A composite dust suppressant for road construction and a preparation method thereof

Abstract

This invention relates to the field of dust suppressant technology, specifically disclosing a composite dust suppressant for highway construction and its preparation method, comprising the following components by mass percentage: 0.5%-0.8% polyacrylamide, 0.5%-1.0% acrylic acid, 0.3%-0.4% thickener, 0.1%-1.0% penetrant, and 4.0%-8.0% soluble calcium salt; the balance being water. In the preparation process of the composite dust suppressant for highway construction, polyacrylamide and acrylic acid are first subjected to electrostatic repulsion under alkaline conditions at 40-50°C, and then thoroughly mixed with the thickener to form hydrogen bonds and entanglements, constructing an elastic primary interpenetrating polymer network. Then, after adding the penetrant, the system is adjusted to acidity, and an aqueous solution of the soluble calcium salt is added dropwise to the acidic main solution while stirring. The dust suppressant of this invention exhibits excellent structural stability and long-lasting dust suppression performance.

Description

Technical Field

[0001] This invention relates to the field of dust suppressant technology, specifically to a composite dust suppressant for highway construction and its preparation method. Background Technology

[0002] The construction of urban sections of highways presents both technical and managerial challenges in terms of dust pollution due to their large scale, long construction period, and dense surrounding residential areas. Statistics show that construction dust contributes 15%-25% to urban air pollution, primarily from earthwork and waste transportation. For existing highway reconstruction and expansion projects, dust can also impair driver visibility, increasing the probability of traffic accidents.

[0003] To date, various solutions have been developed both domestically and internationally to address the dust pollution problem that easily arises during highway construction, including mechanical covering, tarpaulin covering, dedicated container trucks, and methods such as water spraying and dust suppressant application. Among these, mechanical covering, tarpaulin covering, and dedicated container trucks suffer from high costs, implementation difficulties, and reduced transportation efficiency. Compared to these methods, dust suppressant spraying is a low-cost and easy-to-implement dust control method.

[0004] Currently, commonly used dust suppressants mainly include inorganic salts, organic compounds, and biomass-based agents. However, because the binding components in the dust suppressant solution need to evaporate through water and reach a certain concentration before they can bond with dust and other bulk material particles to form a solidified layer, they are highly dependent on the solidification temperature and time. Under low-temperature conditions (especially in winter), the solidification rate is slow, failing to provide rapid dust suppression. Furthermore, even if a solidified layer forms on the dust surface, the dust suppressant used in the field has low bonding strength, resulting in poor compressive strength in practical applications. It is also prone to pulverization and cracking due to moisture evaporation, and may fail under conditions of drying, wind erosion, and rainwater erosion.

[0005] Therefore, developing composite dust suppressants with fast adhesion, high strength, and high durability is of great practical significance. Summary of the Invention

[0006] The purpose of this invention is to provide a composite dust suppressant for highway construction and its preparation method, which has excellent structural stability and thermal stability.

[0007] This invention is achieved through the following technical solution: A composite dust suppressant for highway construction comprises the following components by weight percentage: Polyacrylamide 0.5%-0.8%, acrylic acid 0.5%-1.0%, thickener 0.3%-0.4%, penetrant 0.1%-1.0%, soluble calcium salt 4.0%-8.0%; balance is water. In the preparation process of composite dust suppressant for highway construction, polyacrylamide and acrylic acid are first electrostatically repelled in an alkaline environment at 40-50℃ and then fully mixed with a thickener to form hydrogen bonds and entanglements, constructing an elastic primary interpenetrating polymer network. After adding a penetrant, the system is adjusted to be acidic. In the acidic main solution, a soluble calcium salt aqueous solution is added dropwise to the acidic main solution and stirred.

[0008] The thickener of the present invention is a thickener containing hydroxyl groups (-OH).

