Road asphalt material and preparation method thereof

Abstract

The invention discloses a road asphalt material and a preparation method thereof. The preparation method of the road asphalt material comprises the following steps: (1) performing supercritical solvent deasphalting separation on catalytic slurry oil to separate out different components of DAO, namely five components of 1 # DAO, 2 # DAO, 3 # DAO, 4 # DAO and DOA; (2) respectively contacting the 2 # DAO, 3 # DAO and 4 # DAO separated in the step (1) with a solid strong acid catalyst for reaction to obtain a product I, a product II and a product III; and (3) mixing vacuum residue with the product I, the product II and the product III obtained in the step (2) to obtain the road asphalt material. The road asphalt material obtained by the preparation method provided by the invention meets the technical requirements of the existing road petroleum asphalt grade A, while the performance of the road asphalt is considered, the oil slurry resource is reasonably utilized, and the comprehensive performance of the road asphalt is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of road asphalt, and specifically relates to a high-quality road asphalt material and a preparation method thereof. Background Art

[0002] Catalytic slurry oil is the remaining aromatic-rich waste slurry discharged from a catalytic cracking unit during the petroleum refining process. Most catalytic cracking processes blend vacuum residue or atmospheric residue. With the continuous heavy and inferior quality of crude oil, the total amount of metal pollutants, high-molecular-weight asphalt and gum, and heteroatom compounds such as sulfur and nitrogen shows an obvious increasing trend. At the same time, the increase in the ratio of residue blending in the feedstock has brought adverse effects such as poor product distribution and decreased unit throughput to catalytic slurry oil. To address this problem, discharging the slurry oil externally is an often-used effective method. Currently, Chinese catalytic slurry oil is mainly used as a blending component for fuel oil or heavy fuel oil, with a small scope of use and low economic benefits.

[0003] The properties of catalytic slurry oil are unstable. It usually contains about 30% - 50% saturated hydrocarbons, mainly paraffins; 40% - 60% aromatics and polycyclic aromatics, with relatively less content of mono- and di-cyclic aromatics, more content of tri- and tetra-cyclic aromatics, and few and short aromatic side chains, as well as 10% gum and asphaltene. The slurry oil contains 1% catalyst dust. As the conversion rate of the catalytic cracking feedstock increases, the density and aromatic content of the slurry oil will increase. However, the low-condensation-degree aromatics have poor temperature sensitivity and anti-aging properties and are not suitable for directly processing high-grade road asphalt.

[0004] CN104559241B discloses a method for preparing road asphalt using catalytic slurry oil. In this method, the catalytic slurry oil is subjected to vacuum distillation to obtain a topped slurry oil, and then a crosslinking agent and an activated crosslinking assistant are added to the topped slurry oil for crosslinking condensation reaction to obtain a modified slurry oil. Then, the modified slurry oil is blended with base asphalt to obtain a road asphalt product. The activated crosslinking assistant used in this method is a strong oxidizing substance, which has strong corrosion to the device, does not reasonably utilize the light components of the topped slurry oil, and requires blending with high-quality base asphalt to maintain the product properties.

[0005] CN108728147A discloses a method for preparing mesophase pitch and carbon fiber by rapid pyrolysis pretreatment of heavy oil - catalytic polycondensation. In this method, the raw material is subjected to short-term high-temperature pyrolysis pretreatment and then mixed with a catalyst to prepare mesophase pitch. The softening point of the mesophase pitch prepared by this method exceeds 230 °C and cannot be used as road asphalt. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides a road asphalt material and a preparation method thereof. The road asphalt material obtained by the preparation method of the present invention meets the technical requirements of existing Class A road petroleum asphalt. While taking into account the performance of road asphalt, the slurry resources are reasonably utilized, and the comprehensive performance of road asphalt is effectively improved.

