Road asphalt based on qualified coal asphalt and preparation method thereof

Abstract

The invention relates to the technical field of road materials, in particular to road asphalt based on qualified coal pitch and a preparation method of the road asphalt, and the road asphalt based on the qualified coal pitch comprises 10-25 parts of deashed coal pitch, 45-55 parts of petroleum asphalt, 5-15 parts of unsaturated fatty acid, 20-40 parts of petroleum extract oil, 1-10 parts of a coupling agent and 1-10 parts of a plasticizer. The preparation process of the de-ashed coal pitch comprises the following steps: mixing qualified coal pitch with a solvent, stirring, centrifuging, and carrying out reduced pressure distillation to obtain the de-ashed coal pitch. According to the method, the qualified coal pitch is subjected to ash removal, so that the coal pitch can meet the requirement of serving as a road asphalt raw material, and efficient utilization of the low-cost qualified coal pitch in the road asphalt is realized. Meanwhile, the road asphalt provided by the invention has good construction performance, thermal stability and low-temperature ductility, meets the requirements of various indexes of 70 # road asphalt, and is suitable for paving high-grade roads.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road materials, in particular to a road asphalt based on qualified coal pitch and a preparation method thereof. BACKGROUND

[0002] In traditional road construction, petroleum asphalt has always been the main cementing material. However, petroleum asphalt is expensive, and finding a substitute for petroleum asphalt has become a research hotspot in the field of road engineering. Coal pitch, as a residue after distillation of coal tar, is abundant in production. However, due to the significant difference between the structure of coal pitch and petroleum asphalt, the high content of ash and free carbon leads to many deficiencies in performance. For example, the ductility of coal pitch is poor, which makes the road surface prone to cracking at low temperatures after the application of coal pitch to road materials, affecting the service life of the road and driving safety. And in the process of use, it may release some harmful gases and substances, which pose a potential threat to the environment and human health. Although coal pitch can be used as an additive component mixed with petroleum asphalt, due to its own defects, the amount of addition is greatly limited. If the coal pitch is directly modified, such as using oxidation, polymer modification and other methods, not only the process is complex, but also the cost is high. This has led to the fact that coal pitch has always been difficult to meet the technical indicators of road asphalt and cannot be widely used in road construction. SUMMARY

[0003] The purpose of the present application is to provide a road asphalt based on qualified coal pitch and a preparation method thereof, to solve the problems of poor mechanical properties and low environmental protection of road asphalt when coal pitch is used as a raw material for road asphalt, to realize the efficient use of coal pitch in road asphalt, and to reduce the dependence of road construction on petroleum asphalt.

[0004] To achieve the above-mentioned purpose, the present application provides a road asphalt based on qualified coal pitch, which comprises the following raw materials in mass fraction: deashed coal pitch 10-25 parts, petroleum asphalt 45-55 parts, unsaturated fatty acid 5-15 parts, petroleum extract oil 20-40 parts, coupling agent 1-10 parts, plasticizer 1-10 parts; The preparation process of deashed coal pitch includes: mixing qualified coal pitch with a solvent, stirring, centrifugation, and reduced pressure distillation to obtain deashed coal pitch.

[0005] In the present application, the solvent includes a mixed solution of petroleum ether and aromatic solvent oil or a mixed solution of petroleum ether, aromatic solvent oil and diesel oil.

[0006] In the present application, the aromatic solvent oil includes 120 (grade) solvent oil, and the diesel oil includes at least one of light diesel oil or heavy diesel oil.

[0007] In the application, the softening point of the qualified coal pitch is 140-160 DEG C, the ductility of the qualified coal pitch is 0-0.8 cm, the penetration of the qualified coal pitch is 0-1 (unit: 0.1 mm), the quinoline insoluble (QI) of the qualified coal pitch is less than or equal to 1.0%, and the ash content of the qualified coal pitch is less than or equal to 22%. The coal pitch selected in the application is the qualified coal pitch, which has low cost and is widely available.

[0008] In the application, the qualified coal pitch meets the requirements of GB / T 38772-2020.

[0009] In the application, the mass ratio of the qualified coal pitch to the solvent is 1:1-3.

[0010] In the application, the mixing temperature is 80-130 DEG C, the centrifugal temperature is 80-95 DEG C, the centrifugal time is 10-20 min, and the centrifugal speed is 3000-5000 rpm.

[0011] In the application, the mixing time is not limited, and the qualified coal pitch can be dissolved until the mixing time.

