing and forming the paste to form a green body, placing the green body in a roasting furnace to be roasted in a protective gas atmosphere for 24-48h, and then transferring the green body to a graphitization furnace to be sintered for 72-96h, thereby obtaining the high-strength graphite material for rectifying tower;

[0018] Further, the temperature for the pressing and forming is 90-110℃, and the pressure is 40-50MPa; the temperature for the roasting is 800-900℃; and the temperature for the sintering in the graphitization furnace is 2500-3000℃.

[0019] Further, the preparation method of the modified pitch coke comprises the following steps:

[0020] Step (1): soak the pitch coke in acid solution, stir at room temperature, take out and wash with water to neutral, dry, calcine in protective gas, cool down with the furnace, and obtain purified pitch coke;

[0021] Step (2): mix the purified pitch coke and grinding medium, grind in protective gas atmosphere, and screen to obtain modified pitch coke;

[0022] Further, the preparation method of the modified pitch coke comprises the following specific steps:

[0023] Step (1): soak the pitch coke in acid solution, stir at room temperature for 1-2h, take out and wash with water to neutral, dry at 100-105℃ for 3-4h, calcine in protective gas at 1000-1050℃ for 5-10min, cool down with the furnace, and obtain purified pitch coke;

[0024] Further, the ratio of the amount of acid solution to pitch coke is 5-8mL:1-1.5g; the acid solution is a mixture of hydrochloric acid solution and nitric acid solution with a volume ratio of 2-3:1;

[0025] Further, the concentration of the hydrochloric acid solution is 1-1.5mol / L; the concentration of the nitric acid solution is 0.5-1mol / L;

[0026] In step (1), the pitch coke is soaked in acid solution to remove metal oxide impurities, and then calcined in protective gas to remove adsorbed oxygen and organic sulfur, volatile impurities, etc., so as to avoid the impurities in the pitch coke generating gas and low-melting-point substances at high temperature, and destroying the structure of the graphite material;

[0027] Step (2): mix the purified pitch coke and grinding medium, grind in protective gas atmosphere at a speed of 400-500rpm for 2-3h, and screen to obtain modified pitch coke;

[0028] Further, the ratio of the amount of purified pitch coke to grinding medium is 1g:5-10g; the grinding medium is zirconia ball with a size of 1-3mm; and the particle size of the modified pitch coke is 5-10μm.

[0029] The synergist is a mixture of silica sol, boron-containing compound and small molecule polyol with a ratio of 1g:0.5-1g:5-10g;

[0030] Further, the small molecule polyol is one of ethylene glycol, propylene glycol, 1,3-butanediol and glycerol.

[0031] Further, the preparation method of the boron-containing compound comprises the following steps:

[0032] The boric acid is added into deionized water, stirred at 80-85 DEG C for 10-15 min, filtered while hot, concentrated under reduced pressure to obtain a concentrated solution, and the concentrated solution is added with nitric acid solution at 80-85 DEG C, stirred for 20-25 min, filtered while hot, and rotary evaporated to obtain a boron-containing compound;

[0033] Further, the boric acid and deionized water are used in a ratio of 5-6 g: 100-120 mL; the concentrated solution and the nitric acid solution are used in a volume ratio of 10-12 mL: 0.5-0.7 mL; and the concentration of the nitric acid solution is 1-2 mol / L.

[0034] Further, the filtrate is concentrated under reduced pressure at 90-95 DEG C for 5-10 min.

[0035] The beneficial effects of the present application are:

[0036] 1. The present application discloses a high-strength graphite material for rectifying tower and a preparation method thereof, wherein the high-strength graphite material for rectifying tower is obtained by mixing the particle size graded calcined coke, modified pitch coke, coal pitch and synergist, and then mixing, kneading, molding, baking and graphitizing, through the reasonable proportioning of raw materials, and the mixing and kneading of the particle size graded calcined coke and coal pitch, and then adding the modified pitch coke and synergist for further mixing and kneading, the calcined coke and modified pitch coke are more easily infiltrated and combined with the liquid coal pitch binder, so as to improve the compactness and mechanical strength of the graphite material.