[0007] The first aspect of the present invention provides a preparation method of a road asphalt material, comprising the following steps:

[0008] (1) Perform supercritical solvent deasphalting separation on catalytic slurry to separate DAO with different components, namely five components: 1#DAO, 2#DAO, 3#DAO, 4#DAO, and DOA;

[0009] (2) React the 2#DAO, 3#DAO, and 4#DAO separated in step (1) with a solid strong acid catalyst respectively to obtain Product I, Product II, and Product III;

[0010] (3) Mix the vacuum residue and Product I, Product II, and Product III obtained in step (2) to obtain the road asphalt material.

[0011] Further, the catalytic slurry in step (1) is a catalytic slurry produced by a catalytic cracking unit from natural petroleum, which is a mixture rich in aromatics; the content of aromatics in the slurry is 60% - 80% (by mass); the mass content of saturated hydrocarbons in the slurry is less than 30%.

[0012] Further, the method for separating the catalytic slurry in step (1) is supercritical solvent deasphalting, and the solvent used is a lower carbon alkane, preferably one or a mixture of lower carbon alkanes with carbon numbers C3, C4, and C5.

[0013] Further, the method for separating the catalytic slurry in step (1) is supercritical solvent extraction deasphalting, that is, the deasphalting is carried out by keeping the extraction temperature constant and gradually increasing the extraction pressure to achieve the separation of different fractions; wherein, the extraction temperature is 80 - 110 °C, the initial pressure of the extraction pressure is 4 - 5 MPa, and the maximum pressure does not exceed 12 MPa.

[0014] Further, the catalytic slurry separation method in step (1) comprises the following steps:

[0015] A separation method for supercritical solvent deasphalting of catalytic slurry oil, in which an alkane solvent is used to extract the catalytic slurry oil, and 1#DAO, 2#DAO, 3#DAO, 4#DAO and DOA are obtained in sequence from light to heavy. Among them, the mass ratio of 1#DAO is 12% - 17%, the mass ratio of 2#DAO is 12% - 17%, the mass ratio of 3#DAO is 17% - 23%, the mass ratio of 4#DAO is 22% - 28%, and the mass ratio of DOA is 22% - 28%.

[0016] Further, in step (2), the solid strong acid catalyst is SO4 2- / ZrO2, SO4 2- / TiO2, SO4 2- / Fe2O3, SO4 2- / Fe2O3 - Al2O3, SO4 2- / MoO3 - TiO2, and at least one of them is preferably SO4 2- / ZrO2. In step (2), in the solid strong acid catalyst, the mass content of sulfur is 9.5% - 15%. The particle size of the solid strong acid catalyst is 120 - 300 mesh. The inventor found that using the above solid strong acid catalyst in the preparation method can obtain a road asphalt material with outstanding properties.

[0017] Further, in step (2), 2#DAO in step (1) is reacted under the action of a catalyst, and the mass ratio of 2#DAO to the catalyst is (10 - 20):(1 - 3).

[0018] Further, in step (2), the reaction of 2#DAO and the catalyst in step (1) is carried out during stirring. The stirring speed is 100 r / min - 200 r / min, the reaction temperature is 150°C - 170°C, the reaction pressure is 1.5 MPa - 2.0 MPa, and the reaction time is 3 h -  6 h. When the kinematic viscosity of the material at 60°C reaches 80 - 160 Pa·s, the reaction is stopped to obtain product I.

[0019] Further, in step (2), 3#DAO in step (1) is reacted under the action of a catalyst, and the mass ratio of 3#DAO to the catalyst is (10 - 20):(1 - 3).

[0020] Further, in step (2), the reaction of 3#DAO and the catalyst in step (1) is carried out during stirring. The stirring speed is 100 r / min - 200 r / min, the reaction temperature is 170°C - 190°C, the reaction pressure is 1.5 MPa - 2.0 MPa, and the reaction time is 3 h - 5 h. When the kinematic viscosity of the material at 60°C reaches 120 - 180 Pa·s, the reaction is stopped to obtain product II.