[0009] This invention uses polyacrylamide as the main binder and acrylic acid as a structural molding additive. In preparing the composite dust suppressant for highway construction, this invention employs a step-by-step preparation and pH-sequential control process: First, the thickener and polyacrylamide (PAM) are dissolved separately. Then, under weakly alkaline conditions, the acrylic acid and PAM solutions are mixed, generating electrostatic repulsion. The amide groups (-CONH2) of PAM and the hydroxyl groups (-OH) of the subsequently added thickener form physical entanglements through intermolecular hydrogen bonds, allowing the carboxyl, amide, and hydroxyl groups between polymer chains to fully form hydrogen bonds and entanglements, constructing an elastic primary interpenetrating polymer network. After stirring, the viscous solution is thoroughly mixed with this network. After the system is adjusted to a weakly acidic state, a soluble calcium salt solution is slowly added dropwise to avoid excessively high local concentrations that could lead to flocculation. This process solves the problems of poor component compatibility and uneven network structure in traditional dust suppressant preparation, laying the foundation for subsequent calcium ion-directed crosslinking.

[0010] The soluble calcium salt of this invention is a hygroscopic agent. The addition of the soluble calcium salt not only absorbs and retains moisture but also participates in the construction of the cross-linked network: most of the soluble calcium salt is physically encapsulated in the polymer network in a free state, increasing the free water content and providing a good water-absorbing environment for the polyacrylamide; a few soluble calcium salts form chemical cross-links with the polymer due to coordination with the polymer chains. After being sprayed onto the dust surface, as the water evaporates and the environmental pH changes naturally, calcium ions (Ca... 2+ ) and the carboxylate groups (-COO) gradually exposed in the polymer network - Ionic crosslinking occurs, tightly binding the flexible organic polymer network with the inorganic calcium ion crosslinking points. This dual-action mechanism solves the problems of slow water evaporation and low consolidation rate under low-temperature conditions, while also enhancing the thermal stability of the film.

[0011] Therefore, by combining polyacrylamide, acrylic acid, thickener containing hydroxyl (-OH), penetrant and hygroscopic agent in a certain proportion, the dust suppressant prepared in this invention has excellent structural stability and thermal stability.

[0012] Preferably, the mass ratio of polyacrylamide to acrylic acid is greater than or equal to 1; more preferably, the mass ratio of polyacrylamide to acrylic acid is 1-1.6; and even more preferably, the mass ratio of polyacrylamide to acrylic acid is 1.

[0013] Experiments revealed that the mass ratio of polyacrylamide to acrylic acid affects the structural stability of the prepared dust suppressant, specifically its wind erosion rate.

[0014] In a preferred embodiment, the composite dust suppressant for highway construction comprises the following components by weight percentage: Polyacrylamide 0.5%-0.8%, acrylic acid 0.5%, thickener 0.3%-0.4%, penetrant 0.1%-1.0%, soluble calcium salt 6.0%-8.0%; balance is water.

[0015] Preferably, the thickener includes polyvinyl alcohol; the penetrant includes sodium dodecylbenzenesulfonate; and the soluble calcium salt includes at least one of calcium chloride and calcium nitrate.

[0016] Preferably, the pH of the alkaline environment is 8-9; and the pH of the acidic main solution is 5-6.

[0017] A method for preparing a composite dust suppressant for highway construction includes the following steps: S1. Dissolve the thickener in hot water to make a viscous solution; dissolve the polyacrylamide in room temperature water to make a PAM solution; S2. Slowly add acrylic acid to the PAM solution and mix at 40-50℃ and 300-500r / min. Adjust the pH to alkaline by using an alkali and stir for 20-30 minutes to ensure that the PAM and acrylic acid are fully mixed. Then add the viscous solution and continue stirring. S3. Add penetrant, stir well, add acid to adjust the solution to acidity, and obtain acidic main solution; S4. Dissolve the soluble calcium salt in the remaining water to obtain a soluble calcium salt aqueous solution. Then, add the soluble calcium salt aqueous solution dropwise to the acidic main solution obtained in step S3 and stir to obtain a composite dust suppressant for highway construction.