[0012] In the application, the reduced pressure distillation can recover the solvent and reduce the production cost.

[0013] The preparation process of the deashed coal pitch provided in the application can remove the ash and free carbon impurities in the qualified coal pitch, and the ash content in the final obtained deashed coal pitch is only 0.1-2.0%.

[0014] In the application, the petroleum pitch is 70# petroleum pitch.

[0015] In the application, the unsaturated fatty acid includes vegetable acid.

[0016] In the application, the vegetable acid includes cottonseed oil or soybean oil.

[0017] In the application, the petroleum extract oil includes molecular sieve dewaxing extract oil.

[0018] In the application, the coupling agent includes aromatic diacid ester or silane coupling agent, the aromatic hydrocarbon content of the aromatic diacid ester is greater than or equal to 10%, and the plasticizer includes aromatic rubber oil, and the aromatic hydrocarbon content is greater than or equal to 10%.

[0019] The application also provides a preparation method of the road pitch based on the qualified coal pitch, which comprises the following preparation steps: The deashed coal pitch, the petroleum pitch, the unsaturated fatty acid, the petroleum extract oil, the coupling agent and the plasticizer are mixed and stirred to obtain the road pitch.

[0020] In the present application, the temperature of stirring is 120-180 DEG C, the rotating speed of stirring is 500-1000 r / min, and the time of stirring is 20-50 min.

[0021] The present application has the following beneficial effects: The present application provides a kind of road asphalt based on qualified product coal pitch, including the following mass parts of raw materials: deashing coal pitch 10-25 parts, petroleum pitch 45-55 parts, unsaturated fatty acid 5-15 parts, petroleum extract oil 20-40 parts, coupling agent 1-10 parts, plasticizer 1-10 parts;The preparation process of deashing coal pitch includes: after mixing qualified product coal pitch with solvent, stirring, centrifugation, reduced pressure distillation, obtain deashing coal pitch.

[0022] The present application uses qualified product coal pitch (qualified product coal pitch specified in GB / T 38772-2020) as raw material, realizes efficient utilization of low-cost qualified product coal pitch in road asphalt. By deashing (preparation process of deashing coal pitch) qualified product coal pitch, the ash and quinoline insoluble in qualified product coal pitch are effectively removed, so that it meets the requirement of being used as raw material of road asphalt, reduces the dependence of road asphalt on high-quality coal pitch, and significantly reduces the production cost of road asphalt.

[0023] The road asphalt provided by the present application has excellent low-temperature stability and adhesion, improves the cracking phenomenon of road asphalt at low temperature. At the same time, it has excellent anti-aging performance, prolongs the service life, and meets the strict requirements of road construction on road asphalt.

[0024] The road asphalt provided by the present application meets the requirements of 70# road asphalt in terms of penetration, softening point and ductility, and is suitable for high-grade highway paving.

[0025] The present application further limits the solvent to include a mixed solution of petroleum ether and aromatic solvent oil or a mixed solution of petroleum ether, aromatic solvent oil and diesel oil. Among them, petroleum ether can dissolve low molecular weight aromatic hydrocarbons (such as acenaphthene and fluorene) in qualified product coal pitch, release the wrapped ash particles and improve the ash exposure rate. Aromatic solvent oil releases the wrapped ash particles by directional depolymerization of the condensed ring aromatic hydrocarbon network of quinoline insoluble (QI) through π-π interaction. Diesel oil can reduce the viscosity of the system and improve the flowability, so that the free ash and quinoline insoluble in qualified product coal pitch can be better separated.

[0026] The technical solutions of the present application will be further described in detail through examples. DETAILED DESCRIPTION

[0027] The present application will be further described in connection with the following examples. Unless otherwise defined, the technical or scientific terms used in the present application shall have the ordinary meaning as understood by a person having ordinary skill in the art to which the present application pertains. The features mentioned in the present application or the features mentioned in the specific examples can be combined in any manner, and the specific examples are only used to illustrate the present application and not to limit the scope of the present application.

[0028] Example 1 The preparation process of the de-ashed coal pitch includes: The qualified coal pitch 100 parts and the solvent 100 parts are mixed at a temperature of 80℃, stirred, the temperature is kept unchanged, centrifuged at a speed of 4000rpm for 15min, the residue is discarded, the centrifugal liquid obtained by centrifugation is subjected to vacuum distillation, and the de-ashed coal pitch (quinoline insoluble content is 0.4%, ash content is <2%) is obtained, and the solvent obtained in the vacuum distillation process is recovered; Among them, the solvent used above is petroleum ether 30 parts, 120# solvent oil (aromatic hydrocarbon solvent oil) 40 parts and light diesel oil 30 parts.