[0021] Further, in step (2), 4#DAO in step (1) is reacted under the action of a catalyst, and the mass ratio of 4#DAO to the catalyst is (10 - 20):(1 - 3).

[0022] Further, the reaction of 4#DAO and the catalyst in step (1) in step (2) is carried out during stirring. The stirring speed is 100 r / min - 200 r / min, the reaction temperature is 190°C - 230°C, the reaction pressure is 1.5 MPa - 2.0 MPa, and the reaction time is 3 h - 5 h. When the dynamic viscosity of the material at 60°C reaches 140 - 220 Pa·s, the reaction is stopped to obtain Product III.

[0023] Further, in step (3), the vacuum residue is stirred and mixed with Product I, Product II, and Product III obtained in step (2) according to the mass ratio of (50 - 70):(8 - 17):(12 - 20):(10 - 18). The stirring speed is 200 r / min - 500 r / min, the stirring temperature is 170°C - 200°C, and the stirring time is 1 h - 2 h to obtain a high-quality road asphalt material.

[0024] Further, the vacuum residue in step (3) is a product produced by a natural petroleum through a distillation device; the fraction below 460°C in the vacuum residue does not exceed 7%.

[0025] The second aspect of the present invention provides a road asphalt material obtained by the above method for preparing a road asphalt material.

[0026] Further, the road asphalt material meets the technical requirements of road petroleum asphalt in JTG F40. Among them, the penetration (0.1 mm) of the road asphalt material of the present invention at 25°C is 40 - 100, meeting the requirements of Grade A of No. 50, No. 70, and No. 90; the softening point is not lower than 45°C, meeting the requirements of Grade A of No. 50, No. 70, and No. 90; the ductility at 10°C is not lower than 45 cm, meeting the requirements of Grade A of No. 50, No. 70, and No. 90; the dynamic viscosity at 60°C is not less than 160 Pa·s, meeting the requirements of Grade A of No. 50, No. 70, and No. 90.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) In the method provided by the present invention, the various components in the road asphalt material cooperate with each other and act together, making the material have outstanding stability, meeting the technical requirements of Grade A of the existing road petroleum asphalt. Moreover, while taking into account the performance of the road asphalt, the slurry resources are fully and reasonably utilized, having a high resource utilization value.

[0029] (2) In the method provided by the present invention, the supercritical solvent deasphalting process is used to precisely separate the components of the catalytic slurry, making the characteristics of each component slurry more concentrated, the reaction easier to control, and realizing the precise hierarchical utilization of the slurry.

[0030] (3) In the method provided by the present invention, the components of the catalytic slurry are separated, specific components of the catalytic slurry are selected, and the reaction is directionally controlled according to the characteristics to realize the molecular-level utilization of the slurry; in addition, the catalyst preparation method of the present invention is simple, the properties are stable, and when acting on the components of the catalytic slurry, it can improve the reaction rate of the oligomers in the catalytic slurry, has a good catalytic effect on the oligomerization reaction, and does not require a complex separation process to separate the catalyst remaining in the product. The components of the catalytic slurry of the present invention and the catalyst react to cause the unsaturated bonds in the catalytic slurry to condense and crosslink, reducing the small molecule substances and increasing the macromolecule substances in the catalytic slurry, and the thermal stability and chemical stability of the molecules are better, thereby improving the thermal stability of the road asphalt material.

[0031] (4) Each component in the road asphalt material provided by the present invention cooperates with each other and acts together, making the material have outstanding stability, meeting the technical requirements of Grade A of road petroleum asphalt in JTG F40, and while taking into account the performance of the road asphalt, the slurry resources are fully and reasonably utilized, having a high resource utilization value. Specific embodiments

[0032] The technical solutions and effects of the present invention will be further described below through examples. The examples are implemented on the premise of the technical solutions of the present invention, and the detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following examples.