[0037] 2. The modified pitch coke used in the present application is obtained by soaking the pitch coke in acid and high-temperature calcination to remove impurities, so as to avoid the generation of gas and low-melting-point substances from the impurities in the pitch coke at high temperature, which can destroy the structure of the graphite material and maintain the integrity of the graphite material; and then the pitch coke after impurity removal is ground and sieved to a particle size of 5-10 um, which can fill the small pores of the graphite material and improve the compactness of the graphite material.

[0038] 3. The synergist used in the present application is a mixture of silica sol, boron-containing compound and small-molecule polyol in a specific ratio, wherein silicon reacts with carbon at high temperature to form silicon carbide, which has high hardness and good thermal stability and can be used as a reinforcing phase to improve the mechanical strength of the graphite material at high temperature in the rectifying column; the boron atom radius (0.085 nm) in the boron-containing compound is close to the carbon atom radius (0.077 nm), and under a suitable amount, the boron atom can be embedded into the interlayer gap of carbon, reduce the bending energy of the carbon layer, promote the ordered arrangement of carbon atoms, reduce the adverse effects of impurities in boric acid on graphitization, and improve the graphitization degree; the small-molecule polyol not only can cross-link with silica sol and boric acid to improve the stability of the synergist and make the synergist more uniform when mixed with other raw materials, but also can decompose during high-temperature heating to promote the filling of small pores of the modified pitch coke into the graphite material and enhance the denseness of the graphite material. Through the synergistic effect of generating a reinforcing phase, regulating the graphitization degree and enhancing the denseness, the graphite material is endowed with high mechanical strength at high-temperature working conditions.

[0039] 4. The high-strength graphite material for rectifying columns of the present application has low cost, simple preparation steps, good wettability and combination between raw materials, and the treatment method of the raw materials is easy to implement, which is expected to provide a new selection of high performance and low cost for graphite materials for rectifying columns. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] Embodiment 1

[0042] The preparation method of the modified pitch coke comprises the following steps:

[0043] Step (1): soak the pitch coke (supplier: Shanghai Youai Metallurgical Material Co., Ltd., fineness 0-3 mm) in acid solution, stir at room temperature for 1 h, wash with water to neutral, dry at 100℃ for 3 h, calcine at 1000℃ for 5 min in nitrogen, and cool down with the furnace to obtain purified pitch coke; the amount ratio of the acid solution to the pitch coke is 5 mL: 1 g; the acid solution is a mixture of 1 mol / L hydrochloric acid solution and 0.5 mol / L nitric acid solution in a volume ratio of 2:1;

[0044] Step (2): mixing the purified pitch coke and grinding medium, grinding for 2 h under nitrogen atmosphere at a rotation speed of 400 rpm, and sieving to obtain modified pitch coke; the use amount ratio of the purified pitch coke and the grinding medium is 1 g:5 g; the grinding medium is a zirconium oxide ball with a size of 1 mm; and the particle size of the modified pitch coke is 5 μm.

[0045] Example 2

[0046] The modified pitch coke is prepared by the following steps:

[0047] Step (1): soaking pitch coke (a supplier: Shanghai Youai Metallurgical Material Co., Ltd., fineness 0-3 mm) in acid liquid, stirring at room temperature for 1.5 h, washing with water to neutral, drying at 103 ℃ for 3.5 h, calcining in nitrogen at 1020 ℃ for 8 min, and cooling in the furnace to obtain purified pitch coke; the use amount ratio of the acid liquid and the pitch coke is 6.5 mL:1.2 g; the acid liquid is a mixed solution of 1.3 mol / L hydrochloric acid solution and 0.8 mol / L nitric acid solution with a volume ratio of 2.5:1;

[0048] Step (2): mixing the purified pitch coke and grinding medium, grinding for 2.5 h under nitrogen atmosphere at a rotation speed of 450 rpm, and sieving to obtain modified pitch coke; the use amount ratio of the purified pitch coke and the grinding medium is 1 g:8 g; the grinding medium is a zirconium oxide ball with a size of 2 mm; and the particle size of the modified pitch coke is 8 μm.

