Method for rapidly quantifying toluene insoluble substances in asphalt

Abstract

The invention discloses a method for rapidly quantifying toluene insoluble substances in asphalt, which comprises the following steps: S1, placing an asphalt sample in a conical flask of a sample dissolving system, and adding normal-temperature toluene; s2, mounting a condenser pipe on a conical flask, opening a cooling water valve, placing the conical flask on a heating table, starting stirring and heating, and refluxing and dissolving the asphalt sample for 30-60 minutes after the temperature reaches a set temperature; s3, suction filtration: pouring the dissolved asphalt sample into a sand core funnel of a suction filtration system, carrying out suction filtration while the sample is hot, washing a conical flask with toluene at 50-60 DEG C, and pouring the washed conical flask into the sand core funnel of the suction filtration system; and S4, after suction filtration is finished, drying the sand core funnel, cooling, weighing, and calculating the content of the toluene insoluble substances in the asphalt. The method solves the problems that the traditional method for quantifying the content of toluene insoluble (TI) consumes long time, is poor in operation flexibility and cannot accurately quantify the content of TI in the ultrahigh softening point asphalt.

Description

Technical Field

[0001] This invention relates to the field of detection and analysis technology, specifically to a method for rapid quantitative determination of toluene-insoluble matter in asphalt, especially for special asphalt with an ultra-high softening point ≥280℃. Background Technology

[0002] Toluene-insoluble matter in coal tar pitch consists of high-molecular-weight and high-melting-point substances such as polycyclic aromatic hydrocarbons, quinoline, and carbazole. Its high content significantly increases the softening point and viscosity of coal tar pitch, thereby improving its high-temperature stability and oxidation resistance. Simultaneously, toluene-insoluble matter is a major component in the formation of binding coke during coal tar pitch roasting, significantly impacting the strength and porosity of roasted products. If the toluene-insoluble matter content is too low, it will affect the strength of roasted products, making them more brittle, and will also increase porosity. If the toluene-insoluble matter content is too high, it may affect the binding properties of coal tar pitch and cause the roasted products to expand in volume during roasting. Therefore, accurately quantifying the toluene-insoluble matter content in coal tar pitch is crucial for industries such as graphite and refractory materials. Currently, the method for quantifying the toluene-insoluble matter content in coal tar pitch is the national standard GB / T 2292-2018. This method has a long analysis time and is not applicable to special pitches with ultra-high softening points ≥280℃.

[0003] In view of the above, there is an urgent need to develop a method that can quickly quantify toluene-insoluble matter in coal tar samples, which can solve the problems of traditional methods for quantifying toluene-insoluble matter (TI) content being time-consuming, having poor operational flexibility, and being unable to accurately quantify TI content in ultra-high softening point asphalt. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a rapid method for quantifying toluene-insoluble matter (TI) in asphalt. This method solves the problems of traditional methods being time-consuming, having poor operational flexibility, and being unable to accurately quantify TI content in ultra-high softening point asphalt. The present invention is simple to operate, quick to use, highly flexible in operation, and provides good reproducibility and repeatability of quantitative results.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a method for rapidly quantifying toluene-insoluble matter in asphalt, comprising the following steps:

[0007] S1, Place the asphalt sample in the conical flask of the sample dissolution system and add room temperature toluene;

[0008] S2, install a condenser on the conical flask, turn on the cooling water valve, place the conical flask on the heating platform, turn on the stirring and start the heating. After the temperature reaches the set temperature, let the asphalt sample reflux and dissolve for 30 to 60 minutes.

[0009] S3, filtration: Pour the dissolved asphalt sample onto the sand core funnel of the filtration system and filter it while it is hot. At the same time, rinse the conical flask with toluene at 50-60°C and then pour it onto the sand core funnel of the filtration system.

[0010] S4. After filtration, the sand core funnel is dried, cooled, and weighed to calculate the content of toluene-insoluble matter in the asphalt.

[0011] Preferably, in step S1, the requirements for the asphalt sample are as follows:

[0012] Asphalt with a concentration of SP≯80℃ was directly heated in an electric furnace to melt into a liquid and then sampled. The mass of the asphalt sample was 1.0~3.0g.