[0033] Example 1

[0034] Using a supercritical solvent deasphalting device, propane as the solvent, and a constant temperature and pressure increase method to extract and separate the catalytic slurry (the catalytic slurry is the catalytic slurry produced by a catalytic cracking unit from natural petroleum and is a mixture rich in aromatics. The mass content of aromatics in 3 kg of the slurry is 73%. The mass content of saturated hydrocarbons in the slurry is 19%). The extraction temperature is 98 °C, the initial extraction pressure is 4.3 MPa, and the maximum is 12 MPa. By mass, the initial 15% fraction is obtained as 1#DAO, the 15% - 30% fraction is obtained as 2#DAO, the 30% - 50% fraction is obtained as 3#DAO, the 50% - 75% fraction is obtained as 4#DAO, and the fraction greater than 75% is obtained as DOA. The specific composition and content are shown in Table 1.

[0035] Table 1 Component content obtained by solvent deasphalting of catalytic slurry

[0036] Component Name 1#DAO 2#DAO 3#DAO 4#DAO DOA Component mass content, % 15 15 20 25 25

[0037] The catalyst is SO4 2- / Fe2O3. Among them, the mass content of sulfur is 10.6%. The particle size is 200 mesh.

[0038] Add 2# DAO and the catalyst into the reaction kettle and stir to carry out the reaction. The mass ratio of 2# DAO to the catalyst is 15:3, the stirring speed is 150 r / min, the reaction temperature is 160 °C, the reaction pressure is 2.0 MPa, and the reaction time is 5 h. When the dynamic viscosity of the material at 60 °C reaches 120 Pa·s, stop the reaction to obtain Product I.

[0039] Add 3# DAO and the catalyst into the reaction kettle and stir to carry out the reaction. The mass ratio of 3# DAO to the catalyst is 20:3, the stirring speed is 150 r / min, the reaction temperature is 180 °C, the reaction pressure is 1.6 MPa, and the reaction time is 3 h. When the dynamic viscosity of the material at 60 °C reaches 150 Pa·s, stop the reaction to obtain Product II.

[0040] Add 4# DAO and the catalyst into the reaction kettle and stir to carry out the reaction. The mass ratio of 4# DAO to the catalyst is 10:1, the stirring speed is 150 r / min, the reaction temperature is 220 °C, the reaction pressure is 1.5 MPa, and the reaction time is 3 h. When the dynamic viscosity of the material at 60 °C reaches 180 Pa·s, stop the reaction to obtain Product III.

[0041] Take 1.9 kg of vacuum residue (the fraction below 460 °C in the vacuum residue is 6.7%) and stir and mix the products I, II, and III after the reaction of 2# DAO, 3# DAO, and 4# DAO according to the mass ratio of 58:16: :14:12, the stirring speed is 350 r / min, the stirring temperature is 185 °C, and the stirring time is 1 h to obtain a high-quality road asphalt material.

[0042] Example 2

[0043] The components and contents obtained by catalytic slurry solvent deasphalting are the same as those in Example 1, and the specific contents are shown in Table 1.

[0044] The catalyst is SO4 2- / Fe2O3 - Al2O3. Among them, the mass content of sulfur is 11.3%. The particle size is 200 mesh.

[0045] Add 2# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 2# DAO to the catalyst is 15:1, the stirring speed is 150 r / min, the reaction temperature is 150 °C, the reaction pressure is 2.0 MPa, and the reaction time is 4 h. When the dynamic viscosity of the material at 60 °C reaches 120 Pa·s, stop the reaction to obtain Product I.

[0046] Add 3# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 3# DAO to the catalyst is 15:2, the stirring speed is 150 r / min, the reaction temperature is 170 °C, the reaction pressure is 1.6 MPa, and the reaction time is 4 h. When the dynamic viscosity of the material at 60 °C reaches 150 Pa·s, stop the reaction to obtain Product II.