[0049] Example 3

[0050] The modified pitch coke is prepared by the following steps:

[0051] Step (1): soaking pitch coke (a supplier: Shanghai Youai Metallurgical Material Co., Ltd., fineness 0-3 mm) in acid liquid, stirring at room temperature for 2 h, washing with water to neutral, drying at 105 ℃ for 4 h, calcining in nitrogen at 1050 ℃ for 10 min, and cooling in the furnace to obtain purified pitch coke; the use amount ratio of the acid liquid and the pitch coke is 8 mL:1.5 g; the acid liquid is a mixed solution of 1.5 mol / L hydrochloric acid solution and 1 mol / L nitric acid solution with a volume ratio of 3:1;

[0052] Step (2): mixing the purified pitch coke and grinding medium, grinding for 3 h under nitrogen atmosphere at a rotation speed of 500 rpm, and sieving to obtain modified pitch coke; the use amount ratio of the purified pitch coke and the grinding medium is 1 g:10 g; the grinding medium is a zirconium oxide ball with a size of 3 mm; and the particle size of the modified pitch coke is 10 μm.

[0053] Example 4

[0054] A synergist is a mixture of silica sol, boron-containing compound, and ethylene glycol in a ratio of 1g:0.5g:5g;

[0055] The boron-containing compound is prepared by the following steps:

[0056] Boric acid is added to deionized water, stirred at 80℃ for 10min, filtered while hot, and the filtrate is concentrated under reduced pressure at 90℃ for 5min to obtain a concentrated solution, boric acid, deionized water in a ratio of 5g:100mL; the volume ratio of concentrated solution, nitric acid solution is 10mL:0.5mL; the concentration of nitric acid solution is 1mol / L.

[0057] Example 5

[0058] A synergist is a mixture of silica sol, boron-containing compound, and propylene glycol in a ratio of 1g:0.8g:8g;

[0059] The boron-containing compound is prepared by the following steps:

[0060] Boric acid is added to deionized water, stirred at 83℃ for 13min, filtered while hot, and the filtrate is concentrated under reduced pressure at 93℃ for 8min to obtain a concentrated solution, boric acid, deionized water in a ratio of 5.5g:110mL; the volume ratio of concentrated solution, nitric acid solution is 11mL:0.6mL; the concentration of nitric acid solution is 1.5mol / L.

[0061] Example 6

[0062] A synergist is a mixture of silica sol, boron-containing compound, and 1,3-butanediol in a ratio of 1g:1g:10g;

[0063] The boron-containing compound is prepared by the following steps:

[0064] Boric acid is added to deionized water, stirred at 85℃ for 15min, filtered while hot, and the filtrate is concentrated under reduced pressure at 95℃ for 10min to obtain a concentrated solution, boric acid, deionized water in a ratio of 6g:120mL; the volume ratio of concentrated solution, nitric acid solution is 12mL:0.7mL; the concentration of nitric acid solution is 2mol / L.

[0065] Example 7

[0066] A high-strength graphite material for rectifying tower, comprising the following raw materials by weight: calcined coke 40 parts, modified pitch coke 30 parts, coal pitch 25 parts, synergist 0.5 parts;

[0067] A preparation method of the high-strength graphite material for rectifying tower, comprising the following steps:

[0068] Step S1, the calcined coke (supplier: Lingzhou Dongfeng Mineral Processing Plant, specification 3-6mm) is crushed by a crusher, and then sieved by a vibrating screen to obtain particle size graded calcined coke; the particle size of the particle size graded calcined coke ranges from 2-4mm, 0.5-2mm and 0.074-0.5mm respectively; the mass ratio of the particles with particle size ranges of 2-4mm, 0.5-2mm and 0.074-0.5mm is 40:25:15 respectively;