[0018] In step S2, the pH is adjusted to 8-9, and in step S3, the pH of the acidic main solution is 5-6.

[0019] In step S4, a soluble calcium salt aqueous solution is added dropwise to the acidic main solution obtained in step S3 at a rotation speed of less than 200 r / min.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. This invention combines polyacrylamide, acrylic acid, thickener, penetrant, and hygroscopic agent in a specific ratio, enabling the product to simultaneously possess multiple functions such as rapid adhesion, dense film formation, moisture absorption and retention, and penetrating wetting. The components work synergistically within a specific ratio range, preventing the failure of any single component under complex conditions such as wind erosion, drying, and rain erosion, ensuring the dust suppressant has excellent structural and thermal stability, thereby ensuring a long-lasting and stable dust suppression effect.

[0021] 2. The dust suppressant of this invention is designed with the convenience of spraying operations at the construction site in mind. The product has stable performance, is easy to dilute and spray, and the single spraying amount is 2-2.5L / m². 2 The cured film exhibits a wind erosion rate as low as 0.52% and a rain erosion rate as low as 0.026 g / cm³ at a wind speed of 20 m / s. 2 • h; The dust reduction rate remained as high as 87.29% 15 days after spraying, demonstrating excellent stability. This invention solves the problems of frequent spraying and high maintenance costs associated with traditional dust suppressants, meeting the long-term dust suppression needs of scenarios such as highway construction, material stockpiling, and spoil transportation. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating the preparation process of the composite dust suppressant for highway construction according to the present invention. Figure 2 This is a schematic diagram of the membrane structure of the composite dust suppressant for highway construction of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. The embodiments described below are some, but not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, materials, or methods are not specifically described to avoid obscuring the invention. Unless otherwise specified, the materials, instruments, and reagents used in the following embodiments are commercially available. Unless otherwise specified, the techniques used in the embodiments are conventional methods well known to those skilled in the art.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Example: A composite dust suppressant for highway construction, comprising the following components by weight percentage: Polyacrylamide 0.5%-0.8%, acrylic acid 0.5%-1.0%, thickener 0.3%-0.4%, penetrant 0.1%~1.0%, soluble calcium salt 4.0%-8.0%; the balance is water; wherein, the thickener is polyvinyl alcohol; the penetrant is sodium dodecylbenzene sulfonate; the soluble calcium salt can specifically be calcium chloride or calcium nitrate, and this example uses calcium chloride for illustration; In the preparation of composite dust suppressants for highway construction, polyacrylamide and acrylic acid are first electrostatically repelled under alkaline conditions at 40-50℃ and thoroughly mixed with a thickener to form hydrogen bonds and entanglements, constructing an elastic primary interpenetrating polymer network. Then, a penetrant is added, and the system is adjusted to an acidic state. A soluble calcium salt aqueous solution is then added dropwise to the acidic main solution while stirring. The pH of the alkaline environment is 8-9, and the pH of the acidic main solution is 5-6.

[0027] Preferably, the composition includes 0.5%-0.8% polyacrylamide, 0.5% acrylic acid, 0.3%-0.4% thickener, 0.1%-1.0% penetrant, 6.0%-8.0% soluble calcium salt, and the balance being water.

[0028] Preferably, the mass ratio of polyacrylamide to acrylic acid is greater than or equal to 1; more preferably, the mass ratio of polyacrylamide to acrylic acid is 1-1.6; and even more preferably, the mass ratio of polyacrylamide to acrylic acid is 1.