[0013] For asphalt with SP > 80℃, use a disc crusher to crush it until it passes through an 80-mesh sieve. When taking samples, the mass of asphalt samples with 80 < SP < 150℃ should be 1.0 to 1.5g, and the mass of asphalt samples with SP > 80℃ should be 0.2 to 0.5g.

[0014] Preferably, the amount of toluene used at room temperature is 100-150 mL.

[0015] Preferably, in step S2, the stirring speed is 120-180 rpm and the heating temperature is 130-175°C.

[0016] Preferably, in step S3, when rinsing the conical flask with toluene at 50-60°C, the first 1-3 times are ultrasonically treated with ultrasound for 1-3 minutes.

[0017] Preferably, in step S3, the pore size of the sand core funnel is 5-15 μm, and the sand core funnel is preheated in an oven at 150-180°C before filtration.

[0018] Preferably, in step S4, the sand core funnel is placed in a forced-air drying oven at 150-180°C for 15-45 minutes and then cooled in a desiccator for 15-45 minutes before being weighed.

[0019] Preferably, in step S4, the content of toluene-insoluble matter in the asphalt is calculated using the following formula:

[0020] TI (%) = (M2 - M1) / m * 100%

[0021] Where TI is the content of toluene-insoluble matter in asphalt, m is the mass of the asphalt sample, M1 is the mass of the sand core funnel, and M2 is the total mass of the dried sand core funnel and toluene-insoluble matter.

[0022] The beneficial effects of this invention are as follows:

[0023] The national standard method GB / T 2292-2018 is time-consuming, requiring approximately 2 hours to obtain data for ordinary samples. Determining the extraction endpoint simultaneously demands considerable operator experience, and it is inaccurate for the Ti analysis of high softening point asphalt, necessitating the addition of silica sand. This invention, however, ensures complete dissolution of the asphalt sample through simultaneous stirring and reflux. It also replaces filter paper in the national standard method with a sand core funnel and replaces silica wool scrubbing with ultrasonic rinsing, as filter paper and silica wool are prone to absorbing water, making data reproducibility difficult to guarantee. Furthermore, the sand core funnel allows for a higher drying temperature, significantly shortening the analysis time. Attached Figure Description

[0024] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 The flowchart below shows the method for rapid quantitative determination of toluene-insoluble matter in coal tar according to the present invention.

[0026] Figure 2 This is a schematic diagram of the sample dissolution system used in the method for rapid quantitative determination of toluene-insoluble matter in coal tar according to the present invention.

[0027] Figure 3 This is a schematic diagram of the filtration system used in the method for rapid quantitative determination of toluene-insoluble matter in coal tar according to the present invention. Detailed Implementation

[0028] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way.

[0029] Combination Figure 1 As shown, the method for rapid quantitative determination of toluene-insoluble matter in asphalt provided by the present invention includes the following steps:

[0030] S1, Place the asphalt sample in the conical flask of the sample dissolution system and add room temperature toluene;

[0031] Sample preparation requirements:

[0032] Asphalt with a temperature of SP≯80℃ was directly heated in an electric furnace until it was melted into a liquid, and then samples were taken.

[0033] Asphalt with a temperature of SP > 80℃ is pulverized using a disc pulverizer until it passes through an 80-mesh sieve.

[0034] Sample quantity:

[0035] Weigh 1.0–3.0 g of asphalt sample (accurate to 0.1 mg) for asphalt with a temperature of SP ≯ 80℃.

[0036] For asphalt at temperatures between 80°C and 150°C, weigh a 1.0–1.5 g asphalt sample (accurate to 0.1 mg).

[0037] For asphalt with SP > 80℃, weigh 0.2 to 0.5 g of asphalt sample (accurate to 0.1 mg);

[0038] Place the above asphalt sample in the conical flask of the sample dissolution system, and pour 100-150 ml of room temperature toluene into the conical flask;

[0039] S2, install a condenser on the conical flask, turn on the cooling water valve, place the conical flask on the heating platform, turn on the stirring and start the heating. After the temperature reaches the set temperature, let the asphalt sample reflux and dissolve for 30 to 60 minutes.