[0029] A road asphalt based on qualified coal pitch includes the following mass parts of raw materials: The de-ashed coal pitch 10 parts, 70# petroleum pitch 55 parts, cottonseed oil (unsaturated fatty acid) 5 parts, molecular sieve dewaxing extracted oil (petroleum extracted oil) 20 parts, aromatic dibasic acid ester (coupling agent) 5 parts, and aromatic rubber oil (plasticizer) 5 parts.

[0030] The preparation method of the road asphalt includes the following preparation steps: The de-ashed coal pitch 10 parts, 70# petroleum pitch 55 parts, cottonseed oil 5 parts, molecular sieve dewaxing extracted oil 20 parts, aromatic dibasic acid ester 5 parts, and aromatic rubber oil 5 parts are mixed, stirred at a speed of 500rpm at a temperature of 180℃ for 50min, and then the road asphalt is obtained.

[0031] Example 2 The preparation process of the de-ashed coal pitch includes: The qualified coal pitch 100 parts and the solvent 150 parts are mixed at a temperature of 90℃, stirred, the temperature is kept unchanged, centrifuged at a speed of 4000rpm for 10min, the residue is discarded, the centrifugal liquid obtained by centrifugation is subjected to vacuum distillation, and the de-ashed coal pitch (quinoline insoluble content is 0.4%, ash content is <2%) is obtained, and the solvent obtained in the vacuum distillation process is recovered; Among them, the solvent used above is petroleum ether 50 parts, 120# solvent oil (aromatic hydrocarbon solvent oil) 60 parts and light diesel oil 40 parts.

[0032] A road asphalt based on qualified coal pitch includes the following mass parts of raw materials: The above de-ashed coal pitch 15 parts, 70# petroleum pitch 55 parts, soybean oil (unsaturated fatty acids) 10 parts, molecular sieve dewaxing extracted oil (petroleum extracted oil) 25 parts, aromatic dibasic acid ester 5 parts (coupling agent), aromatic rubber oil (plasticizer) 10 parts.

[0033] The above preparation method of the road pitch comprises the following preparation steps: The de-ashed coal pitch 15 parts, 70# petroleum pitch 55 parts, soybean oil 10 parts, molecular sieve dewaxing extracted oil 25 parts, aromatic dibasic acid ester 5 parts, aromatic rubber oil 10 parts are mixed, stirred at a temperature of 180°C and a speed of 500 rpm for 40 min, and then the road pitch is obtained.

[0034] Example 3 The preparation process of the de-ashed coal pitch comprises: The qualified coal pitch 100 parts and the solvent 200 parts are mixed at a temperature of 95°C, stirred, centrifuged at a speed of 4000 rpm for 15 min, and the residue is discarded. The centrifugal liquid obtained by centrifugation is subjected to reduced pressure distillation to obtain the de-ashed coal pitch (the quinoline insoluble content is 0.3%, and the ash content is <1%), and the solvent obtained in the reduced pressure distillation process is recovered. The above solvent comprises petroleum ether 80 parts, 120# solvent oil (aromatic hydrocarbon solvent oil) 55 parts, and heavy diesel oil 65 parts.

[0035] A road pitch based on qualified coal pitch comprises the following raw materials in mass parts: The above de-ashed coal pitch 20 parts, 70# petroleum pitch 50 parts, cottonseed oil (unsaturated fatty acids) 8 parts, molecular sieve dewaxing extracted oil (petroleum extracted oil) 40 parts, aromatic dibasic acid ester (coupling agent) 10 parts, and aromatic rubber oil (plasticizer) 8 parts.

[0036] The above preparation method of the road pitch comprises the following preparation steps: The de-ashed coal pitch 20 parts, 70# petroleum pitch 50 parts, cottonseed oil 8 parts, molecular sieve dewaxing extracted oil 40 parts, aromatic dibasic acid ester 10 parts, and aromatic rubber oil 8 parts are mixed, stirred at a temperature of 180°C and a speed of 1000 rpm for 30 min, and then the road pitch is obtained.