[0047] Add 4# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 4# DAO to the catalyst is 15:3, the stirring speed is 150 r / min, the reaction temperature is 210 °C, the reaction pressure is 1.5 MPa, and the reaction time is 4 h. When the dynamic viscosity of the material at 60 °C reaches 180 Pa·s, stop the reaction to obtain Product III.

[0048] Mix 1.7 kg of vacuum residue (the fraction below 460 °C in the vacuum residue is 6.7%) with Products I, II, and III after the reaction of 2# DAO, 3# DAO, and 4# DAO by stirring at a mass ratio of 56:13:16:15. The stirring speed is 350 r / min, the stirring temperature is 185 °C, and the stirring time is 1 h to obtain a high-quality road asphalt material.

[0049] Example 3

[0050] The components and contents obtained by catalytic slurry solvent deasphalting are the same as those in Example 1, and the specific contents are shown in Table 1.

[0051] The catalyst is SO4 2- / ZrO2. Among them, the mass content of sulfur is 10.2%. The particle size is 200 mesh.

[0052] Add 2# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 2# DAO to the catalyst is 15:1, the stirring speed is 150 r / min, the reaction temperature is 170 °C, the reaction pressure is 2.0 MPa, and the reaction time is 6 h. When the dynamic viscosity of the material at 60 °C reaches 120 Pa·s, stop the reaction to obtain Product I.

[0053] Add 3# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 3# DAO to the catalyst is 15:3, the stirring speed is 150 r / min, the reaction temperature is 190 °C, the reaction pressure is 1.6 MPa, and the reaction time is 5 h. When the dynamic viscosity of the material at 60 °C reaches 150 Pa·s, stop the reaction to obtain Product II.

[0054] Add 4# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 4# DAO to the catalyst is 15:2, the stirring speed is 150 r / min, the reaction temperature is 230 °C, the reaction pressure is 1.5 MPa, and the reaction time is 5 h. When the dynamic viscosity of the material at 60 °C reaches 180 Pa·s, stop the reaction to obtain Product III.

[0055] Mix 1.3 kg of vacuum residue (the fraction below 460 °C in the vacuum residue is 6.7%) with the reaction products I, II, and III of 2# DAO, 3# DAO, and 4# DAO according to the mass ratio of 55:9:19:17, stir at a speed of 350 r / min, a temperature of 185 °C, and a time of 1 h to obtain a high-quality road asphalt material.

[0056] Comparative Example 1

[0057] The components and contents obtained by solvent deasphalting of catalytic slurry are the same as those in Example 1, and the specific contents are shown in Table 1.

[0058] The catalyst is the same as that in Example 1.

[0059] Add 2# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 2# DAO to the catalyst is 15:6, the stirring speed is 150 r / min, the reaction temperature is 160 °C, the reaction pressure is 2.0 MPa, and when the reaction time is 5 h, stop the reaction to obtain Product I.

[0060] Add 3# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 3# DAO to the catalyst is 20:7, the stirring speed is 150 r / min, the reaction temperature is 180 °C, the reaction pressure is 1.6 MPa, and when the reaction time is 3 h, stop the reaction to obtain Product II.

[0061] Add 4# DAO and the catalyst into a reaction kettle and stir to carry out the reaction. The mass ratio of 4# DAO to the catalyst is between 10:2, the stirring speed is 150 r / min, the reaction temperature is 220 °C, the reaction pressure is 1.5 MPa, and when the reaction time is 3 h, stop the reaction to obtain Product III.

[0062] Mix the vacuum residue (the fraction below 460 °C in the vacuum residue is 6.7%) with the reaction products I, II, and III of 2# DAO, 3# DAO, and 4# DAO in a mass ratio of 58:16:14:12, stir at a speed of 350 r / min, a temperature of 185 °C, and for 1 h to obtain a road asphalt material.

[0063] Comparative Example 2

[0064] The components and contents obtained by catalytic slurry solvent deasphalting are the same as in Example 1, and the specific contents are shown in Table 1.