[0040] Combination Figure 2 As shown, the sample dissolution system used in this step includes a magnetic heating stage 1, a conical flask 2 for holding the asphalt sample, a magnetic rotor 4 for stirring, and a condenser tube 3 for condensing the asphalt sample.

[0041] Install the condenser tube on the conical flask, turn on the cooling water valve, and securely fix the conical flask on the heating platform. Wrap the conical flask with insulation cotton to prevent heat loss. Turn on the stirrer and start the heating. The stirring speed is 120-180 rpm, and the heating temperature is 130-175℃. After the temperature reaches the set temperature, allow the sample to fully reflux and dissolve for 30-60 minutes. Then proceed to step S3 for hot filtration.

[0042] S3, filtration: Pour the dissolved asphalt sample onto the sand core funnel of the filtration system and filter it while it is hot. At the same time, rinse the conical flask with toluene at 50-60°C and then pour it onto the sand core funnel of the filtration system.

[0043] Combination Figure 3 As shown, the filtration system used in this step includes a filtration flask 5, a sand core funnel 6 set on the filtration flask 5, and a vacuum pump 7 for filtration. The sand core funnel 6 is installed on the filtration flask 5 through a rubber stopper 8.

[0044] Pour the dissolved asphalt sample from the conical flask onto the sand core funnel of the filtration system and filter it while it is hot. At the same time, rinse the sample from the conical flask with toluene at 50-60°C. For the first 1-3 times, use ultrasound to sonicate for 1-3 minutes to ensure that the sample remaining on the inner wall of the conical flask and the rotor is thoroughly cleaned and transferred to the sand core funnel.

[0045] The pore size of the sand core funnel is 5-15 μm. Before filtration, the sand core funnel is preheated in an oven at 150-180℃.

[0046] S4. After filtration, the sand core funnel is dried, cooled, and weighed to calculate the toluene insoluble content in the asphalt.

[0047] After filtration, place the sand core funnel in a forced-air drying oven at 150-180℃ for 15-45 minutes, and then weigh it after cooling in the desiccator for 15-45 minutes.

[0048] The toluene-insoluble content in asphalt is calculated using the following formula:

[0049] TI (%) = (M2 - M1) / m * 100%

[0050] Where TI is the content of toluene-insoluble matter in asphalt, m is the mass of the asphalt sample; M1 is the mass of the sand core funnel, and M2 is the total mass of the dried sand core funnel and toluene-insoluble matter.

[0051] The following section provides a further description of a method for rapidly quantifying toluene-insoluble matter in asphalt according to the present invention, using specific examples.

[0052] Example 1

[0053] The method for rapid quantitative determination of toluene-insoluble matter in asphalt in this embodiment is as follows:

[0054] Weigh 2g of coal tar pitch into an Erlenmeyer flask, pour in about 100ml of toluene, install the condenser, turn on the cooling water, set the temperature to 130℃ and 120rpm, and after the temperature reaches 130℃, allow it to fully dissolve for 30 minutes. While the solution in the Erlenmeyer flask is still hot, pour it into the vacuum filtration system. Then, pour 20ml of 60℃ toluene into the Erlenmeyer flask, sonicate for 1 minute, and pour the solution into the vacuum filtration system to continue filtration. Align the mouth of the Erlenmeyer flask with the sintered glass funnel, and use a wash bottle containing 60℃ toluene to rinse all the sample remaining on the inner wall of the Erlenmeyer flask onto the sintered glass funnel. After filtration, place the flask in a 150℃ forced-air oven to dry for 15 minutes, and weigh it after drying and cooling for 15 minutes. The TI results are shown in Table 1. It can be seen that compared with the method of GB / T 2292-2018, the method of this embodiment measures the TI content more accurately and is closer to the standard value.