[0029] The preparation method of the composite dust suppressant for highway construction in this embodiment includes the following steps: S1. Dissolve the thickener in hot water at 40℃ at a mass ratio of 1:5 to prepare a viscous solution; dissolve the polyacrylamide in water at room temperature at a mass ratio of 1:5 to prepare a PAM solution; S2. Slowly add acrylic acid to the PAM solution and mix while stirring at 40℃ and 500r / min. Adjust the pH to alkaline using an alkali, specifically to pH 8-9. Stir for 30 minutes to ensure that the PAM and acrylic acid are fully mixed. Then add the viscous solution and continue stirring. S3. Add penetrant, stir evenly, add acid to adjust the solution to acidity, and obtain acidic main solution. Specifically, the pH of acidic main solution is 5-6. S4. Dissolve the soluble calcium salt in the remaining water to obtain a soluble calcium salt aqueous solution. Then, at a rotation speed of less than 200 r / min, add the soluble calcium salt aqueous solution dropwise to the acidic main solution obtained in step S3 and stir to obtain a composite dust suppressant for highway construction.

[0030] Table 1 shows a list of the main components of the dust suppressant in this embodiment: Table 1 .

[0031] The preparation process in this embodiment abandons the traditional method of simply mixing dust suppressants, and adopts a stepwise pH control strategy to achieve precise control over the formation and cross-linking of the polymer network, such as... Figure 1 As shown: First, under weakly alkaline conditions (pH 8-9), acrylic acid (AA) is slowly added to a partially hydrolyzed polyacrylamide (PAM) solution. At this point, the carboxyl groups (-COOH) of AA fully dissociate into carboxylate groups (-COO₂). - ), and -COO generated by hydrolysis on the PAM chain - Electrostatic repulsion is generated, which promotes the stretching of molecular chains. At the same time, the amide groups (-CONH2) of PAM and the hydroxyl groups (-OH) of the subsequently added polyvinyl alcohol (PVA) form physical entanglement through intermolecular hydrogen bonds, constructing a uniform polymer mixture system and laying the structural foundation for subsequent crosslinking.

[0032] Subsequently, the pH of the system was adjusted to a weakly acidic state (pH 5-6), at which point most of the -COOH groups remained undissociated, and the system tended to stabilize. Under these conditions, calcium chloride solution was slowly added dropwise with low-speed stirring, allowing calcium ions (Ca) to dissociate. 2+ The components are evenly dispersed in the gaps between the network components, avoiding excessively high local concentrations that could lead to flocculation. This pH-controlled process solves the problems of poor compatibility and uneven network structure in multi-component systems, ensuring product stability and repeatability.

[0033] like Figure 2 As shown, this network structure has the following characteristics: PAM, PVA, and acrylic acid form a flexible network through hydrogen bonds and chain entanglement, providing the film with toughness and cohesion; Ca 2+ The ionic crosslinking points formed with carboxylate groups significantly enhance the compressive strength and structural stability of the membrane. Calcium chloride plays a dual role in the system: it slows down water evaporation and maintains the membrane in a moist state, while a small amount of calcium chloride participates in chemical crosslinking, further enhancing the network strength.

[0034] In this embodiment, polyacrylamide serves as the primary binder, providing basic adhesive properties; acrylic acid acts as a structural forming agent, participating in network construction and enhancing film toughness; polyvinyl alcohol acts as a thickener, helping to increase adhesive properties and participating in hydrogen bond network formation; sodium dodecylbenzene sulfonate acts as a penetrant, reducing surface tension and enhancing the wetting and penetration ability of the dust suppressant on dust particles; and anhydrous calcium chloride acts as a hygroscopic agent, both absorbing moisture from the air to keep the film moist and participating in network construction as an ionic crosslinking point.

[0035] Through the aforementioned multi-component synergistic and hybrid network structure design, the dust suppressant in this embodiment forms a cured film layer after spraying that possesses excellent adhesion, film-forming properties, moisture absorption and water retention, wind erosion resistance, rainwater erosion resistance, and thermal stability, meeting the long-term dust suppression requirements of scenarios such as highway construction, material stockpiling, and spoil transportation. The excellent wind erosion resistance and rainwater erosion resistance indicate good structural stability.

