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CN-117986886-B - Modified asphalt and preparation method thereof

CN117986886BCN 117986886 BCN117986886 BCN 117986886BCN-117986886-B

Abstract

The invention relates to modified asphalt and a preparation method thereof, which comprises the steps of (1) mixing styrene tar with a pretreatment solvent, standing and layering, separating an upper layer liquid and a lower layer liquid, (2) respectively removing the pretreatment solvent in the upper layer liquid and the lower layer liquid to obtain a liquid phase Y1 and a liquid phase Y2, (3) mixing waste rubber powder with the liquid phase Y1 for reaction, performing solid-liquid separation to obtain a solid phase G1, simultaneously recovering the separated liquid phase Y3, (4) mixing the solid phase G1 with the liquid phase Y2 for reaction to obtain a mixture G2, and (5) adding the mixture G2 into matrix asphalt to obtain the modified asphalt. The invention pretreats the dangerous waste styrene tar and then uses the pretreated styrene tar as an additive, improves the mixing effect of the waste rubber powder and the matrix asphalt, ensures the product quality, realizes the recycling of the styrene tar and reduces the production cost.

Inventors

  • HUI JUN
  • SUN HAOCHENG
  • LIU CHUNYANG
  • WANG YIDI

Assignees

  • 中国石油化工股份有限公司
  • 中石化（大连）石油化工研究院有限公司

Dates

Publication Date
20260505
Application Date
20221027

Claims (20)

  1. 1. The preparation method of the modified asphalt is characterized by comprising the following steps: (1) Mixing styrene tar with a pretreatment solvent, standing and layering, and separating an upper layer liquid and a lower layer liquid, wherein the pretreatment solvent is at least one of alkane with a liquid phase in a standard state and a carbon number of not more than 12 and a mixture thereof, and the styrene tar is rectification residue of a product rectification link in the production process of preparing styrene by ethylbenzene dehydrogenation, and mainly contains styrene, stilbene, diphenylethane, polycyclic aromatic hydrocarbon and polymerization inhibitor components; (2) Removing pretreatment solvents in the upper layer liquid and the lower layer liquid respectively to obtain a liquid phase Y1 and a liquid phase Y2; (3) Mixing waste rubber powder with liquid phase Y1 for reaction, performing solid-liquid separation after the reaction to obtain solid phase G1, and simultaneously recovering separated liquid phase Y3; (4) Mixing the solid phase G1 with the liquid phase Y2 for reaction to obtain a mixture G2; (5) The mixture G2 is added into the matrix asphalt to prepare the modified asphalt.
  2. 2. The method according to claim 1, wherein the pretreatment solvent in the step (1) is at least one of C4-C12 linear alkane, branched alkane, and cycloalkane.
  3. 3. The method according to claim 2, wherein the pretreatment solvent in the step (1) is at least one of C5-C9 linear alkane, branched alkane, and cycloalkane.
  4. 4. The method according to claim 1,2 or 3, wherein the mass ratio of the styrene tar to the pretreatment solvent in the step (1) is 1:1-4.
  5. 5. The method according to claim 4, wherein the mass ratio of the styrene tar to the pretreatment solvent in the step (1) is 1:2-3.5.
  6. 6. The method of claim 1, wherein the step (2) of removing the pretreatment solvent from the supernatant and the subnatant is performed by evaporation, and the evaporated pretreatment solvent is recycled after being recovered.
  7. 7. A process as claimed in claim 1 or 5, wherein the temperature for removing the pretreatment solvent is 50 to 200 ℃.
  8. 8. The method according to claim 7, wherein the temperature for removing the pretreatment solvent is 90-180 ℃.
  9. 9. The method of claim 1, wherein the waste rubber powder in the step (3) is obtained by crushing waste tires, and the mesh number of the waste rubber powder is 40-80 mesh.
  10. 10. The method of claim 1, wherein the mass ratio of the waste rubber powder to the liquid phase Y1 in the step (3) is 0.1-5:1.
  11. 11. The method of claim 10, wherein the mass ratio of the waste rubber powder to the liquid phase Y1 in the step (3) is 0.2-2:1.
  12. 12. The method according to claim 1 or 10, wherein the reaction temperature in the step (3) is 20-80 ℃, the stirring speed is 20-120r/min, and the reaction time is 2-4h.
  13. 13. The method according to claim 12, wherein the reaction temperature in the step (3) is 30-50 ℃ and the stirring speed is 30-60r/min.
  14. 14. The process according to claim 1, wherein the liquid phase Y3 recovered in step (3) is recycled to the aromatics plant, to the refinery or as a purge oil.
  15. 15. The method according to claim 1, wherein the mass ratio of the liquid phase Y2 to the solid phase G1 in the step (4) is 0.2 to 20:1.
  16. 16. The method according to claim 15, wherein the mass ratio of the liquid phase Y2 to the solid phase G1 in the step (4) is 0.5-3:1.
  17. 17. The method according to claim 1 or 15, wherein the reaction temperature in the step (4) is 30-80 ℃, the stirring speed is 20-120r/min, and the reaction time is 20-60min.
  18. 18. The method according to claim 17, wherein the reaction temperature in the step (4) is 40-60 ℃ and the stirring speed is 30-60r/min.
  19. 19. The method of claim 1, wherein the mass of the mixture G2 in the step (5) is 5-50% of the mass of the matrix asphalt.
  20. 20. The method of claim 19, wherein the mass of the mixture G2 in the step (5) is 10% -30% of the mass of the matrix asphalt.

