Preparation method of stable emulsified asphalt

Abstract

The invention provides a preparation method of stable emulsified asphalt, and relates to the field of asphalt processing. The preparation method of the stable emulsified asphalt comprises asphalt, water, an emulsifier and scleroglucan, and comprises the following steps: S1, heating water accounting for 37.5-48.8% of the total mass of the emulsified asphalt to 55-60 DEG C; s2, adding an emulsifier accounting for 0.3-3% of the total mass of the emulsified asphalt into water at 55-60 DEG C, and stirring until the emulsifier and the water are uniformly mixed to prepare liquid soap; s3, under the condition that the temperature is stable, the pH value of the liquid soap is adjusted to 5-7. By selecting scleroglucan as the mixing amount of the stabilizer and utilizing the physicochemical properties of the scleroglucan, the stability of the emulsified asphalt is greatly improved, the emulsified asphalt is particularly suitable for modifying the emulsified asphalt, meanwhile, according to the actual production difficulty and the properties of the scleroglucan, the link of adjusting the pH value of the liquid soap is creatively provided, and the stability of the emulsified asphalt is improved. And the dissolution efficiency of the scleroglucan powder is greatly accelerated.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt processing, and in particular to a method for preparing stable emulsified asphalt. Background Art

[0002] The main components of emulsified asphalt include asphalt, water, emulsifier and stabilizer. Asphalt is the core component of emulsified asphalt, providing basic bonding properties; water is the dispersion medium, which disperses asphalt particles in it; emulsifier is a surfactant that can reduce the interfacial tension between asphalt and water, so that asphalt particles can be stably dispersed in water; stabilizer is used to improve the stability of emulsified asphalt and prevent asphalt particles from aggregating. It has many significant characteristics. First, it can be constructed at room temperature, saving energy and reducing safety hazards during construction. By changing the type of emulsifier, the variety and mix ratio of asphalt, the performance of emulsified asphalt can be adjusted to meet different engineering application requirements. As a high-performance and multifunctional road construction material, it has shown broad application prospects and great potential in various fields. Scleroglucan is an extracellular polysaccharide produced by the metabolism of the fungus Sclerotium. It is a neutral homopolymeric polysaccharide, a water-soluble non-ionic polymer, and the molecule exists in the form of a rod-shaped triple helix. It is semi-rigid, which makes it have strong thickening ability, temperature resistance, and salt resistance. It is widely used in many fields such as petroleum, paint, medicine, daily chemicals, agriculture, and food.

[0003] When emulsified asphalt is transported and stored, stratification will gradually occur over time due to the polymerization of asphalt, resulting in a decline in quality of the emulsified asphalt or direct scrapping. Therefore, the existing emulsified asphalt will add stabilizers during production to extend the stratification time. In the prior art, application number CN202211286315.8 discloses a sand-containing fog sealing mixture and its application. By adding hard glucan to the asphalt material to increase stability, an emulsified asphalt emulsion with very stable storage is formed. However, in actual production experiments, powdered hard glucan is not easy to dissolve, which brings certain troubles to operators and requires process optimization.

[0004] At the same time, in practical applications, the viscosity of emulsified asphalt at 25°C reflects its pumping and spraying ease. If the viscosity is too high, it is difficult to pump from the finished emulsified asphalt tank to the spreader, and the pumping efficiency is low. If the viscosity is to be reduced, the entire tank needs to be heated; if the viscosity of emulsified asphalt is too high, it is easy to clog the nozzle, and cleaning the nozzle will bring additional manpower consumption; for high-viscosity modified asphalt, due to the high polymer content, this problem is more likely to occur, so the viscosity of Engla is generally required not to exceed 50. In the prior art, with the increase in the amount of hard glucan added, the viscosity of Engla will also increase sharply, which will lead to a decrease in performance. At the same time, the storage stability of emulsified asphalt is also a very important indicator. Poor stability will cause the emulsified asphalt to settle or demulsify in the storage tank. In severe cases, manual tank cleaning is required, resulting in huge economic losses. According to engineering experience, it is usually required that the finished emulsified asphalt meet the one-day and five-day separation tests; especially for modified emulsified asphalt, the storage stability must be strictly controlled, so a stable modified emulsified asphalt preparation method that can take into account stability and Engla viscosity is needed. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the shortcomings of the prior art, the present invention provides a method for preparing a stable emulsified asphalt. By adding a pH adjustment process during production, the dissolution efficiency of scleroglucan powder is improved. At the same time, the above-mentioned problems are solved by further accurately adjusting the amount of scleroglucan added.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented by the following technical scheme: a method for preparing a stable emulsified asphalt, comprising asphalt, water, an emulsifier and scleroglucan, wherein the preparation steps are:

[0009] S1. Heat water accounting for 37.5% to 48.8% of the total mass of emulsified asphalt to 55-60°C;

[0010] S2. Add 0.3% to 3% of the total mass of the emulsified asphalt into water at 55-60°C and stir until the mixture is evenly mixed to form a soap solution;

[0011] S3. While ensuring the temperature is stable, adjust the pH value of the soap solution to 5-7;

[0012] S4. After the pH value of the soap solution is stabilized, 0.02% to 0.08% of the extra mass of the emulsified asphalt scleroglucan powder is added to the soap solution and stirred to dissolve;

[0013] S5. After heating the soap solution to 55-60°C, adjust the pH value of the soap solution to 2, and then add the soap solution into the mill.