[0036] Furthermore, over 98% of the raw materials in the dust suppressant of this embodiment are environmentally friendly. The main components, such as polyacrylamide, polyvinyl alcohol, and acrylic acid, are easily degradable; calcium chloride is an inorganic salt; and sodium dodecylbenzenesulfonate is a biodegradable surfactant. This raw material system avoids the risk of secondary pollution, meets green environmental protection requirements, and solves the environmental burden problems that traditional dust suppressants may cause.

[0037] To better illustrate the technical effects of this embodiment, the following specific examples are used for explanation: Example 1: A composite dust suppressant for highway construction, comprising the following components by weight percentage: Polyacrylamide 0.8%, acrylic acid 0.5%, thickener 0.3%, penetrant 0.1%, calcium chloride 6.0%; balance is water.

[0038] The specific preparation process of the composite dust suppressant for highway construction in this embodiment is the same as that in the above embodiment; the prepared dust suppressant solution should be stored in a cool and ventilated place for later use.

[0039] Example 2: This embodiment is based on Embodiment 1, but differs from Embodiment 1 in that the dosage of each component is different. Specifically: A composite dust suppressant for highway construction, comprising the following components by weight percentage: Polyacrylamide 0.5%, acrylic acid 0.5%, thickener 0.3%, penetrant 0.5%, calcium chloride 6.0%; balance is water.

[0040] Example 3: This embodiment is based on Embodiment 1, but differs from Embodiment 1 in that the dosage of each component is different. Specifically: A composite dust suppressant for highway construction, comprising the following components by weight percentage: Polyacrylamide 0.5%, acrylic acid 0.5%, thickener 0.3%, penetrant 1.0%, calcium chloride 6.0%; balance is water.

[0041] Example 4: This embodiment is based on Embodiment 1, but differs from Embodiment 1 in that the dosage of each component is different. Specifically: A composite dust suppressant for highway construction, comprising the following components by weight percentage: Polyacrylamide 0.5%, acrylic acid 0.5%, thickener 0.3%, penetrant 1.0%, calcium chloride 4.0%; the balance is water.

[0042] Example 5: This embodiment is based on Embodiment 1, but differs from Embodiment 1 in that the dosage of each component is different. Specifically: A composite dust suppressant for highway construction, comprising the following components by weight percentage: Polyacrylamide 0.5%, acrylic acid 0.5%, thickener 0.3%, penetrant 1.0%, calcium chloride 8.0%; balance is water.

[0043] Comparative Example 1: This embodiment is based on Embodiment 1, but differs from Embodiment 1 in that the dosage of each component is different. Specifically: A composite dust suppressant for highway construction, comprising the following components by weight percentage: The composition of this comparative example is as follows: 0.2% polyacrylamide, 0.5% acrylic acid, 0.3% thickener, 0.1% penetrant, and 6.0% calcium chloride; the balance is water. The main difference between this comparative example and Example 1 is that the amount of polyacrylamide used is reduced, and the mass ratio of polyacrylamide to acrylic acid is significantly reduced from 1.6 in Example 1 to 0.4.

[0044] Comparative Example 2: This embodiment is based on Embodiment 1, but differs from Embodiment 1 in that the dosage of each component is different. Specifically: A composite dust suppressant for highway construction, comprising the following components by weight percentage: The composition of this comparative example is: 0.5% polyacrylamide, 1.0% acrylic acid, 0.3% thickener, 0.1% penetrant, and 6.0% calcium chloride; the balance is water. The main difference between this comparative example and Example 1 is the reduced amount of polyacrylamide and a significantly increased mass ratio of polyacrylamide to acrylic acid, decreasing from 1.6 in Example 1 to 0.5.

[0045] Comparative Example 3: A dust suppressant is composed of 0.5% polyacrylamide and water. The preparation process is the same as in the examples. For components not included in this comparative example, the addition of the corresponding components is omitted.

[0046] Comparative Example 4: A dust suppressant is composed of 0.5% polyacrylamide, 0.3% thickener polyvinyl alcohol (same as in the example), and water. The preparation process is the same as in the example. For components not included in this comparative example, the addition of the corresponding components is omitted.