[0069] Step S2, the coal pitch (supplier: Hebei Taihang New Energy Technology Co., Ltd., coking value ≥48%) is heated in a 95℃ water bath for 1h to obtain liquid coal pitch; the particle size graded calcined coke is combined and mixed with the liquid coal pitch, first heated to 115℃ in a kneading pot for 10min, then the modified pitch coke obtained in Example 1 and the synergist obtained in Example 4 are added, and heated to 140℃ for 20min to obtain a paste;

[0070] Step S3, the paste is pressed and formed into a green body, which is placed in a roasting furnace and roasted in a nitrogen atmosphere for 24h, and then transferred to a graphitization furnace for sintering for 72h to obtain a high-strength graphite material for rectifying tower; the temperature for pressing and forming is 90℃, and the pressure is 40MPa; the roasting temperature is 800℃; the sintering temperature in the graphitization furnace is 2500℃.

[0071] Example 8

[0072] A high-strength graphite material for rectifying tower, comprising the following raw materials by weight: calcined coke 50 parts, modified pitch coke 37 parts, coal pitch 30 parts, synergist 0.8 parts;

[0073] A preparation method of the high-strength graphite material for rectifying tower, comprising the following steps:

[0074] Step S1, the calcined coke (supplier: Lingzhou Dongfeng Mineral Processing Plant, specification 3-6mm) is crushed by a crusher, and then sieved by a vibrating screen to obtain particle size graded calcined coke; the particle size of the particle size graded calcined coke ranges from 2-4mm, 0.5-2mm and 0.074-0.5mm respectively; the mass ratio of the particles with particle size ranges of 2-4mm, 0.5-2mm and 0.074-0.5mm is 40:25:15 respectively;

[0075] Step S2, heating coal pitch (supplier: Hebei Taihang New Energy Technology Co., Ltd., coking value ≥ 48%) in a 98℃ water bath for 1.5h to obtain liquid coal pitch; combine the particle size graded calcined coke and mix with the liquid coal pitch, first heat to 122℃ in a kneading pot for 13min, then add the modified pitch coke obtained in Example 2 and the synergist obtained in Example 5, heat to 150℃ for 23min to obtain a paste;

[0076] Step S3, the paste is pressed and formed into a green body, which is placed in a roasting furnace and roasted in a nitrogen atmosphere for 36h, then transferred to a graphitization furnace and sintered for 84h to obtain a high-strength graphite material for rectifying tower; the temperature for pressing and forming is 100℃, the pressure is 45MPa; the roasting temperature is 850℃; the sintering temperature in the graphitization furnace is 2700℃.

[0077] Example 9

[0078] A high-strength graphite material for rectifying tower, comprising the following raw materials by weight: calcined coke 60 parts, modified pitch coke 45 parts, coal pitch 35 parts, synergist 1 part;

[0079] A preparation method of the high-strength graphite material for rectifying tower, comprising the following steps:

[0080] Step S1, the calcined coke (supplier: Lingshou County Dongfeng Mineral Processing Factory, specification 3-6mm) is crushed by a crusher, then sieved by a vibrating screen to obtain particle size graded calcined coke; the particle size ranges of the particle size graded calcined coke are 2-4mm, 0.5-2mm and 0.074-0.5mm respectively; the mass ratio of particles with particle size ranges of 2-4mm, 0.5-2mm and 0.074-0.5mm is 50:35:35;

[0081] Step S2, heating coal pitch (supplier: Hebei Taihang New Energy Technology Co., Ltd., coking value ≥ 48%) in a 100℃ water bath for 2h to obtain liquid coal pitch; combine the particle size graded calcined coke and mix with the liquid coal pitch, first heat to 130℃ in a kneading pot for 15min, then add the modified pitch coke obtained in Example 3 and the synergist obtained in Example 6, heat to 160℃ for 25min to obtain a paste;

[0082] Step S3, the paste is pressed and formed into a green body, which is placed in a roasting furnace and roasted in a nitrogen atmosphere for 36h, then transferred to a graphitization furnace and sintered for 84h to obtain a high-strength graphite material for rectifying tower; the temperature for pressing and forming is 100℃, the pressure is 45MPa; the roasting temperature is 850℃; the sintering temperature in the graphitization furnace is 2700℃.