Description

Modified asphalt and preparation method thereof Technical Field The invention relates to modified asphalt and a preparation method thereof, and belongs to the technical field of road asphalt. Background The waste rubber is a common high-molecular elastic material, has refractory property, heat resistance, biological corrosion resistance and good mechanical strength, is difficult to degrade in a natural state, and is a solid waste with great industrial hazard. The recycling of the waste tires can relieve the environmental pressure, and has positive effects on the resource saving and economic sustainable development of China. The rubber powder obtained by crushing the waste rubber is mixed with asphalt to prepare rubber powder modified asphalt, which is one of common recycling means of the waste rubber. In recent years, the exploration of the rubber powder modified asphalt shows that the rubber powder modified asphalt can obviously improve the durability and crack resistance of a pavement, improve the low-temperature flexibility of the asphalt, improve the viscosity of the asphalt and prolong the fatigue life of the pavement, but the defects that the rubber powder and the asphalt are insufficient in reaction, the rubber powder modified asphalt formed by simple physical blending is easy to separate, the system stability is poor and the like are also present. Wang Hui et al (based on chemistry modified waste rubber powder composite modified asphalt performance and mechanism research [ J ]. Hunan university (Nature) journal 2021, v.48; no.330 (06): 30-37.) respectively prepare common rubber powder modified asphalt and waste rubber powder composite modified asphalt, the two preparation processes are similar, the difference is that the common rubber powder modified asphalt is not added with any other modifier except rubber powder, namely, after the matrix asphalt is heated to 170-180 ℃, 28% of waste rubber powder is slowly added, and stirred uniformly, then 180 ℃ is kept, shearing is carried out for 30min at 5000r/min, and then development is carried out for 45min in a 175 ℃ oven, and the common rubber powder modified asphalt is prepared, and the composite modified asphalt is added with 2% softener, 2.5% of activator and 3% of cross-linking agent in the preparation process. The property monitoring of the modified asphalt and the modified asphalt shows that the modified asphalt has better softening point and higher high-temperature performance than the modified asphalt, and meanwhile, the elastic recovery property of the modified asphalt is higher, so that the addition of the cross-linking agent inhibits the layering of the waste rubber powder and the matrix asphalt, and the rubber powder particles in the modified asphalt are uniformly dispersed in the asphalt. CN202010327928.6 discloses SBS/rubber powder composite modified asphalt based on Xinjiang asphalt and a preparation method, wherein the SBS/rubber powder composite modified asphalt is prepared from the following raw materials, by weight, 100 parts of Xinjiang mixed asphalt, 2-4 parts of SBS, 10-20 parts of rubber powder, 1.5-3.5 parts of compatilizer, 2-4 parts of plasticizer, 1-2 parts of reinforcing agent, 0.5-1 part of coupling agent and 0.2 part of stabilizer. The preparation method specifically comprises the following steps of firstly pretreating SBS, secondly blending Xinjiang asphalt, thirdly modifying and developing asphalt, and fourthly re-developing asphalt. The problems of poor compatibility and difficult modification of the Xinjiang local asphalt (carageenan asphalt, turrified asphalt and the like) with the modifier such as rubber powder, SBS and the like are effectively solved by means of asphalt blending, adding a plurality of auxiliary agents and the like. CN201911149481.1 discloses a preparation method of a regenerated rubber asphalt mixture, which belongs to the technical field of asphalt and comprises the following steps of S1, weighing 10-30 parts of rubber oil and 60-80 parts of rubber powder according to parts by weight, adding the rubber powder into the rubber oil to swell for more than 6 hours at the temperature of 20-40 ℃ to obtain a mixture, S2, adding 60-80 parts of new aggregate according to parts by weight into a container to mix, adding the mixture in the step S1, adding 20-40 parts of pavement reclaimed materials according to parts by weight, 4-10 parts of matrix asphalt, 1.7-2.8 parts of 70# asphalt and 6-12 parts of filler to obtain the regenerated rubber asphalt mixture, wherein the prepared regenerated rubber asphalt has good low-temperature performance. According to the above patent, in the prior art, when the mixing effect of the rubber powder and the matrix asphalt is improved, the additive is added, although a certain effect is achieved, the overall production cost is possibly increased, if the additive can be replaced by adopting industrial byproducts or even solid waste, the quality of the product is not affected, the