[0047] Comparative Example 5: A dust suppressant is composed of 0.5% polyacrylamide, 6.0% calcium chloride, and water. The preparation process is the same as in the examples. For components not included in this comparative example, the addition of the corresponding components is omitted.

[0048] Comparative Example 6: A dust suppressant is composed of 0.5% polyacrylamide, 0.3% thickener polyvinyl alcohol (same as in the example), 6.0% calcium chloride, and water. The preparation process is the same as in the example. For components not included in this comparative example, the addition of the corresponding components is omitted.

[0049] Comparative Example 7: A dust suppressant is composed of 0.5% polyacrylamide, 0.5% acrylic acid, and water. The preparation process is the same as in the examples. For components not included in this comparative example, the addition of the corresponding components is omitted.

[0050] Comparative Example 8: A dust suppressant is composed of 0.5% polyacrylamide, 0.5% acrylic acid, 0.3% thickener polyvinyl alcohol (same as in the example), 6.0% calcium chloride, and water. The preparation process is the same as in the example. For components not included in this comparative example, the addition of the corresponding components is omitted.

[0051] Comparative Example 9: This comparative example is based on Example 1, and differs from Example 1 in that: The pH is not adjusted during the preparation of the dust suppressant.

[0052] The structural stability (wind erosion rate, rain erosion rate) of the cured layer formed after the dust suppressant has cured at room temperature (23±2℃) was tested. The results are shown in Table 2: Table 2

[0053] The testing procedures for wind erosion rate, rain erosion rate, viscosity, and dust settling rate are as follows: (1) Viscosity The viscosity values ​​of different dust suppressants were tested using an NDJ-5S viscometer at room temperature.

[0054] (2) Wind erosion rate The test samples were cured at room temperature (23±2℃) for 2h and 4h respectively. The wind speed of the wind erosion test was 20m / s. The samples were weighed before and after the erosion test to obtain the mass of soil loss after erosion.

[0055] Formula for calculating wind erosion rate: R=(m1-m2) / (m1-m0) In the formula, R represents the wind erosion rate (%). m0 — Weight of empty disk (g) m1—Total weight of dust suppressant and empty disk before erosion (g) m2 — Total weight (g) of dust suppressant and empty disk after erosion. (3) Rain erosion rate The test samples were cured for 7 days at room temperature (23±2℃) and after being sprayed with water for 15 minutes and dried, respectively. The effect of rainwater erosion on the soil solidification of dust suppressant was then tested.

[0056] Rain erosion rate calculation formula: R=(m1-m2) / (S×t) In the formula, m1 represents the weight of the soil before rainfall (g). m2 — Soil weight after rainfall (g) S—Catchment area (cm²) 2 ) t — Rainfall duration (h) (4) Dust reduction rate The test samples were cured at room temperature (23±2℃) for 1 day, 2 days, and 15 days, respectively, with a wind speed of 20 m / s. A dust concentration monitor was used to monitor and record changes in dust concentration in real time. At the same time, the system recorded the dust situation after the application of the dust suppressant.

[0057] Dust reduction rate calculation formula: P = (C0 − C1) / C0 × 100% In the formula, P is the dust suppression rate, C0 is the TSP (total suspended particulate matter) concentration before dust reduction, and C1 is the TSP concentration after spraying the dust suppressant.

[0058] The data in Table 2 shows that: 1) The dust suppressant of this invention forms a cured layer with low wind erosion rate after curing at room temperature (23±2℃) and can effectively resist rainwater erosion. The single spraying amount is 2~2.5L / m². 2 The cured film exhibits a wind erosion rate as low as 0.52% and a rain erosion rate as low as 0.026 g / cm³ at a wind speed of 20 m / s. 2 Even after 15 days, the dust reduction rate was still as high as 87.29%.

[0059] 2) As can be seen from the data of Example 1, Comparative Example 1 and Comparative Example 2, when the mass ratio of polyacrylamide to acrylic acid is too low, the wind erosion rate of the dust suppressant will be significantly increased.