[0065] Add 2# DAO to the reaction kettle and stir to react at a stirring speed of 150 r / min, a reaction temperature of 170 °C, a reaction pressure of 2.0 MPa, and stop the reaction after 6 h to obtain Product I.

[0066] Add 3# DAO to the reaction kettle and stir to react at a stirring speed of 150 r / min, a reaction temperature of 190 °C, a reaction pressure of 1.6 MPa, and stop the reaction after 5 h to obtain Product II.

[0067] Add 4# DAO to the reaction kettle and stir to react at a stirring speed of 150 r / min, a reaction temperature of 230 °C, a reaction pressure of 1.5 MPa, and stop the reaction after 5 h to obtain Product III.

[0068] Mix the vacuum residue (the fraction below 460 °C in the vacuum residue is 6.7%) with the reaction products I, II, and III of 2# DAO, 3# DAO, and 4# DAO in a mass ratio of 55:9:19:17, stir at a speed of 350 r / min, a temperature of 185 °C, and for 1 h to obtain a road asphalt material.

[0069] Comparative Example 3

[0070] The components and contents obtained by catalytic slurry solvent deasphalting are the same as in Example 1, and the specific contents are shown in Table 1.

[0071] The preparation of the catalyst is the same as in Example 1.

[0072] Mix 2# DAO, 3# DAO, and 4# DAO in a mass ratio of 19:9:6, then add them to the reaction kettle with the catalyst and stir to react. The mass ratio of the mixed DAO to the catalyst is 15:3, the stirring speed is 150 r / min, the reaction temperature is 160 °C, the reaction pressure is 2.0 MPa, and stop the reaction after 5 h.

[0073] The materials after the reaction of vacuum residue and mixed DAO were stirred and mixed at a mass ratio of 58:42, with a stirring speed of 350 r / min, a stirring temperature of 185 °C, and a stirring time of 1 h to obtain a road asphalt material.

[0074] The road asphalt materials prepared in Examples 1-3 and Comparative Examples 1-3 were tested with reference to some technical requirements of JTG F40-2004 "Technical Specifications for Construction of Highway Asphalt Pavements". The specific test methods and technical requirements are shown in Table 2, and the test results are shown in Table 3.

[0075] Table 2 Technical Requirements

[0076]

[0077]

[0078] Table 3 Properties of Road Asphalt Materials

[0079]

[0080] From the comparison results in Table 3, the main indicators of Examples 1-3 all meet the requirements of Grade A of road petroleum asphalt, and are significantly better than the performance of Comparative Examples 1-3.

Claims

1. A preparation method of a road asphalt material, comprising the following steps: (1) Perform supercritical solvent deasphalting separation on catalytic slurry oil to separate DAO with different components, namely five components: 1#DAO, 2#DAO, 3#DAO, 4#DAO, and DOA; (2) Contact the 2#DAO, 3#DAO, and 4#DAO separated in step (1) with a solid strong acid catalyst respectively for reaction to obtain Product I, Product II, and Product III; (3) Mix the vacuum residue oil with Product I, Product II, and Product III obtained in step (2) to obtain the said road asphalt material.

2. The preparation method according to claim 1, characterized in that, The catalytic slurry oil in step (1) is the catalytic slurry oil produced by a catalytic cracking unit from natural petroleum, and is a mixture rich in aromatics. The mass content of aromatics in the slurry oil is 60% - 80%; the mass content of saturated hydrocarbons in the slurry oil is less than 30%.

3. The preparation method according to claim 1, wherein In step (1), the separation of the catalytic slurry oil is carried out by the method of supercritical solvent deasphalting, and the solvent used is a lower-carbon alkane.

4. The preparation method according to claim 1, wherein, In step (1), the separation of the catalytic slurry oil is carried out by the method of supercritical solvent deasphalting, that is, the deasphalting is carried out by keeping the extraction temperature constant and gradually increasing the extraction pressure to separate different fractions; among them, the extraction temperature is 80 - 110 °C, the initial pressure of the extraction pressure is 4 - 5 MPa, and the maximum pressure does not exceed 12 MPa.