[0037] Example 4 The preparation process of the de-ashed coal pitch comprises: The qualified coal pitch 100 parts and the solvent 250 parts are mixed at a temperature of 100°C, stirred, and then centrifuged at a speed of 4000 rpm for 15 min at a temperature of 95°C, and the residue is discarded. The centrifugal liquid obtained by centrifugation is subjected to reduced pressure distillation to obtain the de-ashed coal pitch (the quinoline insoluble content is 0.1%, and the ash content is <1%), and the solvent obtained in the reduced pressure distillation process is recovered. The solvent used is a mixture of 100 parts of petroleum ether, 100 parts of solvent naphtha (aromatic hydrocarbon solvent) and 50 parts of heavy diesel oil.

[0038] A road asphalt based on qualified coal pitch, comprising the following raw materials in mass parts: The deashed coal pitch 25 parts, 70# petroleum pitch 45 parts, soybean oil (unsaturated fatty acid) 15 parts, molecular sieve dewaxing extracted oil (petroleum extracted oil) 30 parts, silane coupling agent (coupling agent) 10 parts, aromatic rubber oil (plasticizer) 5 parts.

[0039] The preparation method of the road asphalt, comprising the following preparation steps: The deashed coal pitch 25 parts, 70# petroleum pitch 45 parts, soybean oil 15 parts, molecular sieve dewaxing extracted oil 30 parts, silane coupling agent 10 parts, aromatic rubber oil 5 parts are mixed, stirred at a temperature of 180℃ and a speed of 1000 rpm for 30 min, and then the road asphalt is obtained.

[0040] Performance test The road asphalt prepared in the above Examples 1-4 is subjected to performance test, and the results are shown in Table 1.

[0041] Table 1 Performance test results of the road asphalt of Examples 1-4

[0042] As can be seen from Table 1, the road asphalt provided by the present application has the penetration, softening point and ductility meeting the requirements of various indexes of 70# road asphalt. It has good construction performance (penetration), thermal stability (softening point) and low-temperature ductility (ductility).

[0043] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A road asphalt based on qualified coal tar pitch, characterized in that, The raw materials include the following parts by weight: 10-25 parts of deashed coal tar pitch, 45-55 parts of petroleum pitch, 5-15 parts of unsaturated fatty acids, 20-40 parts of petroleum extracted oil, 1-10 parts of coupling agent, and 1-10 parts of plasticizer. The preparation process of deashed coal tar pitch includes: mixing qualified coal tar pitch with a solvent, stirring, centrifuging, and vacuum distilling to obtain deashed coal tar pitch.

2. The road asphalt based on qualified coal tar pitch according to claim 1, characterized in that, Solvents include mixed solutions of petroleum ether, aromatic solvent oil, or petroleum ether, aromatic solvent oil, and diesel oil.

3. The road asphalt based on qualified coal tar pitch according to claim 1, characterized in that, The softening point of qualified coal tar pitch is 140-160℃, and the ductility of qualified coal tar pitch is 0-0.8cm. The penetration of qualified coal tar pitch is 0-1, measured in 0.1 mm units.

4. A road asphalt based on qualified coal tar pitch according to claim 1, characterized in that, The mass ratio of qualified coal tar pitch to solvent is 1:1-3.

5. A road asphalt based on qualified coal tar pitch according to claim 1, characterized in that, The mixing temperature is 80-130℃, the centrifugation temperature is 80-95℃, the centrifugation time is 10-20 min, and the centrifugation speed is 3000-5000 rpm.

6. A road asphalt based on qualified coal tar pitch according to claim 1, characterized in that, Unsaturated fatty acids include phytic acid.

7. A road asphalt based on qualified coal tar pitch according to claim 1, characterized in that, Petroleum extracted oil includes molecular sieve dewaxing extracted oil.

8. A road asphalt based on qualified coal tar pitch according to claim 1, characterized in that, Coupling agents include aromatic diesters or silane coupling agents, and plasticizers include aromatic rubber oils.

9. A method for preparing road asphalt based on qualified coal tar pitch according to any one of claims 1-8, characterized in that, The preparation steps include the following: Road asphalt is obtained by mixing and stirring deashed coal tar pitch, petroleum asphalt, unsaturated fatty acids, petroleum extract, coupling agent, and plasticizer.

10. A method for preparing road asphalt based on qualified coal tar pitch according to claim 9, characterized in that, The stirring temperature is 120-180℃, the stirring speed is 500-1000 r / min, and the stirring time is 20-50 min.

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