[0060] 3) As can be seen from the data of Examples 1-5, Comparative Example 1 and Comparative Example 2, the ratio of each component in the dust suppressant will affect the wind erosion rate, rain erosion rate and dust reduction rate of the dust suppressant. Among them, the wind erosion rate and rain erosion rate of the dust suppressants prepared in Examples 2-5 are relatively low, while the dust reduction rate remains at a relatively high level.

[0061] 4) As can be seen from the data of Examples 1-5 and Comparative Examples 3-8, the purpose of this invention can only be achieved through the synergistic effect of polyacrylamide, acrylic acid, thickener, penetrant and calcium chloride in the formulation of this invention.

[0062] 5) As can be seen from the data of Examples 1-5 and Comparative Example 9, when pH adjustment is not performed, the wind erosion rate, rain erosion rate and dust reduction rate of the dust suppressant will be affected.

[0063] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite dust suppressant for highway construction, characterized in that, Includes the following components by weight percentage: Polyacrylamide 0.5%-0.8%, acrylic acid 0.5%-1.0%, thickener 0.3%-0.4%, penetrant 0.1%-1.0%, soluble calcium salt 4.0%-8.0%; balance is water. In the preparation process of the composite dust suppressant for highway construction, the polyacrylamide and acrylic acid are first electrostatically repelled in an alkaline environment at 40-50℃ and then fully mixed with a thickener to form hydrogen bonds and entanglements, constructing an elastic primary interpenetrating polymer network. After adding a penetrant, the system is adjusted to be acidic to obtain an acidic main solution. A soluble calcium salt aqueous solution is then added dropwise to the acidic main solution and stirred.

2. The composite dust suppressant for highway construction according to claim 1, characterized in that, Includes the following components by weight percentage: Polyacrylamide 0.5%-0.8%, acrylic acid 0.5%, thickener 0.3%-0.4%, penetrant 0.1%-1.0%, soluble calcium salt 6.0%-8.0%; balance is water.

3. The composite dust suppressant for highway construction according to claim 1, characterized in that, The thickener includes polyvinyl alcohol.

4. The composite dust suppressant for highway construction according to claim 1, characterized in that, The penetrant includes sodium dodecylbenzenesulfonate.

5. The composite dust suppressant for highway construction according to claim 1, characterized in that, The soluble calcium salt includes at least one of calcium chloride and calcium nitrate.

6. The composite dust suppressant for highway construction according to claim 1, characterized in that, The pH of an alkaline environment is 8-9.

7. A composite dust suppressant for highway construction according to claim 1, characterized in that, The pH of the acidic bulk solution is 5-6.

8. The method for preparing the composite dust suppressant for highway construction as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Dissolve the thickener in hot water to prepare a viscous solution; dissolve the polyacrylamide in room temperature water to prepare a PAM solution; S2. Slowly add the acrylic acid to the PAM solution and mix under stirring at 40-50℃ and 300-500r / min. Adjust the pH to alkaline by using an alkali and stir for 20-30 minutes to ensure that the PAM and acrylic acid are fully mixed. Then add the viscous solution and continue stirring. S3. Add the penetrant, stir evenly, and adjust the solution to acidity by adding acid to obtain an acidic main solution; S4. Dissolve the soluble calcium salt in the remaining water to obtain a soluble calcium salt aqueous solution. Then, add the soluble calcium salt aqueous solution dropwise to the acidic main solution obtained in step S3 and stir to obtain the composite dust suppressant for highway construction.

9. The preparation method according to claim 8, characterized in that, In step S2, the pH is adjusted to 8-9. In step S3, the pH of the acidic main solution is adjusted to 5-6.

10. The preparation method according to claim 8, characterized in that, In step S4, the soluble calcium salt aqueous solution is added dropwise to the acidic main solution obtained in step S3 at a rotation speed of less than 200 r / min.

Images