[0055] Table 1

[0056] GB / T 2292-2018 Example 1 Standard value 11.24％ 11.24％ 11.24％

[0057] Example 2

[0058] The method for rapid quantitative determination of toluene-insoluble matter in asphalt in this embodiment is as follows:

[0059] Weigh 1g of SP140℃ special asphalt into a conical flask, pour in about 120ml of toluene, install the condenser, turn on the cooling water, set the temperature to 140℃ and 140rpm, and after the temperature reaches 140℃, allow it to fully dissolve for 35 minutes. While the solution in the conical flask is still hot, pour it into the vacuum filtration system. Then pour 30ml of 60℃ toluene into the conical flask, sonicate for 1 minute, and pour the solution into the vacuum filtration system to continue filtration. Repeat once. Align the mouth of the conical flask with the sintered glass funnel, and use a wash bottle containing 60℃ toluene to rinse all the sample remaining on the inner wall of the conical flask onto the sintered glass funnel. After filtration, place the flask in a 160℃ forced-air oven to dry for 20 minutes, and weigh it after drying and cooling for 20 minutes. The TI results are shown in Table 2. It can be seen that compared with the method of GB / T 2292-2018, the method of this embodiment measures the TI content more accurately and is closer to the standard value.

[0060] Table 2

[0061] GB / T 2292-2018 Example 1 Standard value 30.54％ 28.24％ 28.26％

[0062] Example 3

[0063] The method for rapid quantitative determination of toluene-insoluble matter in asphalt in this embodiment is as follows:

[0064] Weigh 0.5g of SP250℃ special asphalt into a conical flask, pour in about 140ml of toluene, install the condenser, turn on the cooling water, set the temperature to 160℃ and 150rpm, and after the temperature reaches 160℃, allow it to fully dissolve for 45 minutes. While the solution in the conical flask is still hot, pour it into the vacuum filtration system. Then pour 20ml of 60℃ toluene into the conical flask, sonicate for 1 minute, and pour the solution into the vacuum filtration system to continue filtration. Repeat this process twice. Align the mouth of the conical flask with the sintered glass funnel, and use a wash bottle containing 60℃ toluene to rinse all the sample remaining on the inner wall of the conical flask onto the sintered glass funnel. After filtration, place the sample in a 150℃ forced-air oven to dry for 30 minutes, and after drying and cooling for 30 minutes, weigh it. The TI results are shown in Table 3. It can be seen that compared with the method of GB / T 2292-2018, the method of this embodiment measures the TI content more accurately and is closer to the standard value.

[0065] Table 3

[0066] GB / T 2292-2018 Example 1 Standard value 20.23％ 15.46％ 15.46％

[0067] Example 4

[0068] The method for rapid quantitative determination of toluene-insoluble matter in asphalt in this embodiment is as follows:

[0069] Weigh 0.5g of SP260℃ special asphalt into a conical flask, pour in about 130ml of toluene, install the condenser, turn on the cooling water, set the temperature to 170℃ and 170rpm, and after the temperature reaches 170℃, allow it to fully dissolve for 50min. While the solution in the conical flask is still hot, pour it into the vacuum filtration system. Then pour 40ml of 60℃ toluene into the conical flask, sonicate for 1min, and pour the solution into the vacuum filtration system to continue filtration. Repeat once. Align the mouth of the conical flask with the sintered glass funnel, and use a wash bottle containing 60℃ toluene to rinse all the sample remaining on the inner wall of the conical flask onto the sintered glass funnel. After filtration, place the sample in a 170℃ forced-air oven to dry for 45min, and after drying and cooling for 45min, weigh it. The TI results are shown in Table 4. It can be seen that compared with the method of GB / T 2292-2018, the method of this embodiment measures the TI content more accurately and is closer to the standard value.