[0014] S6. Heat the asphalt accounting for 50% to 60% of the total mass of the emulsified asphalt to 130-185° C. and put it into a mill; mix it with the soap solution and emulsify the asphalt through the mill.

[0015] Preferably, the emulsifier is an existing slow-cracking cationic emulsifier, accounting for 1.2% of the total mass ratio, water accounts for 48.8% of the total mass ratio, and the asphalt is 70# at 130°C, accounting for 50% of the total mass ratio.

[0016] Preferably, the emulsifier is an existing medium-split cationic emulsifier, accounting for 3% of the total mass ratio, water accounts for 47% of the total mass ratio, and the asphalt is a mixed asphalt at 175°C, accounting for 53% of the total mass ratio.

[0017] Preferably, the emulsifier is an existing fast-cracking cationic emulsifier, accounting for 2.5% of the total mass ratio, the water temperature is 60°C, accounting for 37.5% of the total mass ratio, and the asphalt is a high-viscosity SBS modified asphalt at 185°C, accounting for 60% of the total mass ratio.

[0018] Preferably, the grinding method of the mill is indoor circulating shear grinding.

[0019] Preferably, the grinding method of the mill is one-time grinding in a pilot mill.

[0020] (III) Beneficial effects

[0021] The present invention provides a method for preparing a stable emulsified asphalt, which has the following beneficial effects:

[0022] 1. The present invention uses scleroglucan as the stabilizer dosage and utilizes the physical and chemical properties of scleroglucan itself to greatly increase the stability of emulsified asphalt, making it particularly suitable for modified emulsified asphalt. At the same time, based on the actual production difficulties and the properties of scleroglucan itself, it creatively proposes to increase the step of adjusting the pH value of the soap solution, which greatly accelerates the dissolution efficiency of the scleroglucan powder. By improving the production process, the soap solution production efficiency is greatly improved, and there is no need to make large-scale modifications to the production line, thereby reducing the modification cost.

[0023] 2. The present invention has discovered through actual experiments that the Engela viscosity of the high-viscosity SBS modified asphalt will increase sharply with the increase of the scleroglucan addition amount. By limiting the range of scleroglucan addition, the emulsification stability of the high-viscosity SBS modified asphalt can be increased while ensuring that the Engela viscosity of the product is within the good product range, thereby improving the practicability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a one-day stability data test table of 0.04% scleroglucan dosage in Example 1 of the present invention;

[0025] Figure 2 This is a comparison chart of scleroglucan dosage data of Example 1 of the present invention;

[0026] Figure 3 This is a one-day stability data test table of 0.08% scleroglucan dosage in Example 2 of the present invention;

[0027] Figure 4 This is a five-day stability data test table of 0.08% scleroglucan dosage in Example 2 of the present invention;

[0028] Figure 5 This is a comparison chart of scleroglucan dosage data of Example 2 of the present invention;

[0029] Figure 6 This is a one-day stability data test table of 0.06% scleroglucan dosage in Example 3 of the present invention;

[0030] Figure 7 This is a five-day stability data test table of 0.06% scleroglucan dosage in Example 3 of the present invention;

[0031] Figure 8 This is a comparison chart of scleroglucan dosage data of Example 3 of the present invention.

[0032] Among them, SG is sclerosing glucosamine. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Embodiment 1:

[0035] like Figure 1-2 As shown, an embodiment of the present invention provides a method for preparing a stable emulsified asphalt, comprising 70# asphalt, water, a slow-cracking cationic emulsifier and scleroglucan, and the preparation steps are as follows:

[0036] S1. Heat water accounting for 48.8% of the total mass of emulsified asphalt to 60°C;

[0037] S2, adding 1.2% of the total mass of the emulsified asphalt into water at 60°C and stirring until the mixture is evenly mixed to form a soap solution;

[0038] S3. While ensuring the temperature is stable, adjust the pH value of the soap solution to 5-7;

[0039] S4. After the pH value of the soap solution is stabilized, 0.02% to 0.06% of the mass of the emulsified asphalt scleroglucan powder is additionally added to the soap solution and stirred to dissolve;

[0040] S5, after heating the soap solution to 55-60°C again, adjusting the pH value to 2 again, and then adding the soap solution into the mill;

[0041] S6, heating 70# asphalt accounting for 50% of the total mass of the emulsified asphalt to 130°C and putting it into a mill; emulsifying the asphalt by circulating shearing mill in the mill chamber to form slow-cracking emulsified asphalt;

[0042] According to the process of T0656-1993 "Test method for storage stability of emulsified asphalt", the following results can be obtained: Figure 1 and Figure 2 of the detection data.