[0083] Comparative Example 1

[0084] Comparing with Example 9, the paste-1 is used to replace the paste in step S2, and the rest is completely the same as Example 9, to prepare the graphite material;

[0085] The preparation steps of the paste-1 are as follows: the size-graded calcined coke is combined, mixed with the liquid coal pitch, the modified pitch coke obtained in Example 3, and the synergist obtained in Example 6, first heated to 130°C in the kneading pot for 15 min, and then heated to 160°C for 25 min to obtain the paste-1.

[0086] Comparative Example 2

[0087] Comparing with Example 9, the paste-2 is used to replace the paste in step S2, and the rest is completely the same as Example 9, to prepare the graphite material;

[0088] The preparation steps of the paste-2 are as follows: the size-graded calcined coke is combined, mixed with the liquid coal pitch, and the modified pitch coke obtained in Example 3, first heated to 130°C in the kneading pot for 15 min, then the synergist obtained in Example 6 is added, heated to 160°C for 25 min to obtain the paste-2.

[0089] Comparative Example 3

[0090] Comparing with Example 9, the paste-3 is used to replace the paste in step S2, and the rest is completely the same as Example 9, to prepare the graphite material;

[0091] The preparation steps of the paste-3 are as follows: the size-graded calcined coke is combined, mixed with the liquid coal pitch and the synergist obtained in Example 6, first heated to 130°C in the kneading pot for 15 min, then the modified pitch coke obtained in Example 3 is added, heated to 160°C for 25 min to obtain the paste-3.

[0092] Comparative Example 4

[0093] Comparing with Example 9, the particle size of the modified pitch coke used is 74 μm, and the rest is completely the same as Example 9, to prepare the graphite material.

[0094] Comparative Example 5

[0095] Comparing with Example 9, the synergist used is replaced by synergist-1, and the rest is completely the same as Example 9, to prepare the graphite material; the synergist-1 is a mixture of silica sol, boron-containing compound and water in a ratio of 2g:2g:10g.

[0096] Comparative Example 6

[0097] Comparing with Example 9, the synergist used is replaced by synergist-2, and the rest is completely the same as Example 9, to prepare the graphite material; the synergist-2 is a mixture of silica sol and 1,3-butanediol in a ratio of 2g:10g.

[0098] Comparative Example 7

[0099] The used synergist was replaced by synergist-3, and the rest was exactly the same as Example 9, to prepare the graphite material; synergist-3 was a boron-containing compound, 1,3-butanediol was mixed in a ratio of 2g:10g.

[0100] The graphite material prepared by the present application was further tested for effect, and the test results are shown below.

[0101] High temperature compressive strength: the high temperature compressive strength was tested according to GB / T 13465.11-2014 "Test methods for impermeable graphite materials Part 11: High temperature compressive strength";

[0102] High temperature flexural strength: the high temperature flexural strength was tested according to GB / T 3074.4-2016 "Test methods for high temperature flexural strength of graphite materials";

[0103] The results are recorded in Table 1;

[0104] Table 1: Test results

[0105]

[0106] According to the data in Table 1, the high-strength graphite material for rectifying column of the present application has strong high temperature compressive strength and high temperature flexural strength.

[0107] Comparing Example 9 with Comparative Example 1, Comparative Example 2 and Comparative Example 3, it can be seen that the paste used in the present application has strong high temperature compressive strength and high temperature flexural strength.

[0108] Comparing Example 9 with Comparative Example 4, it can be seen that the particle size of the modified pitch coke used is 74μm, which is not conducive to filling small pores, and the high temperature compressive strength and high temperature flexural strength of the obtained graphite material have decreased.