[0070] Table 3

[0071] GB / T 2292-2018 Example 1 Standard value 56.23％ 48.15％ 48.98％

[0072] Example 5

[0073] The method for rapid quantitative determination of toluene-insoluble matter in asphalt in this embodiment is as follows:

[0074] Weigh 0.2g of special asphalt at SP285.2℃ and place it in a conical flask. Pour in approximately 150ml of toluene, install the condenser, turn on the cooling water, set the temperature to 175℃ and 180rpm. After the temperature reaches 175℃, allow it to fully dissolve for 60 minutes. While the solution in the conical flask is still hot, pour it into the vacuum filtration system. Then, pour 30ml of 60℃ toluene into the conical flask, sonicate for 1 minute, and pour the solution back into the vacuum filtration system for further filtration. Repeat this process twice. Align the mouth of the conical flask with the sintered glass funnel and use a wash bottle containing 60℃ toluene to rinse all the sample remaining on the inner wall of the conical flask onto the sintered glass funnel. After filtration, place the sample in a 180℃ forced-air oven to dry for 40 minutes. After drying and cooling for 40 minutes, weigh the sample. The TI results are shown in Table 5. It can be seen that compared with the method in GB / T 2292-2018, the method in this embodiment measures the TI content more accurately and is closer to the standard value.

[0075] Table 5

[0076] GB / T 2292-2018 Example 1 Standard value 76.23％ 62.15％ 61.98％

[0077] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for rapidly quantifying toluene-insoluble matter in asphalt, characterized in that, Includes the following steps: S1, Place the asphalt sample in the conical flask of the sample dissolution system and add room temperature toluene; S2, install a condenser on the conical flask, turn on the cooling water valve, place the conical flask on the heating platform, turn on the stirring and start the heating. After the temperature reaches the set temperature, let the asphalt sample reflux and dissolve for 30 to 60 minutes. S3, filtration: Pour the dissolved asphalt sample onto the sand core funnel of the filtration system and filter it while it is hot. At the same time, rinse the conical flask with toluene at 50-60°C and then pour it onto the sand core funnel of the filtration system. S4. After filtration, the sand core funnel is dried, cooled, and weighed to calculate the content of toluene-insoluble matter in the asphalt.

2. The method for rapid quantitative determination of toluene-insoluble matter in asphalt as described in claim 1, characterized in that, In step S1, the requirements for the asphalt sample are as follows: Asphalt with a concentration of SP≯80℃ was directly heated in an electric furnace to melt into a liquid and then sampled. The mass of the asphalt sample was 1.0~3.0g. For asphalt with SP > 80℃, use a disc crusher to crush it until it passes through an 80-mesh sieve. When taking samples, the mass of asphalt samples with 80 < SP < 150℃ should be 1.0 to 1.5g, and the mass of asphalt samples with SP > 80℃ should be 0.2 to 0.5g.

3. The method for rapid quantitative determination of toluene-insoluble matter in asphalt as described in claim 2, characterized in that, The amount of toluene used at room temperature is 100-150 mL.

4. The method for rapid quantitative determination of toluene-insoluble matter in asphalt as described in claim 1, characterized in that, In step S2, the stirring speed is 120-180 rpm and the heating temperature is 130-175℃.

5. The method for rapid quantitative determination of toluene-insoluble matter in asphalt as described in claim 1, characterized in that, In step S3, when rinsing the conical flask with toluene at 50-60°C, ultrasonic treatment is performed for the first 1-3 times, with an ultrasonic treatment time of 1-3 minutes.

6. The method for rapid quantitative determination of toluene-insoluble matter in asphalt as described in claim 1, characterized in that, In step S3, the pore size of the sand core funnel is 5-15 μm, and the sand core funnel is preheated in an oven at 150-180°C before filtration.

7. The method for rapid quantitative determination of toluene-insoluble matter in asphalt as described in claim 1, characterized in that, In step S4, the sand core funnel is placed in a forced-air drying oven at 150-180°C and dried for 15-45 minutes, and then weighed after cooling in a desiccator for 15-45 minutes.

8. The method for rapid quantitative determination of toluene-insoluble matter in asphalt as described in claim 1, characterized in that, In step S4, the content of toluene-insoluble matter in the asphalt is calculated using the following formula: TI (%) = (M2 - M1) / m * 100% Where TI is the content of toluene-insoluble matter in asphalt, m is the mass of the asphalt sample; M1 is the mass of the sand core funnel, and M2 is the total mass of the dried sand core funnel and toluene-insoluble matter.

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