[0043] Embodiment 2:

[0044] according to Figure 3-5 The difference between this embodiment and the first embodiment is that: a method for preparing a stable emulsified asphalt includes mixed asphalt, water, a medium-crack cationic emulsifier and hard glucan, and the preparation steps are:

[0045] S1. Heat water accounting for 47% of the total mass of emulsified asphalt to 60°C;

[0046] S2, adding 3% of the total mass of the emulsified asphalt into water at 60°C and stirring until the mixture is evenly mixed to form a soap solution;

[0047] S3. While ensuring the temperature is stable, adjust the pH value of the soap solution to 5-7;

[0048] S4. After the pH value of the soap solution is stabilized, 0.04% to 0.08% of the mass of the emulsified asphalt scleroglucan powder is additionally added to the soap solution and stirred to dissolve;

[0049] S5, after heating the soap solution to 55-60°C again, adjusting the pH value to 2 again, and then adding the soap solution into the mill;

[0050] S6. Heat the mixed asphalt accounting for 53% of the total mass of the emulsified asphalt to 175° C. and put it into a mill; emulsify the mixed asphalt by circulating shearing in the mill chamber to form a non-stick wheel emulsified asphalt.

[0051] According to the process of T0656-1993 "Test method for storage stability of emulsified asphalt", the following results can be obtained: Figure 3 , Figure 4 and Figure 5 of the detection data.

[0052] Embodiment three:

[0053] The difference between this embodiment and the first embodiment is that: a method for preparing a stable emulsified asphalt, comprising high-viscosity SBS modified asphalt, water, a fast-cracking cationic emulsifier and scleroglucan, and the preparation steps are:

[0054] S1. Heat water accounting for 37.5% of the total mass of emulsified asphalt to 60°C;

[0055] S2, adding 2.5% of the total mass of the emulsified asphalt into water at 60°C and stirring until the mixture is evenly mixed to form a soap solution;

[0056] S3. While ensuring the temperature is stable, adjust the pH value of the soap solution to 5-7;

[0057] S4. After the pH value of the soap solution is stabilized, 0.02% to 0.08% of the mass of the emulsified asphalt scleroglucan powder is additionally added to the soap solution and stirred to dissolve;

[0058] S5, after heating the soap solution to 60°C again, adjusting the pH value to 2 again, and then adding the soap solution into the mill;

[0059] S6. The high-viscosity SBS modified asphalt accounting for 60% of the total mass of the emulsified asphalt is heated to 185° C. and then placed in a mill; the high-viscosity SBS modified asphalt is emulsified by a one-time grinding method of a pilot mill to form a high-viscosity SBS modified emulsified asphalt.

[0060] According to the process of T0656-1993 "Test method for storage stability of emulsified asphalt", the following results can be obtained: Figure 6 , Figure 7 and Figure 8 of the detection data.

[0061] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a stable emulsified asphalt, comprising asphalt, water, an emulsifier and scleroglucan, characterized in that: The preparation steps are: S1. Heat water accounting for 37.5% to 48.8% of the total mass of emulsified asphalt to 55-60°C; S2. Add 1.2% to 3% of the total mass of the emulsified asphalt into water at 55-60°C and stir until the mixture is evenly mixed to form a soap solution; S3. While ensuring the temperature is stable, adjust the pH value of the soap solution to 5-7; S4. After the pH value of the soap solution is stabilized, 0.02% to 0.08% of the extra mass of the emulsified asphalt is added to the soap solution and stirred to dissolve; S5. After heating the soap solution to 55-60°C, adjust the pH value of the soap solution to 2, and then add the soap solution into the mill. S6. Heat the asphalt accounting for 50% to 60% of the total mass of the emulsified asphalt to 130-185°C and put it into a mill; mix it with the soap solution and emulsify the asphalt through the mill.

2. A method for preparing a stable emulsified asphalt according to claim 1, characterized in that: The emulsifier is an existing slow-cracking cationic emulsifier, accounting for 1.2% of the total mass ratio, water accounts for 48.8% of the total mass ratio, and the asphalt is 70# at 130°C, accounting for 50% of the total mass ratio.

3. A method for preparing a stable emulsified asphalt according to claim 1, characterized in that: The emulsifier is an existing medium-crack cationic emulsifier, accounting for 3% of the total mass ratio, water accounts for 47% of the total mass ratio, and the asphalt is a mixed asphalt at 175°C, accounting for 53% of the total mass ratio.

4. A method for preparing a stable emulsified asphalt according to claim 1, characterized in that: The emulsifier is an existing fast-cracking cationic emulsifier, accounting for 2.5% of the total mass ratio, the water temperature is 60°C, accounting for 37.5% of the total mass ratio, and the asphalt is a high-viscosity SBS modified asphalt at 185°C, accounting for 60% of the total mass ratio.

5. A method for preparing a stable emulsified asphalt according to claim 2 or 3, characterized in that: The grinding method of the mill is indoor circulating shearing grinding.

6. A method for preparing a stable emulsified asphalt according to claim 4, characterized in that: The grinding method of the mill is one-time grinding in a pilot mill.

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