[0109] Comparing Example 9 with Comparative Example 5, Comparative Example 6 and Comparative Example 7, it can be seen that the used synergist is replaced by synergist-1, synergist-2 and synergist-3 respectively, and the graphite material prepared by the synergist used in the present application has stronger high temperature compressive strength and high temperature flexural strength.

[0110] The above is only an example and description of the concept of the present application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific examples, as long as they do not deviate from the concept of the present application or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A high-strength graphite material for distillation columns, characterized in that: The raw materials include the following parts by weight: 40-60 parts calcined coke, 30-45 parts modified pitch coke, 25-35 parts coal tar pitch, and 0.5-1 parts synergist; The modified pitch coke is prepared by the following steps: Step (1): Soak the pitch coke in acid solution, stir at room temperature, take it out and wash it with water until neutral, dry it, calcine it in a protective gas, and cool it in the furnace to obtain purified pitch coke; Step (2): Mix the purified pitch coke and grinding media, grind them in a protective gas atmosphere, and sieve them to obtain modified pitch coke; The synergist is a mixture of silica sol, boron-containing compounds, and small molecule polyols in a ratio of 1g:0.5-1g:5-10g. The boron-containing compound is prepared by the following steps: Boric acid was added to deionized water and stirred at 80-85℃ for 10-15 min. The mixture was filtered while hot and concentrated under reduced pressure to obtain a concentrated solution. Nitric acid solution was added to the concentrated solution at 80-85℃ and stirred for 20-25 min. The mixture was filtered while hot and then rotary evaporated to obtain a boron-containing compound. The preparation method of the high-strength graphite material for the distillation column includes the following steps: Step S1: The calcined coke is crushed by a crusher and then screened by a vibrating screen to obtain calcined coke with particle size classification. Step S2: Heat coal tar pitch in a water bath to obtain liquid coal tar pitch; combine the particle size-graded calcined coke and mix it with the liquid coal tar pitch. First, heat and knead in a kneading pot, then add modified pitch coke and synergist, and continue heating and kneading to obtain a paste. Step S3: Press the paste into a blank, place the blank in a calcination furnace, calcinate it in a protective gas atmosphere, and then transfer it to a graphitization furnace for sintering to obtain a high-strength graphite material for distillation towers.

2. The high-strength graphite material for distillation columns according to claim 1, characterized in that: In step (1), the ratio of acid solution to pitch coke is 5-8 mL: 1-1.5 g; the acid solution is obtained by mixing hydrochloric acid solution and nitric acid solution in a volume ratio of 2-3:

1.

3. The high-strength graphite material for distillation columns according to claim 1, characterized in that: In step (2), the particle size of the modified pitch coke is 5-10 μm.

4. A method for preparing a high-strength graphite material for a distillation column according to any one of claims 1-3, characterized in that: Includes the following steps: Step S1: The calcined coke is crushed by a crusher and then screened by a vibrating screen to obtain calcined coke with particle size classification. Step S2: Heat coal tar pitch in a water bath to obtain liquid coal tar pitch; combine the particle size-graded calcined coke and mix it with the liquid coal tar pitch. First, heat and knead in a kneading pot, then add modified pitch coke and synergist, and continue heating and kneading to obtain a paste. Step S3: Press the paste into a blank, place the blank in a calcination furnace, calcinate it in a protective gas atmosphere, and then transfer it to a graphitization furnace for sintering to obtain a high-strength graphite material for distillation towers.

5. The method for preparing a high-strength graphite material for a distillation column according to claim 4, characterized in that: In step S1, the particle size ranges of the calcined coke after particle size classification are 2-4mm, 0.5-2mm, and 0.074-0.5mm, respectively; the mass ratio of particles with particle size ranges of 2-4mm, 0.5-2mm, and 0.074-0.5mm is 40-50:25-35:15-35.

6. The method for preparing a high-strength graphite material for a distillation column according to claim 4, characterized in that: In step S2, the temperature of the kneading pot is 115-130℃, and the temperature of the kneading pot is further increased to 140-160℃.

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