5. The preparation method according to claim 1 or 4, characterized in that, The method for separating the catalytic slurry oil in step (1) comprises the following steps: The separation method of supercritical solvent deasphalting of catalytic slurry oil, in which the catalytic slurry oil is extracted with an alkane solvent, and 1#DAO, 2#DAO, 3#DAO, 4#DAO, and DOA are obtained in order from light to heavy. Among them, the mass ratio of 1#DAO is 12% - 17%, the mass ratio of 2#DAO is 12% - 17%, the mass ratio of 3#DAO is 17% - 23%, the mass ratio of 4#DAO is 22% - 28%, and the mass ratio of DOA is 22% - 28%.

6. The preparation method according to claim 1, characterized in that, In step (2), the solid strong acid catalyst is SO4 2- / ZrO2, SO4 2- / TiO2, SO4 2- / Fe2O3, SO4 2- / Fe2O3 - Al2O3, SO4 2- / MoO3 - TiO2, at least one of them, preferably SO4 2- / ZrO2.

7. The preparation method according to claim 6, characterized in that, In step (2), in the said solid strong acid catalyst, the mass content of sulfur is 9.5% - 15%; and / or, the particle size of the said solid strong acid catalyst is 120 - 300 mesh.

8. The preparation method according to claim 1, characterized in that, In step (2), the 2#DAO in step (1) is reacted under the action of a catalyst, and the mass ratio of 2#DAO to the catalyst is (10 - 20):(1 - 3); and / or, in step (2), the reaction of 2#DAO and the catalyst in step (1) is carried out during stirring, the stirring speed is 100 r / min - 200 r / min, the reaction temperature is 150 °C - 170 °C, the reaction pressure is 1.5 MPa - 2.0 MPa, the reaction time is 3 h - 6 h, and when the kinematic viscosity of the material at 60 °C reaches 80 - 160 Pa·s, the reaction is stopped to obtain Product I.

9. The preparation method according to claim 1, characterized in that, In step (2), the 3#DAO in step (1) is reacted under the action of a catalyst, and the mass ratio of 3#DAO to the catalyst is (10 - 20):(1 - 3); And / or, in step (2), the reaction between 3#DAO in step (1) and the catalyst is carried out during stirring, the stirring speed is 100 r / min to 200 r / min, the reaction temperature is 170 °C to 190 °C, the reaction pressure is 1.5 MPa to 2.0 MPa, the reaction time is 3 h to 5 h, and when the dynamic viscosity of the material at 60 °C reaches 120 to 180 Pa·s, the reaction is stopped to obtain product II.

10. The preparation method according to claim 1, wherein In step (2), 4#DAO in step (1) is reacted under the action of a catalyst, and the mass ratio of 4#DAO to the catalyst is (10 - 20):(1 - 3); And / or, in step (2), the reaction between 4#DAO in step (1) and the catalyst is carried out during stirring, the stirring speed is 100 r / min to 200 r / min, the reaction temperature is 190 °C to 230 °C, the reaction pressure is 1.5 MPa to 2.0 MPa, the reaction time is 3 h to 5 h, and when the dynamic viscosity of the material at 60 °C reaches 140 to 220 Pa·s, the reaction is stopped to obtain product III.

11. According to the preparation method described in claim 1, characterized in that, In step (3), the vacuum residue is stirred and mixed with product I, product II, and product III obtained in step (2) according to the mass ratio of (50 - 70):(8 - 17):(12 - 20):(10 - 18), the stirring speed is 200 r / min to 500 r / min, the stirring temperature is 170 °C to 200 °C, and the stirring time is 1 h to 2 h to obtain a road asphalt material; And / or, in step (3), the fraction of the vacuum residue below 460 °C does not exceed 7%.

12. A road asphalt material obtained by the preparation method according to any one of claims 1 - 11.

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